RESUMEN
BACKGROUND: Interstitial pneumonitis (IP), a fatal complication of DLBCL treatment, can bring great challenges to clinicians. We retrospectively investigated clinical characteristics and risk factors of previous IP patients, and analyzed their survival data. METHODS: 556 DLBCL patients receiving CHOP-like regimens were enrolled between 2013 and 2018 in Sichuan Cancer Hospital. FINDINGS: The IP incidences were 4.9 % (27/556), 1.1 % (2/186), 5.2 % (10/191) and 8.4 % (15/179) in CHOP, R-CHOP and R-CDOP groups respectively (P = 0.005). When IP was diagnosed, monocyte and IL-6 were significantly higher while CD4 and CD4/CD8 significantly lower compared to baseline. 81.5 % (22/27) of IP patients were pathogen-negative with good response to glucocorticoid monotherapy. Only one patient died while the others recovered from IP and subsequently underwent previous chemotherapy. 19.2 % (5/26) of IP patients experienced IP recurrence, likely due to the reason of lower initial dose or faster withdrawal speed of glucocorticoid. Multivariate analysis identified male, in addition to G-CSF, rituximab and pegylated liposomal doxorubicin as risk factors. The 3-year PFS and OS were 74.1 % and 46.9 % respectively for patients with IP. INTERPRETATION: We suggest that IL-6, monocyte and CD4 should be monitored closely, especially in R-CHOP/R-CDOP group. Sufficient initial dose and slow decrease of glucocorticoid based on radiographic remissions were critical strategies to reduce IP recurrence. We speculate that drug-induced immune imbalance could be trigger of developing IP, causing a lower intensity cytokine storm, resulting in a potential immunotherapy. This complication might bring benefit in patients' survival through a mechanism similar to PD-1.