Kynurenine and neopterin in chronic glomerulonephritis.

The results of our clinical observations of 102 patients with chronic glomerulonephritis with normal renal function have shown that hyperkynureninemia in 22.5% of patients develops in cases of pyridoxal-5-phosphate deficiency (hyperkynureninemia after peroral L-tryptophan load), but in 14.8% of patients through the stimulation of the cellular immune system (hyperkynureninemia at fasting state, increase of serum neopterin concentration). In all 20 patients with chronic renal failure hyperkynureninemia develops due to decreased renal function (increased serum kynurenine, neopterin and creatinine concentrations). Therefore, L-tryptophan peroral loading test with the determination of serum concentration of kynurenine before and at 3rd hour after the load, as well as the detection of serum concentration of neopterin and creatinine are helpful for the differentiation of following pathologies in patients with chronic glomerulonephritis: pyridoxal-5-phosphate deficiency, cellular immune stimulation and chronic renal failure.