The Significance And Level Of Mannose-binding Lectin In Patients With Systemic Lupus Erythematosus And Combined Infections

ObjectivesTo test the level of serum mannose-binding lectin (MBL) in patients with systemic lupus erythematosus (SLE) and that combined infections, and then carries on the relevant analysis with their clinical and the laboratory target; To discuss the relationship of the MBL level and the SLE activity, the internal organs damage and the infection initially.MethodsBlood samples were obtained from 65 patients with SLE and 20 healthy volunteers, and then serum MBL level was determined by ELISA. All patients were recruited at the General Hospital of Tianjin Medical University from February,2009 to October,2009.65 cases were divided into 3 groups according to SLE Disease Activity Index(SLEDAI):stable group(<9),mild-activity group(9～14), moderate-high-activity group(≥15);Patients were divided 3 groups according to Prednisone(PDN) daily dose:PDN<15mg group,15mg≤PDN<50mg group and PDN≥50mggroup; 65 cases were divided into infectious and non-infectious group. Collect and collate clinical and laboratory data of SLE patients. The clinical data include gender, age, disease process, SLEDAI, internal organs damage and hormone dosage, etc. Laboratory indicators:blood routine test, hepatic and renal function, erythrocyte sedimentation rate (ESR), C-reactive protein(CRP),24h urinary protein quantity, immunoglobulin G(IgG), immunoglobulin A(IgA), immunoglobulin M(IgM), complement 3(C3),complement 4(C4), circulating immune complex(CIC), anti-Sm antibody, anti-double-stranded DNA antibody, anti-UIRNP antibody, anti-ACL antibody, etc.We analyzed by SPSS13.0 statistics software.Results1.Competed to healthy volunteers, the level of MBL was lower in patients in stable group, mild-activity group, moderate-high-activity group;Competed to stable group, the level of MBL was lower in moderate-high-activity group. 2. MBL level gets negative correlation to SLEDAI.3.The level of MBL in serum decreased obviously in the condition of high-IgG, or/and raising-24h urinary protein quantity.4.In comparison with group PDN<15mg, the MBL level in SLE patients decreased obviously in group 15mg≤PDN<50mg and PDN≥50mg; In comparison with group 15mg≤PDN<50mg, the level of MBL decreased obviously in group PDN≥50mg.5.Disease process, SLEDAI, Prednisone daily dose, the level of MBL,24h urinary protein quantity, and CRP were significantly different between infectious and non-infectious group.6.Multivariate regression showed that the level of MBL and Prednisone daily dosage were independent factors for infection in patients with SLE, what's more, Prednisone daily dosage was risk, and the level of MBL was protective.Conclusions1.Compared to control group, serum MBL level was lower in SLE group, what'more, MBL level in mild-activity group was lower than that in stable group, and these suggested that MBL maybe make sense in SLE pathogenesis;simultaneously, because of getting negative correlation to SLEDAI, MBL level could be an index to evaluate SLE activity.2.The level of serum MBL in SLE patients with higher IgG level was lower than that those with common IgG, and this suggested MBL maybe cause immunity functional disorder.3.Decline of serum MBL level got relationship to raising of urine protein quantity, and we considered that maybe MBL take important part in renal involvement.4.Univariate analysis in infection group and non-infectional group suggested that serum MBL level, disease process, SLEDAI, Prednisone daily dose, urine protein quantity, and CRP got statistically significant. Further multivariate analysis suggested that serum MBL level was a protective factor to SLE combined with infection, and Prednisone daily dose was a risk factor to SLE combined with infection. The higher of MBL level, the lower risk to SLE combined with infection; the higher Prednisone daily dose, the higher risk of SLE combined with infection, and considered that, MBL could be a serum marker to predict whether SLE patients would get infection.