Characterization of T-Cell Subpopulations in Skin and Peripheral Blood of Patients with Cutaneous T-Cell Lymphomas and Benign Inflammatory Dermatoses

Abstract

Using a series of monoclonal antibodies, the distribution of T-cell subpopulations in the skin and peripheral blood was investigated in 21 patients with a cutaneous T-cell lymphoma and 14 patients with benign inflammatory dermatoses, histologically characterized by a bandlike mononuclear infiltrate, e.g., atopic dermatitis, chronic eczema, and lichen planus. In Sezary's syndrome the large majority of the neoplastic cells, both in the skin and the peripheral blood, reacted with Leu-1, Leu-3a, OKT3, OKT4, and TA-1 antisera (T helper/inducer phenotype). The cutaneous infiltrates in mycosis fungoides showed a predominance of Leu-3a + , OKT4 + cells (T helper/inducer phenotype), varying numbers of Leu-2a + , OKT8 + cells (T cytotoxic/suppressor phenotype), and, in contrast to Sezary's syndrome, not only large numbers of nondendritic HLA-DR + cells (probably activated T-cells) but also many dendritic nonlymphoid cells expressing HLA-DR and/or OKT6 antigens, which presumably represent cells of the Langerhans cell/interdigitating reticulum cell series. However, the number of HLA- DR + cells in the peripheral blood was not increased. In the advanced stages of mycosis fungoides a loss of certain T-cell antigens (Leu-1, OKT3, and/or Leu-3a and OKT4) was observed both in the skin and peripheral blood. The distribution of T-cell subsets, OKT6 + and HLA-DR + cells in the skin and peripheral blood of patients with atopic dermatitis and chronic eczema was similar as compared to the early stages of mycosis fungoides. These results indicate that the monoclonal antibodies used in the present study have limited value in discriminating between the early stages of mycosis fungoides and benign inflammatory dermatoses. However, the loss of reactivity with some of these anti-T-cell anti-sera in patients with well-established mycosis fungoides may have prognostic significance.