Search

Background: It has been widely reported that the key biomarkers of homocysteine metabolic pathways have emerged as markers or independent risk factors for cardiovascular disease and many other diseases. To improve the accuracy of evaluation in China, we establish the reference intervals of serum homocysteine (Hcy), cysteine (Cys), and methionine (Met) in apparently healthy Chinese adults., Methods: We examined 1553 subjects aged ≥20 years who underwent Hcy metabolic pathway tests, in the Chaoyang Central Hospital between January 2019 and December 2020. The serum Hcy, Cys, and Met levels were simultaneously determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Multiple regression analysis was performed to identify sources of variation. A nonparametric method was used to establish the reference intervals., Results: Gender differences were observed in Hcy and Met, with higher levels in males. Reference intervals for males were 6.09-17.00 μmol/L (Hcy) and 19.31-33.68 μmol/L (Met); conversely, the reference intervals for females were 4.61-14.61 μmol/L (Hcy) and 16.16-30.35 μmol/L (Met). The serum Cys reference intervals were seen to be gender-independent, but age-dependent reference intervals were needed; those for Cys were 188.85-334.27 μmol/L, 200.48-340.66 μmol/L, and 216.03-349.67 μmol/L in <40, 40-50, and ≥50 years, respectively., Conclusions: By this study, the gender- or age-specific reference intervals of Hcy, Cys, and Met that were matched with the Chinese population were established, providing valuable references for clinical work and laboratory researches.

Schizophrenia is a debilitating psychiatric disorder affecting approximately 1% of the population worldwide. Disturbances in the homocysteine metabolism are an important factor in the pathophysiology of schizophrenia. In this research, a novel validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) quantification procedure was developed to investigate three significant compounds of homocysteine metabolism: homocysteine, cysteine, and methionine in patients with schizophrenia and healthy controls. Sample preparation involved a reduction with dithiothreitol followed by protein precipitation, and the chromatographic runtime was 2 min. The LC–MS/MS method was validated according to CLSI C62‐A and the Chinese Guidance for Liquid Chromatography and Mass Spectrometry Clinical Application. The performance of the method was excellent with a coefficient of variation for precision in the range of 0.5–6.9%, an accuracy of 90.4–101.6%. In addition, the practical applicability of the method was demonstrated by applying it in the routine sample analysis for a schizophrenic patient. Increased homocysteine levels and decreased cysteine levels were observed in the patient with schizophrenia. These results indicate that the activity of the transsulfuration pathway may play a key role in the pathogenesis of schizophrenia. [ABSTRACT FROM AUTHOR]