Diagnostic Value of Serum Humanin-Like 3 Levels in Multiple Sclerosis Patients with Predominant Optic Nerve and Spinal Cord Involvement: A Preliminary Study.

Introduction: Our aim was to determine whether serum levels of humanin-like 3 (encoded by the MTRNR2L3 gene) may serve as a diagnostic biomarker for differentiation of NMOSD from relapsing remitting multiple sclerosis (RRMS) presenting with clinical features reminiscent of NMOSD. Methods: Humanin-like 3 levels were measured by ELISA in sera of 30 RRMS patients, 10 NMOSD patients, 15 RRMS patients presenting predominantly with spinal cord and optic nerve attacks (MS-SCON) and 23 healthy controls. Results: MS-SCON patients showed significantly higher humanin-like 3 levels than other groups. Receiver operating characteristic (ROC) curve analysis showed that 5.26 ng/ml cut-off value of humanin-like 3 level discriminated MS-SCON from NMOSD by 66.7% sensitivity and 90% specificity. Humanin-like 3 levels did not correlate with demographic and clinical variables of MS and NMOSD. Conclusion: Serum humanin-like 3 level might potentially be used as a biomarker in differential diagnosis of MS patients presenting with NMOSD-like features. Elevated humanin-like 3 levels of MS-SCON patients might be an indicator of increased stress on neuronal survival in this MS subgroup.