Clinical and serological characterization of autoimmune hemolytic anemia in a tertiary care hospital in North India

Clinical and serological characterization of autoimmune hemolytic anemia (AIHA) helps in the diagnosis, management, and monitoring course of disease. In the present study, we serologically characterized the red-cell-bound autoantibodies in diagnosed AIHA patients with regards to antibody class, subclass, direct antiglobulin test (DAT) strength, and their correlation with in vivo hemolysis. A total of 157 samples were evaluated for DAT. Clinically and serologically, 43 of them were diagnosed as AIHA. Detailed serological characterization of autoantibodies was performed in these 43 patients using the gel technology. Hematological and biochemical parameters were obtained from the Hospital Information System. Polyspecific (immunoglobulin G (IgG)+C3) DAT-positive samples were tested for monospecific DAT (IgG, IgM, IgA, C3c, and C3d) and IgG subclass (IgG1 and IgG3). Thermal amplitude of autoantibodies was determined on eluates. Median age of the patients was 31 years (range, 12-70 years) with male to female ratio of 1:3.3. In 55.8% of patients, AIHA was secondary to an underlying disorder. Patients with strong reactive DAT had increased likelihood of hemolysis (p=0.000). IgG was the solitary autoantibody coating the red cells in 72.1% of patients. Red cells coated with multiple immunoglobulins/complements and IgG subclass IgG1 and/or IgG3 were more susceptible to undergo hemolysis. Gel technology helps the immunohematologist to diagnose and serologically characterize AIHA patient with regard to red-cell-bound autoantibodies' class, subclass, and titer as these correlate with in vivo hemolysis