Tissue factor/its pathway inhibitor system and kynurenines in chronic kidney disease patients on conservative treatment

Abstract

The abnormalities of tissue factor (TF) and its inhibitor (TFPI) system could potentially contribute to high incidence of thrombotic complications and atherosclerosis in patients with chronic kidney disease (CKD). Recently, the role of the kynurenine (KYN) pathway of tryptophan (TRP) degradation has been postulated in the progression of cardiovascular complications. We compared the plasma TF, TFPI and the metabolites of TRP degradation: KYN and 3-hydroxykynurenine (3-HKYN) levels in 55 CKD patients on conservative treatment and 19 healthy controls; and we tried to establish whether or not there is an association between TF/TFPI system and above-mentioned metabolites in these patients. Compared with the controls, the patients with CKD showed a significant increase in plasma concentrations of TF (P < 0.01), KYN, 3-HKYN (both P < 0.0001), KYN-to-TRP (kyn/trp) ratio (P < 0.001) and 3-HKYN-to-KYN (3-hkyn/kyn) ratio (P < 0.05). In contrast, TRP concentrations were significantly decreased in the CKD group compared with controls (P < 0.001). The difference in TFPI levels between CKD patients and controls was not statistically significant. TF/TFPI system was inversely correlated with TRP, whereas it was positively related to the 3-HKYN, kyn/trp and 3-hkyn/kyn ratios. Moreover, both the TF/TFPI system and KYNs were associated with the markers of kidney function. These data suggested for the first time a significant relationship between TF/TFPI system and KYN pathway in CKD patients on conservative treatment.