Post-treatment improvement of NK cell numbers predicts better survival in myeloma patients treated with thalidomide-based regimens.

Multiple myeloma (MM) is a disease characterized by antitumoral immune dysfunction. The objective of the present study was to determine lymphocyte subsets (B, T, NK, NKT, iNKT, dendritic cells, and regulatory T cells) in 68 newly diagnosed patients and 113 healthy donors. Lymphocyte subsets were studied in the same patients 6 months after treatment. Pre-treatment values of CD4+ T cells, NK cells, type 2 dendritic cells, and B cells in MM patients were lower than in healthy donors. Forty patients (59%) received MPT treatment and 28 (41%) thal-dex. Patients with no response to treatment, exhibited a decrease in CD4+ T cells and NK cells, as well as an increase in Treg cell numbers. Median DFS and OS was lower in patients not achieving response, in patients having low numbers of NK cells, and higher values of LDH. The number of CD4 T cells, NK, DC2, and B cells at diagnosis is lower in patients with MM. Non-responder patients had lower CD4 and NK, but higher Treg cell values. Patients in which response is not achieved, and those holding lower values of NK cells and higher levels of LDH, have poor DFS and OS.