The Relationship Between Neutrophil-To-Lymphocyte Ratio And Disease Severity In Patients With First-Episode Neuromyelitis Optica Spectrum Disorder

Background:Neuromyelitis optica spectrum disorder(NMOSD)is an autoimmune inflammatory demyelinating disease of the central nervous system(CNS)primarily involving the optic nerve and spinal cord.Acute optic neuritis and transverse myelitis,which occur simultaneously or successively,are the most common clinical features.AQP-4 antibody is a sensitive and highly specific biomarker for NMOSD,which induces astrocyte damage by activating complement,and then mediates the release of inflammatory mediators,participating in the pathogenesis of the disease.A recent global epidemiological survey showed that the incidence and prevalence of NMOSD vary by ethnicity and geographic region,with an annual incidence of 0.037-0.73 per 100,000 people and a prevalence of 0.7-10 per 100,000 people.Although the incidence and prevalence of NMOSD are low,most patients present with a recurrent disease course,which eventually causes severe disabilities such as blindness or paralysis.Therefore,finding cheap,easily available and reliable biological indicators to diagnose early and assess the disease severity of NMOSD will be crucial for the timely treatment and improved prognosis of patients.The neutrophil-to-lymphocyte ratio(NLR)is a novel inflammatory marker that more stably reflects the inflammatory state than blood cell count alone.It has been proven to be an inflammatory biomarker for predicting prognosis in tumors,cardiovascular and cerebrovascular diseases,and autoimmune diseases.At the same time,studies have shown that NLR is related to the disease activity of multiple sclerosis(MS)and NMOSD.However,there are few studies on the relationship between NLR and the severity of neurological impairment in patients with NMOSD.Objective:This study explored the relationship between NLR and disease severity on admission in patients with first-episode NMOSD by comparing the clinical data of patients with first-episode NMOSD of different severity and analyzing their correlation with the Extended Disability Status Scale(EDSS)score.Method:A total of 259 patients with first-episode NMOSD who were hospitalized in the First Affiliated Hospital of Zhengzhou University from January 2013 to January 2020 and 169 healthy people who underwent physical examination in our hospital during the same period were included and divided into NMOSD group and control group.The general clinical data and complete blood count of the two groups were analyzed.The EDSS score was used to assess the disease severity in the NMOSD group,and the NLR was calculated as the absolute number of neutrophils to the absolute number of lymphocytes.The patients in the NMOSD group were divided into mild-to-moderate group and severe group according to the EDSS score on admission.The clinical data of the mild-to-moderate group and the severe group were analyzed,including general clinical data,imaging,cerebrospinal fluid(CSF)cytology,complete blood count,etc.Logistic regression was used to explore independent risk factors for disease severity on admission in patients with first-episode NMOSD.Receiver operating characteristic(ROC)curve was used to evaluate the predictive power of NLR for disease severity on admission in patients with first-episode NMOSD and to determine its optimal critical value.Result:1.White blood cell,neutrophil,and monocyte counts and the NLR were significantly higher(all P<0.001)and the lymphocyte(P=0.005)and eosinophil(P<0.001)counts were significantly lower in the NMOSD group than in the control group.There was no significant between-group difference in the red blood cell,platelet,or basophil count(all P>0.05).2.Compared with patients in the mild-to-moderate group,those in the severe group were significantly older(P=0.041),were significantly more likely to have hypertension(13.8%vs 3.5%,P=0.011).There was no significant between-group difference in sex,past medical history(diabetes,autoimmune disease,or mental disease),smoking history,or drinking history(all P>0.05).3.The incidence of dyskinesia as the first symptom of NMOSD patients in the severe group was significantly higher than that in the mild-to-moderate group(64.4%vs 21.2%,P<0.001),but the incidence of dizziness and ataxia was significantly lower than that in the mild-to-moderate group(3.4%vs 10.6%,P=0.043).There was no significant difference in other clinical manifestations between the two groups(P>0.05).4.The incidence of MRI abnormalities(89.7%vs 78.8%,P=0.018)and the number of spinal cord involvement segments(P<0.001)in the severe group were significantly higher than those in the mild-to-moderate group.There was no significant difference in CSF leukocyte,CSF lymphocyte ratio or AQP4-Ab status between the two groups(P>0.05).5.Compared with patients in the mild-to-moderate group,those in the severe group had significantly higher neutrophil counts(P=0.001),NLR value(P<0.001);they also had significantly lower lymphocyte(P<0.001)and eosinophil(P=0.027)counts.There was no significant difference in other blood cell counts between the two groups(all P>0.05).6.NLR(OR 1.201,95%CI 1.037-1.393,P=0.015),comorbid hypertension(OR 4.199,95%CI 1.082-16.304,P=0.038)and dyskinesia(OR 6.721,95%CI 3.339-13.530,P<0.001)were independent risk factors for disease severity on admission in patients with first-episode NMOSD.7.The area under the ROC curve of NLR for predicting disease severity in patients with first-episode NMOSD was 0.687(95%CI 0.618-0.755).The optimal critical value was 2.754,the sensitivity was 57.5%,and the specificity was 76.5%.Conclusions:1.The NLR level was significantly higher in the NMOSD patients than in healthy controls.2.The NLR level of NMOSD patients in the severe group was significantly higher than that in the mild-moderate group.NLR was an independent risk factor and predictor of disease severity on admission in patients with first-episode NMOSD.