[Selective IgA deficiency in patients with systemic lupus erythematosus and rheumatoid arthritis].

In this study, antinuclear antibody (ANA), rheumatoid factor (RF) studied and IgA was determined with single radial immunodiffusion (RID) technic in the sera of 96 patients with systemic lupus erythematosus, 25 with rheumatoid arthritis and 100 normal individuals. In normal control group, the average level of IgA was found to be 212 mg/dl. In one patient (1: 100), IgA deficiency was detected with a level of 2.1 mg/dl, the average level of IgA in 96 patients with SLE was 320 +/- 16.25 mg/dl. In 3 patients of this group IgA deficiency was observed. According to this finding, the prevalence of IgA deficiency in the group of SLE ise 1: 32. This prevalence is higher than that of the normal population. The average level of IgA in 25 patients with RA 302.66 +/- 36.57 mg/dl. In this group we observed IgA deficiency only in one patient which means a prevalence of 1: 25, that is higher than the normal group. Reports indicate that the incidence of IgA deficiency in general populations may vary from 1: 400 up to 1: 3080. But in patients with SLE and RA, this may be encountered more frequently as we observed in our cases.