What should pediatrician know about selective IgA deficiency (update 2017)

Abstract

The article presents analysis of the current state of selective immunoglobulin A deficiency (SIgAD) from the point of view of the world’s leading experts, based on the results of epidemiological, genetic, molecular studies with high level of evidence. Selective IgA deficiency is the most common primary immunodeficiency and is characterized by an isolated deficiency of IgA, with usually normal levels of IgM and IgG in patients older than 4 years. Some IgG subclasses may be reduced in some patients with IgA deficiency. It is assumed that the overall incidence of selective IgA deficiency is 1 : 500–1 : 2000, but may be higher as most SIgADs have asymptomatic course, and there is no IgA deficiency screening program. IgA deficiency is facilitated by a complex network of genetic effects, namely IFIH1 loci on chromosome 2 and HLA-DQA1 on chromosome 6, with IgA-deficient-linked PVT1 (8 chromosomes), ATG13-AMBRA1 (11 chromosomes), AHI1 (6 chromosomes), and CLEC16A (16 chromosomes), including genes that are known to affect the physiology of IgA production. Most people with SIgAD are asymptomatic carriers, for some patients, pulmonary infections, allergies, autoimmune diseases, gastrointestinal diseases and malignant neoplasms are characteristic. Monitoring of patients with SIgAD consists of various methods, including education, the treatment of allergic or autoimmune diseases, the use of long courses or even the prophylactic use of antibiotics, the use of polyvalent pneumococcal vaccines and intravenous or subcutaneous substitution therapy with immunoglobulins. SIgAD prognosis mainly depends on the phenotype. There have been rare cases of spontaneous recovery, especially in young patients. Rarely, selective IgA deficiency may progress to the overall variable immunodeficiency. We consider it expedient to use the world experience in the diagnosis and treatment of selective IgA deficiency as the basis for patients’ monitoring in Ukraine.

Keywords

• selective IgA deficiency
• diagnosis
• prevention of complications