selective IgA deficiency
Jump to navigation
Jump to search
Etiology
- pharmaceutical agents reported to cause IgA deficiency
Epidemiology
- most common immunoglobulin deficiency
- found in approximately 1/600 healthy subjects
Pathology
- frequently associated with IgG subclass IgG2 & IgG4 deficiency (may be risk factor for severe infection)
- most patients have normal levels of circulating B-cells which fail to differentiate into plasma cells secreting IgA
- pulmonary disease is common & often severe
- infections are most frequently caused by encapsulated organisms
- decreased antibody response to carbohydrate antigens such as pneumococcal vaccine
- bronchiectasis & obstructive airway disease occur in 40% of patients
- patients may make IgE anti-IgA
Genetics
- associated with defects in TNFRSF13B (type2), also seen with common variable immunodeficiency
Clinical manifestations
- most patients are asymptomatic or minimally symptomatic
- recurrent sinopulmonary infections due to Streptococcus pneumoniae &/or Haemophilus influenzae
- diarrhea, malabsorption or gastrointestinal infections (giardiasis) may occur
- autoimmune disease may also occur[2]
- atopic dermatitis
- urticaria
- asthma
Laboratory
Complications
- greater prevalence of:
- anaphylactoid reactions have occurred when IgA-deficient patients are given blood transfusions or IgG preparations containing small amounts of IgA (IgE anti-IgA)
Management
- not an indication for intravenous immunoglobulin, except for patients who are also deficient in IgG2 or IgG4 (monitor closely)
- caution with blood transfusions
- fresh-frozen plasma is the main blood component containing IgA
- IgA-deficient donor may be option
- washing erythrocytes & platelets can decrease incidence of anaphylaxis[2][4]
- no specific measures except preventive measures against known complications
- as needed antibiotics for recurrent sinopulmonary infections[2]
- pneumococcal vaccination
More general terms
Additional terms
References
- ↑ Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 747
- ↑ 2.0 2.1 2.2 2.3 2.4 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2009, 2012, 2015, 2018, 2021.
Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022 - ↑ Yel L. Selective IgA deficiency. J Clin Immunol. 2010 Jan;30(1):10-6 PMID: https://www.ncbi.nlm.nih.gov/pubmed/20101521
- ↑ 4.0 4.1 Sandler SG. How I manage patients suspected of having had an IgA anaphylactic transfusion reaction. Transfusion. 2006 Jan;46(1):10-3. PMID: https://www.ncbi.nlm.nih.gov/pubmed/16398725
- ↑ Singh K, Chang C, Gershwin ME. IgA deficiency and autoimmunity. Autoimmun Rev. 2014 Feb;13(2):163-77. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/24157629