Peripheral blood inflammatory cell ratios derived from complete blood count as predictors of multiple sclerosis disease activity and severity

Multiple Sclerosis (MS) is an autoimmune disorder that affects the central nervous system causing different types of disability. Complete blood count (CBC) parameters are considered as markers of systemic inflammation and were linked to many diseases as predictors of prognosis. This study aimed at evaluating the role of Neutrophil, Monocyte and Platelet-to-Lymphocyte Ratios in predicting MS severity and activity. This was a retrospective cohort study, performed through medical records analysis of 98 MS patients attended the hospital during 2025 for follow up. Disease activity and severity were estimated. The baseline CBC that performed shortly after MS diagnosis and prior to initiating disease modifying therapy was analyzed. High Neutrophil-Lymphocyte ratio (NLR) exhibited the strongest predictive value for both disease activity and severity, as confirmed by binary regression. A NLR cutoff of >2.681 yielded excellent sensitivity (97.6%) and specificity (85.7%) for predicting severe disease. High Monocyte-Lymphocyte ratio (MLR) also showed meaningful associations with disease severity and activity, although its predictive value was less pronounced. High Platelet-Lymphocyte ratio (PLR) was found to be predictive of high disease activity but not of disease severity, suggesting a more limited role compared to NLR. In conclusion, NLR is a strong and readily available biomarker for predicting clinical activity and severity of MS, outperforming MLR and PLR. These simple inflammatory indices may aid early risk stratification and clinical decisions in MS cases.