Immunocytochemical localization of type B collagen: a component of basement membrane in human liver.

An indirect immunofluorescent method for localizing specific types of collagen was applied to unfixed cryostat sections of autopsy and biopsy specimens of normal and fibrotic human livers. Monospecific antibodies to Types I, III, and B collagens were raised in goats by injecting collagens extracted from normal and fibrotic human livers. The antibody against B collagen stained the delicate sinusoidal meshwork within the lobule that closely paralleled in distribution the staining of reticulin fibers as seen in classical silver preparations. Antibody to Type III collagen stained at the sinusoidal aspect of the hepatocytes in a pattern similar to anti-B antibody. All three antibodies tested strongly stained the portal tracts and the fibrotic bands in specimens with cirrhosis. These observations indicate that reticulin fibers within the liver lobule contain both Type III and Type B collagen.