CD16+ as predictive marker for early relapse in aggressive B-NHL/DLBCL patients

Abstract

Assessing the prognosis of patients with aggressive non-Hodgkin B cell lymphoma mainly relies on a clinical risk score (IPI). Standard first-line therapies are based on a chemo-immunotherapy with rituximab, which mediates CD16-dependent antibody-dependent cellular cytotoxicity (ADCC). We phenotypically and functionally analyzed blood samples from 46 patients focusing on CD16+ NK cells, CD16+ T cells and CD16+ monocytes. KaplanMeier survival curves show a superior progression-free survival (PFS) for patients having more than 1.6% CD16+ T cells (p=0.02; HR=0.13 (0.007–0.67)) but an inferior PFS having more than 10.0% CD16+ monocytes (p=0.0003; HR=16.0 (3.1-291.9)) at diagnosis. Surprisingly, no correlation with NK cells was found. The increased risk of relapse in the presence of >10.0% CD16+ monocytes is reversed by the simultaneous occurrence of >1.6% CD16+ T cells. The unexpectedly strong protective function of CD16+ T cells could be explained by their high antibodydependent cellular cytotoxicity as quantified by real-time killing assays and single-cell imaging. The combined analysis of CD16+ monocytes (>10%) and CD16+ T cells (<1.6%) provided a strong model with a Harrell’s C index of 0.80 and a very strong power of 0.996 even with our sample size of 46 patients. CD16 assessment in the initial blood analysis is thus a precise marker for early relapse prediction.