Clinical Study On The Correlation Between Complement Fragment C5a And Systemic Lupus Erythematosus And Its Nerve System Damage

Objective:To detect the level of complement fragment C5 a in serum and cerebrospinal fluid(CSF)of patients with systemic lupus erythematosus(SLE),and to explore the relationship between C5 a and SLE and its nervous system damage and its clinical significance.Methods:Twenty-three patients with SLE admitted to the Department of Rheumatology and Immunology of Tianjin Medical University General Hospital were enrolled.And 17 healthy volunteers were selected as subjects.The clinical symptoms and related serological indicators of each SLE patient were recorded separately.The neuropsychiatric lupus(NPSLE)group(n=16)and non-NPSLE group(n=7)were included according to the presence or absence of neuropsychiatric involvement.Eight patients in the NPSLE group were treated with high-dose glucocorticoid combined with cyclophosphamide,and compared before and after treatment.The MRI imaging data of the patients in the NPSLE group were collected and divided into 8 cases of the head MRI normal group and 8 cases of the head MRI abnormal group.Peripheral blood and cerebrospinal fluid of SLE patients were collected,and 17 healthy controls were collected from peripheral blood.The levels of C5 a in serum and cerebrospinal fluid were determined by ELISA.The differences of C5 a in serum and cerebrospinal fluid between the above groups were compared.The correlation between serum C5 a and C5 a in cerebrospinal fluid was analyzed by Pearson correlation.Results:1.The serum C5 a level in patients with SLE was higher than that in healthy controls,and the difference was statistically significant(P<0.001).2.The serum C5 a level of NPSLE patients was higher than that of non-NPSLE patients(P<0.05);The C5 a level of cerebrospinal fluid in NPSLE patients was higher than that of non-NPSLE patients(P<0.0001);There was no significant difference in the positive rate of serum aCL antibody,anti-ribosomal P protein antibody and anti-C1-q antibody between NPSLE patients and non-NPSLE patients(P>0.05).3.Compared with before treatment,the serum and cerebrospinal fluid C5 a levels in patients with NPSLE decreased after treatment,the difference was statistically significant(P<0.05);4.There was no significant difference in serum and cerebrospinal fluid C5 a levels between normal MRI patients and patients with abnormal MRI(P>0.05).5.There was a positive correlation between serum C5 a level and cerebrospinal fluid C5 a level in NPSLE patients(r=0.703 P=0.002).Conclusion:1.Serum C5 a levels in patients with SLE are abnormally elevated.2.The serum and cerebrospinal fluid C5 a levels in the NPSLE group were significantly higher than those in the non-NPSLE group,suggesting that C5 a is involved in the pathogenesis of NPSLE.3.The serum and cerebrospinal fluid C5 a levels were significantly decreased after high-dose glucocorticoid shock combined with cyclophosphamide,suggesting that C5 a may be associated with NPSLE disease activity and is expected to be a biological indicator for evaluating disease.4.The serum C5 a level in NPSLE patients was positively correlated with the C5 a level in cerebrospinal fluid,suggesting that C5 a in the serum of NPSLE patients may enter the cerebrospinal fluid through the damaged blood-brain barrier to participate in local tissue and cell damage.