Selective iga deficiency

[Agnes]

Selective IgA deficiency is an IgA level lt; 7 mg/dL (lt; 70 mg/L) with normal IgG and IgM levels. It is the most common primary immunodeficiency. Many patients are asymptomatic, but some develop recurrent infections and autoimmune disorders. Some patients develop common variable immunodeficiency over time, and some remit spontaneously. Diagnosis is by measuring serum immunoglobulins. Treatment is antibiotics as needed (sometimes prophylactically) and usually avoidance of blood products that contain IgA.
(See also Overview of Immunodeficiency Disorders and Approach to the Patient With an Immunodeficiency Disorder.)
IgA deficiency involves B cell defects. Prevalence ranges from 1/100 to 1/1000.
The inheritance pattern is unknown, but having a family member with selective IgA deficiency increases the risk by about 50 times.
Some patients have mutations in the TACI (transmembrane activator and calcium-modulator and cyclophilin ligand interactor) gene. Selective IgA deficiency also commonly occurs in patients with certain HLA haplotypes; rare alleles or deletions of genes in the major histocompatibility complex (MHC) class III region are common.
Drugs such as phenytoin , sulfasalazine , gold, and D-penicillamine may lead to IgA deficiency in some patients.