[Immunohistologic study on focal lymphocytic infiltration in the liver of the elderly autopsy cases]

Immunologic and immunohistologic analyses were performed on lymphocytic infiltration in periportal areas of the liver obtained from 105 autopsy cases over 60 years of age and 63 cases under 60 years of age, all cases showing no symptoms of overt liver diseases. Lymphocytic infiltration in the periportal areas began to be found in the livers of young autopsy cases in the 4th decade, with an incidence of more than 60%. The incidence reached 100% in cases of 6th decade and over, accompanied by increased severity. The infiltrating lymphocytes consisted mainly of T cells, (approximately 85%), regardless of sex, age and underlying diseases. In terms of T cell subsets composing the infiltrating lymphocytes, there were 3 types; A:CD4+ cells greater than CD8+ cells. B:CD4+ cells = CD8+ cells. C:CD4+ cells greater than CD8+ cells. Type A was seen in 60/105 cases (57%), type B in 10/105 (9%) and type C in 35/105 (34%). The presence of cases with predominant CD8+ cells appeared to be characteristic of lymphocytic infiltration lesions in the liver, and was different from lesions in other organs. It was suggested that lesion of lymphocytic infiltration in the periportal areas of the liver might be of an autoimmune nature, gradually advancing with age.