Testing for IgA deficiency
Selective deficiency of immunoglobulin A (IgA) is the most common primary immunoglobulin deficiency. In IgA deficiency, the IgA concentration in plasma/serum is below the limit of determination of the test method. IgA deficiency is diagnosed only in about a half of those whose IgA concentration is below the limit of determination. The deficiency may involve the formation of anti-IgA antibodies. This finding has relevance for the safety of blood transfusions.
IgA deficiency testing is carried out in people whose IgA levels (P-IgA or S-IgA) have been below the limit of determination as tested in a hospital laboratory. The test package for IgA deficiency is described in the testing manual (in Finnish). The referral form can be found here.