Immunotherapy-associated autoimmune hemolytic anemia induced by anti-PD-1 therapy in esophageal cancer: A case report and literature review

Rationale:Numerous immune checkpoint inhibitors have been approved for clinical use in metastatic advanced esophageal cancer. While immunotherapy brings therapeutic benefits, immune-related adverse events (irAEs) should nevertheless not be overlooked. This paper reports on the first documented case of Autoimmune hemolytic anemia (AIHA) caused by anti-programmed cell death protein-1 therapy in esophageal squamous cancer.Patient concerns:An 84-year-old female patient with metastatic squamous esophageal cancer developed chest tightness, generalized weakness, and a yellowing of the skin after 2 cycles of sintilimab treatment.Diagnoses:Initial examination revealed severe anemia with elevated levels of bilirubin, reticulocytes, lactate dehydrogenase, decreased levels of haptoglobin, and a positive direct antihuman globulin test. The patient was diagnosed with immunotherapy-associated AIHA.Interventions:The patient was promptly treated with corticosteroids and human immunoglobulin, supportive transfusion with washed erythrocytes.Outcomes:Her AIHA was controlled after treatment. Subsequent immunotherapy was not continued, and there was no recurrence of AIHA.Lessons:We have identified a rare case of serious adverse reaction caused by anti-PD-1 therapy. We summarize the clinical presentations, diagnosis, and treatment of this case of immunotherapy-related AIHA and discuss the pathogenesis and therapeutic advances in immunotherapy-related AIHA, as well as sintilimab-induced irAEs, in detail. These findings underscore the importance of the early detection, diagnosis, and treatment of these rare and potentially fatal irAEs.