Canterbury DHB

Pure Red Cell Aplasia

Introduction and Key Points

Pure Red Cell Aplasia is a rare condition that occurs in congenital and acquired forms. The latter may be transient or chronic.

Key Points

• Acquired Pure Red Cell Aplasia (PRCA) in adults is often persistent and may respond to immunosuppression.
• Acquired PRCA in children is often transient and may be secondary to viral infections including parvovirus.
• Congenital forms of PRCA are extremely rare.

For review of PRCA, see UpToDate.

Classification

Inherited: Diamond Blackfan Syndrome and other conditions.

Acquired:

• Transient: Common in childhood. Viral-related, especially parvovirus B19.
• Sustained: Mainly occurs in adults:
  • Idiopathic.
  • Associated with lymphoid malignancies, e.g. NHL, CLL
  • Thymoma
  • Drugs
  • Recent recombinant erythropoietin treatment

Diagnosis

• The patient presents with the symptoms of anaemia. Congenital abnormalities may be see in the Diamond Blackfan syndrome, and in 30% of these children, thumb abnormalities are seen. There may be a history of viral illness, or the patient may have other diseases which predispose to the development of PRCA.
• Transient PRCA is more severe if it complicates a pre-existing haemolytic anaemia, e.g., hereditary spherocytosis.
• The anaemia is usually normocytic, with no abnormal white cells present. Reticulocytes are low and the bone marrow shows hypoplasia of the red cell series. Granulocytes and platelets are normal.
• Where appropriate, seek antibodies to parvovirus B19 and/or PCR for the viral genome.
• In persistent PRCA, search for any underlying cause and establish a diagnosis of thymoma or lymphoma if these are present.

Management

Transient erythroblastopenia of childhood usually occurs between the ages of 6 months and 3 years. Parvovirus B19 binds to the P antigen on the red cell surface, and IgG antibodies directed against erythroblasts can be detected. Treatment is supportive, although blood transfusion may be needed, particularly if the patient has an inherited haemolytic anaemia.

Chronic acquired PRCA is an autoimmune disorder which often responds to immunosuppression. Blood transfusion again may be required. Erythropoeitin is not helpful. Thymectomy may be effective. Steroids, ATG, and cyclosporin may all be successful, but cytotoxic therapy is usually without benefit. Rituximab may produce prompt improvement (Karra K, Leuk Res 2006, 30). Up to half of acquired PRCA patients show some response to treatment.

Note: Following an ABO mismatched allogeneic stem cell transplant, about 20% of patients will have a significant period of red cell aplasia due to the recipients' anti A or B production.

Topic Code: 4939