RESEARCH SUMMARY

Study Points to Renal Dysfunction as a Potential Risk Factor for Relapse, Biomarker in Patients With NMOSD

Anthony Calabro, MA

In a retrospective cohort study, researchers found that renal dysfunction, specifically high glomerular filtration rate (eGFR) and damaged urine concentration, are risk factors for relapse in patients with their first onset of aquaporin-4 (AQP4)-immunoglobulin G (IgG)-seropositive neuromyelitis optica spectrum disorder (NMOSD). The researchers also determined that renal dysfunction could be used as a biomarker to differentiate between NMOSD and multiple sclerosis (MS), a notable finding considering the similar characteristics between the two disorders.

Researchers included patients with AQP4-IgG-seropositive NMOSD (n = 135) and MS (n = 128) between February 2016 and May 2020, and the median follow-up time was 3.1 years. Researchers also recruited 136 healthy controls (HCs). For patients with AQP4-IgG-seropositive NMOSD, the mean onset age was 39.1 years, and 80% of the patients with NMOSD were women.

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The results indicated that eGFR was higher in patients with AQP4-IgG-seropositive NMOSD compared with patients with MS (p < 0.001) and HCs (p < 0.001). Additionally, urine pH in AQP4-IgG-seropositive NMOSD group was higher than both the MS and HC groups (p < 0.001).

Regarding differentiating between NMOSD and MS, a ROC curve analysis by the researchers found that eGFR, serum cystatin C, urinary β2-microglobulin, urine specific gravity, serum creatinine, urine pH, and serum urea could potentially distinguish AQP4-IgG-seropositive NMOSD from MS.

This study had limitations. The researchers noted that a longer follow-up time is needed to avoid misclassification bias, considering that kidney function changes with time. Additionally, the researchers did not have any patient information on lifestyle, BMI, or muscle mass.

“Our findings provide a novel independent predictor for prognosis and may improve current predictive systems for screening and monitoring for relapse in patients with AQP4-IgG-seropositive NMOSD,” the authors concluded.

 

Reference:
Chen Y, Wang Y, Jin R, et al. Renal dysfunction in AQP4 NMOSD and MS; a potential predictor of relapse and prognosis. Clin Immunol. 2024;259:109875. doi:10.1016/j.clim.2023.109875