Clinical features, treatment and risk factors for interstitial pneumonia in B-cell non-Hodgkin lymphoma patients

BACKGROUND: Interstitial pneumonia (IP) is a common and fatal adverse effect of rituximab-containing immunochemotherapy in lymphoma patients. Following prophylactic treatment with trimethoprim-sulfamethoxazole (TMP-SMX), the clinical features, treatment, and risk factors for IP development remain largely undefined. METHODS: From April 2015 and April 2018, 294 patients diagnosed with CD20+ B-cell non-Hodgkin lymphoma (NHL) were included in this study. All patients received front-line RCHOP-like chemotherapy and prophylactic treatment of TMP-SMX once daily. We summarized the clinicopathologic characteristics and treatment outcomes of IP in these patients and explored the possible risk factors of IP. RESULTS: The overall incidence of IP was 8.16%. Typical clinical symptoms included fever for 1–3 days in 11 patients, dyspnea in 4 patients, expectoration in 5 patients, and dry cough in 7 patients. A total of 8 patients showed no apparent symptoms. Prior to IP, the median number of chemotherapy cycles was 4. The median time for IP initiation was 63 days, and the median duration of IP treatment was 11 days. All patients recovered from IP after treatment. A total of 6 patients continued to receive chemotherapy without rituximab, and 14 patients received rituximab combined with chemotherapy. No patients experienced IP recurrence. In univariate and multivariate analysis, male, diabetes, low lymphocyte counts (<1.0×10(9)/L) and low CD4/CD8 counts were identified as risk factors of IP. Patients with no risk factors were included in the low-risk group; 1 to 2 factors: intermediate-risk; ≥3: high-risk. The occurrence of IP differed across three groups (low risk, 0%; intermediate risk, 7%; high risk, 14.5%; P=0.059). CONCLUSIONS: The incidence of IP was 8.16% in patients with CD20+ B-cell NHL. Males, diabetes, low absolute lymphocyte counts (ALC) (<1.0×10(9)/L) and low CD4/CD8 were identified as risk factors of IP.