A potential of serum anti-C1P IgG antibodies as biomarkers in differential diagnosis of relapsing-remitting multiple sclerosis.

There is a growing interest in the role of sphingolipids in the background of multiple sclerosis (MS). The goal of this study was to evaluate the serum levels of antibodies against ceramide-1-phosphate (C1P) subclasses and their relationships with clinical status in MS. The study groups comprised 39 patients with relapsing-remitting MS (RRMS), 26 patients with other neurological diseases (OND) and 12 healthy subjects (HS). Anti-C1P IgG levels in serum were determined using ELISA test. Levels of anti-C18:0-C1P and anti-C24:1-C1P IgG were significantly increased (p = 0.003; p < 0.0001, respectively) in RRMS compared to HS, while anti-C16:0-C1P and anti-C24:0-C1P IgG – significantly lower p < 0.0001 in RRMS compared to OND, with large effect size (r ≥ 0.5) in all above cases. In both settings the acceptable discriminatory performance for RRMS subtype from HS (AUC = 78.1%, 95% CI 66.1–90.4 and AUC = 76.9%, 95% CI 60.3–93.6, respectively) as well as from OND (AUC = 79.8%, 95% CI 68.2–91.4 and AUC = 94.2%, 95% CI 88.6–99.8, accordingly) by receiver operating curve (ROC) was shown. Validation of ROC by cluster analysis confirmed the ability of these anti-C1P IgG panels to discriminate between the study groups. No relationships were found between levels of antibodies in the anti-C1P IgG panel in RRMS group and disease duration, degree of disability or Link index. These findings highlight the relevant role of C1P as a target and/or mediator of autoimmune response in MS and potential value of anti-C1P antibodies as biomarkers in differential diagnosis of this disease.