Objective To present the pooled quantitative evidence of clinical features and current treatments of programmed death 1 (PD-1) / programmed death-ligand 1 (PD-L1) inhibitor-associated vasculitis. Methods Medline, Embase, EBM, CNKI, WanFang Data and VIP databases were searched for all available studies reporting PD-1/PD-L1 inhibitor-associated vasculitis till March 23, 2022. We summarized and systematically reviewed the included articles, and analyzed the data results with descriptive statistical methods. Results A total of 38 articles were included, including 43 patients. The median age [median (minimum, maximum)] was 62 (31, 89) years, and most of patients were male (64.3%). Lung cancer was the most common tumor (47.6%). The median onset time of vasculitis [median (minimum, maximum)] was 12 (1, 120) weeks after medication. Small vasculitis (62.8%) and cutaneous vasculitis (26.7%) were the most common types. The Common Terminology Criteria for Adverse Events of vasculitis was predominantly 3-4 (83.7%). After diagnosed with vasculitis, PD-1/PD-L1 inhibitors were discontinued in 81.6% of patients, and glucocorticoid was administrated in 88.4% of patients. After treatment, 90.0% of patients had significant improvement during follow-up. However, when the discontinuation of PD-1/PD-L1 inhibitors, 55.6% of patients tumor progressions, and 35.0% of patients dead. Conclusions Special attention should be paid to the occurrence of vasculitis when using PD-1/PD-L1 inhibitors for malignant tumor therapies. Stopping PD-1/PD-L1 inhibitors and using glucocorticoid are the essential methods to treat vasculitis, but the above treatments may bring a high risk of tumor progression.
