High leukocyte-to-lymphocyte ratio is associated with acute relapse in multiple sclerosis patients

Background Multiple sclerosis (MS) is an immune-mediated chronic disease characterized by inflammatory demyelination in the central nervous system (CNS). As there is limited evidence on whether leukocyte-to-lymphocyte ratios (LLRs) are associated with MS, we carried out an investigation on the association between LLRs and MS as favorable markers and aimed to determine the cut-off LLR for the identification of early-stage MS patients. Methods A matched case-control study enrolled a total of 120 MS inpatients and 120 age- and sex-matched non-MS inpatients from January 2013 to June 2018. LLRs were tested from peripheral venous blood routinely during hospitalization. Conditional logistic regression analyses were used to explore differences in LLRs between cases and controls. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic ability of LLRs and determine the best cut-off value. Disease disability was assessed using the Expanded Disability Status Scale (EDSS). Results The LLR was significantly associated with MS in hospitalized patients (OR: 2.372, 95% CI: 1.282 to 4.387, p < 0.001) after adjusting for potential confounders. The area under the curve (AUC) value was 0.793 (95% CI: 0.736 to 0.851). The cut-off value for LLR was 3.18, with sensitivity and specificity values of 62.5% (95% CI: 53.2% to 71.2%) and 88.3% (95% CI: 81.2% to 93.5%), respectively. The EDSS scores of the higher LLR group were significantly higher than the lower group. Conclusion Systemic inflammation measured using LLRs may be an inflammatory marker among MS inpatients. LLRs may serve as favorable inflammatory markers with which to discriminate MS among Chinese subjects.