PURPOSE: It is not clear that the development of glomerular injury and aggravation by tumor necrosis factor alpha (TNF-alpha) is related to intrarenal or serum concentration of TNF-alpha. So, we studied the relationship between the concentration of TNF-alpha and aggravation of glomerular damage in the Henoch-Schonlein nephritis(HSN) and idiopathic nephrotic syndrome(INS). METHODS: We collected the sera and urines of 21 patients with Henoch-Schonlein purpura(HSP) and 22 patients with INS visited Chungbuk National University hospital from March 1998 to March 2001. The concentration of TNF-alpha in the sera and urines were measured by sandwich ELISA. RESULTS: Serum TNF-alpha levels in the HSP patients with renal involvement were significantly higher than those without renal involvement(P=0.009). But urine TNF-alpha levels have no correlation with renal involvement(P=0.088). In the HSN patients, proteinuria have a significant correlation with serum TNF-alpha levels(P=0.004) but less correlation with urine TNF-alpha levels(P=0.053). Otherwise, proteinuria have no correlation with serum TNF-alpha levels(P=0.763) but have a significant correlation with urine TNF-alpha levels(P=0.007) in INS. CONCLUSION: These result suggest that the serum concentration of TNF-alpha would be important to glomerular involvement in HSP. And, it is interesting that proteinuria shows a significant relation with serum TNF-alpha levels in the HSN, but with urine TNF-alpha levels in the INS. This means the major production of TNF-alpha may be originated by extrarenal inflammation in the HSN and by intrarenal tubulo-interstitial damage due to proteinuria in the INS.