Tissue localization of C1q in HBs antigen positive liver disease patients by direct immunofluorescent technique
Related Experiment Videos
Insights
Complement component CLq localizes in connective tissues and on lymphocyte surfaces. In Hepatitis B-positive liver cancer, immune deposits were found, indicating complement activation.
Area of Science:
- Immunology
- Pathology
- Gastroenterology
Background:
- The first component of complement (CLq) plays a crucial role in immune complex recognition and clearance.
- Understanding CLq tissue distribution is vital for diagnosing and understanding inflammatory and neoplastic liver diseases.
Purpose of the Study:
- To investigate the tissue localization of CLq in hepatocellular carcinoma and chronic hepatitis.
- To determine if CLq is present in immune deposits associated with Hepatitis B surface antigen (HBs Ag) positivity.
Main Methods:
- Direct immunofluorescence was employed on postmortem liver tissue and biopsy specimens.
- Tissue samples were fixed and treated with para-formaldehyde and ammonium sulfate.
- Localization of CLq, C3, and C4 was assessed.
Main Results:
- CLq was predominantly found in collagen fibers and fibroblast cytoplasm within connective tissues.
- Significant CLq localization was observed in gastric fundal glands and on lymphocyte membranes, particularly in mesenteric lymph nodes.
- Immune deposit-like substances, confirmed by C3 and C4 presence, were identified intra-hepatically and in renal glomeruli in HBs Ag-positive cases.
- While C3 and C4 were present in hepatic cell cytoplasm, CLq was not consistently demonstrated in all hepatic cells.
Conclusions:
- CLq exhibits distinct tissue localization patterns, primarily in connective tissues and on immune cells.
- The presence of CLq, C3, and C4 in HBs Ag-positive liver tissues suggests complement system activation and immune complex formation.
- Further research is needed to elucidate the specific role of CLq in hepatic cell cytoplasm during liver disease.
Abstract:
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.