The interesting world of Heme! Evans Syndrome

Evans Syndrome

We recently mentioned Evans Syndrome (ES) in Morning Report.

This condition was initially described by Evans and colleagues in 1951, when describing a cohort of patients whose clinical presentation and course was characterized by autoimmune hemolytic anemia and immune thrombocytopenia; interesting, a few patients also had neutropenia as well.

Evans Syndrome (ES) includes the following features: Coombs-positive warm autoimmune hemolytic anemia (IgG), and immune thrombocytopenia (ITP). Some patients also have autoimmune neutropenia. Interestingly, the antibodies that play a role in hemolysis are different from those that result in the destruction of platelets:

• Antibodies involved in RBC destruction: directed against a base protein found in the Rh blood group
• Antibodies that destroy platelets: often directed against GPIIb/IIIa                                                                    NOTE: The typical course is one that is chronic and relapsing.

Etiology: the etiology is not completely understood, but it is postulated to involve non-cross reacting autoantibodies directed against antigens specific to RBCs, platelets, and neutrophils 

• Many cases: idiopathic
• Associations: SLE, lymphoproliferative disorders, autoimmune lymphoproliferative syndrome, common variable immunodeficiency, hypogammaglobulinemia, post-allogenic hematopoietic cell transplant

Treatment: medical management can be challenging, with varying response to therapy even within the same individual patient throughout their disease course!

• First line: course of glucocorticoid (i.e. Prednisone 1-2 mg/kg/day)
• IVIG may help those that are dependent on steroids
• Second line: studies in small case series à danazol, cyclophosphamide, azathioprine
•  Third line: Consideration of Rituximab (chimeric human/mouse monoclonal antibody that targets CD20 on lymphocytes)
•  Splenectomy
•  Hematopoietic cell transplantation

NOTE: there are no randomized controlled trials (RCTs) on the treatment of ES. There is insufficient information in the literature to choose one agent over the other. Recent literature includes more support for success with the use of Rituximab

Resources:

 Blood (2009). Michel, M. et al. “The spectrum of Evans syndrome in adults: new insight into the disease based on the analysis of 68 cases”