A 52-year-old male patient with recurrent Hodgkin′s lymphoma was treated with a combination therapy of gemcitabine, oxaliplatin, and sintilimab for 6 cycles, and sintilimab monotherapy for 15 cycles. Because of disease progression, the therapy was switched to decitabine (10 mg intravenous infusion on day 1-5) and penpulimab (200 mg intravenous infusion on day 8), with 21 days as one cycle. On the 5th day after the last administration of the 10th cycle, the patient experienced discomfort such as headache and poor appetite; on the 7th day, he suddenly developed unconscious and faint. The patient had a body temperature of 38.1 ℃ and mild yellowish skin and mucous membranes throughout the body. Laboratory tests showed platelet count 9×10 ⁹/L, red blood cell count 4.1×10 ¹²/L, hemoglobin 113 g/L, prothrombin time 15.6 s, blood creatinine 101.6 μmol/L, total bilirubin 61.1 μmol/L, and creatine kinase isoenzyme 43 U/L. Based on laboratory and imaging examinations, immune checkpoint inhibitors causing acquired thrombotic thrombocytopenic purpura was considered. The patient underwent 3 times of plasma exchanges, and received intravenous infusion of methylprednisolone 80 mg once daily and other symptomatic treatments for 5 days. The patient′s yellowish skin and mucous membranes throughout the body disappeared. The glucocorticoid was decreased gradually. Two months later, the patient′s laboratory test indicators such as platelet count and total bilirubin returned to normal.