From the Guidelines
Evan syndrome is a rare autoimmune disorder characterized by the simultaneous or sequential development of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP), as noted in the context of secondary ITP causes 1.
Definition and Characteristics
Evan syndrome is associated with autoimmune thrombocytopenia with coincident hemolytic anemia, as described in the American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia 1. This condition involves the immune system mistakenly attacking and destroying both red blood cells and platelets.
Clinical Presentation
Patients with Evan syndrome typically present with symptoms of anemia, such as fatigue, weakness, and pale skin, along with signs of thrombocytopenia, including easy bruising, petechiae, and bleeding from mucous membranes.
Diagnosis and Evaluation
The diagnosis of Evan syndrome involves a comprehensive workup, including history and physical examination, complete blood count (CBC), peripheral blood smear, reticulocyte count, and direct antigen testing to rule out concurrent conditions 1. A bone marrow evaluation may be necessary if abnormalities are found in the initial testing.
Treatment Approach
Treatment for Evan syndrome usually begins with corticosteroids, such as prednisone at 1-2 mg/kg/day for 2-4 weeks, followed by a gradual taper, as suggested for managing immune-related adverse events in patients treated with immune checkpoint inhibitor therapy 1. For patients who do not respond adequately to first-line treatment, second-line options may include rituximab, intravenous immunoglobulin, or immunosuppressants like azathioprine, cyclosporine, or mycophenolate mofetil. In severe cases, splenectomy may be considered.
Monitoring and Follow-Up
Regular monitoring of blood counts is essential during and after treatment for Evan syndrome, as relapses are common and may require adjustment of therapy. This approach prioritizes minimizing morbidity, mortality, and improving the quality of life for patients with this condition.
From the Research
Definition of Evan Syndrome
- Evan syndrome is a rare disease defined as autoimmune hemolytic anemia plus immune thrombocytopenia 2
- It is characterized by the simultaneous or sequential development of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP) and/or immune neutropenia 3
- Evan syndrome (ES) is a rare immune disorder defined as the simultaneous or sequential occurrence in a single patient of immune thrombocytopenia (ITP) and warm autoimmune hemolytic anemia (wAIHA) ± autoimmune neutropenia (AIN) 4
Clinical Characteristics
- ES represents approximately 5% to 10% of all wAIHA and 2%-5% of all ITP cases in adults 4
- The mortality rate of ES is high, and it can be primary or secondary and isolated or associated with another underlying disorder 4
- ES can portend a poorer prognosis and a more aggressive line of management than either condition presenting alone 5
Diagnosis and Management
- The diagnosis procedure must rule out differential diagnoses such as thrombotic microangiopathies, anaemia due to bleedings complicating ITP, vitamin deficiencies, myelodysplastic syndromes, paroxysmal nocturnal haemoglobinuria, or specific conditions like HELLP when occurring during pregnancy 6
- The management of ES is mostly empirical with a low level of evidence, and treatment options include corticosteroids, rituximab, splenectomy, and supportive therapies 4, 6
- The place for thrombopoietin receptor agonists, erythropoietin, immunosuppressants, haematopoietic cell transplantation, and thromboprophylaxis is also discussed in the literature 6