Analysis Of Serum Positive NMO-IgG And Correlative Factors In Various Kinds Of Demyelinating Diseases In Central Nervous System

To detect serum NMO-IgG of common demyelinating diseases in CNS and to compare the positive rate of them; To analyse clinic features, laboratory findings and radiologic results and to find out the factors which correlate to the serum positivity of NMO-IgG; To do multi-factor analysis of the possible correlative factors of serum NMO-IgG.(1) With indirect fluorescence assay using brain slices of mice,serum NMO-IgG was respectively detected in 50 NMO patients,18 MS patients,20 optic neuritis patients, 25 myelitis patients and 6 ADEM patients.(2) Clinic informations, including clinical manifestations, laboratory findings, evoked potentials and radiology results of all the patients who have undergone NMO-IgG tests were collected for multi-factor analysis of the correlative factors of NMO-IgG seropositivity.(1) NMO is the most common demyelinating disease of CNS in our study (42.02%);(2) The seropositivity of NMO-IgG in NMO and NMO spectrum patients was 72.00% (36/50) and 63.51% (47/74) respectively, which are significantly higher than those in MS 27.78% (5/18) and non-NMO spectrum patients 21.05% (8/38).The seropositivity of NMO-IgG in optic neuritis and myelitis patients was 36.00%(9/25) and 25.00% (5/20). High positive rate was found in ADEM and CPMS patients, which was 66.67% (4/6) and 80.00% (4/5) respectively. However, just few cases were enrolled in both groups.(3) Single-factor analysis showed that onset age<40, brain MRI showing NMO typical lesions, spinal MRI showing longitudinal (≥3 vertebral segments) lesions, severely delayed latency in VEP were correlative factors of NMO-IgG seropositivity;(4) Multi-factor analysis indicated that only NMO typical lesions in brain MRI and longitudinal spinal lesions in spinal MRI were correlated to serum NMO-IgG.Conclusion: NMO is one of the most common CNS demyelinating diseases in our study, which is consistent with the status reported in Asia. The positive rates of serum NMO-IgG in NMO and NMO spectrum patients are significantly higher than those in MS and non-NMO spectrum patients. Besides the seropositivity of NMO-IgG, NMO spectrum and non-NMO spectrum show differences in clinical manifestations. Furthermore, our study indicates that NMO-IgG may play a key role in the immunopathogenesis of NMO spectrum while other immune factors may contribute to non-NMO spectrum patients. Multi-factor analysis indicates that brain NMO typical lesions, longitudinal spinal lesions are correlative factors of NMO-IgG seropositivity. The specificity of lesion distribution in NMO further confirms the pathogenicity of NMO-IgG.. The length of spinal lesion segment is correlative to the severity of the disease.