目的: 检测类风湿关节炎(rheumatoid arthritis, RA)患者外周血B10细胞核因子κB受体活化因子配体(receptor activator of nuclear factor kappa B ligand, RANKL)的表达,并分析其与RA患者临床和实验室指标的关系,探讨B10细胞在RA发病中的作用及其免疫调节功能缺陷的潜在机制。方法: 选取RA患者25例(近半年未使用糖皮质激素、免疫抑制剂及生物制剂)和20名健康对照者(healthy controls, HC),利用流式细胞仪(flow cytometry, FCM)、聚合酶链式反应(polymerase chain reaction, PCR)检测RANKL在健康对照组和RA患者外周血B10细胞及非B10细胞中的表达,分析表达RANKL的B10 细胞比例与RA患者临床特征和实验室指标的相关性,体外刺激实验评价肿瘤坏死因子α(tumor necrosis factor α, TNF-α)和白细胞介素1β(interleukin 1β, IL-1β)对B10细胞表达RANKL的影响。数据分析采用独立样本t检验、Pearson和Spearman相关分析。结果: 健康人外周血B10细胞能表达低水平RANKL, RA患者外周血表达RANKL的B10细胞比例较健康对照组显著升高(3.65%±1.59% vs. 2.25%±0.68%, P<0.01)。RA患者表达RANKL的B10 细胞比例与关节压痛数、关节肿胀数及28-关节疾病活动度分值(disease activity score in 28 joints,DAS28)呈正相关(分别为r=0.479,P=0.035;r=0.519,P=0.008;r=0.526, P=0.019),与年龄、病程、红细胞沉降率(erythrocyte sedimentation rate, ESR)、C反应蛋白(C-reactive protein, CRP)、类风湿因子(rheumatoid factor, RF)及抗环瓜氨酸多肽抗体(anti-cyclic citrullinated peptide antibody, ACPA)无显著相关性。TNF-α能促进B10细胞高表达RANKL(P<0.01)。结论: RA患者外周血表达RANKL的B10细胞比例升高,与关节肿痛数及疾病活动度正相关,提示RA患者B10细胞免疫调节功能受损的同时可能参与了RA的发病及骨破坏。

Objective: To detect receptor activator of nuclear factor kappa B ligand (RANKL) expressed on B10 cells in rheumatoid arthritis (RA) and to evaluate the correlation between RANKL-producing B10 cells in RA and clinical features and laboratory parameters, trying to reveal the possible role of B10 cells in the pathogenesis of RA and the potential mechanism of impaired immunosuppressive capacities.Methods:25 RA patients and 20 healthy volunteers were enrolled. These RA patients did not received treatment with glucocorticoids, disease-modifying anti-rheumatic drug and biologics during the recent half of a year. The levels of RANKL-producing B10 cells were measured by flow cytometry (FCM) and polymerase chain reaction (PCR). The correlation between the frequencies of RANKL-producing B10 cells in RA and clinical data, laboratory parameters were analyzed. The role of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in inducing RANKL expression in B10 cells was evaluated by in vitro stimulation assay. Independent samples t test, Pearson and Spearman correlation were used for statistical analysis.Results:B10 cells were capable of producing RANKL at a low level in health controls. The frequencies of RANKL-producing B10 cells were markedly higher in RA patients than in health controls (3.65%±1.59% vs. 2.25%±0.68%, P<0.01). The frequencies of these cells correlated po-sitively with RA tender joint counts, swollen joint counts and disease activity score in 28 joints (DAS28) (r=0.479, P=0.035;r=0.519, P=0.008;r=0.526, P=0.019). However, no correlation was found between these cells and RA patient age, disease duration, or the levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA). After in vitro stimulation by TNF-α, but not IL-1β, B10 cells isolated from healthy donors demonstrated fundamentally upregulated expression of RANKL.Conclusion:Our studies showed the frequencies of RANKL-producing B10 cells were markedly higher in RA patients, and their frequencies were positively correlated with RA tender joint counts, swollen joint counts and DAS28. These findings suggested that B10 cells might be involved in RA bone destruction.