FOCAL LYMPHOCYTIC AGGREGATES IN CHRONIC HEPATITIS-C - OCCURRENCE, IMMUNOHISTOCHEMICAL CHARACTERIZATION, AND RELATION TO MARKERS OF AUTOIMMUNITY

Intrahepatic lymphocytic aggregates are observed in chronic hepatitis C as well as in autoimmune chronic hepatitis. Autoantibodies and autoi mmune manifestations may occur in hepatitis C. It has been suggested t hat the lymphocytic aggregates play a role in the liver injury of chro nic hepatitis C by an immune mediated mechanism. We studied the occurr ence of intrahepatic lymphocytic aggregates and of autoantibodies in a consecutive series of 128 patients with chronic hepatitis C. For the phenotypic characterization of the lymphocytic aggregates cryostat sec tions and microwaved paraffin embedded sections were immunostained wit h mono clonal antibodies directed against T cell subsets, B cells, kil ler/natural killer cells, follicular dendritic cells, and macrophages. Autoantibodies were tested by immunofluorescence (antinuclear, anti-s mooth muscle, antimitochondrial) and by enzyme-linked immunosorbent as say (anti-soluble liver antigen, anti-liver/kidney microsome, anti-hum an receptor for asialoglycoprotein). Focal lymphocytic aggregates in p ortal tracts were observed in 76 of 128 (59%) patients, The cellular c omposition of the aggregates was constant: a core of B cells mixed wit h many T helper/inducer lymphocytes, and an outer ring was prominently formed by T suppressor/cytotoxic lymphocytes. A germinal center was r arely identifiable. The presence of lymphocytic aggregates was inverse ly correlated with the degree of fibrosis, Lymphocytic aggregates appe ared more frequently in chronic persistent and chronic active hepatiti s in comparison with cirrhosis and in the presence of bile duct damage . No correlation was found between lymphocytic aggregates and autoanti bodies or other markers of autoimmunity. The lymphocytic aggregates ar e frequent in chronic hepatitis C, Their cellular composition is simil ar to that of primary lymphoid follicles in lymph nodes. Their presenc e does not seem to be correlated with features of autoimmunity.