SIGNIFICANCE OF IGA ANTIPHOSPHOLIPID ANTIBODIES

IgA anticardiolipin (IgA aCL) and IgA anti beta(2)-glycoprotein-I(IgA anti beta(2)GP1) antibodies are common in SLE and have been associated in some studies with thromboses and thrombocytopenia. Experimental wo rk suggests that IgA aCL are as prothrombotic as the IgG-IgM isotypes. However, in SLE there appears to be less concordance between IgA aCl and IgA anti beta(2)GP1 as compared with the concordance between IgG a nd IgM isotypes, suggesting significant differences in their origins a nd specificities. For example, there may be a greater mucosal contribu tion to production of IgA anti beta(2)GP1 than IgA aCL. Infections may have a greater role in the presence of IgA aCL than IgA anti beta(2)G P1 antibodies.