Presence and function of CD14+CD16-HLADRlow monocytes in the peripheral blood of patients with Β-cell non-Hodgkin lymphoma (NHL).

e19539 Background: The antitumor immune response in patients with B-cell NHL plays an important role in determining clinical outcome. We have previously shown that an increased absolute monocyte count in the peripheral blood of lymphoma patients is associated with a poor prognosis. Furthermore, we have identified a population of CD14+HLADRlow monocytes in NHL patients that are immunosuppressive. The goal of this study was to further define the phenotype of suppressive monocytes in lymphoma patients and to identify the conditions that promote their expansion. Methods: Peripheral blood specimens were obtained from patients with newly diagnosed, untreated B-cell NHL (n=20) and 20 matched controls; and the phenotype of the monocyte fraction was analyzed by 10-color flow cytometry. Monocytes from an additional 15 healthy controls were polarized to express a phenotype similar to that seen in lymphoma patients. Serum from 361 lymphoma patients and 337 matched controls were used to confirm differences in cytokine...