Clinical Manifestation, Risk Factors, and Immune Checkpoint Inhibitor Rechallenge of Checkpoint Inhibitor–Associated Pneumonitis in Patients With Lung Cancer

Immune-related adverse effects can lead to damage to various systems of the body, checkpoint inhibitor-associated pneumonitis (CIP) is one of the potentially lethal immune-related adverse effects. However, evidence regarding the risk factors associated with CIP is limited. To timely and accurate identification and prompt treatment of CIP, understanding the risk factors for multimorbidity among diverse study populations becomes crucial. We retrospectively analyzed the clinical data of 1131 patients with lung cancer receiving immunotherapy to identify 110 patients with CIP, the clinical characteristics and radiographic features of patients with CIP were analyzed. A case-control study was subsequently performed to identify the risk factors of CIP. The median treatment cycle was 5 cycles and the median time to onset of CIP was 4.2 months. CIP was mainly grade I or II. Most cases improved after discontinuation of immune checkpoint inhibitors (ICIs) or hormone therapy. Severe CIP tended to occur earlier in comparison to mild to moderate cases. The recurrence rate was 20.6% in ICI-rechallenged patients, and patients with relapsed CIP were usually accompanied by higher-grade adverse events than at first onset. Among the 7 patients with relapse, ICI-associated deaths occurred in 2 patients (28.6%). For rechallenging with ICIs after recovery from CIP, caution should be practiced. Male [odds ratio (OR): 2.067; 95% CI: 1.194-3.579; P = 0.009], history of chest radiation (OR: 1.642; 95% CI: 1.002-2.689; P = 0.049) and underlying lung disease (OR: 2.347; 95% CI: 1.008-5.464; P =0.048) was associated with a higher risk of CIP.