Prevalence of autoimmune hemolytic anemia in multiple myeloma: A prospective study

Autoimmune hemolytic anemia (AIHA) is frequently associated with B-cell lymphoproliferative disorders, and patients rarely develop overt clinical manifestations of AIHA. AIHA is rare in patients with multiple myeloma (MM). We conducted a prospective study to detect the presence of AIHA in MM patients and its impact on clinical presentation and outcome of the disease.

Sixty-six patients were diagnosed to have MM. Seventeen of these patients who had severe anemia (hemoglobin < 6 g/dL) requiring frequent blood transfusions with or without features of hemolysis were screened for AIHA by performing direct and indirect antiglobulin (Coombs') test.

Seven (10.6%) of these 17 patients were found to be complicated with AIHA and carried autoantibodies in their sera. Five patients had de novo MM and two had relapsed MM. Six patients (85.7%) had stage IIIA disease and one (14.3%) had stage IIIB disease. The IgG subclass of the antibody binding to red cell membrane was compared with that of M-protein and these findings showed full correlation in all the seven patients. All of these patients were positive for subtypes of IgG and one patient had simultaneous positivity for IgA and IgG2, with presence of cold antibodies in the serum. Patients with primary disease showed remission of AIHA with therapy, whereas both the patients with relapsed disease showed no response to treatment and remained positive for antiglobulin test.

AIHA should be suspected in MM patients with severe anemia requiring frequent blood transfusions.