The Safety and Efficacy of Zanubrutinib in Refractory/Relapsed Autoimmune Hemolytic Anemia

Inclusion Criteria: * Age from 6 to 70 * Diagnosis of Coombs-negative AIHA * Diagnosis of warm AIHA, mixed AIHA or Evans syndrome. * Meets the criteria of relapsed / refractory AIHA * ECOG ≤ 3 * Willing and able to comply with the requirements for this study and written informed consent. Exclusion Criteria: * Diagnosis of any of the following diseases: Cold agglutinin disease, cold agglutinin syndrome, mixed AIHA, paroxysmal cold hemoglobinuria (PCH). * Diagnosis of active stage of connective tissue disease. * History of lymphoproliferative tumors or any other malignant. * Diagnosis of other inherited or acquired hemolytic diseases. * Secondary AIHA caused by drugs or infection. * Previously received organ or stem cell transplantation. * History of thrombosis or organ infarction. * Received rituximab within 8 weeks before enrollment. * Previously treated with BTK inhibitor ≥ 2 weeks. * Received low-molecular-weight heparin or warfarin within 1 week before enrollment and need to continue the drug treatment. * Received CYP3A4 Enzyme Inhibitors or Inducers within 1 week before enrollment and need to continue the drug treatment. * Uncontrolled systemic fungal, bacterial, or viral infection (defined as ongoing signs/symptoms related to the infection without improvement despite appropriate antibiotics, antiviral therapy, and/or other treatment), known human immunodeficiency virus (HIV), known evidence of active infectious hepatitis B, and/or known evidence of active hepatitis C. * Any severe and/or uncontrolled medical conditions: refractory hypertension, clinically significant cardiac diseases, renal diseases, liver diseases and metabolic diseases, etc. * History of mental illness. * Participation in another clinical trial within 4 weeks before the start of this trial. * Pregnant or breast-feeding patients. * Patients considered ineligible for the study by the investigator for reasons other than the above.