title: IgA deficiency:  what is new?
abstract: OBJECTIVE
  To summarize recent publications on clinical and genetic aspects of IgA deficiency (IgAD).
  
  
  RESULTS
  Both major histocompatibility complex (MHC) and non-MHC genes contribute to susceptibility to the disease. The former genes appear to be located in different parts of the MHC region depending on the HLA haplotype. The latter show a marked overlap with genes associated with a variety of autoimmune disorders including Graves' disease, systemic lupus erythematosus, type 1 diabetes and celiac disease, suggesting common pathophysiological mechanisms. Various cytokines, recently shown to include interleukin 21, can induce IgA synthesis in vitro in cells from patients with IgAD, suggesting a regulatory basis of the disease.
  
  
  CONCLUSIONS
  IgAD is the most common primary immunodeficiency in the Western world with a prevalence of approximately 1 : 600 in the general population. It appears to be a polygenic disorder and several of the genes involved have recently been identified. The involvement of genes associated with autoimmunity may suggest that IgAD in itself is an autoimmune disease.
authors.affiliation: Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarström
mesh_terms: D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000627:therapeutic use; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D017098:IgA Deficiency / Q000235:genetics / Q000276:immunology* / Q000628:therapy*; D008285:Major Histocompatibility Complex / Q000235:genetics / Q000276:immunology
chemical_list: D016207:Cytokines