PMID: 15387763Jan 1, 1997Paper

Direct Coombs test-negative autoimmune hemolytic anemia and low-affinity IgG class antibodies

Immunohematology
R J SokolB Paul

Abstract

Autoimmune hemolytic anemia, in which the direct antiglobulin test (DAT) is negative or weakly positive, may be due to low-affinity autoantibodies. We describe two such cases. An 8-year-old male presented with weight loss, jaundice, a hemoglobin of 33 g/L, reticulocytes of 306 x 10(9)/L, and haptoglobin of < 0.1 g/L. The DAT was negative. After washing the red blood cells (RBCs) with saline at 4 degrees C, the DAT was positive for IgG and an eluate contained an IgG3 autoantibody, thus confirming a diagnosis of autoimmune hemolytic anemia (AIHA). Red cell transfusions and corticosteroids were given with eventual complete recovery. A 73-year-old male had a hemoglobin of 89 g/L and haptoglobin of < 0.1 g/L. The DAT was initially negative but was positive for IgG using cold-washed (4 degrees C) RBCs; it was also positive with unwashed cells in the DiaMed system and an eluate contained IgG1 autoantibody. AIHA was therefore confirmed and prednisolone started but continued hemolysis necessitated splenectomy before full recovery occurred. Although RBCs may be strongly sensitized with low-affinity autoantibodies in vivo, the IgG is easily removed when RBCs are washed at room temperature for a DAT. The DiaMed system that uses unwashed RB...Continue Reading

Related Feeds

Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) occurs when antibodies directed against the person's own red blood cells (RBCs) cause them to burst (lyse), leading to an insufficient number of oxygen-carrying red blood cells in the circulation. Discover the latest research on AIHA here.