Selective IgM deficiency (sIgMD) is classified under primary humoral immunodeficiencies and characterized by low serum IgM (<2SD for age), normal IgG-IgA levels. Our aim was to define immunologic and clinical features of sIgMD.
We assessed a retrospective medical record of patients who admitted to Pediatric Immunology department. Patients who repeatedly (at least twice in a 6-month period) fulfilled the definition of sIgMD were enrolled into the study.
Out of fifty five patients, thirteen patients were diagnosed as PID during the follow-up. Most of the patients presented with infection. Seventeen patients (40%) have no additional disorder or disease.Seven patients (16%) had allergic disorders. Six patients (14%) had chromosomal anomaly or syndrome (22q11.2 deletion (n=3), trisomy 21 (n=2), 1p deletion, CHARGE syndrome, Cohen Syndrome). Six patients (14%) have autoimmune/inflammatory diseases, such Sjogren‘s syndrome, Behcet’s disease, immune thrombocytopenic purpura, Crohn disease, Guillain Barre syndrome, diabetes mellitus. Three patients (7%) have developed malignancy (myeloid cell leukemia (n=2), tubular adenoma (n=1)). Thirteen patients, who developed PID,were diagnosed as combined immunodeficiency (CID) (n=6), common variable immunodeficiency (n=2), autoimmune lymphoproliferative syndrome (n=2), chronic granulomatous disease (n=1), adenosine deaminase deficiency (n=1), congenital neutropenia (n=1).
The ratio of sIgMD is found as %0.15 in our immunology out-patient clinic. SIgMD could be asymptomatic. However genetic disorders, allergic and autoimmune/inflammatory diseases may accompany. We observed that some patients get diagnosis of PID during follow-up period and most of the diagnosis were CID. Thus, patients with sIgMD should be followed regularly in immunology clinics.