most of the glomerular diseases , either primary or secondary..touching all the aspects including light microscopy, electron microscopy and immunoflourescence.
2. RENAL BIOPSY
In order to evaluate a kidney biopsy, the pathologist should
correlate complete clinical and laboratory information with
light microscope, immunofluorescence and ultrastructural
findings.
Biopsy adequacy:
1-2 glomeruli Electron Microscopy
3-5 glomeruli Immunofluoresence
5-10 glomeruli light Microscopy
3. RENAL BIOPSY
1- Fixation (Immediate):
10% NB Formalin /Zenker’s/Bouin’s (paraffin sections)
4%Gluteraldehyde (EM)
No fixation (Immunofluorescence)
2- Paraffin sections cut at 3μ thickness
3- Stains: PAS is the most useful, easiest to perform.
Hematoxylin and eosin.
Masson trichrome
Silver preprations
4- Immunohistochemistry (IG, C, other antigens)
4. NEEDLE BIOPSY
OPEN BIOPSY
Most of renal biopsy are done by ether the
percutaneous route using cutting needle or by direct
exposure of kidney (open Biopsy).
5. Ideally, two biopsy cores should be obtained
when a needle biopsy is performed.
6. STAINS FOR RENAL BIOPSY
1. H&E General
2. PAS Basement M. & Mesangial matrix
3. Trichrome Fibrosis
4. Silver Basement M. & Mesangial matrix
5. Congo red Amyloid
7. A BRIEF INTRODUCTION ABOUT
IMMUNOFLORESCENCE TECHNIQUE
Immunofluorescence is a technique for light microscopy with
a fluorescence microscope and is used primarily
on biological samples.
This technique makes it possible to visualize antigens in the
tissue section , cultured cell lines, or individual cells, and may
be used to analyze the distribution of proteins, glycans, and
small biological and non-biological molecules.
A fluorochrome is a dye that absorbs light and then emits its
own light at a longer wavelength. This phenomenon of
absorption and emission of light is called fluorescence.
When the fluorochrome is attached or conjugated to antibody,
the sites of reaction between antigen and labeled antibody can
be visualized easily.
8. A BRIEF INTRODUCTION ABOUT
IMMUNOFLUORESCENCE TECHNIQUE
The most commonly used fluorochromes in
immunofluorescence technique are fluorescein
isothiocyanate (FITC) and rhodamine.
Both of these dyes absorb light that is not visible (UV)to
the human eye and emit light that is visible.
Virtually any antigen can be detected by
immunofluorescence.
In most routine histopathology laboratories, kidney and
skin biopsy specimens are examined with
immunofluorescence technique.
9. A BRIEF INTRODUCTION ABOUT
IMMUNOFLORESCENCE TECHNIQUE
• Immunofluorescence microscopy provided insight not only into
the pathogenesis of glomerular diseases but also is very useful in
diagnosing primary renal diseases, assessing the nature and
severity of renal involvement in various systemic disorders and
in addition, yields important correlations and prognostic
features.
• Correct diagnosis of glomerulonephritis requires renal biopsy
and histopathological examination by light,
immunofluorescence and electron microscopic examination,
and correlation with clinical features and biochemical
parameters.
• Facilities for electron microscopic study is not readily available
in many institutions. In most cases light microscopy (LM) and
direct immunofluorescence (DIF) study are more than enough
for definitive diagnosis of glomerulonephritis.
10. OVERVIEW OF A NORMAL GLOMERULUS
The glomerulus is a vascular structure composed of a
tuft of specialized capillaries that arises from the
afferent arteriole to form lobules that rejoin the
vascular pole to drain into efferent arteriole.
Normally, the lobules are poorly defined, but they are
highlighted in some disease processes.
Each lobule is supported by branching framework, the
mesengium.
This tuft of capillaries lies within the lumen of the
expanded proximal end of the nephron, which is lined
by the epithelial cells overlying a thick basement
membrane.
11. NORMAL GLOMERULUS
The normal glomerulus of the kidney at high power
has thin, delicate capillary loops and the mesangium
is not prominent.
12. NORMAL GLOMERULUS
NORMAL GLOMERULUS
Light micrograph of a normal glomerulus. There are only 1 or 2 cells per
capillary tuft, the capillary lumens are open, the thickness of the glomerular
capillary wall (long arrow) is similar to that of the tubular basement
membranes (short arrow), and the mesangial cells and mesangial matrix are
located in the central or stalk regions of the tuft (arrows).
13. NORMAL GLOMERULUS
Each glomerulus measures approximately 200 micrometers.
The cellularity of the glomerulus varies in different diseases,
and an accurate assessment requires histological preparations 2
to 4 microns thick.
The presence of more than three cells in an individual
glomerular mesangial region away from the vascular pole is
considered hypercellularity.
The glomerular basement membrane is a trilaminar structure
composed of central lamina densa, bordered by lamina rara
interna and externa. In adults GBM measures 310 to 380
nanometers and its thickness is altered in various glomerular
diseases.
Visceral epithelial cells have foot processes are involved in
basement membrane synthesis and plays a role in glomerular
permeability.
14. GLOMERULAR DISEASES
Glomerular diseases constitute some of the major
problems in nephrology.
Glomerulonephritis is an inflammation of the glomerulus,
while glomerulopathy is a term for disorder affecting this
structure.
Glomeruli may be injured by variety of factors and in
course of several systemic diseases.
Most of the glomerular diseases are immunologically
mediated, whereas tubular and interstitial disorders are
frequently caused by toxic or infectious agents.
15. CLASSIFICATION OF GLOMERULAR
DISEASE BY DISTRIBUTION
A)Classification of disease distribution when many
glomeruli are considered.
FOCAL:- Disease affecting only some of glomeruli.
DIFFUSE:- Disease affecting most or all glomeruli.
B)Classification of disease distribution when single
glomeruli are considered.
SEGMENTAL:- a lesion involving only a part of the
glomerulus
GLOBAL:- a lesion involving the entire glomerulus.
16. CLINICOPATHOLOGICAL CLASSIFICATION OF
GLOMERULAR DISEASE.
Primary glomerular disease :- in this the glomeruli are
the predominant site of involvement.
Secondary glomerular disease:- includes certain
systemic and hereditary diseases which secondarily
involve the glomeruli.
17. THE GLOMERULAR SYNDROMES
SYNDROME MANIFESTATIONS
Nephritic syndrome Hematuria, azotemia, variable proteinuria, oliguria,edema
and hypertension
Rapidly progressive Acute nephritis, proteinuria and acute renal failure
glomerulonephritis
Nephrotic syndrome >3.5 gm/day proteinuria, hypoalbuminemia,
hyperlipidemia,lipiduria.
Chronic renal failure Azotemia progressing to Uremia over months to years.
Isolated urinary Glomerular hematuria and/or subnephrotic proteinuria.
abnormalities
18. A schema of the average patient ages associated with
various common forms of nephrotic syndrome
19. HISTOLOGICAL ALTERATIONS IN
GLOMERULOPATHIES
Characterized by one or more of four basic tissue reactions :-
Hypercellularity characterized by Increase in the number of cells in
the glomerular tufts. This hypercellularity is comprised of one or more
combination of mesangeal or endothelial cell proliferation, leukocyte
infiltration or formation of crescents.
Basement Membrane Thickening on light microscopy appears as
thickening of the capillary walls and is best seen by PAS staining. On
electron microscopy it can have one of the two forms:-
a) Deposition of amorphous electron dense material on endothelial or
epithelial side of GBM or within the GBM itself.
b) Thickening of the basement membrane due to increased synthesis
of its protein components as occurs in diabetic glomerulosclerosis.
20. HISTOLOGICAL ALTERATIONS IN
GLOMERULOPATHIES contt…
Hyalinosis denotes the accumulation of material that is
homogenous and eosinophilic by light microscopy. By electron
microscopy the hyaline is extracellular ,amorphous made up of
leaked plasma proteins from circulation into glomerular
structures. Hyalinosis is a consequence of endothelial or
capillary wall injury.
Sclerosis is characterized by accumulation of extracellular
collagenous matrix either confined to mesengeal areas or
involving the capillary loops or both.
21. PATHOGENESIS OF GLOMERULAR
INJURY
Immune mechanisms underlie most forms of primary
glomerulopathies and many of secondary glomerular disorders.
ANTIBODY MEDIATED
IN SITU IMMUNE COMPLEX DEPOSITION
CIRCULATING IMMUNE COMPLEX MEDIATED
CYTOTOXIC ANTIBODIES CELL MEDIATED IMMUNE INJURY
ACTIVATION OF ALTERNATIVE COMPLEMENT PATHWAY
22. Pathogenesis of Glomerular Disease
Immune
disorder
Kidney
involvement
Injury by
inflammation and
other mediators
Glomerular
dysfunction
26. ACUTE PROLIFERATIVE
GLOMERULONEPHRITIS
This condition is characterized histologically
by diffuse proliferation of glomerular cells,
associated with influx of leucocytes.
These lesions are typically caused by immune
complexes.
The inciting antigen may be exogenous or
endogenous.
The prototype exogenous antigen-induced
disease pattern is postinfectious
glomerulonephritis.
27. ACUTE PROLIFERATIVE
GLOMERULONEPHRITIS
APGN has mainly two types-
POST STREPTOCOCCAL GLOMERULONEPHRITIS.
NON - STREPTOCOCCAL GLOMERULONEPHRITIS.
28. ACUTE PROLIFERATIVE
GLOMERULONEPHRITIS
POST STREPTOCOCCAL GLOMERULONEPHRITIS.
Produces the nephritic syndrome (hematuria, red
cell casts, moderate proteinuria and edema) in
children two weeks following a respiratory or skin
infection with a "nephritogenic strain" of group A,
beta-hemolytic streptococci.
Clinically, this disease is manifested by a rather
abrupt onset of gross hematuria, edema,
proteinuria, hypertension and impaired renal
function.
The serum levels of hemolytic complement
activity and C3 protein are abnormally reduced.
29. ACUTE PROLIFERATIVE
GLOMERULONEPHRITIS
POST STREPTOCOCCAL GLOMERULONEPHRITIS.
Latent period between infection and onset of
nephritis is compatible with the time required for
the production of antibodies and formation of
immune complexes.
There is deposition of circulating immune
complexes which fix complement and attract
PMN's.
This chokes off their blood supply, making the
glomeruli hypercellular and bloodless.
This explains the oliguria, edema, and hypertension
2% to 5% patient die during acute episode.
30. ACUTE PROLIFERATIVE GLOMERULONEPHRITIS
LIGHT MICROSCOPY
Enlarged , hypercellular glomeruli.
Hypercellularity is caused by infiltration of both leucocytes and monocytes, proliferation of
endothelial and mesenchymal cells and in severe cases there crescent formation.
Interstitial edema
Tubules often contain red cell casts
32. ACUTE PROLIFERATIVE GLOMERULONEPHRITIS
ELECTRON MICROSCOPY
The findings are discrete, amorphous, electron dense deposits on the epithelial side of
basement membrane, often having appearance of humps
34. ACUTE PROLIFERATIVE
GLOMERULONEPHRITIS
NON – STREPTOCOCCAL GLOMERULONEPHRITIS
This similar form of glomerulonephritis occurs
sporadically in association with other infections,
including
Bacterial:- staphylococcal endocarditis, pneumococcal pneumonia
and meningococcemia.
Viral:-hepatitis B, hepatitis C, mumps, HIV, varicella.
Parasitic:-malaria, toxoplasmosis.
In these settings, granular immunofluorescent deposits
and subepithelial humps characteristic of immune
complex nephritis are present.
36. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
Severe form of glomerulonephritis in which
majority of the glomeruli are involved by epithelial
crescents.
RPGN is characterized by rapid and progressive
loss of renal function accompanied by hematuria,
variable proteinuria and severe oliguria.
Most common histological picture is the presence
of crescents in most of glomeruli.
37. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
CLASSIFICATION BASED ON IMMUNOLOGICAL FINDINGS
TYPE I (ANTI-GBM ANTIBODY)
Renal limited
Goodpasture syndrome
TYPE II (IMMUNE COMPLEX)
Idiopathic The common
Post infectious glomerulonephritis
denominator in all
Lupus Nephritis
types of RPGN is
Henoch-Schonlein purpura
severe glomerular
Others
TYPE III (PAUCI- IMMUNE)
injury
ANCA-associated
Idiopathic
Wegener granulomatosis
Microscopic Polyangitis
38. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
TYPE I It is anti-GBM antibody induced disease, characterized by
RPGN linear deposits of IgG and C3 in the GBM.
In some individuals, the anti- GBM antibodies cross react
with pulmonary aleveolar basement membraneand produces
pulmonary hemorrhage associated with renal failure
(Goodpastures Syndrome)
The Goodpasture antigen is a peptide within the
noncollagenous portion of the α3 chain of collagen type IV.
TYPE II It is a result of immune complex deposition.
RPGN It can be a complication of any of the immune complex
nephritides.
In all its types I/F study reveals granular pattern of staining
characterized of immune complex deposition.
Also called pauci-immune type.
TYPE III
Defined by lack of anti-GBM antibodies or immune
RPGN
complexes by immunofluorescence and electron microscopy.
Most patients with this type of RPGN have circulating
antineutrophil cytoplasmic antibody (ANCAs), hence there is
a component of systemic vasculitis seen.
40. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
Light microscopy can provide useful information to help
distinguish which subclass (RPGN I, II, III) of crescentic
glomulonephritis is present.
RPGN type II have more segmental hypercellularity than
types I and III.
Necrotizing changes of glomerular tufts are more common
in RPGN types I and III.
In particular, comparing RPGN Type I to RPGN type III,
the pauci-immune disease is more often associated with
necrotizing arteritis
41. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
LIGHT
MICROSCOPY
Glomeruli may
show focal
necrosis, diffuse
or focal
endothelial
proliferation and
mesengial
proliferation.
The histological
picture is
dominated by
distinctive
crescents.
Crescentric glomerulonephritis. Collapsed glomerular tuft and
crescent-shaped mass of proliferating parietal epithelial cells.
42. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
WHAT ARE
CRESCENTS ?
Crescents are formed by proliferation of partial cells
and by migration of monocytes and macrophages into
urinary space.
The crescents eventually obliterate bowman space and
compress the glomerular tuft.
Fibrin strands are frequently prominent between the
cellular layers in the crescents.
The escape of fibrinogen into bowman space and its
conversion to fibrin are an important contributor to
crescent formation.
43. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS
IMMUNOFLUORESCENCE
Type I RPGN
•Anti GBM
disease
•Good pasture
syndrome
Direct immunofluorescence shows smooth, linear staining of the glomerular capillary
basement membranes for IgG. Similar staining pattern would also be seen for C3.
48. MEMBRANOUS NEPHROPATHY
Common cause of nephrotic syndrome in adults.
Characterized by diffuse accumulation of electron
dense, Ig-containing deposits along the sub-
epithelial side of basement membrane.
In about 85% patients no associated condition can
be uncovered and are considered idiopathic.
In about 15% patients there is other systemic
condition associated with it and is referred to as
secondary membranous glomerulopathy.
Formation of membrane attack protein {C5b-C9}
causes the capillary damage and hence leakage of
proteins.
49. MEMBRANOUS NEPHROPATHY contt…
SECONDARY MEMBRANOUS GLOMERULOPATHY
It is a form of chronic immune complex-mediated disease.
The inciting antigens can sometimes be identified in the
immune complexes. For eg exogenous antigen (hepatitis B or
Treponema), Endogenous nonrenal antigens (thyroglobin),
Endogenous renal antigens (membrane protein antigen)
The most notable associations are seen with
Drugs— penicillamine, captopril,gold NSAIDs
Malignant tumors --- Ca lung, Ca colon , Melanoma
SLE--- 10%-15% of glomerulonephritis in SLE is of membranous type
Infections--- Hepatitis B, Hepatitios C, Syphilis, malaria.
Auto immune disorders--- Thyroiditis.
50. MEMBRANOUS NEPHROPATHY contt…
LIGHT MICROSCOPY
Uniform, diffuse thickening of the glomerular capillary wall.
Basement membrane material is laid down between these deposits, appearing as
irregular spikes protruding from the GBM.
These spikes are best seen by silver stains, which color the basement membrane black.
Marked diffuse thickening of the capillary walls without an increase in the
number of cells. There are prominent spikes projecting from basement
membrane.
52. MEMBRANOUS NEPHROPATHY contt…
IMMUNOFLUORESCENCE
Immunofluorescence
microscopy: granular
deposits contain both
immunoglobulins and
various amounts of
complement .
The course of the disease is
variable but generally
indolent.
Although proteinuria
persists in more than 60%
of patients, only about 10%
die or progress to renal
failure within 10 years, and
no more than 40%
eventually develop renal
insufficiency.
53. MEMBRANOUS NEPHROPATHY contt…
ELECTRON MICROSCOPY
Electron micrograph showing electron dense deposits along the
epithelial side of the basement membrane. There is effacement of
foot processes overlying deposits.
55. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
Derived from the characteristic histological changes by
light microscopy
Accounts for 10% to 20% of cases of nephrotic
syndrome.
MPGN is characterized by alteration of glomerular cells
and leukocyte infiltration.
Proliferation is predominantly in the mesengium and
involves capillary loops also , hence a synonym
mesengiocapillary glomerulonephritis is used.
Persistent and slowly progressive.
56. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
CLASSIFICATION
Primary MPGN :- when the cause is idiopathic.
on the basis of distinct ultra structural,
immunofluorescence and pathological findings it is
divided into:-
A) Type I MPGN
B) Type II MPGN (dense deposit disease)
C) Type III MPGN (very rare, it is characterized by a
mixture of subepithelial deposits and the typical
pathological findings of Type I disease)
Secondary MPGN :- when associated with other
systemic disorders.
57. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
TYPE I MPGN
Account for approx 5% of the cases of end stage renal disease.
Children and young adults more frequently involved.
Approx one third of patients present with nephritic syndrome.
Approx two thirds of the patients develop
hypocomplementemia with predominant depletion in C3 levels.
Evidence of immune complexes in the glomerulus and
activation of both classical and alternative complement pathways.
Antigens involved are unknown, sometimes believed to be
protein derived from infectious agents like hepatitis C and B
viruses.(planted antigens)
58. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
TYPE II MPGN (Dense Deposit Disease)
Shows unique morphological appearance of basement
membrane best seen by electron microscopy.
Much more rare than type 1.
Type II MPGN tends to present with nephritis while MPGN
type I presents more often with nephrotic features.
There is activation of alternative complement pathway.
Serum levels of C3 remains low for a longer period than type I
disease.
More than 70% of patients have a circulating antibody termed
C3 nephiritic factor ( C3NeF ).
59. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
LIGHT MICROSCOPY
Light microscopy of both types of MPGN are similar , but the cellular
proliferation, and especially the circumferential mesengeal interposition is
less prominent in type 2 MPGN.
Glomeruli are large and hypercellular.
Hypercellularity is produced both by proliferation of cells in the
mesengium and endocapillary also.
Glomeruli have lobular appearance due to proliferating mesengial cells and
increased mesengeal matrix.
The GBM is thickened, often segementally.
The glomerular capillary wall often show a double contour or tram-track
appearance especially evident in silver or PAS stains. This is caused by
splitting of GBM.
60. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
LIGHT MICROSCOPY
Thickening of
capillary walls,
usually global and
diffuse.
There is also
hypercellularity.
Much of this
hypercellularity is
mesangial
proliferation, and
some of the capillary
wall thickening is
caused by mesangial
interposition into the
subendothelial zone
of the capillary loops.
61. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
IMMUNOFLUORESCENCE Type I MPGN
There are C3, IgG and IgM deposits, being those of C3 more frequent
and constant. These deposits are granular in the capillary walls.
Often they are elongated and smooth in their external edge because
they are subendothelial and they are molded to the GBM.
62. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
IMMUNOFLUORESCENCE Type II MPGN
The bright deposits scattered along capillary walls and in the
mesangium by immunofluorescence microscopy with antibody to
complement component C3 are typical for membranoproliferative
glomerulonephritis, type II.
63. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
ELECTRON MICROSCOPY TYPE I (MPGN)
Marked thickening of glomerular capillary
wall by immune deposits and by
Normal glomerular capillary loop showing
interposition of mesengeal cell processes.
normal endothelial cells, GBM and epithelial
There are two layers of GBM surrounding
cells.GBM is thin and no electron dense
the mesengeal interposition that account
deposits are present.
for double contour appearance on light
microscopy.
64. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
ELECTRON MICROSCOPY TYPE II (MPGN)
Normal glomerular capillary loop Dense ribbon like appearance of sub-
showing normal endothelial cells, GBM endothelial and intramembranous
and epithelial cells.GBM is thin and no material and narrowing of the
electron dense deposits are present. capillary lumen due to proliferation of
cells.
65. MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS
SECONDARY MPGN
More common in adults and arises in the following conditions
Infections HepatitisB and C, endocarditis, Visceral abscesses,
malaria, schistisomiasis, mycoplasma, HIV and EB
virus infection
Immunological SLE, Scleroderma, sjogren’s syndrome, rheumatoid
disorders arthritis, sarcoidosis.
Neoplastic Carcinoma, CLL, NHL, melanoma.
diseases
Hereditary α1 antitrypsin deficiency, complement deficiency,
diseases hereditary angioedema
Miscellaneous Drug abuse, kartagener’s syndrome, turner’s syndrome,
down’s syndrome
67. IgA NEPHROPATHY
It is the commonest form of glomerulonephritis resulting in
ESRD throughout the world. Male predominance.
Also known as
IgA nephritis,
Berger's disease,
Synpharyngitic glomerulonephritis
Frequent cause of gross and microscopic hematuria
Characterized by the presence of prominent IgA deposits in the
mesengeal region.
Suspected by light microscopy, but diagnosis is made only by
immunochemical method.
68. IgA NEPHROPATHY
PATHOGENESIS
Abnormalities of immune regulation leads to
increased IgA synthesis in response to respiratory or
gastrointestinal exposure to environmental agents.
IgA1 (nephritogenic form) and IgA1-containing
immune complexes are then trapped in the
mesengium, where they activate the alternative
complement pathway and initiate glomerular injury.
IgA nephropathy occurs with increased frequency in
individuals with gluten enteropathy and in liver
diseases (defective hepatobiliary clearence of IgA
complexes)
69. IgA NEPHROPATHY
LIGHT MICROSCOPY
Glomeruli may be normal or may show mesengial widening and
endocapillaryproliferation.The mesengial widening is due to cell
proliferation, accumulation of matrix and immune deposits.
70. IgA NEPHROPATHY
IMMUNOFLUORESCENCE
The IF pattern parallels the distribution of deposits seem by EM. It
shows deposits of IgA often with C3 and properdin and lesser amounts
of IgG or IgM. Early complement components are usually absent.
71. IgA NEPHROPATHY
ELECTRON MICROSCOPY
Portion of a glomerulus from a patient with IgA nephropathy showing
electron-dense mesengial deposits
73. MINIMAL CHANGE DISEASE
Accounts for 80% of all cases of the idiopathic nephrotic syndrome in children.
Majority of cases seen in 3 to 4 year age groups.
Male predominance of 2.5:1 in children but no difference seen in adults.
80-90% idiopathic.
Associated with infectious disease, recent immunization, ingestion of heavy
metals.
In adults related to use of NSAIDS.
A full blown nephrotic syndrome with heavy proteinuria often of selective type is
the most common presentation.
On light microscopy changes are seen in the convoluted tubules where large
amounts of lipid and protein droplets accumulate in the cell cytoplasm.(lipoid
nephrosis)
In contrast all the glomeruli appear normal.
74. MINIMAL CHANGE DISEASE
LIGHT MICROSCOPY
The glomerulus is normocellular, the capillary loops are patent,
and the basement membrane is normal in thickness
76. MINIMAL CHANGE DISEASE
ELECTRON
MICROSCOPY
Portion of a glomerulus from a patient with minimal change
glomerulopathy showing obliteration of foot processes. The epithelial
cell cytoplasm is hyperactive and shows microvillus and cyst formation.
78. FOCAL SEGMENTAL
GLOMERULOSCLEROSIS
Focal segmental glomerulosclerosis (FSGS) defines a
characteristic pathologic pattern of glomerular injury
and is not necessarily a distinct disease.
The hallmark of kidney biopsy is an increased
degree of scarring seen on light microscopy of some
but not all of the glomeruli present (focal) that
involves some but not all portions of the affected
glomeruli (segmental).
Characterized by proteinuria commonly in
nephrotic range.
79. FOCAL SEGMENTAL
GLOMERULOSCLEROSIS
CLASSIFICATION
FSGS may be primary (idiopathic) or secondary to various etiologies.
PRIMARY SECONDARY
Typical FSGS Unilateral renal agenesis
Collapsing HIV infection
glomerulopathy Heroin addiction
Glomerular tip lesion Morbid obesity
Sickle cell disease
Congenital heart disease
Glycogen storage disease
Hypertensive
nephropathy
80. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
Primary FSGS makes up approx 10% to 15% of nephrotic
syndrome in children and 20% to 30% in adults.
It is the predominant cause of idiopathic nephrotic syndrome
in adults.
Mainly sporadic type.
Involves children under 5 years of age and adults in 3rd and
4th decades.
Onset is insidious.
40% to 60% of patients progress to end stage renal disease
within 10 to 20 years.
81. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
LIGHT MICROSCOPY
Focal and segmental lesions may involve only a minority of the glomeruli and
may be missed if the biopsy specimen contains an insufficient number of
glomeruli.
The lesion initially tends to involve the juxtamedullary glomeruli and
subsequently becomes generalized.
In the sclerotic segments there is collapse of capillary loops, increase in
matrix and segmental deposition of plasma proteins along the capillary wall
(hyalinosis).
The hyalinosis may become so pronounced as to occlude the capillary lumen.
Lipid and foam cells are often present.
Glomeruli that do not show segmental lesion usually appear normal.
82. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
LIGHT MICROSCOPY
Biopsy from a
patient with
FSGS.
One of the
glomeruli shows
segmental
sclerosis while
others appear
unremarkable.
Tubular atrophy
is also seen.
83. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
COLLAPSING GLOMERULOPATHY
It is clinically and
pathologically distinct variant
of FSGS
Characterized by
widespread collapse of
glomerular capillary loops.
Poor prognosis with rapid
loss of renal function and no
response to therapy.
It can occur as an idiopathic
disease or as secondary
process associated with i/v
drug abuse or HIV infection.
Collapsing glomerulopathy. Visible retraction of the glomerular tuft,
narrowing of capillary lumens, proliferation and swelling of visceral epithelial
cells, and prominent accumulation of intracellular protein absorption droplets
in the visceral epithelial cells.
84. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
GLOMERULAR TIP LESION
Variant of FSGS.
Characterized by a
consolidation of the glomerular
segment adjacent to the origin of
proximal tubule.
The capillary Lumina of
sclerotic loops may appear
obliterated by swelling of
endothelial cells and presence of
foamy cells.
The epithelial cells adjacent to
the involved segment are
enlarged, vacuolated and often
contain hyaline droplets.
In this glomerulus we can see the location of the lesions characterized
by a "tip" (from the glomerular tip). There are adhesions and sclerosis,
hyaline deposits and endocapillary hypercellularity.
86. FOCAL SEGMENTAL GLOMERULOSCLEROSIS
ELECTRON MICROSCOPY
Early focal and segmental glomerulosclerosis. There is mild segmental
prominence of the mesangium (upper third) and vacuolization of the
epithelial cell cytoplasm. A lipid-laden intracapillary cell with foamy
cytoplasm is also present (arrows).
88. DIABETIC NEPHROPATHY
Diabetic nephropathy is the leading cause of chronic renal failure
in the industrialised world.
It is also one of the most significant long-term complications in
terms of morbidity and mortality for individual patients with
diabetes.
Diabetes is responsible for 30-40% of all end-stage renal disease
(ESRD) cases.
Most of the patients who develop diabetic nephropathy have had
diabetes for at least 10 years, so it is more frequent in type I DM
than in type II DM.
By far the most common lesions involve the glomeruli and are
associated clinically with three glomerular syndromes: non-
nephrotic proteinuria, nephrotic syndrome and chronic renal
failure.
89. DIABETIC NEPHROPATHY
Three lesions that are encountered in diabetic nephropathy are :-
GLOMERULAR LESIONS.
CAPILLARY BASEMENT MEMBRANE THICKENING
DIFFUSE GLOMERULOSCLEROSIS
NODULAR GLOMERULOSCLEROSIS
INSUDATIVE LESIONS
RENAL VASCULAR LESIONS, PRINCIPALLY ARTERIOLOSCLEROSIS.
PYELONEPHRITIS, INCLUDING NECROTIZING PAPILLITIS.
90. DIABETIC NEPHROPATHY
CAPILLARY BASEMENT MEMBRANE THICKENING
There is wide spread thickening of
the GBM and occurs virtually in all
cases of diabetic nephropathy and
forms the part and parcel of diabetic
microangiopathy.
Pure capillary basement
membrane thickening can be
detected only by electron
microscopy.
Thickening begins as early as 2
years after the onset of type I DM
and by5 years amounts to about a 30
% increase.
RENAL GLOMERULUS SHOWING MARKEDLY THICKNED
GLOMERULAR BASEMENT MEMBRANE
91. DIABETIC NEPHROPATHY
DIFFUSE GLOMERULOSCLEROSIS
Most common lesion in diabetic
nephropathy.
Diffuse increase in mesangial
matrix and thickening of capillary
wall.
Mesangial increase is typically
associated with overall thickening of
GBM.
Matrix deposition is PAS-positive.
As the disease progresses, the
expansion of mesangial areas can
extend to nodular configuration.
Early diffuse diabetic glomerulosclerosis showing a mild increase in
mesangial matrix and thickened capillary walls. The arteriole shows the
typical hyaline appearance of an insudative lesion.
92. DIABETIC NEPHROPATHY
NODULAR GLOMERULOSCLEROSIS
Also known as Intercapillary
glomerulosclerosis or Kimmelstiel-wilson
disease.
Consists of largely acellular nodules
that are located in the intercapillary
regions.
Nodules vary in size and often have
laminated appearance.
They are ecsinophilic, argyrophilic, PAS-
positive and stain green with masson’s
trichrome stain and blue with mallory’s
stain.
Ultrastructurally they are composed of
masses of extra cellular mesangial matrix
which is the result of both increased
synthesis and decreased degradation of
mesangial matrix.
NODULE OF DIABETIC
GLOMERULOSCLEROSIS
93. DIABETIC NEPHROPATHY
INSUDATIVE LESIONS
The nodular lesion are frequently accompanied by prominent accumulations of hyaline
material in capillary loops (fibrin caps) or adherent to bowman’s capsule (capsular drops).
Histological and immunofluorescence studies indicate that this insudative material
represents infiltration by constituents of the plasma, including protein, lipids and
mucopolysaccharides.
FIBRIN CAP CAPSULAR DROP
94. DIABETIC NEPHROPATHY
IMMUNOFLUORESCENCE
Diffuse linear localization of IgG along glomerular and tubular basement membranes and
bowman’s capsule is the most common immunofluorescence finding in diabetic nephropathy.
Diabetic glomerulosclerosis with linear staining for IgG along the
glomerular basement membrane.
96. LUPUS NEPHRITIS
Immune mediated nephritis is the common complication of SLE.
The pathogenesis of this lesion is likely to be related to the
inflammation response resulting from the presence of immune
aggregates at the site of injury.
The most constant feature, which is found in nearly all patients with
clinical lupus nerhritis is proteinuria.
A kidney biopsy is essential in the renal assessment of patients with
SLE.
The pathological findings of lupus nephritis are extremely diverse and
may occur in any or all four renal compartments: glomeruli, tubules,
interstitsium and blood vessels.
This diversity may be the result of differences in the immune response
in different patients or in same individual over a period of time.
97. WHO LUPUS WITH PATHOLOGICAL CORRELATION
CLASSIFICATION OF NEPHRITIS
Class I Light microscopy findings Normal
Minimal mesangial lupus IF/EM Findings Mesangial immune deposits
nephritis
Class II Light microscopy findings Purely mesangial hypercellularity or mesangial matrix
Mesangial proliferative expansion with mesangial immune deposits
lupus nephritis IF/EM Findings Mesangial immune deposits; few immune deposits in
subepithelial or subendothelial deposits possible
Class III Light microscopy findings Active or inactive focal, segmental, or global
Focal lupus nephritis glomerulonephritis involving <50% of all glomeruli
IF/EM Findings Subendothelial and mesangial immune deposits
Class IV Active or inactive diffuse, segmental or global
Diffuse lupus nephritis glomerulonephritis involving >50% of all glomeruli;
Light microscopy findings
subdivided into diffuse segmental (class IV-S)and diffuse
global (class IV-G)
IF/EM Findings Subendothelial immune deposits
Class V Light microscopy findings Diffuse thickening of glomerular basement membrane
Membranous lupus without inflammatory infiltrate .
nephritis IF/EM Findings Subepithelial and intramembranous immune deposits
Class VI Light microscopy findings Advanced glomerular sclerosis involving >90% of
Advanced sclerosis lupus glomeruli, interstitial fibrosis, and tubular atrophy.
nephritis IF/EM Findings Few , if any immune deposits.
98. LUPUS NEPHRITIS
CLASS II : There is mild diffuse
mesangial hypercellularity and an
increase in matrix. These
mesangial deposits can be
identified by
immunofluorescence.
CLASS III : There is focal and
segmental glomerulonephritis
characterized by segmental
necrosis, adhesions to bowman’s
capsule, and leucocytic
infiltration.
99. LUPUS NEPHRITIS
CLASS IV : lupus nephritis
showing a well circumscribed area
of necrosis containing small
hematoxylin bodies.
CLASS IV: glomerulus showing
several wire-loop lesions
100. LUPUS NEPHRITIS
CLASS IV: Glomerulus with an
epithelial crescent showing two
hyaline thrombi.
CLASS IV: IF prepration for IgG
showing large amounts of
immunocomplex deposits not only
in the mesengium and along the
glomerular capillary loops, but also
around the tubular basement
membrane, interstitium.
101. LUPUS NEPHRITIS
CLASS V : The capillary walls
are thickened and the
mesangial matrix increased.
Advanced glomerular
sclerosis in lupus nephritis
class VI
103. RENAL AMYLOIDOSIS
It designates a group of conditions characterized by extracellular deposition
of fibrillar proteins that have a β-pleated sheet configuration on X-ray
diffraction analysis.
Nonselective proteinuria, with or without nephrotic syndrome is the most
common manifestation of renal involvement by amyloidosis.
Most significant deposition of amyloid in the kidneys is in the glomeruli, but
it also takes place around tubules, within interstitium and the walls of blood
vessels.
The glomerular deposits first appear as subtle thickenings of the mesangial
matrix, accompanied by uneven widening of the basement membranes.
Eventually the amyloid deposits obliterate the glomerulus completely.
The morphological features of the deposits do not differ in AL or AA
amyloidosis.
104. RENAL AMYLOIDOSIS
H & E STAINING
Panoramic image of a renal biopsy showing glomeruli with massive
distension of the mesangial areas by amyloid. The wall of an arteriole
(right side of image) is also laden with amyloid (H&E stain)..
105. RENAL AMYLOIDOSIS
CONGO RED STAINING
The production of an apple green color
by polarized light in congo red stained
sections is probably the most reliable
light microscopic method for diagnosing
amyloidosis.
Staining procedure must be performed
on sections that are at least 8 μm thick.
The fibrils of primary AL and secondary
AA amyloidosis can be distinguished by
pretreating tissue sections with
potassium permanganate before congo
red staining. Under these conditions,AA
amyloid fibrils lose their affinity for
congo red stain and the birefringence is
lost, where as AL amyloid is not affected.
Glomerulus from renal biopsy stained with congo red and examined by
polarization microscopy. The characteristic "apple-green" birefringence
of amyloid is apparent (Congo red stain).
106. RENAL AMYLOIDOSIS
FLUORESCENT STAINING
Fluorescent stains like thioflavin-S or T bind to amyloid and fluoresce
yellow under ultraviolet light (i.e amyloid emits secondary fluorescence)
107. RENAL AMYLOIDOSIS
ELECTRON MICROSCOPY
Electron micrograph of a glomerulus showing the characteristic non-
branching fibrils of amyloid in a random "felt-like" pattern of
distribution.
108. RENAL AMYLOIDOSIS
Immunofluorescence may reveal the accumulation of immunoglobulin's
in a non specific pattern.
By using antibodies specific for amyloid AA and light chains, it is
possible to differentiate between amyloids AA and AL.
KAPPA LAMBDA
Anti-immunoglobulin light chains (κ or λ) are useful for
amyloid AL diagnosis
110. Fibrillary glomerulonephritis and immunotactoid glomerulopathy
FIBRILLARY GLOMERULONEPHRITIS
It is a morphological variant of glomerulonephritis associated with characteristic
fibrillar deposits in the mesangium and glomerular capillary walls.
These fibrillar deposits resemble amyloid fibrils superficially but differ
ultrastructurally and do not stain with congo red.
The fibrils most often are 18 t0 24 nm in diameter and hence are larger than 10 to 12 nm
fibrils characteristic of amyloid.
The glomerular lesions usually show MPGN like pattern under light microscopy, and
by immunofluorescence microscopy, there is selective deposition of polyclonal IgG, C3
and light chains.
Clinically the patient develops nephrotic syndrome.
IMMUNOTACTOID GLOMERULOPATHY
It is much rare condition.
The deposits are microtubular in structure and are 30 to 50 nm in width
111. Fibrillary glomerulonephritis and immunotactoid
glomerulopathy
Fibrillary glomerulonephritis. Immunotactoid glomerulopathy
Randomly arranged microfibrillary showing intramembranous fibrils with
deposits (diameter: 18–23 nm). MES, a diameter of around 45nm. (× 20,000)
mesangium.
113. Renal involvement in Plasma cell dyscrasias
Patients with plasma cell dyscrasias (myeloma) may
exhibit a variety of renal manifestations as a result of
damage from circulating light- and heavy-chain
immunoglobulin components produced by the
neoplastic plasma cells.
It is associated with:-
[1] Amylodosis, in which the fibrils are usually
composed of monoclonal λ light chains.
[2] Deposition of monoclonal immunoglobins or light
chains in GBM.
[3] Distinctive nodular glomerular lesions resulting
from the deposition of nonfibrillar light chains.
114. Renal involvement in Plasma cell dyscrasias
LIGHT MICROSCOPY
Affected glomeruli are enlarged and the deposition of the markedly PAS- positive material
produces capillary wall thickening and nodular expansion of mesangium.
The extend of glomerular involvement can vary in a biopsy from mild mesangial expansion to a
fully developed nodular glomerulosclerosis that resembles diabetic glomerulosclerosis.
LIGHT CHAIN DISEASE HEAVY CHAIN DISEASE
Light and heavy chain deposition disease. There are similar findings in light and heavy chain
deposition disease with mesangial nodularity. Prominent hypercellularity is associated with heavy
chain deposition disease compared with light chain deposition disease
115. Renal involvement in Plasma cell dyscrasias
IMMUNOFLUORESCENCE
Immunofluorescence microscopy demonstrates staining of the abnormal light
chain along the glomerular and tubular basement membranes, as well as in
the mesengium, vessel walls, and interstitium.
A B
Light chain deposition disease. Note linear staining along peripheral
capillary walls in glomeruli and tubular basement membranes in A and
predominantly granular mesangial staining for light chains in B.
117. Henoch-SchӦnlein purpura
Henoch-SchӦnlein purpura (HSP) is a systemic vasculitis
characterized by purpuric skin lesions unrelated to any
underlying coagulopathy. The classic clinical triad of HSP
is palpable purpura, joint symptoms, and abdominal
pain. However, renal involvement is the most serious
complication.
A small number of patients develop a rapidly progressive
form of glomerulonephritis with many crescents.
IgA is deposited in the glomerular mesangium in a
distribution similar to that of IgA nephropathy
118. Henoch-SchӦnlein purpura
Light microscopic finding varies from mild focal mesangial proliferation to
diffuse mesangial proliferation and/or crescentric glomerulonephritis.
Immunofluorescence microscopy shows deposition of IgA, sometimes with
IgG and C3, in the mesangial region
Moderate to marked mesangial Glomerular deposits of IgA show a
matrix expansion can be seen in global homogenous and granular
this glomerulus mesangial pattern by
120. MIXED CRYOGLOBULINEMIA
Cryoglobulins are complexes of one or more
different classes of immunoglobulins that
precipitate at lower temperature (4 degree) and
become soluble again when temperatures are
elevated.
Mixed cryoglobulinemia ia a systemic condition
in which deposits of cryoglobulins composed
principally of IgG-IgM complexes induce
vasculitis, synovitis and a proliferative
glomerulonephritis typically MPGN.
121. MIXED CRYOGLOBULINEMIA
LIGHT MICROSCOPY
The most common finding in renal
biopsies from patients with mixed
cryoglobulinemia is a diffuse
proliferative glomerulonephritis
often with membranoproliferative
pattern.
In more acute cases, the deposits
produce the appearance of thrombi
or wire loops comparable to what is
seen in lupus glomerulonephritis.
IMMUNOFLUORESCENCE
Immunofluorescence usually
demonstrates positivity for the
immunoglobins present in the
cryoglobulins in the glomeruli and
vessels. C3 is often found in these
locations.
123. Goodpasture syndrome, Microscopic polyangitis,
Wegener granulomatosis
They are all associated with glomerular lesions.
Glomerular lesions in these three conditions can be
histologically similar and are principally characterized by
foci of glomerular necrosis and crescent formation.
In early or mild form of involvement, there is focal and
segmental, sometimes necrotizing, glomerulonephritis.
In more severe cases associated with RPGN , there is more
extensive necrosis, fibrin deposition, and extensive
formation of epithelial crescents and leads to global
scarring.
125. ALPORT’S SYNDROME
Alports Syndrome is a primary basement membrane
disorder manifested by progressive nephritis(hematuria
and proteinuria), deafness and ocular abnormalities.
Approx 80%-85% of patients have X linked form of
syndrome resulting from mutation of COL4A5.
Gross or microscopic hematuria is the most common
and earliest manifestation.
126. ALPORT’S SYNDROME
LIGHT MICROSCOPY
Light microscopy findings
are nonspecific.
There is focal and
segmental glomerular
hypercellularity of the
mesangial and
endothelial cells.
Renal interstitial foam
cells can be found and
represent lipid-laden
macrophages which can
be seen in many renal
diseases.
127. ALPORT’S SYNDROME
IMMUNOFLUORESCENCE
Monoclonal antibodies directed against α3(IV), α4(IV), and α5(IV) chains of type IV
collagen can be used to evaluate the GBM for the presence or absence of these chains.
The absence of these chains from the GBM is diagnostic of AS and has not been
described in any other condition.
Normal diffuse linear staining for α5(IV). Staining for α5(IV) completely negative
128. ALPORT’S SYNDROME
ELECTRON MICROSCOPY
The most significant
morphological finding of
alport's syndrome can only
be seen by electron
microscopy.
The typical lesion is
thickening of glomerular
basement membrane with
transformation of lamina
densa into multiple
interwoven lamellae which
enclose electron-lucent
areas containing round
granules of variable density.
Glomerular capillary loop showing diffuse, irregular thickening of GBM . The
lamina densa is split into multiple interwoven lamellae
130. THIN BASEMENT MEMBRANE LESION
It is a common hereditary entity manifested by
familial asymptomatic hematuria.
There is thinning of GBM to between 150- 250 nm.
The anomaly is due to mutation in genes
encoding α3 or α4 chains of type IV collagen.
This disorder is to be distinguished from IgA
nephropathy (other cause of hematuria) and
Alports syndrome.
131. THIN BASEMENT MEMBRANE LESION
ELECTRON MICROSCOPY
Ultrastructural nature of the glomerular basement membrane in thin basement
membrane nephropathy (A) Normal adult male kidney (B) In TBMN, the GBM does not
revel any structural abnormalities, but it is characteristically thinned, sometimes
having only approximately half of the thickness in a normal kidney
133. FABRY’S DISEASE
Also called Angiokerotoma corporis diffusum universale.
Fabry’s disease is an X-linked recessive lysosomal storage
disease that is caused by deficient activity of the lysosomal
enzyme α-galactosidase A (α-Gal A).
This deficiency results in accumulation of
globotriaosylceramide (Gb3). Gb3 accumulates in many
cells, particularly in renal epithelial cells, endothelial cells,
pericytes, vascular smooth muscle cells, cardiomyocytes,
and neurons of the autonomic nervous system .
134. FABRY’S DISEASE
LIGHT MICROSCOPY
Glomeruli on light microscopy show hypertrophic glomerular visceral epithelial cells
(podocytes) distended with foamy appearing vacuoles, mesangial widening, and
varying degrees of glomerular obsolescence .
Within the glomerulus, the largest amount of lipid material is seen in podocytes,
followed by the parietal epithelial, mesangial, and glomerular endothelial cells.
Glomerulus showing extensive inclusion Plastic embedded tissue showing in-site deposition
bodies of glycolipid in podocytes and mild of glycolipid in glomerular podocytes (toluidine
mesangial widening (PAS stain) blue stain)
135. FABRY’S DISEASE
ELECTRON MICROSCOPY
Vast majority of
laminated
inclusion bodies
are present in the
cytoplasm of
affected cells.
They are either
round with a
concentric myelin-
like structure, or
ovoid with parallel
layers called Zebra
bodies.
Portion of a glomerulus from a patient with Fabry’s disease demonstrating
numerous laminated inclusions in the epithelial cell cytoplasm.
137. Nail-Patella syndrome
Also called Onycho-osteodysplasia or Fog’s syndrome.
Is an autosomal dominant disorder.
Occurs due to point mutation in chromosome no 9.
Renal involvement occurs in approx 30% to 55% of patients.
Light microscopy shows non specific changes.
By electron microscopy, the GBM appears irregularly thickened and often
exhibits electron-lucent areas giving it “moth eaten” appearance.
These areas are occupied by collagen like fibers.
Collagen-like fibers in
the GBM in nail–
patella syndrome
