The value of HMGB1 and Toll-like receptor 4 in peripheral blood mononuclear cells and serum of rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect and possible mechanism of high mobility group box (HMGB) 1 in the development and progress of rheumatoid arthritis.Methods PBMC and serum samples were obtained from 74 RA patients (38 in active stage and 36 in stable stage) and 26 healthy controls.The expression of HMGB1 mRNA and protein was detected by RT-PCR and ELISA.Flow cytometry analysis ( FCM ) was used to detect the expression of Toll-like receptor 4 on PBMC.Results ①The expression of HMGBI mRNA and protein in active RA patients was significantly higher than that in healthy controls and inactive RA patients [2.63 vs 0.71，0.93 and (10.2±1.2) vs (7.5±1.8)，(8.3±1.8) ng/ml，respectively](P＜0.01 ).② The relative expression of TLR4 protein on CD14+ monocytes and CD3+ lymphocytes in active RA patients was increased than that in inactive RA and healthy controls (P＜0.05 or P＜0.01 ).It was also higher in inactive RA than in healthy controls (P＜0.05 or P＜0.01 ).③ Level of HMGB1 protein in serum of RA patients was positively correlated with ESR，CRP，RF，the numbers of tender joints and swollen joints as well as radiographic changes.Conclusion HMGB1 can be synthesized and released by PBMC of active RA patients，and then bind to TLR4 of PBMC to promote inflammatory responses and bone erosion.