Abstract: Objective To investigate the incidence of rituximab⁃induced interstitial lung disease (RILD) in newly treated patients with diffuse large B⁃cell lymphoma (DLBCL) and its correlation with clinicopathological features. Methods The clinicopathological data of 110 patients with DLBCL who were treated in the Department of Hematology of Beijing Tongren Hospital from January 2020 to December 2022 were retrospectively collected. All patients received rituximab⁃ containing first⁃line treatment regimen, and the specific regimen was adjusted on an individual basis, with one cycle every 21 days. The occurrence of RILD was assessed by chest CT or PET⁃CT examinations after the completion of the 2nd and 4th cycles of chemotherapy, and the 8th cycle of rituximab treatment, respectively. The risk factors of RILD were assessed by chi⁃square test and multivariate Logistic regression analysis to construct risk prediction model, and a nomogram model was constructed to predict the occurrence rate of RILD. Results The terminal complete remission rate of 110 DLBCL patients was 84.2% after treatment. Twenty⁃one patients (19.1%) developed RILD during treatment, and the median time of occurrence was the 4th cycle of first⁃line treatment(range: 2~8 cycles). The median duration of treatment for RILD was 10 days (range: 5~60 days). Except for 5 patients with no obvious symptoms or mild symptoms, 16 patients with moderate and severe symptoms received glucocorticoid⁃containing regimens, and the situations of all the patients improved after treatment. The incidence of RILD in the patients who received pegylated liposomal doxorubicin (PLD) regimens was significantly higher than those treated with pirarubicin regimens (29.7% vs 13.7%,P=0.043). The patients who smoked (25.9% vs 16.9%, P=0.298) and were more than 60 years old (23.2% vs 12.2%, P=0.156) also had a higher incidence of RILD, but the difference was not statistically significant. The RILD risk prediction model was constructed according to the risk factors, and the patients were divided into the high⁃risk group and low⁃risk group, and the incidence of RILD was significantly different between the two groups (P=0.027). The results of nomogram model analysis showed that the incidence of RILD was above 35% in patients ≥60 years old with a history of smoking who used PLD. Conclusion The patients with DLBCL should be alert to the occurrence of RILD after using rituximab⁃containing chemotherapy, especially in smoking and elderly patients. The prevention and monitoring of RILD should be strengthened after using PLD. 

Key words: Diffuse large B?cell lymphoma, Rituximab, Interstitial pneumonia, Pegylated liposomal doxorubicin