Urinary neopterin might be a useful biomarker to distinguish pediatric multiple sclerosis (MS) from other inflammatory childhood demyelinating diseases such as neuromyelitis optica spectrum disorder (NMOSD), a new study published in Multiple Sclerosis and Related Disorders found.
This biomarker may also distinguish acute disseminated encephalomyelitis and myelin oligodendrocyte glycoprotein antibody-associated disorder. Differentiating between these diseases and achieving correct diagnoses has long been a problem for clinicians, leading to delayed diagnoses, sometimes for months, the authors said.
In previous studies on the central nervous system (CNS) autoimmune diseases, serum kynurenine-tryptophan pathway products and serum neopterin have been suggested as potential biomarkers, leading the authors to consider their potential usefulness in pediatric demyelinating diseases.
Read more about NMOSD differential diagnosis
“Because urine is a reliable and repeatable source for analysis of these products with the additional advantage of easy sampling, we measured neopterin concentrations in serum and urine samples, urinary biopterin and serum kynurenine-tryptophan levels in autoimmune demyelinating diseases,” the authors explained.
High-performance liquid chromatography was employed for serum analyses of neopterin, biopterin, and creatinine in urine and kynurenine and tryptophan, and enzyme-linked immunosorbent assay was used to determine serum neopterin.
The analyses revealed that urine neopterin levels were higher in all patient groups than in controls, and they were significantly higher in the pediatric MS group. Receiver operating characteristic analyses determined a cut-off point of urinary neopterin >167.75 μmol/mol creatinine, which distinguished the patients from controls with a sensitivity of 71% and specificity of 90%.
This study is the first to assess pteridine pathway products in urine and serum in children with demyelinating disease. The results highlight the need for further research to confirm the ability of these molecules to assist in the differential diagnosis of patients with pediatric MS from other demyelinating diseases of the CNS.
Kayaoglu M, Girgin G, Solmaz I et al. Urine neopterin in childhood acute demyelinating diseases: potential for differential diagnosis. Mult Scler Relat Disord. Published online February 4, 2022. doi:10.1016/j.msard.2022.103662