Prevalence of IgAl deposits in Henoch-Schoenlein purpura (HSP) nephritis.

A study on the detection of IgA1, IgA2 and the J("joining") chain in glomeruli from renal biopsy specimens in patients with Henoch-Schoenlein purpura (HSP) nephritis is described. Renal biopsy specimens from five patients with HSP nephritis were stained with FITC-labelled anti-human IgA1, IgA2 and J chain, and then examined with a fluorescent microscope. IgA1 was detected in glomeruli from all patients with HSP nephritis examined in this study. IgA2 was not observed in any patients. These findings were similar to those for IgA nephropathy reported previously. Histopathological findings of glomeruli in HSP nephritis were almost identical to those in IgA nephropathy. The levels of serum IgA in patients with HSP nephritis increased as observed in IgA nephropathy. It is suggested that there are some immunopathological similarities between HSP nephritis and IgA nephropathy.