The Study On The Relationship Between Anti NMDA Antibody And Clinical And Immunological Index Of Patients With NPSLE

Objective: To investigate the serum level of anti NMDA receptor antibody in patients with neuropsychiatric systemic lupus erythematosus, and establish the correlation between anti NMDA antibody and clinical and immunological studies in patients with NPSLE.Method: The levels of anti NMDA receptor antibody in blood samples from 36 patients with cognitive dysfunction of systemic lupus erythematosus,30 cases with normal cognitive function of NPSLE groups,64 patients with no-NPSLE,100 patients with the other connective tissue disease and 30 healthy controls were measured by enzyme linked immunosorbent assay, and the reports of Mini-Mental State Examination were made in those with cognitive dysfunction of NPSLE group, normal cognitive function of NPSLE group, no-NPSLE group and CTD group,and the laboratory indexes and clinical features were recorded. At the same time, the patients who were confirmed as cognitive dysfunction of NPSLE were treated with hormone(1mg. kg-1. d-1) and cyclophosphamide. then the serum levels of anti NMDA receptor antibody and the scores of MMSE were investigated again in cognitive dysfunction of NPSLE group who were treated after 2 weeks. The comparison of multi-group was measured by means of single factor analysis of variance or rank test, the Pearson or Spearman correlation analysis was used to analyze the correlation between variables.Result:(1)The level of anti NMDA receptor antibody in the patients with cognitive dysfunction of the NPSLE group(OD: 1.297±0.268) above normal cognitive function of NPSLE group(OD: 0.470±0.076),no-NPSLE group(OD: 0.469±0.067),the other connective tissue disease(OD: 0.417±0.037)and the healthy controls(OD: 0.352±0.060),(P<0.05)the difference was statistically significant. The sensitivity is 79.2% and specificity was 76.0%, when the level of antibody(OD) was 0.91.(2)The scores of the patients with cognitive dysfunction of the NPSLE group were significantly less than those with normal cognitive function of NPSLE group, the no-NPSLE group and the CTD group(Z=-6.569,P=0.000;Z=-7.305,P=0.000;Z=-9.076,P=0.000),but the difference in the score of those with normal cognitive function of NPSLE group, the no-NPSLE group and the CTD group was no statistically significant(Z=-0.890,P=0.374;Z=-0.350,P=0.727;Z=-1.650,P=0.099), and the serum levels of anti NMDA receptor antibody in patients confirmed NPSLE existed a negative correlation with the intelligent score(r=-0.330, P=0.000).(3)The levels of anti NMDA receptor antibody were positively correlated with the levels of Ig G(r=0.684,P=0.014), but had no correlation with Ig M,Ig A,C3,C4,RF,CRP,ESR,ANA,U1 RNP,ENA(Sm,SSA,SSB,Rib,JO-1,SCL-70) and rash, dry eye/xerostomia, oral/nasal ulcer, hair loss, Raynaud’s phenomenon, serous inflammation, morning stiffness, photosensitivity, joint pain, pulmonary artery enlargement, pulmonary interstitial fibrosis(P>0.05).(4) The levels of ds-DNA, hs CRP, blood creatinine, and urea and the positive rate of ACA- Ig G, and Rib in cognitive impairment of NPSLE group and normal cognition of NPSLE patients were significantly higher than that of group no-NPSLE, besides, the levels of C4, leucocyte count and platelet count were significantly lower than those in group no-NPSLE. But the discrepancy between the cognitive impairment of NPSLE group and the normal cognition was not statistically significant on those(P>0.05).(5)The levels of anti NMDA receptor antibody before treatment are higher than after, and the statistical difference was significant(t=2.269,P=0.047).Conclusion:(1)Anti NMDA receptor antibody may be used as a new self- antibody in the early diagnosis of cognitive dysfunction in patients with NPSLE.(2)There is a positive correlation between the disease activity of NPSLE patients with cognitive impairment and the level of anti NMDA receptor antibody,and anti NMDA receptor antibodies may be used in disease surveillance of NPSLE with cognitive dysfunction.