The effects of neopterin levels and the kynurenine pathway on inflammatory and neurodegeneration in Multiple sclerosis and Parkinson's disease

Inflammation and neurodegeneration are involved in the pathogenesis of two chronic neurological diseases of the central nervous system, multiple sclerosis and Parkinson's disease. In this study, which we conducted to evaluate the role of pteridine and kynurenine pathway in inflammation and neurodegeneration, three groups were formed among the patients who applied to the neurology clinic of Hacettepe University Faculty of Medicine, by obtaining consent from those who met the inclusion criteria for the study. Three groups of 37 multiple sclerosis, 29 Parkinson's patients and 21 controls were studied. The multiple sclerosis group is subdivided into primary progressive, secondary progressive, relapsing remitting and naive multiple sclerosis patients. The Parkinson group is divided into subgroups as idiopathic, GBA mutation and PARKN mutation. Neopterin in urine was evaluated by high pressure liquid chromatography technique, and neopterin, tryptophan, kynurenine, quinolinic acid and kynurenic acid levels in serum samples were evaluated by enzyme-mediated immunosorbent assay method. There was no significant difference between the groups in the metabolites examined. It has been observed that there is a significant correlation between the disease disability rate and the serum kynurenine/tryptophan ratio in multiple sclerosis disease, and this rate is directly proportional to the urinary neopterin level. In the multiple sclerosis group, a negative correlation was found between the rate of disease disability and the level of quinolinic acid. Among the parameters affecting the risk of Parkinson's disease, the ratio of kynurenine/tryptophan and neopterin were found to be significant. While it was shown that there was a significant correlation between hoehn yahr scale and tryptophan in the Parkinson group, a negative correlation was found between urinary neopterin level and age, and a positive correlation between serum kynurenic acid and quinolinic acid levels.