Neopterin and kynurenine in mesangioproliferative glomerulonephritis

Serum kynurenine and neopterin concentrations were determined in patients with chronic mesangioproliferative glomerulonephritis with normal renal function and in patients with chronic renal failure. Significantly increased kynurenine and neopterin levels have been observed in 28% of mesangioproliferative glomerulonephritis patients. In vitro, interferon-χ induces the formation of neopterin in human monocytes/macrophages. Also the degradation of tryptophan via the kynurenine pathway is induced by interferon-χ. Our data show increased kynurenine and neopterin concentrations in serum in the case of mesangioproliferative glomerulonephritis. There was a positive correlation between serum kynurenine and neopterin levels. The same association between kynurenine and neopterin have been found in patients with chronic renal failure. At the end stage of renal disease, elevated levels of kynurenine and neopterin corresponded to the decrease of renal functions. In 59% of patients with mesangioproliferative glomerulonephritis, we detected also pyridoxal-5- phosphate deficiency concomitant with the increase of serum concentration of kynurenine. L-tryptophan peroral loading test could be useful for differentiation the both causes of hyperkynureninemia.