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Management of hepatitis c pma
- 1. MANAGEMENT OFMANAGEMENT OF HEPATITIS CHEPATITIS C Dr Nasir KhokharDr Nasir Khokhar Professor of MedicineProfessor of Medicine Consultant GastroenterologistConsultant Gastroenterologist Shifa International HospitalShifa International Hospital IslamabadIslamabad
- 3. Model of Human Hepatitis C Virus Lipid Envelope Capsid Protein Nucleic Acid Envelope Glycoprotein E2 Envelope Glycoprotein E1 Reprinted with permission. Henderson LE. Available at http://www.hepcprimer.com.
- 4. Model of HCV Replication Racanelli V, et al. Trends Immunol. 2003;24:456-464. ER HCV Endosome Uncoating Translation Entry Receptor NS2 NS3/4A NS4B NS5B NS5A + - Replication Progeny genomes Golgi E1 E2 Core E1-E2 Assembly E1-E2 Release Exocytosis Nucleus Cytoplasm
- 5. Hepatitis C Virus Infection:Hepatitis C Virus Infection: Population at RiskPopulation at Risk Centers for Disease Control and Prevention. Available at: http://www.cdc.gov/ncidod/diseases/hepatitis/c/fact.htm. Accessed September 27, 2006. Transplant or transfusion of blood products before 1992Transplant or transfusion of blood products before 1992 Injection drug useInjection drug use Nasal inhalation of cocaineNasal inhalation of cocaine Chronic renal failure on dialysisChronic renal failure on dialysis IncarcerationIncarceration Multiple sexual partners, MSMMultiple sexual partners, MSM Occupational exposure to blood productsOccupational exposure to blood products Body piercing and possibly tattooBody piercing and possibly tattoo
- 6. <1 % 1–2.4 % 2.5–4.9 % 5–10 % > 10 % No data available HCV Has Broad Global PrevalenceHCV Has Broad Global Prevalence
- 7. Pakistani PerspectivePakistani Perspective Blood Donors: Replacement 5.14% Non-Blood Donors: Replacement 5.14% Non- remunerated 2.46%remunerated 2.46% General population: 5.13%General population: 5.13% Pregnant Women: 4.8%Pregnant Women: 4.8% Asif, Khokhar, Ilahi. Pak J Med Sci 2004;20:24-28 Khokhar, Gill, Malik. JCPSP 2004;14:127 Khokhar, Raja, Javaid. JPMA 2004;54:135
- 10. Hepatitis C VirusHepatitis C Virus Fate of Acute InfectionFate of Acute Infection 15% Chronic 85% Spontaneous resolution Alter MJ, et al. N Eng J Med. 1999;341:556-562.
- 11. 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0 10 20 30 40 50 FMETAVIR Years Progression of Liver Fibrosis inProgression of Liver Fibrosis in HCV-Infected Patients With Normal ALTHCV-Infected Patients With Normal ALT Slow Normal ALT IntermediateRapid Matched
- 12. Chronic Hepatitis C WithChronic Hepatitis C With Normal Serum ALT: ALTNormal Serum ALT: ALT Patterns and FlaresPatterns and Flares ULN 0 20 40 60 80 100 120 0 3 6 9 12 15 18 21 24 Month ALT(IU/mL) Single elevations Periodic elevations Always normal Illustration by Mitchell L. Shiffman, MD.
- 23. Summary of Risk FactorsSummary of Risk Factors Reuse of syringes Blood transfusion Contaminated surgical instruments / Endoscopes / Dialysis machines Dental instruments/ Tooth brushes Reuse of infected shaving blades Ear piercing / Tattooing
- 24. Clinical FeaturesClinical Features Asymptomatic Fatigue Chronic HCV: an indolent Disease extending over many years Acute attack is usually unrecognized, no clinical features 80% patients will develop chronic hepatitis
- 25. Chronic Hepatitis C VirusChronic Hepatitis C Virus Extrahepatic ManifestationsExtrahepatic Manifestations Nonspecific antibodiesNonspecific antibodies Essential mixed cryoglobulinemiaEssential mixed cryoglobulinemia GlomerulonephritisGlomerulonephritis Porphyria cutanea tardaPorphyria cutanea tarda Leukocytoclastic vasculitisLeukocytoclastic vasculitis Mooren’s corneal ulcerMooren’s corneal ulcer Non-Hodgkin’s lymphomaNon-Hodgkin’s lymphoma Autoimmune thyroiditisAutoimmune thyroiditis Diabetes mellitusDiabetes mellitus
- 26. HCV and CryoglobulinemiaHCV and Cryoglobulinemia DermatitisDermatitis Occurs inOccurs in dependent areasdependent areas Deposition ofDeposition of cryoglobulins incryoglobulins in small capillariessmall capillaries Ulcerations mayUlcerations may developdevelop PruriticPruritic
- 27. Zein CO, et al. Am J Gastroenterol. 2005;100:48-55. Chronic HCV and DiabetesChronic HCV and Diabetes MellitusMellitus Prevalence of diabetesPrevalence of diabetes mellitus and insulinmellitus and insulin resistance notedresistance noted Compared with expectedCompared with expected rate based on NHANESrate based on NHANES III study after adjusting forIII study after adjusting for Age, Sex, RaceAge, Sex, Race Prevalence of DM orPrevalence of DM or insulin resistance higherinsulin resistance higher in those with chronic HCVin those with chronic HCV 0 4 8 12 16 20 Females Males NumberofCases Observed Expected
- 28. Nagao Y, et al. J Gastroenterol Hepatol. 2004;19:1101-1113. Extrahepatic Effects of HCVExtrahepatic Effects of HCV Lichen PlanusLichen Planus Occurs in < 1% of the general populationOccurs in < 1% of the general population 10%-30% of patients with chronic HCV10%-30% of patients with chronic HCV AppearanceAppearance Flat topped, violaceous, pruritic papulesFlat topped, violaceous, pruritic papules Throughout bodyThroughout body Oral mucosaOral mucosa HistologyHistology Dense infiltration of dermis with TDense infiltration of dermis with T lymphocyteslymphocytes
- 30. Determining Who to ScreenDetermining Who to Screen Primary care physicians are the frontline inPrimary care physicians are the frontline in identifying patients with risk factorsidentifying patients with risk factors Anyone with history of transfusionAnyone with history of transfusion Anyone with a history of IDUAnyone with a history of IDU Persons with a history of noninjection drugPersons with a history of noninjection drug use and/or multiple sexual partnersuse and/or multiple sexual partners Persons infected with HIVPersons infected with HIV Any abnormal ALT levelAny abnormal ALT level Normal ALT does not exclude diseaseNormal ALT does not exclude disease
- 31. HCV GenotypesHCV Genotypes USA 1,2,3 Europe 1,2,3 Australia 1,2,3 Far East 1,2 Middle East 4 North Africa 4 South Africa 5 Pakistan 3
- 32. HCV Serotypes in PakistanHCV Serotypes in Pakistan Serotypes 6.005.004.003.002.001.00Missing Numberofpatients 600 500 400 300 200 100 0 Khokhar et al. Hepatology 2003;38:270-1
- 33. Fibrosis EvaluationFibrosis Evaluation 1498552133N = Fibrosis score 4.003.002.001.00.00 AST/ALTRatio 2.2 2.0 1.8 1.6 1.4 1.2 1.0 .8 .6 Khokhar. JPMA 2003;53:103-104
- 34. Fibrosis EvaluationFibrosis Evaluation 1498552133N = Fibrosis Score 4.003.002.001.00.00 PlateletCount 300000 200000 100000 0 Khokhar. JPMA 2003;53:103-104
- 35. Role of Liver Biopsy in PatientRole of Liver Biopsy in Patient Assessment and ManagementAssessment and Management NONO YESYES Patient wants treatmentPatient wants treatment regardlessregardless of biopsy findings, even ifof biopsy findings, even if no fibrosisno fibrosis HCV treatment absolutelyHCV treatment absolutely contraindicatedcontraindicated Pregnancy, severePregnancy, severe depression, ESLD, severedepression, ESLD, severe cardiopulmonary diseasecardiopulmonary disease Genotype 2 or 3 and willingGenotype 2 or 3 and willing to take treatmentto take treatment Patient wants treatment ifPatient wants treatment if medically necessary asmedically necessary as indicated by liver histologyindicated by liver histology Patient fails to achieve SVRPatient fails to achieve SVR andand no recent biopsy availableno recent biopsy available
- 36. Chronic HCVChronic HCV Tests UtilizedTests Utilized Disease SeverityDisease Severity Response toResponse to TherapyTherapy AST/ALTAST/ALT BilirubinBilirubin AlbuminAlbumin Pro-time (INR)Pro-time (INR) Platelet countPlatelet count Liver histologyLiver histology ALTALT HCV RNAHCV RNA HCV genotypeHCV genotype Liver histologyLiver histology LFTs
- 37. Hepatitis C VirusHepatitis C Virus Diagnostic TestingDiagnostic Testing Diagnostic Test TypeDiagnostic Test Type SpecificationsSpecifications SerologicSerologic VirologicVirologic Mode of detectionMode of detection AntibodiesAntibodies VirusVirus SensitivitySensitivity > 95%> 95% > 98%> 98% SpecificitySpecificity VariableVariable > 98%> 98% DetectionDetection postexposurepostexposure 2-6 months2-6 months 2-6 weeks2-6 weeks UseUse ScreeningScreening ConfirmationConfirmation
- 38. Testing forTesting for HCV RNAHCV RNA Confirm HCV infectionConfirm HCV infection Persistently normal serum ALTPersistently normal serum ALT HCV antibody positiveHCV antibody positive Antinuclear antibodiesAntinuclear antibodies Prior to initiating therapyPrior to initiating therapy Assess effectiveness of treatmentAssess effectiveness of treatment Predict likelihood of response before andPredict likelihood of response before and during therapyduring therapy Confirm response after therapy completedConfirm response after therapy completed
- 39. Testing for HCV PCRTesting for HCV PCR Virologic AssaysVirologic Assays PCRPCR TMATMA b-DNAb-DNA PolymerasePolymerase chain reactionchain reaction TranscriptionTranscription mediatedmediated amplificationamplification Branched chainBranched chain DNADNA Amplifies targetAmplifies target Amplifies targetAmplifies target Amplifies probeAmplifies probe QualitativeQualitative QuantitativeQuantitative QualitativeQualitative QuantitativeQuantitative
- 40. Hepatitis C Virus InfectionHepatitis C Virus Infection Identification of PatientsIdentification of Patients Found to have elevated serum ALT duringFound to have elevated serum ALT during Routine physical examinationRoutine physical examination Routine blood testing after starting certainRoutine blood testing after starting certain medicationsmedications Test positive for anti-HCV duringTest positive for anti-HCV during Volunteer blood donationVolunteer blood donation Health or life insurance applicationsHealth or life insurance applications PhysicianPhysician Inquires about previous risk behaviorsInquires about previous risk behaviors
- 42. FDA Approved, Marketed HCV Drugs Generic NameGeneric Name Trade Name (manufacturer)Trade Name (manufacturer) DosingDosing Interferon alfa-2aInterferon alfa-2a RoferonRoferon®® -A (Roche)-A (Roche) 3 MIU SC TIW3 MIU SC TIW Interferon alfa-2bInterferon alfa-2b Intron AIntron A®® (Schering-Plough)(Schering-Plough) 3 MIU SC TIW3 MIU SC TIW Interferon alfacon-1Interferon alfacon-1 InfergenInfergen®® (InterMune)(InterMune) 99 µµg SC TIWg SC TIW 1515 µµg SC TIWg SC TIW** Peginterferon alfa-2aPeginterferon alfa-2a PegasysPegasys®® (Roche)(Roche) 180180 µµg SC QWg SC QW Peginterferon alfa-2bPeginterferon alfa-2b Peg-IntronPeg-Intron®® (Schering-Plough)(Schering-Plough) 1.01.0––1.51.5 µµg/kg SC QWg/kg SC QW Ribavirin**Ribavirin** CopegusCopegus®® (Roche)(Roche) RebetolRebetol®® (Schering-Plough)(Schering-Plough) RibasphereRibasphereTMTM (Three Rivers)(Three Rivers) 0.80.8––1.2 g/day, PO1.2 g/day, PO†† 0.80.8––1.2 g/day, PO1.2 g/day, PO†† 0.80.8––1.2 g/day, PO1.2 g/day, PO†† Pawlotsky JM, et al. Hepatology. 2004;39:554- 567. * Interferon relapsers and nonresponders; **Ribavirin is not approved for monotherapy, but as part of combination with interferon alfa; † Depending on HCV genotype and patient body weight
- 43. Treatment RegimenTreatment Regimen Interferon-alpha 3 MIU TIW SC Ribavirin 800-1200 mg/day According to the body weight for 6-12 months
- 44. Type I IFNs: Exhibit Multiple Activities - Many cell types B lymphocytes Immunoregulatory Activity – Proliferation, differentiation, activation of different cell types heavily involved in immune responses Natural killer cells T lymphocytes Activation Proliferation Survival Dendritic cells Muscle Fibroblasts Antifibrotic Antiviral Activity - Many cell types Adipocytes IFN α/β Antiangiogenic Antiproliferative Activity Stark G, et al. Annu Rev Biochem. 1998;67:227-264. Theofilopoulos AN, et al. Annu Rev Immunol. 2005;23:307-335. Brierley M, et al. J Interferon Cytokine Res. 2002;22:835-845.
- 49. Predictors of ResponsePredictors of Response Younger age (less than 40) Female sex Short duration of disease (less than 5 years) Low HCV-RNA at baseline (Less than 2 million copies) HCV genotypes other than 1a/1b Absence of fibrosis or cirrhosis No immunosuppression No coinfection with HBV
- 52. Time Course of Interferon SideTime Course of Interferon Side EffectsEffects Severity Flu-like symptoms Fatigue Depressive/anxiety symptoms IFN Treatment (Weeks) 0 2 4 6 8 10 12
- 57. What Are Future TherapiesWhat Are Future Therapies for Hepatitis C?for Hepatitis C?
- 58. HCV Helicase UnwindsHCV Helicase Unwinds Double-Stranded RNADouble-Stranded RNA
- 59. HCV Helicase CrystalHCV Helicase Crystal Crystallization by vaporCrystallization by vapor diffusion methoddiffusion method Crystallization conditions:Crystallization conditions: 50 mM Ca acetate, 8%50 mM Ca acetate, 8% PEG 5000, 20 mM NaPEG 5000, 20 mM Na cacodylate, pH 6.5cacodylate, pH 6.5
- 60. 3 Domains of HCV-RNA Helicase:3 Domains of HCV-RNA Helicase: NTPaseNTPase,, RNARNA Binding,Binding, HelicalHelical
- 61. Superposition of Two IndependentSuperposition of Two Independent Molecules Reveals Domain MovementMolecules Reveals Domain Movement Switch regionSwitch region T A T P P C 520 480 340 N 440 200 620 320 460 300 600 360 380 560 540 220 420 280 500 580 400 240 260 DomainDomain rotationrotation
- 67. HistoryHistory A 39-year-old male bank executive wasA 39-year-old male bank executive was diagnosed 6 months ago with genotype 1diagnosed 6 months ago with genotype 1 hepatitis C virus (HCV) infection discoveredhepatitis C virus (HCV) infection discovered during screening before blood donation.during screening before blood donation. Laboratory studies confirmed the diagnosis ofLaboratory studies confirmed the diagnosis of chronic hepatitis C and ruled out other liverchronic hepatitis C and ruled out other liver diseases.diseases. A liver biopsy demonstrated grade 2A liver biopsy demonstrated grade 2 inflammation and stage 3 fibrosis and steatosisinflammation and stage 3 fibrosis and steatosis without significant iron accumulation. Abdominalwithout significant iron accumulation. Abdominal U/S was negative for portal hypertension andU/S was negative for portal hypertension and signs of cirrhosis. His body mass index was 22.8signs of cirrhosis. His body mass index was 22.8 kg/m2.kg/m2.
- 68. Laboratory FindingsLaboratory Findings HCV RNA: 1,500,000 IU/mLHCV RNA: 1,500,000 IU/mL Aspartate aminotransferase (AST): 72 U/LAspartate aminotransferase (AST): 72 U/L Alanine aminotransferase (ALT): 101 U/LAlanine aminotransferase (ALT): 101 U/L Total bilirubin: 0.4 mg/dLTotal bilirubin: 0.4 mg/dL Albumin: 4 g/LAlbumin: 4 g/L Nonfasting glucose: 90 mg/dLNonfasting glucose: 90 mg/dL Hemoglobin (Hb): 15.4 g/dLHemoglobin (Hb): 15.4 g/dL Platelet count: 168,000 cells/mm3Platelet count: 168,000 cells/mm3 Prothrombin time: 10.9 secondsProthrombin time: 10.9 seconds TSH: 2.5 IU/mL (normal: 0.60-3.30 IU/mL)TSH: 2.5 IU/mL (normal: 0.60-3.30 IU/mL) Ferritin: 150 ng/mL (normal: 27-377 ng/mL)Ferritin: 150 ng/mL (normal: 27-377 ng/mL) Alpha-fetoprotein: 2.5 ng/mLAlpha-fetoprotein: 2.5 ng/mL
- 69. TreatmentTreatment He was started on interferon alfa-2a TIW plusHe was started on interferon alfa-2a TIW plus ribavirin 1000 mg/day.ribavirin 1000 mg/day. After 4 weeks he presents with Hb: 12.5 g/dL;After 4 weeks he presents with Hb: 12.5 g/dL; HCT: 37.5% and WBC: 2600; ANC: 1600. TheHCT: 37.5% and WBC: 2600; ANC: 1600. The patient's HCV RNA is now 750,000 IU/mL. He ispatient's HCV RNA is now 750,000 IU/mL. He is tolerating therapy but initially experiencedtolerating therapy but initially experienced fatigue and flu-like symptoms, which havefatigue and flu-like symptoms, which have improved over the past 2 weeks. The patientimproved over the past 2 weeks. The patient denies having chest pain, shortness of breath,denies having chest pain, shortness of breath, abdominal pain, chronic fever, vision changes,abdominal pain, chronic fever, vision changes, rashes, depression, suicidal or homicidalrashes, depression, suicidal or homicidal ideation, irritability, or difficulty sleeping. He isideation, irritability, or difficulty sleeping. He is working full time with some fatigue at the end ofworking full time with some fatigue at the end of the day.the day.
- 70. How will you manage his treatmentHow will you manage his treatment at 4 week?at 4 week? A. The patient is a nonresponder andA. The patient is a nonresponder and treatment should be discontinuedtreatment should be discontinued B.B. Continue current regimen and check viralContinue current regimen and check viral load at treatment Week 12load at treatment Week 12 C.C. Increase ribavirin dose to improveIncrease ribavirin dose to improve response and recheck viral count in 4response and recheck viral count in 4 weeksweeks
- 71. The patient continues theThe patient continues the current treatment regimen andcurrent treatment regimen and returns at Week 12 of treatmentreturns at Week 12 of treatment to undergo further evaluation.to undergo further evaluation.
- 72. EvolutionEvolution The patient’s mild adverse effects areThe patient’s mild adverse effects are managed by behavior modification andmanaged by behavior modification and analgesics. No increases in anemia oranalgesics. No increases in anemia or neutropenia severity are noted. Heneutropenia severity are noted. He remains motivated to continue therapy andremains motivated to continue therapy and to take full treatment doses as scheduled.to take full treatment doses as scheduled. He has also experienced a mild increaseHe has also experienced a mild increase in irritability but is still able to work fullin irritability but is still able to work full time. The patient’s Week 12 HCV RNA istime. The patient’s Week 12 HCV RNA is negative, his AST is 34 U/mL, and his ALTnegative, his AST is 34 U/mL, and his ALT is 28 U/mL.is 28 U/mL.
- 73. How will you manage his treatmentHow will you manage his treatment at 12 week?at 12 week? A. The patient is a nonresponder andA. The patient is a nonresponder and treatment should be discontinuedtreatment should be discontinued B. Continue on current doses and return atB. Continue on current doses and return at Week 48 for further evaluationWeek 48 for further evaluation C. Continue on current doses and return atC. Continue on current doses and return at Week 24 for further evaluationWeek 24 for further evaluation
- 74. Further EvolutionFurther Evolution HCV PCR is negative again. HeHCV PCR is negative again. He completes 48 weeks of therapy and hascompletes 48 weeks of therapy and has normal LFT and negative HCV PCR.normal LFT and negative HCV PCR.
- 75. How will you manage his treatmentHow will you manage his treatment at 48 week?at 48 week? Congratulate him on successful treatmentCongratulate him on successful treatment and advise him to come back if any furtherand advise him to come back if any further complaints.complaints. Follow every month for six months withFollow every month for six months with further tests.further tests. Advise maintenance interferon for 3-6Advise maintenance interferon for 3-6 months without ribavirinmonths without ribavirin
- 76. The Many Faces of HCVThe Many Faces of HCV SummarySummary Chronic HCV infection leads to cirrhosisChronic HCV infection leads to cirrhosis and liver failure in a large number ofand liver failure in a large number of personspersons Primary care physicians must recognizePrimary care physicians must recognize that chronic HCV is common disorder inthat chronic HCV is common disorder in our countryour country Effective treatment of chronic HCV canEffective treatment of chronic HCV can prevent fibrosis progression and reduceprevent fibrosis progression and reduce complications of HCVcomplications of HCV
- 77. THANK YOU FORTHANK YOU FOR YOUR ATTENTIONYOUR ATTENTION
Notas do Editor
- Model of Human Hepatitis C Virus HCV was first recognized as a separate entity in 1975 after it was determined that the majority of cases of transfusion-related hepatitis were not caused by the 2 types of hepatitis recognized at the time (hepatitis A and B). The disease was called “non-A non-B” hepatitis until the virus was cloned and sequenced in 1989. At that time the virus was renamed hepatitis C virus. HCV is a linear single-strand RNA virus 40 to 50 nm in size that belongs to the Flaviviridae family and the Hepacivirus genus. The virus is covered with a lipid envelope and is encased with glycoprotein peplomers or “spikes.” Reprinted with permission. Henderson LE. A Hepatitis C Primer. Available at http://www.hepcprimer.com/3dmodel.html. Accessed March 8, 2005. National Institute of Health Consensus Conference. Available at: www.hepnet.com/nih/purcell.html. Accessed March 8, 2005.
- Model of HCV Replication This slide illustrates the putative replication cycle of HCV. The HCV envelope proteins bind to receptors on the cell surface that may include CD81 or the LDL receptor. HCV virions likely uncoat within endosomes and release the genome into the cytoplasm. Translated HCV nonstructural proteins, the HCV RNA template, and host-cell factors form a replication complex in a virus-induced, perinuclear membranous web. The first step is the production of a negative-strand copy of the RNA genome that is used as a template to generate progeny positive-strand RNA. The assembly of virions appears to begin through the interaction of capsid proteins and genomic RNA, forming a nucleocapsid. The nucleocapsid then acquires an envelope and is released from the infected cell as a mature virion. Racanelli V, Rehermann B. Hepatitis C virus infection: when silence is deception. Trends Immunol. 2003;24:456-464.
- MSM, men who have sex with men. People at risk for chronic HCV infection and subsequent development of this progressive liver disease include those who had transplants or exposure to blood products before the development of hepatitis C testing; intermittently used or currently use intravenous drugs or inhaled cocaine; or had chronic renal failure on dialysis. Patients with renal failure or on dialysis have a high risk of HCV exposure, either through blood products used to treat chronic renal failure or because of contamination in dialysis units. Incarcerated individuals, many of whom have used drugs, have a high prevalence of HCV infection. People who have multiple sexual partners and men who have sex with men are also at risk for exposure. Occupational exposure to blood products is a potential low-risk mode of exposure, as are body piercing and tattooing.
- This map shows the prevalence of HCV worldwide; the darkness of the shading reflects the degree of prevalence. It was created using data from published studies or submitted to the World Health Organization by130 countries or other geopolitical entities as of August 1997. Unfortunately, the figures given on the map reflect current reported data and, therefore, only approximates the prevalence in each country. Also, because of differences in the populations studied and in methods of data collection and interpretation, the data presented here may not represent the true prevalence in each country. New reports from 16 countries and updated data from 10 countries have further increased the estimated numbers of infected individuals in these regions.
- As previously mentioned, the majority of individuals exposed to HCV will develop chronic infection; however, 15% of patients exposed to HCV are somehow capable of spontaneously resolving this infection. Research is currently ongoing to better understand how these people can resolve their infection, and this may shed some light on how to better treat hepatitis C in the future.
- This graph shows the results of a study conducted by Prof Thierry Poynard (Service d’Hépato-Gastroentérologie, Groupe Hospitalier Pitié Salpétrière, France) and his associates in 53 patients with HCV (determined by RT-PCR) and more than 3 normal measurements of ALT. These patients were matched with 101 control patients who were similar with respect to sex, age at biopsy, age at infection, duration of infection, and alcohol consumption. These factors are related independently to rate of progression. The mean rate of progression in patients with normal ALT levels, as determined by METAVIR analysis, was close to the rate seen in patients who were considered slow progressors. Thus, patients with normal ALT do progress, albeit slowly. It is important to note that this is the mean rate, and some patients with normal ALTs will progress more rapidly.
- ULN, upper limit of normal It was previously thought that HCV-infected patients who had normal ALT levels were less likely to progress to fibrosis or cirrhosis than those who had elevated ALTs. However, it is now known that patients with normal ALT levels can progress. These patients may have intermittent elevations that are not detected during routine analysis and which may account for disease progression. Furthermore, there is no consensus on what defines normal ALT levels. For instance, should a white female with an ALT level of 35 IU/L be considered normal when the majority of patients have ALT levels of ~20 IU/L? Is a persistently normal ALT level associated with a decreased rate of progression to fibrosis vs an elevated ALT level? The findings of 3 studies presented at the Digestive Disease Week 2006 conference in Los Angeles suggested that patients with normal ALT levels were less likely to have significant liver disease. Both Persisco and Bocato presented data showing that patients with elevated ALT levels were more likely to have fibrosis or progression to fibrosis. Loayza and colleagues made a similar observation but noted that 50% of patients with normal ALT levels had cirrhosis on biopsy. Keep in mind that a single ALT measurement is a snapshot of the disease and serial monitoring is necessary to fully determine whether a patient has persistently normal ALT levels. Additionally, Blacks tend to have lower transaminase levels than whites do. Mihas and colleagues from Virginia Commonwealth University reported at the same meeting that black patients with persistently normal ALT levels had significantly lower incidence of fibrosis than patients with elevated ALT levels.
- Hepatitis C is associated with many extrahepatic manifestations, including nonspecific antibody production, essential mixed cryoglobulinemia, glomerular nephritis, porphyria cutanea tarda (PCT), leukoclastic vasculitis, non-Hodgkin’s lymphoma, autoimmune thyroiditis, diabetes, and Sjögren’s syndrome.
- This slide illustrates the dermatitis of cryoglobulinemia—a patchy discoloration in the lower extremities resulting from deposition of cryoglobulins in small capillaries. Ulcerations may develop, and these areas can be very pruritic.
- Diabetes has recently been recognized to be associated with hepatitis C. In this study prevalence of diabetes mellitus and insulin resistance was much higher in patients with hepatitis C than in healthy individuals from the National Health and Nutrition Examination Survey study when adjusted for age, race, and sex.
- Lichen planus is another dermatologic disorder commonly seen in individuals with hepatitis C. Lichen planus is seen in less than 1% of the general population. In total, HCV infection will be seen in 10% to 30% of patients with lichen planus. Lichen planus is characterized by pruritic papules that look like flat-topped, raised lesions on the skin. The lesions can occur anywhere on the body but are most commonly seen in the oral mucosa. Histologically, the affected skin is densely packed with T lymphocytes, which is another manifestation of hepatitis C.
- IDU, injection drug use. Primary care offices are the frontline in identifying patients with risk factors for HCV infection. However, there is a stigma associated with difficult questions regarding previous drug use and multiple sexual partners. Patients may be reluctant to reveal elements of their life that may be perceived as embarrassing, disappointing, or illegal. Patients without obvious risk factors should be questioned about surgeries prior to 1985, as informed consent was not required at that time for blood transfusions. Patients with military or combat experience should also be questioned regarding blood exposures if they were injured or went into shock in the field, as buddy‑to‑buddy transfusions were commonplace in combat operations in the Vietnam era. Patients with known HIV infection should be screened, as up to 40% of this population will be coinfected with HCV; by contrast, patients with known HCV infection only carry a 1% risk of coinfection with HIV. Patients should be approached with an open mind and without prejudice to demonstrate a safe environment and promote open dialogue. Anyone with risk factors should be encouraged to be tested. While an elevated alanine aminotransferase (ALT) level is reason for HCV testing, patients should know that a normal ALT level does not exclude the possibility of infection.
- ESLD, end-stage liver disease; SVR, sustained virologic response The liver biopsy remains controversial due to the invasive nature of the procedure and the potential for complications and sample inaccuracy. Currently, most experts agree that patients with HCV genotypes 2 or 3 typically will not require a biopsy prior to therapy and can proceed with treatment due to the higher SVR rates associated with these genotypes; however, if a patient wishes to delay therapy, a biopsy may assist in guiding the appropriate therapeutic approach. For patients infected with HCV genotype 1, the usefulness of a liver biopsy is more controversial. In patients with obvious signs and symptoms of cirrhosis, a biopsy may be contraindicated. Yet, for patients who do not have obvious biochemical functions consistent with cirrhosis, a biopsy may alleviate fear of the severity of their liver disease. However, patients in the early or middle stages of hepatitis C should feel free to pursue future therapy. These patients may opt to await newer therapies or to undergo therapy at a different time. Ultimately, the decision to pursue therapy should be that of the patient.
- This first slide looks at the tests that are used to identify patients with hepatitis C and assess disease severity and response to therapy. The first, aspartate aminotransferase and ALT tests, are not really liver function tests although many physicians refer to them as such. Rather, they measure liver transaminases, which are indicative of inflammation or irritation to the liver. The true tests to measure liver function include bilirubin, albumin, and prothrombin time or international normalized ratio. When the liver has dysfunction, these tests start to show abnormalities. Unfortunately, that does not occur until patients develop cirrhosis. Therefore, the majority of patients with chronic hepatitis C show normal liver function based upon these liver function tests. One of the most sensitive tests of advanced liver disease is the platelet count. A large number of studies have now demonstrated that thrombocytopenia—platelet counts below the lower limit of normal—is indicative of cirrhosis in individuals who do not have some sort of primary platelet or bone marrow disorder. Identifying thrombocytopenia is an easy way to identify patients with cirrhosis, and clearly liver histology represents the gold standard of determining the severity of disease and histologically can identify cirrhosis and the degree of scarring or fibrosis is present in the liver. One test we monitor to determine treatment response is serum ALT. If treatment is working effectively, we expect that the ALT levels will drop back down into the normal range on therapy. We also monitor the level of HCV RNA, and the goal is to have virus levels become undetectable during treatment. Hepatitis C virus genotype determines how long we need to treat patients, and liver histology can be used as a marker to show that the liver has improved after therapy.
- This next slide lists the 2 types of virologic tests available: serologic tests and virologic tests. Serologic tests measure circulating antibodies within the blood stream of patients exposed to HCV. Serologic tests are highly sensitive, but the specificity varies depending on the patient population being evaluated. Antibodies develop very early in the infection—typically 2-6 months after exposure—depending on levels of immune suppression. Individuals who are immunosuppressed, such as HIV patients and patients with chronic renal failure, may take many months to develop antibodies against hepatitis C after exposure. Serologic tests are generally used for screening because they are cheaper and are very sensitive. Virologic tests measure virus levels, and they are both highly sensitive and highly specific. Again, there can be intermittent viremia early after infection so a true, persistently positive virus test for individuals recently exposed to HCV will be present approximately 2-6 weeks after exposure. Again, virologic tests are used to confirm active infection after the screening test is positive.
- The first indication for using HCV RNA assays is to confirm HCV infection. This is particularly helpful for ruling out false positives in antibody-positive patients with persistently normal serum ALT and a lack of risk factors and in persons with antinuclear antibodies and for making certain the virus is present before initiating treatment. HCV RNA assays are also used to evaluate the effectiveness of treatment, to predict the likelihood of response before initiating therapy, and to confirm response (virus negativity) after therapy is completed.
- There are 3 basic types of virologic assays available commercially. The most common and widely used is the polymerase chain reaction (PCR) assay. This assay amplifies virus from the serum, reproducing and creating millions of copies within the test tube. This allows for easy detection and quantification; both qualitative and quantitative PCR assays are available. A newer assay, which is similar to PCR but amplifies the target in a different way, is the transcription-mediated amplification (TMA) assay. Currently this test is only qualitative, meaning it provides only a positive or negative result. In the future it may be quantitative as well. Finally, there is the quantitative branched DNA assay, which is very accurate for measuring virus levels. It functions by attaching a probe to the virus and then amplifying the probe. The assay is highly reproducible. The primary limitation is that the assay has a limit of detection below which virus cannot be detected. It is therefore typically combined with a PCR or TMA assay to confirm results in individuals who measure undetectable via bDNA testing.
- How do we identify patients with hepatitis C? There are a couple of ways. First, we find patients with elevated serum liver transaminases either during routine physical examination or routine blood testing after starting certain medications. Patients may also test positive for anti-HCV during volunteer blood donations or for life or health insurance physicals. However, one of the most important ways that physicians can identify patients with hepatitis C is to inquire about previous risk behaviors and screen patients who disclose these behaviors.
- FDA Approved, Marketed HCV Drugs This slide illustrates the approved and available agents for the treatment of HCV. Standard interferons (eg, IFN alfa-2a, IFN alfa-2b, IFN alfacon-1) were the first agents available. These agents are administered in 3-times-weekly regimens. IFN alfacon-1 or consensus IFN (CIFN), at a higher dose, is also approved for the treatment of patients who do not respond to, or who relapse after, prior IFN treatment. Pegylated interferons contain an inert molecule, polyethylene glycol (PEG) that extends the half-life of the active drug and therefore allows less frequent dosing (once weekly). Oral ribavirin is added to IFN as part of a combination regimen to improve response rates. The FDA-approved dosing of ribavirin is 0.8–1.2 g/day divided BID. Pawlotsky JM, McHutchison JG. Hepatitis C. Development of new drugs and clinical trials: promises and pitfalls. Summary of an AASLD hepatitis single topic conference, Chicago, IL, February 27—March 1, 2003. Hepatology. 2004;39:554-567.
- Type I IFNs: Exhibit Multiple Activities Type 1 IFNs have a large number of biological actions; most of these actions involve the immune system. IFN induction, early in the innate immune response, provides a priming mechanism that influences many subsequent innate and adaptive immune responses. For example, type 1 IFNs can activate natural killer cells and increase T lymphocyte survival. The primary action of type 1 IFNs is an antiviral effect. IFNs can inhibit viral replication at one of several sites and by one of several mechanisms, including at entry and/or uncoating, during replication, by influencing RNA stability, during the initiation of translation, or at maturation, assembly, or release. Type 1 IFNs also have antiproliferative, antifibrotic, antiangiogenic biologic actions. Stark GR, Kerr IM, Williams BR, Silverman RH, Schreiber RD. How cells respond to interferons. Annu Rev Biochem. 1998;67:227-264. Theofilopoulos AN, Baccala R, Beutler B, Kono DH. Type I interferons (alpha/beta) in immunity and autoimmunity. Annu Rev Immunol. 2005;23:307-335. Brierley MM, Fish EN. IFN-alpha/beta receptor interactions to biologic outcomes: understanding the circuitry. J Interferon Cytokine Res. 2002;22:835-845.
- IFN, interferon Typically, patients experience flu-like symptoms during the first few weeks of HCV therapy which dissipates in intensity over time. Fatigue generally begins early in therapy but may not become bothersome until later. Depression typically begins as fatigue and may be exacerbated by factors such as insomnia, myalgias, and arthralgias.
- The relevance of new advances in the molecular and structural biology of HCV to the development of new drugs are of special interest and importance. The HCV helicase represents one of the best targets for new drug development. The recently determined 3-dimensional structure of the helicase will facilitate identification of helicase inhibitors for drug development.
- The HCV helicase, a product of the NS3 portion of the HCV genome, is essential for HCV replication. This essential viral enzyme is involved in the modulation of RNA structure during viral replication. Specifically, the helicase unwinds the double-stranded RNA. Therefore, the helicase necessarily binds RNA. In addition, the helicase also catalyzes hydrolysis of nucleoside triphosphates, which provide the energy for unwinding of the duplex. One of the most interesting features of the helicase is how hydrolysis of ATP is coupled to the unwinding of RNA.
- To determine the 3-dimensional structure of the helicase by x-ray crystallography, preparation of high-quality, well-ordered crystals were required. A technique known as vapor diffusion—in which the final conditions for crystallization are achieved through a slow process of diffusion—was used to prepare the crystals. The final conditions under which the helicase was crystallized are shown here: 50 mM Ca acetate, 8% PEG 5000, 20 mM Na cacodylate, pH 6.5. The crystal shown is a rectangular bipyramid.
- Shown here is the HCV helicase 3-dimensional fold showing a triangular arrangement of 3 domains. The domain in red binds ATP, the domain in yellow binds RNA, and the third domain in blue is the helical domain. A very deep grove separates the RNA binding domain from the other2 domains of the structure. The RNA-binding domain was found to be extended on the surface.
- By examining 2 independent views of the helicase molecule, it could be demonstrated that the RNA-binding domain was at 2 different orientations relative to the rest of the molecule. A domain with the conserved amino acid sequence TATPP (ie, threonine-alanine-threonine-proline-proline) was found. This domain appears to be part of a switch mechanism that is involved in coupling ATP hydrolysis to RNA unwinding.
- In summary, chronic HCV infection leads to cirrhosis and liver failure in a large number of individuals. It is important for primary care physicians to recognize that chronic hepatitis C is a common driver of non-liver disorders and that effective treatment of chronic hepatitis C can prevent fibrosis and disease progression and reduce complications of hepatitis C including cirrhosis and liver cancer.