LANGERHANS CELLS AND LYMPHOCYTE SUBSETS IN HUMAN GASTROINTESTINAL CARCINOMAS - AN IMMUNOHISTOLOGICAL STUDY ON FROZEN-SECTIONS

In an immunohistochemical study of 38 human gastric and 40 human colonic carcinomas Langerhans cells, suppressor and helper lymphocytes were identified on frozen sections by using anti-CD1, anti-CD8 and anti-CD4 monoclonal antibodies. Tumours were divided into those with few (<3 per high power field) and those with many (>3 per high power field) Langerhans cells as well as into those with high number of CD4 and CD8 cells (>30 per high power field). No significant difference in the number of Langerhans cells regarding histologic types, degree of differentiation and metastatic/non-metastatic groups of either gastric or colonic carcinomas was found. On the contrary the numbers of Langerhans cells related significantly (p<0.05) to density of T-cell and especially CD4 cell infiltrations of gastric and colonic carcinomas. This finding supports the role of Langerhans cells as antigen presenting cells and their involvement in T-cell activation against neoplastic cells of human gastrointestinal carcinomas.