Maury C P J, Aittoniemi J, Tiitinen S, Laiho K, Kaarela K, Hurme M
Department of Medicine, University of Helsinki, Helsinki, Finland.
J Intern Med. 2007 Oct;262(4):466-9. doi: 10.1111/j.1365-2796.2007.01838.x.
The aim of this study was to investigate whether polymorphism of the mannose-binding lectin 2 (MBL2) gene is related to the occurrence of systemic AA amyloidosis in patients with rheumatoid arthritis (RA).
MBL2 structural gene polymorphisms at codon 52 (CGT-->TGT, Arg-->Cys; D), codon 54 (GGC-->GAC, Gly-->Asp; B) and codon 57 (GGA-->GAA, Gly--> Glu; C), and MBL2 promoter region polymorphism at position -221 (G-->C) were examined in 57 patients with RA complicated by biopsy-proven reactive amyloidosis and 51 control RA patients without amyloid.
A strong association was found between the presence of a structural MBL2 gene variant O (B, D or C) and the occurrence of amyloidosis in RA patients: 29 of 57 (50.9%) of the RA patients with amyloid had a variant allele compared with 12 of 51 (23.5%) of the RA patients without amyloid (OR 3.37, 95% CI 1.47-7.72; P = 0.004).
We conclude that variant MBL2 structural genotype constitutes a significant risk factor for reactive amyloidosis in RA and that the increased risk is probably related to MBL-mediated impairment of mononuclear phagocyte function.
本研究旨在调查甘露糖结合凝集素2（MBL2）基因多态性是否与类风湿关节炎（RA）患者系统性AA淀粉样变性的发生有关。
对57例经活检证实患有反应性淀粉样变性的RA患者和51例无淀粉样变性的对照RA患者，检测其MBL2结构基因第52密码子（CGT→TGT，精氨酸→半胱氨酸；D）、第54密码子（GGC→GAC，甘氨酸→天冬氨酸；B）和第57密码子（GGA→GAA，甘氨酸→谷氨酸；C）的多态性，以及MBL2启动子区-221位（G→C）的多态性。
发现MBL2结构基因变异体O（B、D或C）的存在与RA患者淀粉样变性的发生之间存在密切关联：57例患有淀粉样变性的RA患者中有29例（50.9%）存在变异等位基因，而51例无淀粉样变性的RA患者中有12例（23.5%）存在变异等位基因（比值比3.37，95%可信区间1.47 - 7.72；P = 0.004）。
我们得出结论，MBL2结构基因变异型构成RA患者发生反应性淀粉样变性的重要危险因素，且风险增加可能与MBL介导的单核吞噬细胞功能受损有关。
