T H Rea

Altered distribution of B and T lymphocytes in lymph-nodes from homosexual men with Kaposi's sarcoma.

Abstract Immunostaining of lymph-nodes from 10 homosexual men with Kaposis sarcoma by anti-B lymphocyte monoclonal antibodies revealed an abnormally exuberant follicular hyperplasia with erosion of the mantle zone and disruption of surrounding follicles. There were numerous IgD-positive and B-1-positive lymphocytes (B cells) in the interfollicular areas; these cells were uncommon at these sites in normal lymphoid tissue. In the interfollicular T zone of lymph-nodes from patients with Kaposis sarcoma the helper:suppressor ratio (0·9±0·3 SD) was significantly different from the value in controls (2·9±1·0). In nodes from Kaposis sarcoma patients there were numerous suppressor cells in the hyperplastic follicular centres and mantle regions; in normal lymphoid tissue suppressor cells were uncommon at these sites. These results implicate B lymphocyte proliferation in the pathogenesis of altered immunological status in homosexual men with Kaposis sarcoma.

Immunoperoxidase techniques applied to dermatopathology

Immunoperoxidase techniques provide the pathologist with the capability for staining a wide range of antigens in tissue sections. More than 100 different antigens have been successfully demonstrated in fixed paraffin sections; other antigens can only lie visualized in frozen sections. This latter group particularly includes lymphocyte surface antigens detectable by monoclonal antibodies. This review describes the current state of the art and provides several illustrations of the use of monoclonal antibodies for the identification of T‐lymphocyte phenotypes in fro/en section from cases of leprosy, mycosis fungoides, halo nevus, Kaposis sarcoma, lichen planus and atopic dermatitis. Technical details and potential applications arc discussed. The growing availability of commercial immunostaining kits makes these techniques more accessible to the surgical pathologist; indeed a whole new range of truly specific, special stains are available, as pathologists we must simply learn to use them.