ABNORMALITIES OF CIRCULATING T-CELL SUBPOPULATIONS IN PATIENTS WITH CUTANEOUS T-CELL LYMPHOMA - CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN EXPRESSION ON T-CELLS CORRELATES WITH EXTENT OF DISEASE

The recent characterization of the cutaneous lymphocyte-associated ant igen (CLA) as a skin-selective homing receptor for skin-associated mem ory T cells has suggested a possible mechanism for the tropism demonst rated by the neoplastic T cells in cutaneous T-cell lymphoma (CTCL). I n this study, we used five parameter flow cytometry to evaluate expres sion of CLA and the peripheral lymph node homing receptor L-selectin o n circulating T cells in a series of patients with CTCL. Because CTCL cells were previously shown to be CD7-, we looked at expression of the se receptors on the CD7- T-cell subset as well as on total T cells. Ou r results indicate that CTCL patients have increased levels of both CL A+ and CD7- cells in their peripheral blood and that these abnormaliti es are not seen in patients with other cutaneous disorders. The levels of the CLA-bearing subset correlated with extent of cutaneous but not lymph nods disease. By contrast, the CD7- L-selectin+ subset correlat ed with peripheral lymph node involvement by CTCL. Only the CD7- L-sel ectin- subset correlated with the number of morphologically abnormal l ymphocytes in the peripheral blood. The results support the hypothesis that expression of tissue-selective homing receptors contributes to t he unique pattern of tissue involvement seen in patients with CTCL.