Tissue localization of C1q in HBs antigen positive liver disease patients by direct immunofluorescent technique.

Tissue localization of a subcomponent of the first component of complement (CLq) was examined in one postmortem case of HBs antigen (HBs Ag) positive hepatocellular carcinoma and in six cases of chronic hepatitis from liver biopsy specimens. The direct immunofluorescent method was used after fixation with 2% para-formaldehyde in concentrated ammonium sulfate. CLq localization was found in collagen fibers and the cytoplasm of fibroblasts in the connective tissues of specimens examined. The localization was particularly marked in the region of the fundal glands of the gastric wall. Apart from collagen fibers, other sites of localization included the surface membrane of lymphocytes, especially those cells of the mesenteric lymph nodes. In HBs Ag positive specimens, immune deposit-like substances appeared localized intra-hepatically and in the renal glomeruli. Since C3 and C4 were identified concomitantly, it indicates that these substances were indeed immune diposits. Despite the finding that C3 and C4 were identified together in the hepatic cell cytoplasm, C1q itself was not demonstrated in all hepatic cell cytoplasms.