occurs in 1 in 400 to 1 in 18,500 depending upon ethnic population
it is a heterogeneous disorder and may be partial or total deficiency
it has a similar gene defects as does CVID, selective IgG subclass deficiencies, and the syndrome of recurrent sinopulmonary infections with normal serum immunoglobulin such as:
mutation in the tumor necrosis factor receptor family member TACI (transmembrane activator and calcium-modulator and cyclophilin ligand interactor) - TACI facilitate isotype switching in B cells
function-loss mutations in several non–major histocompatibility complex (MHC) genes
~20% of patients have a family history of either SIGAD or CVID
variable genetics, but may also be acquired from infections or drugs although in these cases tends to be reversible
drugs which may cause reversible IgA deficiency include phenytoin, carbamazepine, valproic acid, zonisamide, sulfasalazine, gold compounds, D-penicillamine, hydroxychloroquine, NSAIDs, captopril, and thyroxine
cyclosporin A has been reported to cause permanent IgA deficiency
these patients have B cells but they have been developmentally arrested and lack the ability to differentiate into IgA-secreting plasma cells may be caused by the deficiency of cytokines, such as interleukins IL-4, IL-6, IL-7, and IL-10
usually asymptomatic
may cause:
as 10-44% have anti-IgA antibodies, rarely, severe allergic reactions to blood transfusions may occur as these contain IgA
occurs in ~2% of patients with
coeliac disease while celiac disease occurs in 10-30% of these patients
the condition may result in failed diagnosis of celiac disease as the high levels of certain IgA antibodies usually seen in celiac disease do not occur
may be associated with increased risk of cancers such as:
may be associated with deficiencies in antipneumococcal antibodies
IgG2 and IgG4 subclass deficiencies are often found in persons who are more severely affected
may progress to CVID
-