Introduction:
Evans syndrome arises from the destruction of red blood cells and platelets by the body’s own immune system. This causes diminishing levels of blood cells resulting in anemia and bleeding disorders. Since it is idiopathic, all the other differential diagnoses should be ruled out to confirm the diagnosis of Evans syndrome. The treatment options are drug therapy, blood transfusions, splenectomy, monoclonal antibody therapy, or stem cell transfusions.
What Is Evans Syndrome?
Evans syndrome is an autoimmune condition where the body produces antibodies against its own blood cells. This leads to abnormally low blood count, especially for red blood cells and platelets. White blood cells are less commonly targeted. Hence, autoimmune hemolytic anemia (destruction of red blood cells) and idiopathic thrombocytopenia purpura (low levels of platelets) are the two characteristic features of Evans syndrome. It can occur as a primary disorder or in association with other conditions.
What Are the Signs and Symptoms of Evans Syndrome?
The severity of symptoms can differ for each person, depending on the course of the disorder. However, the symptoms develop over time gradually and mainly include the effects of low levels of red blood cells and platelets.
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Low Levels of Red Blood Cells: When the destruction is faster than what the body can replace, it rapidly lowers red blood cells. This condition is known as anemia and can cause symptoms like tiredness, pale skin color, shortness of breath, lightheadedness, rapid heartbeat, and dark-colored urine. Some may show symptoms of jaundice as well.
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Low Levels of Platelets: This may cause red or purple spots on the skin (petechiae), bleeding from blood vessels under the skin causing larger purple patches (ecchymosis), and the rash of multiple purple spots (purpura). In addition, patients may show spontaneous bleeding and easy bruising.
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Low Levels of White Blood Cells: This occurs less frequently and may cause fever, frequent infections, poor health, and oral ulcers.
Additionally, patients with Evans syndrome may show enlarged spleen, liver, and lymph nodes periodically.
What Causes Evans Syndrome?
It is an autoimmune disorder caused by the production of autoantibodies against blood cells. The triggering event for such a reaction is not exactly specified by researchers but can be an infection or an underlying condition. It can be primary Evans syndrome or secondary Evans syndrome, associated with other conditions such as autoimmune lymphoproliferative syndrome, lupus, antiphospholipid syndrome, Sjogren’s syndrome, common variable immunodeficiency, IgA deficiency, certain lymphomas, and chronic lymphocytic leukemia.
How to Diagnose Evans Syndrome?
Thorough clinical examination, patient history, specified symptoms, and specialized tests can help diagnose Evans syndrome accurately. Lab tests that can be helpful for diagnosis are:
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Complete Blood Count and Peripheral Blood Examination: It will help to detect anemia, thrombocytopenia, reticulocytosis, and poikilocytosis if present.
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Direct Antiglobulin Test: Positive test will confirm the ongoing hemolysis.
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Additional Antibody Assays: This will help to detect antibodies against platelets, anti-granulocyte antibodies, and other antibodies associated with autoimmune disorders.
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Computed Tomography Scans of the Abdomen, Chest, and Pelvis: Helps to detect any malignancy due to associated autoimmune disorders such as systemic lupus erythematosus and autoimmune lymphoproliferative syndrome.
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Bone Marrow Biopsy.
What Is the Differential Diagnosis for Evans Syndrome?
Some other conditions which may show overlapping symptoms with Evans syndrome are:
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Paroxysmal Nocturnal Hemoglobinuria: It is characterized by hemolytic anemia, pancytopenia, and thrombosis.
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Hemolytic Uremia: It is characterized by leukocytosis, microangiopathic hemolytic anemia, thrombocytopenia, and a negative DAT test.
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Acquired Thrombotic Thrombocytopenic Purpura: It is characterized by microangiopathic hemolytic anemia, fever, leukocytosis, and neurological or kidney impairment.
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Kasabach-Merritt Syndrome: It is characterized by microangiopathic hemolytic anemia, low fibrinogen levels, thrombocytopenia, increment of D-dimer, and giant hemangioma.
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Autoimmune Lymphoproliferative Syndrome: It is characterized by the presence of antibodies against erythrocytes and platelets, the presence of chronic lymphoproliferation, and increased levels of double-negative T-cells.
Specific laboratory tests should be performed to rule out any of these conditions and confirm Evans syndrome's diagnosis.
What Is the Treatment for Evans Syndrome?
Treatment of Evans syndrome is challenging, and there is no specific cure available. It mainly focuses on relieving the symptoms of the patient. Age, general health, the severity of symptoms, blood cell count levels, and other such elements are the deciding factor for the specific treatment of the particular individual.
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Corticosteroids: Such as Prednisolone, are used as first-line therapy for Evans syndrome. It helps to suppress immunity to lower the production of autoantibodies.
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Intravenous Immunoglobulin Therapy: It comprises direct infusion of antibody solution from a healthy individual into a patient’s vein. This therapy changes the activity of the immune system.
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Splenectomy (Surgical Removal of Spleen): It is performed in patients who are not responsive to other drug therapies. The effectiveness of this method is yet to be confirmed by researchers.
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Blood or Platelet Transfusions: It is effective during an acute episode. However, it should be avoided as much as possible.
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The Monoclonal Antibody or Biologic Therapy: Rituximab is used as a medication that acts like an antibody in this therapy. It avoids serious immunosuppression and other side effects associated with other immunosuppressive agents.
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Multi-Agent Therapy: Mycophenolate mofetil is used in combination with other drugs as second-line drug therapy.
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Stem Cell Transplantation: Stem cells are specialized cells that manufacture different blood cells. In this procedure, healthy stem cells are infused into the patient’s bone marrow. This is used as a last resort for treating Evans syndrome when there is no response from other therapies. The effectiveness of transplantation is still under clinical trials.
Conclusion:
Evans syndrome is a rare autoimmune disease where the body produces antibodies against its own blood cells, leading to abnormally low blood count, especially for red blood cells and platelets. It is difficult to diagnose and treat this condition. It requires an interprofessional team of doctors, nurses, and pharmacists to identify and treat the patient successfully. Corticosteroids and immunosuppressive drugs usually help manage it, but the response to particular treatment differs from patient to patient.
