Overview
Absolute lymphocyte count (ALC) is a marker of immune status, but its prognostic role in diffuse large B-cell lymphoma (DLBCL) in the era of T-cell-directed therapies remains understudied. This retrospective study evaluated 8,777 adults with DLBCL in the US Flatiron Health Research Database to assess associations between lymphopenia (ALC < 1.0 × 10^9/L) and clinical outcomes.
At diagnosis, 34.3% of patients had lymphopenia. Baseline lymphopenia was independently associated with poorer outcomes, including shorter median real-world overall survival (82 vs 101 months) and shorter time to next treatment (26 vs 63 months). Patients with baseline lymphopenia were also more likely to eventually receive T-cell-directed therapy. Among 559 patients who received CAR T or bispecific antibody therapy, severe pre-treatment lymphopenia (ALC < 0.5 × 10^9/L measured within 90 days prior to therapy) was independently associated with shorter overall survival (median 13.6 vs 54 months).
Why this matters
This study demonstrates that baseline and pre-treatment lymphopenia are independent prognostic factors in DLBCL. The substantial differences observed, particularly among patients receivingT-cell-directed therapies, suggest that systemic immune reserve may play an important role in treatment outcomes.