PATHOMORPHOLOGICAL AND IMMUNOHISTOLOGICAL CHANGES IN LYMPH-NODES OF COWS SPONTANEOUSLY INFECTED BY BOVINE LEUKEMIA-VIRUS

Prescapular lymph nodes from 109 cows seropositive to bovine leukaemia virus (BLV) were subjected to histologic, cytochemic and in dubious c ases also to immunohistologic examination for the presence of light ch ains of bovine immunoglobulin (Ig) kappa or lambda. By their morpholog ical features, the histologically detected changes were divided into B -zonal hyperplasia (23 cases, 21.1%), T-zonal hyperplasia (52 cases, 4 7.7%), pulp proliferation (6 cases, 5.5%) hyperplasia of mixed type (1 8 cases, 16.5%), and atrophy (10 cases, 9.2%). Some changes resembled those reported in infections with human or feline immunodeficiency vir us. Eosinophilic infiltration was a frequent feature. Immunohistochemi cal examination revealed only a lambda Ig chain in the cytoplasm of pl asma cells or plasmacytoid cells and immunoblasts in pulp proliferatio n. Cytochemical examination showed a considerable number of cells with a diffuse positive reaction to acid phosphatase (AP).