The study was designed to investigate IL-1 production from P388D1 cell using serum from 40 cases with IgA nephropathy (IgAN) as stimulative factor. It was found that there was a relationship between IL-1 and renal morphological change. The result indicated that IL-1 production by P388D1 cell was much higher in the presence of the serum than that in the absence (CPM: 47597 +/- 26213 vs 36567 +/- 14377 P less than 0.05). The level of IL-1 correlated obviously to the renal morphologic changes (r = 0.406, P less than 0.05). It is suggested that in the serum of IgAN patients there are certain factors stimulating P388D1 cell to produce IL-1, which may contribute to the pathogenesis of IgAN.