Tryptophan degradation and neopterin levels in treated rheumatoid arthritis patients

Abstract

Increased kynurenine/tryptophan-reflects trytophan degradation-and neopterin levels have been regarded as a biochemical marker of cell-mediated immune response and inflammation. This study was designed to evaluate the usefulness of tryptophan degradation and neopterin levels in active rheumatoid arthritis patients under therapy. In this case-control study, kynurenine and tryptophan levels were determined by HPLC; neopterin and tumor necrosis factor-α levels were measured with ELISA in 32 active rheumatoid arthritis patients and 20 healthy controls. Although mean values of tryptophan, kynurenine, ratio of kynurenine to tryptophan, neopterin, and tumor necrosis factor-α levels did not show statistically significant differences between patient and control groups, neopterin levels correlated positively with kynurenine (r = 0.582, p < 0.02), kynurenine/tryptophan (r = 0.486, p < 0.05), erythrocyte sedimentation rate (r = 0.472, p < 0.05) and RF (r = 0.478, p < 0.05) in the rheumatoid arthritis group. CRP levels of the patient group correlated with kynurenine levels (r = 0.524, p < 0.03). Determination of tryptophan degradation and neopterin levels in chronic inflammatory disease may provide a better understanding of progression of the disease.

Circulating Biomarkers of Tryptophan and the Kynurenine Pathway and Lung Cancer Risk

“…This suggests adequate preanalytical samples handling because hydroxylated kynurenines are degraded in serum and plasma at room temperature or during prolonged storage at À25 C (30,32). KTR showed positive associations with age and BMI as previously shown (33)(34)(35)(36)(37), and with neopterin, which can be explained by the fact that both neopterin and IDO are stimulated by INF-g (38)(39)(40). Both KTR and neopterin were negatively associated with PLP, which is in accordance with multiple observations of inflammation or immune activation in subject with low PLP status (41).…”

Relationship Between Leptin and Neopterin Levels and Disease Activation Parameters in Patients With Rheumatoid Arthritis

“…Ozkan et al 38 detected a correlation between neopterin, ESR, and RF in patients with RA; while we detected no correlation between these parameters in our RA patients.…”

“…Increased neopterin concentrations have been demonstrated in infection, autoimmune diseases, cancer, renal failure, coronary artery disease, and allograft rejections. [32][33][34][35][36][37] Similar to results obtained by Ozkan et al, 38 we found no difference between serum neopterin concentrations of patients with RA and healthy controls in our study. However, Schroecksnadel et al 28 and D'agostino et al 39 showed higher levels of neopterin levels in patients with RA when compared with those of the controls.…”

Association of neopterin as a marker of immune system activation and juvenile rheumatoid arthritis activity

“…The results of this study were in agreement with that in the current study. In 2012, Ozkan et al 18 evaluated the usefulness of tryptophan degradation and neopterin levels in active rheumatoid arthritis patients under therapy. They found that neopterin levels correlated positively with kynurenine (r = 0.582, p < 0.02), kynurenine/tryptophan (r = 0.486, p < 0.05), erythrocyte sedimentation rate (r = 0.472, p < 0.05), and RF (r = 0.478, p < 0.05) in a group of rheumatoid arthritis patients, which are in concordance with the results of the present study.…”