Alemtuzumab therapy for leukemic cutaneous T-cell lymphoma: diffuse erythema as a positive predictor of complete remission.

Abstract

To the editor Low dose alemtuzumab (LDA) is a highly effective and generally well tolerated therapy for refractory cutaneous T cell lymphoma (CTCL) patients with peripheral blood disease.1 LDA is effective in patients with blood involvement (leukemic disease) but ineffective in MF, reflecting the fact that these lymphomas derive from distinct T-cell subsets. Malignant T cells in patients with blood disease have the phenotype of CCR7+/L-selectin+ central memory cells (TCM), migratory cells that recirculate between skin, blood and lymph nodes whereas MF T cells are derived from non-migratory skin resident memory T cells (TRM).2 Because the mechanism of T cell depletion with LDA requires neutrophils and/or NK cells, cells frequent in blood but rare in skin, LDA kills T cells in blood but not in skin.1 In patients with blood disease, LDA depletes all circulating T cells and purges the skin over time of recirculating malignant T cells, leading to complete and often durable remissions in 50% of patients while sparing benign T cells in skin.1 We present here our findings that clinical appearance can be used to discriminate patients likely to experience a complete remission following LDA from those that will have persistent and/or worsening skin disease.