Lymphatic Follicles and Immunologic Cell Reaction in Human Jejunal Mucosa Obtained by Peroral Biopsy in Infectious Hepatitis

Abstract

The concept that the lymphoid tissue of the gastrointestinal tract is primarily involved in the immune defense mechanism has been repeatedly maintained by several investigators [1, 2]. Activation of intestinal lymphocytes to large pyroninophilic cells has been observed in cases where the lymphocytes, after crossing the basement membrane, have penetrated between or into the cells of the covering epithelium of intestinal villi [3, 4, 5, 6]. Such lymphatic transformation has been interpreted as an immunological reaction, but the most overwhelming evidence of the immunological function of the intestinal lymphoid tissue was provided by studies of Good and co-workers [7, 8, 9, 10], showing that the Peyer’s-patch-type of intestinal lymphoid tissue represents the mammalian counterpart of the bursa Fabricii in birds. On the other hand, it has been shown that the plasma cells of the intestinal mucosa constitute the major source of gamma-A immunoglobulins [11] and that gamma-A and gamma-M immunoglobulins are significantly increased in infectious hepatitis [12], which has been considered a generalized disease [13, 14]. Because the jejunal mucosa in infectious hepatitis occasionally shows a partial villous atrophy and frequently shows a marked cellular infiltration within the tunica propria [15], we undertook the present investigation. This study was performed to ascertain whether the intestinal infiltration contains immunologically activated cells, to determine the quantity of these cells, and to investigate the behavior of the lymphatic follicles and germinal centers of the duodenojejunal mucosa during the course of infectious hepatitis. These findings could be related to recent concepts of the immunological function of the lymphoid tissue in gastrointestinal tract.

Supported by “The Blood Research Foundation”, Washington, D. C., U. S. A.