Pei Zhu ¹ Qingming Sun ² Sheng Xu ² Wanhui Dong ^2*

• ¹ Anhui University of Traditional Chinese Medicine Affiliated Liu'an Traditional Chinese Medicine Hospital, Lu 'an, China
• ² Lu'an Hospital of Traditional Chinese Medicine, Lu'an, Anhui Province, China

Interstitial pneumonia is a group of pathologies affecting the pulmonary interstitium, characterized by interstitial fibrosis and extensive alveolar consolidation.This disease can extend to the surrounding blood vessels and pulmonary interstitium, sometimes affecting the entire lung, resulting in functional limitations, including restrictive ventilatory defect, impaired gas exchange, and hypoxemia. Severe interstitial pneumoniaIP can lead to death. Antitumor drugs can induce interstitial pneumoniaIP.Sintilimab is an immune checkpoint inhibitor, a recombinant fully human immunoglobulin G-type programmed death protein-1 monoclonal antibody inhibitor.S-1 is a compound preparation consisting of gimeracil, oteracil potassium, and ftorafur.There have been cases of interstitial pneumonia caused by treatment with sintilimab or S-1 in clinical settings, but no cases of interstitial pneumoniaIP caused by treatment with a combination of sintilimab and S-1 have been reported.A 52-year-old male patient diagnosed with gastric cancer underwent nine courses of was treated treatment with using a chemotherapy regimen of combined oxaliplatin combined with S-1. for nine courses, resulting in a chest enhanced CT scan showing scattered chronic inflammatory lesions in both lungs. Due to severe bone marrow suppression myelosuppression and gastrointestinal adverse reactions, the treatment was switched to a regimen of sintilimab in combined combination with S-1 therapy .for one course, This change resulting resulted in the development ofin chest CT scans showing interstitial pneumonia, as revealed by non-contrast chest Computed Tomography scans.. Following a review of blood test results and a multidisciplinary consultation, we suspect that the interstitial pneumonia may have been caused either by Sintilimab alone or by the combined effects of sintilimab and S-1. The treatment was discontinued, and after receiving adequate glucocorticoid therapy, the pulmonary lesions showed slight improvement.seven days of glucocorticoid treatment, the pulmonary lesions showed