Interstitial lung disease presents with varying characteristics in patients with non-Hodgkin lymphoma undergoing rituximab-containing therapies.

Although the incidence and outcomes of rituximab-induced interstitial lung disease (RILD) have been partially reported, there are no systematic studies on the characteristics and types of RILD. This study aimed to investigate the clinical characteristics, bronchoalveolar lavage (BAL) findings, and treatment course of RILD in patients with non-Hodgkin lymphoma. We retrospectively analyzed the data from 321 patients with non-Hodgkin lymphoma who developed RILD between 2020 and 2022. The extent, distribution, and radiologic patterns of interstitial lung disease were determined using high-resolution computed tomography of the chest. BAL was performed in 299 (93.1%) patients to determine cellular distribution patterns and identify pathogenic microorganisms using metagenomic next-generation sequencing. All patients received combination therapy, with cyclophosphamide, doxorubicin, vincristine, and prednisone being the most commonly administered regimens. The median time from treatment to RILD development was 1.7 months. In the 217 patients who underwent metagenomic next-generation sequencing, 179 pathogenic microorganisms were detected, including 77 (43.0%) bacteria, 45 (25.1%) viruses, 28 (15.6%) Pneumocystis jirovecii strains, 17 (9.5%) fungi, 6 (3.5%) Mycobacterium tuberculosis, and 6 (3.5%) atypical pathogens. All RILD diagnoses were based on multidisciplinary team discussions and compliance with international standards. In conclusion, RILD exhibits a range of radiological and BAL patterns, reflecting different interstitial lung disease types. The most common patterns of RILD are infectious lung disease, organizing pneumonia, and nonspecific interstitial pneumonia. These findings enhance the understanding of RILD in patients with non-Hodgkin lymphoma and serve as a reference for best management guidelines in these patients.