Circulating immune complexes, the concentration of serum IgA and the distribution of HLA antigens in IgA nephropathy.

A series of 40 IgA nephropathy patients is presented. IgA nephropathy was the most common (24%) type of glomerulonephritis in our renal biopsy material. Circulating immune complexes were measured by five methods that gave a positive result in 9-69% of the patients. The platelet aggregation test with heated serum (PAT2) was by far the most commonly positive. The serum concentrations of IgA were measured by two methods, radial immunodiffusion and laser nephelometry. Both tests gave similar results. 58% of the patients had elevated serum IgA. There was no statistically significant association between HLA antigens and IgA nephropathy as compared with the control material.