Low total gamma globulin level discovery at diffuse large B-cell lymphoma diagnosis predicts high risk of infection-related death: data from a monocentric retrospective study.

Abstract

Diffuse large B-cell lymphoma can complicate the course of B-cell primary immunodeficiencies or induce lowering of total gamma globulin levels, whose clinical status as an effective secondary immunodeficiency remains unspecified. This study aimed to assess the frequency, and clinical and prognostic relevance of the low total gamma-globulin levels discovered at diagnosis of diffuse large B-cell lymphoma. In a 2-year monocentric retrospective study, 96 patients diagnosed with diffuse large B-cell lymphoma who had a serum electrophoresis were included. Patients were divided into those with lower (L-TGL and higher (H-TGL) total gamma-globulin levels (total gamma-globulin levels ≤5.5 g/l and >5.5 g/l) and compared for outcomes, including fatal infectious events. Twelve (12.5%; 8 males; age median 68 years, range 55-82 years) exhibited L-TGL. There was no difference between the both groups regarding demographics, Ann Arbor lymphoma stage, inflammatory parameters or chemotherapy regimen. However, overall death rates (10/12, 83.3% versus 22/96, 26.2%; p = 0.03) and infection-related death rates (10/12, 83% versus 6/96, 6.2%; p <0.001) were significantly higher in the L-TGL group. We demonstrate for the first time the strong negative impact of L-TGL on overall and infection-related mortality in diffuse large B-cell lymphoma. Prospective studies should distinguish immunodeficiencies secondary to the lymphoma from pre-existing humoral primary immunodeficiencies, using biomolecular testing and post-treatment total gamma-globulin level monitoring, to determine the best management strategy for infectious risk during diffuse large B-cell lymphoma treatment in the context of L-TGL.