Department of Rheumatology, The Queen Elizabeth Hospital, 28 Woodville Rd, Woodville South, South Australia 5011, Australia.
Arthritis Res Ther. 2012 Feb 7;14(1):R28. doi: 10.1186/ar3731.
Low copy number (CN) of the Fc gamma receptor 3B (FCGR3B) gene has been associated with systemic autoimmune disease. This receptor for IgG is present almost exclusively on neutrophils and plays a role in their interaction with immune complexes. At present the relationship between FCGR3B and rheumatoid arthritis (RA) is unclear. The aim of the present study was to investigate whether low CN of the FCGR3B gene is associated with susceptibility to RA.
The FCGR3B CN was determined using a custom Taqman® CN assay (Hs04211858; Applied Biosystems, Foster City, CA, USA) in 197 RA patients, recruited from a tertiary setting, and in 162 population matched controls. Odds ratios for low CN (< 2) and high CN (> 2), both relative to the normal diploid 2CN, were estimated by logistic regression.
A significant association between RA and low FCGR3B CN was observed, with frequencies of 13.7% in RA patients compared with 6.2% in controls (odds ratio 2.5, 95% confidence interval 1.2 to 5.4, P = 0.017). No association was observed between low CN and the presence of rheumatoid factor, anti-cyclic citrullinated peptide antibodies or radiographic erosions in RA patients. A meta-analysis including six previous studies confirmed an association between RA and low FCGR3B CN (odds ratio 1.47, 95% confidence interval 1.13 to 1.92, P = 0.004).
The present study confirms that a low CN of the FCGR3B gene is associated with susceptibility to RA. The association may be stronger in patients recruited from a tertiary setting, which may relate to disease severity and/or complications. The mechanism of susceptibility remains unclear and further study is required.
Fc 受体 γ 链 3B（FCGR3B）基因的低拷贝数（CN）与系统性自身免疫性疾病有关。这种 IgG 受体几乎只存在于中性粒细胞上，并在其与免疫复合物的相互作用中发挥作用。目前，FCGR3B 与类风湿关节炎（RA）之间的关系尚不清楚。本研究旨在探讨 FCGR3B 基因低 CN 是否与 RA 易感性有关。
使用定制的 Taqman®CN 测定法（Hs04211858；Applied Biosystems，加利福尼亚州福斯特市），在 197 名来自三级医疗机构的 RA 患者和 162 名匹配的人群对照中测定 FCGR3B CN。通过逻辑回归，分别估计低 CN（<2）和高 CN（>2）相对于正常二倍体 2CN 的比值比（OR）。
RA 患者中 FCGR3B 低 CN 的频率为 13.7%，对照组为 6.2%，RA 与 FCGR3B 低 CN 之间存在显著关联（OR 2.5，95%置信区间 1.2 至 5.4，P = 0.017）。在 RA 患者中，低 CN 与类风湿因子、抗环瓜氨酸肽抗体或放射学侵蚀之间无关联。一项包括六项先前研究的荟萃分析证实，RA 与 FCGR3B 低 CN 之间存在关联（OR 1.47，95%置信区间 1.13 至 1.92，P = 0.004）。
本研究证实 FCGR3B 基因的低 CN 与 RA 易感性有关。在从三级医疗机构招募的患者中，这种关联可能更强，这可能与疾病严重程度和/或并发症有关。易感性的机制尚不清楚，需要进一步研究。
