What are autoimmune problems associated with selective IgA deficiency?
• Systemic autoimmune disorders (SLE, SLE-spectrum of disease [undifferentiated connective tissue disease], RA, juvenile idiopathic arthritis, Sjogren’s, dermatomyositis, vasculitis, etc.) occur in 7% to 36% of patients (four times increased risk).
• Organ-specific autoimmune disorders (diabetes mellitus type I, myasthenia gravis, psoriatic arthritis, inflammatory bowel disease, autoimmune cytopenias, autoimmune endocrinopathies, autoimmune hepatitis, etc.).
IgA deficiency is the most common immunodeficiency with a prevalence of 1/333 to 1/700 in Caucasians. Of these, 20% are familial. It is characterized by absent (<5 mg/dL) levels of serum and secretory IgA, accompanied by normal levels of serum IgG and IgM. Cell-mediated immunity is intact. It is usually asymptomatic, and there are no specific treatments for IgA deficiency, other than to avoid IgA-containing blood products or medications. It may be useful in raising clinical suspicion for one of the autoimmune diseases earlier.