Serum LncRNA XIST and miR-133b as non-invasive biomarkers for diagnosis and progression of Parkinson’s disease

Long non-coding RNA XIST (LncRNA XIST) and microRNA-133b (miR-133b) have been implicated in Parkinson's disease (PD)-related pathophysiology and may serve as potential circulating biomarkers. The aim of this study was to study the serum expression levels of LncRNA XIST and miR-133b in PD patients and healthy controls, assess their correlation with disease severity, and evaluate their diagnostic value. Peripheral blood was obtained from 63 patients with PD and 21 healthy controls. Serum RNA was extracted, and the expression of LncRNA XIST and miR-133b was measured. PD severity was determined through standardized neurological evaluation, incorporating the Unified Parkinson's Disease Rating Scale (UPDRS) for symptom burden and the Hoehn and Yahr (H&Y) scale for disease staging. Serum LncRNA XIST levels were significantly higher in PD patients compared with controls, whereas miR-133b levels were significantly lower. LncRNA XIST positively correlated with UPDRS total score (<i>r</i> = .279, <i>p</i> = .027) and H&Y stage (<i>r</i> = .926, <i>p</i> < .001), while miR-133b showed a strong negative correlation with H&Y stage (<i>r</i> = -.957, <i>p</i> < .001). Receiver operating characteristic analysis revealed that LncRNA XIST had an area under the curve (AUC) of 0.824, miR-133b had an AUC of 0.787, and the combined model yielded an AUC of 0.807. The combined model performed better than miR-133b alone but slightly lower than LncRNA XIST alone. Serum LncRNA XIST and miR-133b are significantly altered in PD and strongly associated with disease stage. Both biomarkers demonstrate good diagnostic performance, and their combined use may provide complementary information for PD diagnosis and monitoring.