Eosinophil cationic protein in Henoch-Schönlein purpura and in IgA nephropathy.

In order to identify the relationship between eosinophil activation in Henoch-Schönlein purpura (HSP) and IgA nephropathy, serum eosinophil cationic protein (ECP) was analyzed in both conditions. The soluble interleukin-2 receptor (sIL-2R) was also analyzed. The levels of ECP were significantly higher in HSP patients (mean 9.7 +/- 1.8 microg/l) than in a control group (mean 4.6 +/- 0.7 microg/l). When the HSP patients were classified into two groups, one with normal urine and one with abnormal urine, the latter showed higher levels of ECP than the former. Levels of ECP were not significantly higher in IgA nephropathy patients than in a control group. The sIL-2R levels were elevated in the serum of HSP and IgA nephropathy patients compared with controls. In conclusion, eosinophil activation may be involved in the pathogenesis of HSP but not in IgA nephropathy.