Experimental
ligation of the biliary tract often results in glomerular deposits of
polymeric IgA commonly associated with
secretory component. These studies offer evidence that, in animals, hepatobiliary transport of
polymeric IgA, which is of mucosal origin, is crucial for its clearance from the serum. We studied a human counterpart of bile duct
ligation--
extrahepatic biliary atresia--for the presence of secretory or polymeric
immunoglobulins in renal glomeruli. Kidney was available at autopsy as
paraffin or frozen blocks from 24 patients with
biliary atresia and age-matched controls (5 weeks to 5 years old). Several of the patients had undergone portoenterostomy (
Kasai procedure) or
liver transplantation. Immunohistologic studies showed glomerular (often mesangial) deposits of
IgA in 10 of 24 and
IgM in 16 of 24 specimens. The differences with controls were highly significant for
IgA but not for
IgM. In frozen sections,
secretory component was positive in glomeruli in seven of 12 specimens. In vitro glomerular binding of purified
secretory component to glomeruli was shown in four of 12 samples, including three with
IgM only. This last observation suggests that
IgM in some of these patients was polymeric and thus derived from a mucosal source. Our study shows that in humans with
biliary atresia,
secretory IgA,
polymeric IgA, and possibly
polymeric IgM are deposited in glomeruli. The study confirms the occurrence of renal immunopathologic findings in
liver disease and supports the existence of an active hepatobiliary immunosecretory transport mechanism even at the early age of these patients.