Warm antibody hemolytic anemia

Other Names: Warm-reacting-antibody hemolytic anemia; Warm antibody autoimmune hemolytic anemia; Warm antibody AIHA

Warm antibody hemolytic anemia is the most common form of autoimmune hemolytic anemia. It is defined by the presence of autoantibodies that attach to and destroy red blood cells at temperatures equal to or greater than normal body temperature. The disease is characterized by symptoms related to anemia, including fatigue, difficulty breathing, jaundice and dark urine. In severe disease, fever, chest pain, syncope or heart failure may occur. Hemolysis (the breakdown of red blood cells) occurs mainly in the spleen, so mild splenomegaly is relatively common.

Cause

AIHA caused by warm autoantibodies (w-AIHA), ie, antibodies that react with their antigens on the red blood cell optimally at 37°C, is the most common type, comprising ∼70% to 80% of all adult cases and ∼50% of pediatric cases.

Risk factors

• W-AIHA Secondary to another disease, such as an antecedent upper respiratory tract infection, systemic lupus erythematosus or a malignancy, such as chronic lymphocytic leukemia (CLL)

• Several medications have been associated with the development of warm AIHA. These medications include quinidine, nonsteroidal anti-inflammatory drugs (NSAIDs), alpha methyldopa, and antibiotics such as penicillins, cephalosporins (such as ceftriaxone and cefotetan), and ciprofloxacin.

Symptoms

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.

80%-99% of people have these symptoms

• Autoimmune hemolytic anemia
• Exertional dyspnea
• Fatigue(Tired)
• Headache(Headaches)
• Pallor

30%-79% of people have these symptoms

• Arthralgia(Joint pain)
• Lymphoproliferative disorder
• Splenomegaly(Increased spleen size)

5%-29% of people have these symptoms

• Abnormal urinary color(Abnormal urinary colour)
• Chronic lymphatic leukemia
• Congestive heart failure(Cardiac failure)
• Fever
• Jaundice(Yellow skin)
• Systemic lupus erythematosus
• Tachycardia(Fast heart rate)

Diagnosis

Diagnosis is made by a positive direct Coombs test, other lab tests, and clinical examination and history. The direct Coombs test looks for antibodies attached to the surface of red blood cells. Laboratory findings include severe anemia, normal MCV (means corpuscular value) , and [[]]hyperbilirubinemia (from increased red cell destruction) that can be of the conjugated or unconjugated type.

Treatment

Treatment typically involves a corticosteroid like prednisone. In cases that don't respond to treatment, splenectomy may be considered. Chronic and severe disease may be treated with Rituximab or immunosuppressive medications. If refractory to both these therapies, other options include danazol, cyclosphosphamide, azathioprine, or ciclosporin.

High-dose intravenous immune globulin may be effective in controlling hemolysis, but the benefit is short lived (1–4 weeks), and the therapy is very expensive.

NIH genetic and rare disease info

• NIH info on Warm antibody hemolytic anemia

Warm antibody hemolytic anemia is a rare disease.