Basic concepts regarding delta bilirubin are presented.

1. What is delta bilirubin?
by
Dr. Ketan Vagholkar
MS, DNB, MRCS, FACS
Consultant General Surgeon

2. Delta Bilirubin
 Glucoronides are chemically reactive
metabolites.
 In adults, with prolonged cholestasis especially if
it is accompanied by renal failure, a fraction of
the bilirubin conjugates readily non enzymatic
ally and irreversibly with serum albumin to give
yellow billiproteins in which bilirubin is
covalently bound to albumin.
 This fraction increases with the duration of
cholestasis and is designated as delta bilirubin.

3. Delta bilirubin
 Delta bilirubin retains its direct reading properties.
 As delta bilirubin is irreversibly bound to albumin it is
not filtered at the glomerulus and its half life reflects that
of albumin.(14 days)
 Consequently it remains in plasma long after other
bilirubin esters have been eliminated giving rise to
conjugated hyperbilirubinemia in the absence of
bilirubinuria and is particularly evident in the recovery
phase of cholestasis.
 Delta bilirubin= Total bilirubin-(Conjugated +
Unconjugated bilirubin)