The ratio between CD4 + and CD8 + cells in the peripheral blood of patients with hematological malignancies is not altered by thalidomide

Abstract

Thalidomide is thought to have anti-angiogenic and immunomodulatory properties, including suppression of tumor necrosis factor-alpha, effects on interleukins and interferons, down-regulation of some cell adhesion molecules, and changes in the proportion of lymphocyte subsets. It is unclear whether the clinical response to thalidomide in patients with multiple myeloma (MM), idiopathic myelofibrosis (IM), and myelodysplastic syndromes (MDS) is related to its ability to inhibit angiogenesis or its immunomodulatory effects. We examined the effect of thalidomide on T-lymphocyte subsets in 18 patients with MDS, 6 patients with MM, 4 patients with IM, and 3 patients with angioimmunoblastic lymphoma (AILD). These patients had either a relapse or progressive disease following cytotoxic chemotherapy including high-dose chemotherapy with autologous stem cell support. Thalidomide was first administered at 100 mg/day p.o. and increased to 400 mg/day. T-lymphocyte subsets (CD4+, CD8+) were measured by fluorescence-activated cell sorter (FACS) before and during treatment with thalidomide. Twenty-six of 31 patients responded to thalidomide, most of them achieving partial remission. The median concentration of CD4+ cells was 443/microl, the median of CD8+ cells was 359/microl (CD3 992/microl). In our cohort, no significant changes in absolute numbers or proportions of CD3+ (P = 0.12), CD4+ (P = 0.668), or CD8+ (P = 0.143) cells were observed following the treatment with thalidomide. Although the CD4/CD8 ratio declined from 1.6 to 1.0 during 3 months of thalidomide treatment, this had no statistical significance (P = 0.1). Our findings show that an effect of thalidomide on the T lymphocytes studied is unlikely to be of major importance for the clinical effects.