RESUMO
Objective To investigate the expression level of oxidized low density lipoprotein (ox-LDL) and its scavenger receptor scavenger receptor that binds phosphatidylserine and oxidized lipoprotein (SRPSOX) in patients with rheumatoid arthritis (RA),and to explore the relationship between ox-LDL and disease activity.Methods The serum ox-LDL in RA patients and healthy control group were detected by enzymelinked immunosorbent assay (ELISA),as well as the fluidox-LDL in RA,osteoarthritis (OA) and inflammatory arthritis (IA).The expression of SR-PSOX in mixed cells of RA and IApatients was detected by western blot.The expression of serum ox-LDL between RA groupand the control group was analyzed by t-test and non-parametric test.The correlation of serum ox-LDL expression levels in RA patients with C-reactive protein (CRP),erythrocyte sedimentation rate (ESR) and other inflammatory factors and disease activitywas analyzed by Pearson linear regression.Results The expression of ox-LDL in the serum of RA patients was significantly higher than that of normal control group [(3 076±131) mU/ml,(2 334±84) mU/ml,t=4.242,P＜0.01].The expression of ox-LDL in synovial fluid of RA patients was significantly higher than that of the OA group [(4 963±354) mU/ml],(3 956±347) mU/ml,t=2.372,P＜0.05).The expression of SR-PSOX in synovial fluid mixed cells of RA patients was higher than that of the IA group [(4.92±0.18) vs (0.24±0.04),t=33.53,P＜0.01].The expression of ox-LDL in serum of RA patients was negatively correlated with ESR,CRP and overall disease activity DAS28 (r=-9.42,P=0.009;r=-0.35,P=0.029 7;r=0.42,P=0.008 4).The expression of ox-LDL in the serum of RA patients with moderate disease activity was significantly higher than those patients with high disease activity [(3 302±138) mU/ml vs (2 464±228) mU/ml,t=3.335,P＜0.01],however,those with low disease activity and disease remission had higher serum ox-LDL expression but without statistical significant differences.After treated with anti-rheumatic drugs (DMARDs),serum ox-LDL of RA patients had a trend of slight increasing butwithout sign-ificant difference.The ox-LDL/LDL-C or ox-LDL/HDL-C was negatively not correlated with disease activity score in 28 (DAS28),ESR,CRP.Conclusion In RA patients,the expression of ox-LDL in the serum and synovial fluid is high and the SR-PSOX expressionin synovial fluid is also high.The serum ox-LDL levels are negatively correlated with ESR,CRP and DAS28,which are related to disease activity of RA.These findings suggest that the ox-LDL and the receptor SR-PSOX may play a role in RA pathogenesis,but needs further study.