The study on the correlation between serum mannose-binding lectin and renal injury in rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To detect the serum level of mannose binding lectin (MBL) in patients with renal injury induced by rheumatoid arthritis (RA), and to investigate the role of MBL in the pathogenesis of renal injury in RA. Methods ELISA was used to measure the serum MBL level of 19 RA patients with renal injury, 49 RA patients without renal injury and 40 healthy individuals. The clinical features and laboratory markers were compared and analyzed by chi-square test, two independent samples t-test and Spearman's correlation analysis. Results Compared with RA patients without renal injury, the number of tender and swollen joints [(15±9) vs (9±11)], duration of morning stiffness [(2.9±1.3) vs (2.3±1.6) h] and extraarticular manifestations (42.1％ vs 16.3％) in RA patients with renal injury were significantly higher (P＜0.05or P＜0.01). There was no significant difference between the two groups in RA disease duration and jointdeformity(P＞0.05). In patients with renal injury, the level of platelet count [(376±155)×109/L vs (304±121)×109/L], CIC[(4.3±3.0) vs (2.9±3.3) g/L], ESR[(79±46) vs (53±31) mm/1 h], RF[(77±42) vs (52±49)U/ml], CRP[(32±28)vs (23±18)mg/L], IgG[(11.7±2.6)vs (8.4±2.4)g/L], C3[(1.18±0.53)vs (0.94±0.21) g/L] were higher than those in RA patients without renal injury (P＜0.01 or P＜0.05); the level of Alb [(26±13) vs (30±9) g/L] was lower than that in RA patients without renal injury (P＜0.05). The level of serum MBL in the two groups of RA patients was significantly lower than that in the healthy group [(3.1±0.5)mg/L](P＜0.01), and the level of serum MBL in RA patients with renal injury [(1.7±1.2) mg/L] was higher than that in RA patients without renal injury [(1.4±1.3) mg/L](P＜0.05). The level of serum MBL in RA patients with renal injury showed a positive correlation with IgG, C3, CRP and 24 h urine protein level (r=0.6, 0.6, 0.47, 0.57; P＜0.05). Conclusion Renal injury in RA patients is immune complex dependent. The serum level of MBL is higher in patients with renal injury, therefore, high-concentration MBL may be one of a potential causes of renal injury in RA patients.