ABSTRACT
BACKGROUND: Selective Immunoglobulin M Deficiency (SIgMD) is known as a rare primary immunodeficiency characterized by an isolated deficiency of serum IgM. Other immunoglobulin levels and T-cell immunity are usually normal; although IgE may be elevated. SIgMD can be asymptomatic or with various bacterial and viral infections. It can also be associated with autoimmune diseases or malignancies. In the present study, we report for the first time, the prevalence of SIgMD in Iranian healthy adult population. MATERIALS AND METHODS: A total of 3436 healthy donors were examined in the study; from August, 2006 to April, 2008. Serum IgM concentration was measured using the nephelometric method. We considered serum IgM less than 30 mg/dl as IgM deficiency. RESULTS: Among 3436 participants, 65% were male and 34% were female; aging from 17 to 72 years (38.18±10.78). Thirteen individuals were detected as IgM deficient subjects with the male to female ratio of 11/2, the prevalence of 0.37% and the frequency of 1/265. The mean serum IgM level was 24±4.56 (16-29 mg/dl) in these cases. Among 13 IgM-deficient subjects, 7 cases were available for evaluating the clinical manifestations. In addition to atopic dermatitis which was the most common symptom in these patients, others were allergic rhinitis, food allergy, urinary tract infection and skin fungal infection. Two patients had no history of infectious disease or atopic conditions. CONCLUSION: In the present study we could determine the prevalence of SIgMD in our adult population (0.37%). The most common comorbid condition was atopy. Neither severe or life-threatening infections, nor autoimmune diseases (based on their history; the antibody screening was not performed as part of this study) or malignancies were found in these patients. Further evaluation is recommended to elucidate the prevalence of SIgMD among patients with recurrent infections.
