[IgA nephropathy--IgA1 disease].

The aim of this study was to prove the increased IgA1 production in patients with IgA nephropathy compared to the control group of healthy subjects, by determination of serum subclasses IgA, IgA1 and IgA2 levels. That with the exclusive presence of IgA1 in kidney tissue, justified the assertion that IgAN was IgA1 disease. Eighteen patients with IgA nephropathy, 15 male and 3 female, average age 17-54 (mean +/- SD = 34.1 +/- 5.18) were included in the prospective study. The diagnosis was proved by immunofluorescent assay of bioptic kidney material obtained by ultrasonically guided biopsy. The total serum IgA and IgA1 and IgA2 subclasses levels were determined in the patients and healthy conscripts from the control group. The methods of immunonephelometry and radial immunodiffusion were used. Increased IgA values were found in 22.75% and of IgA1 subclass in 38.85% patients. Patients with IgA nephropathy had significantly higher IgA1 values (p < 0.01), compared to the control group. There was no significant difference in IgA2 subclass levels. Renal function did not significantly affect IgA1 and IgA2 subclasses values.