Inflammation is thought to be involved in the pathogenesis of autism spectrum disorder (ASD). Pteridine metabolites are biomarkers of inflammation that increase on immune system activation. In this study, we investigated the urinary pteridine metabolites in ASD patients as a possible biomarker for immune activation and inflammation. This observational, cross-sectional, prospective study collected urine samples from 212 patients with ASD and 68 age- and sex-matched healthy individuals. Urine neopterin (NE) and biopterin (BIO) levels were measured. Patients who had chronic disorders, active infection at the time of sampling, or high C-reactive protein levels were excluded. The urine NE and BIO concentrations were determined by high-performance liquid chromatography. The ratios of both NE and BIO to creatinine (CRE) were used to standardise the measurements. The NE/CRE and NE/BIO levels were significantly higher in ASD patients than controls. Univariate and multivariate models revealed a significant increase in NE/CRE and NE/BIO in ASD patients. There was a significant relationship between the NE/BIO [average area under the curve (AUC) = 0.717; range: 0.637–0.797] and NE/CRE (average AUC = 0.756; range: 0.684–0.828) ratios, which distinguished individuals with ASD from controls. The elevated NE/CRE and NE/BIO ratios suggest that inflammation and T cell-mediated immunity are involved in the pathophysiology of autism. NE/BIO could serve as a diagnostic inflammatory marker in the pathogenesis of ASD.

炎症被认为与自闭症谱系障碍（ASD）的发病机制有关。蝶啶代谢物是炎症的生物标志物，随着免疫系统的激活而增加。在这项研究中，我们研究了 ASD 患者的尿液蝶啶代谢物，作为免疫激活和炎症的可能生物标志物。这项观察性、横断面、前瞻性研究收集了 212 名 ASD 患者和 68 名年龄和性别匹配的健康个体的尿液样本。测量尿液新蝶呤（NE）和生物蝶呤（BIO）水平。患有慢性疾病、采样时活动性感染或 C 反应蛋白水平较高的患者被排除在外。采用高效液相色谱法测定尿液中NE和BIO浓度。NE 和 BIO 与肌酐 (CRE) 的比率用于标准化测量。ASD 患者的 NE/CRE 和 NE/BIO 水平显着高于对照组。单变量和多变量模型显示 ASD 患者的 NE/CRE 和 NE/BIO 显着增加。NE/BIO[平均曲线下面积（AUC）=0.717；范围：0.637–0.797] 和 NE/CRE（平均 AUC = 0.756；范围：0.684–0.828）比率，可将 ASD 个体与对照组区分开来。NE/CRE 和 NE/BIO 比率升高表明炎症和 T 细胞介导的免疫与自闭症的病理生理学有关。NE/BIO 可以作为 ASD 发病机制中的诊断炎症标志物。