CD4+ CD28+ lymphocytes on day 5 after high-dose melphalan for multiple myeloma predict a low risk of infections during severe neutropenia and are associated with the number of reinfused T lymphocytes of the autologous stem cell graft

Background aimsNeutropenia following high-dose chemotherapy is associated with a substantial risk of infectious complications. The aim of this study was to identify variables in residual leukocyte subsets during neutropenia that are predictive for neutropenic fever.MethodsResidual leukocytes in the peripheral blood on day 5 after autologous blood stem cell transplantation were analyzed by three-color flow cytometry in 55 consecutive patients with multiple myeloma. Furthermore, the number of T cells transfused with the autografts was determined.ResultsNeutrophil counts at day 5 and neutrophil engraftment were similar in patients with and without neutropenic fever. Low absolute lymphocyte, CD4+ CD28+ and CD45RO+ CD28+ counts at day 5 were associated with neutropenic fever. T-cell counts at day 5 correlated with the CD3+ cell number in the graft.ConclusionsOur data show that the absolute lymphocyte, CD4+ CD28+ and CD45RO+ CD28+ counts play a role in host defense during severe neutropenia. The T-cell number in the graft may help to identify patients at high risk of neutropenic infections.