Evans Syndrome

• immune thrombocytopenia and autoimmune hemolytic anemia
• occurs in individuals of all ages. In a 1997 survey of North American pediatric hematologists, the median reported age at diagnosis was 7.7 years (range 0.2-26.6 y)
• an uncommon but not rare condition; its exact frequency is unknown. Familial occurrence is rare.
• The etiology of Evans syndrome remains speculative. Autoantibodies are directed against specific antigens specific to red cells, platelets, or neutrophils, but they do not cross react.
• has a chronic, relapsing, and sometimes fatal course.
• Evans syndrome is a diagnosis of exclusion. Confounding disorders, such as infections, rheumatologic diseases, malignancies can present with autoimmune cytopenias, must be ruled out.

History: In a national survey, thrombocytopenia was the presenting feature in 76% of patients with Evans syndrome, and anemia was the presenting feature in 67% of these patients. In addition, 24% of patients had neutropenia and 14% had pancytopenia.

Labs:

• The CBC and reticulocyte count show anemia, thrombocytopenia, neutropenia, or combined cytopenias; the reticulocyte count increases if the patient has anemia.
• In Evans syndrome, the direct antiglobulin result (ie, Coombs test result) is positive.
• A variety of antibodies directed against RBCs and platelets (eg, antierythrocyte, antineutrophil, antiplatelet antibodies) occur in association with Evans syndrome.
• Lupus antibody and antinuclear antibody (ANA) tests are used to detect SLE.
• Perform T- and B-cell function tests for quantitative immunoglobulins to evaluate for hypogammaglobulinemia and perturbations in T-cell numbers.
• Bone marrow aspiration helps reveal aplastic anemia or an infiltrative disorder. Bone marrow aspiration may be indicated when patients initially present with pancytopenia.

Treatment

• Prednisone therapy often effectively controls acute episodes, though relapses may be frequent when patients are weaned off prednisone.
• Intravenous immunoglobulin (IVIG) may help patients who are dependent on steroids.
• Other therapies that were effective in small series were danazol, cyclosporine, azathioprine, cyclophosphamide, and vincristine.
• Additional therapies are splenectomy and hematopoietic stem cell transplantation.
  • Splenectomy may improve blood counts and reduce steroid dependence, but relapses are common.
  • Children with Evans syndrome appear to have a higher risk of postsplenectomy sepsis, especially children with pancytopenia.

References:

eMedicine.com. Evans Syndrome. Last Updated: June 15, 2005