Bortezomib Plus Dexamethasone for Acquired Pure Red Cell Aplasia Failure or Relapse After First-line Treatment

Inclusion Criteria: * ECOG ≤ 2. * Age from 18 to 70. * Diagnosed with acquired pure red cell aplasia. * Meets the criteria of first-line treatment failure or relapse. * Organs in good function. * Signed informed consent. Exclusion Criteria: * Nursing woman. * Active bacterial, virus, fungal or parasitic infection, including HIV infection, HBsAg or HBV DNA positive, HCV DNA positive, etc. * Secondary PRCA caused by lymphoproliferative disorders, including large granular lymphocytic leukemia, waldenström macroglobulinemia, small lymphocytic lymphoma/chronic lymphocytic leukemia, etc. * Secondary PRCA caused by either smoldering multiple myeloma or symptomatic multiple myeloma. * Secondary PRCA caused by either ABO major mismatched stem cell transplantation or organ transplantation. * Secondary PRCA caused by solid tumors except for thymoma. * Secondary PRCA caused by drugs or pregnancy. * Secondary PRCA caused by the B19 virus. * Have contraindications for glucocorticoids, or unable to tolerate glucocorticoids for comorbidities. * Previously received treatment in other trials within 4 weeks before enrollment. * Previously treated with the proteasome inhibitor. * Experience active hemorrhage condition, including gastrointestinal bleeding, respiratory tract bleeding and central nervous system bleeding within 2 months before enrollment or during bortezomib/dexamethasone treatment. * Have a history of malignant tumors. * Have a history of mental illness. * Inability to understand or to follow study procedures.