T cells and T-cell subsets in mycosis fungoides and parapsoriasis. A study of 18 cases with anti-human T-cell monoclonal antibodies and histochemical techniques

Abstract

Skin lesions from 15 patients with mycosis fungoides (MF) and from 3 with parapsoriasis were studied immunohistochemically with monoclonal antibodies against T cells (Leu 1) and against T-cell subsets (Leu 2a, Leu 3a). Lymphoid cell reactivity was diverse among these sampled cases. In 2 cases of parapsoriasis and 9 of MF, there was a predominance of helper/inducer (Leu-3a-reactive) cells over suppressor/cytotoxic (Leu-2a-reactive) cells. In 1 case of parapsoriasis and 1 (advanced tumor stage) of MF, there was suppressor/cytotoxic cell predominance. One case of MF showed strong reactivity for both T-cell subset markers. Cases of MF (2 plaque-stage and 2 tumor-stage) featured a predominant cell type in the dermis which was nonreactive for all 3 antibodies. The intraepidermal lymphoid cellularity was Leu-1-reactive in 10 cases of MF and 2 of parapsoriasis. Among these 12 cases, the intraepidermal cellularity was Leu-2a-reactive in 4 and Leu-3a-reactive in 3. The use of such studies of T-cell subsets on in situ cutaneous lymphoid infiltrates may demonstrate a correlation with cytomorphology, clinical stage and disease prognosis.