Gonzalez-Gay M A, Hajeer A H, Dababneh A, Garcia-Porrua C, Amoli M M, Llorca J, Ollier W E R
Division of Rheumatology, Hospital Xeral-Calde, Lugo, Spain.
Clin Exp Rheumatol. 2004;22(6 Suppl 36):S18-20.
Inflammatory cytokines are implicated in the pathogenesis of giant cell arteritis (GCA) and polymyalgia rheumatica (PMR). In this study we have examined the potential association of a CA repeat polymorphism in the first intron of the interferon gamma (IFN-gamma) gene with disease susceptibility and clinical expression of these conditions.
Seventy-nine patients with isolated PMR, 59 biopsy-proven GCA patients and 129 ethnically matched controls from Lugo (NW Spain) were studied. Patients and controls were genotyped by molecular methods for the microsatellite dinucleotide (CA) repeat within the first intron of IFN-gamma gene.
No significant differences in the distribution of alleles for the IFN-gamma gene polymorphism between GCA and isolated PMR patients and controls were found. However, the frequency of IFN-gamma allele *4 (128 bp) was reduced in GCA patients (33.1%) compared with isolated PMR patients (46.2%). Also, GCA patients with visual ischemic manifestations exhibited a significantly reduced frequency of IFN-gamma allele *4 compared with those without visual manifestations (17.9% versus 42.5%; p = 0.05 [OR: 0.36, 95% CI: 0.13-1.00]). Moreover, allele *3 (126 bp) was over-represented in the GCA patients with visual ischemic manifestations (71.4% versus 44.4% in the remaining GCA patients; p = 0.01 [OR = 3.13, 95% CI: 1.27-7.68]).
In GCA, IFN-gamma functional polymorphisms are associated with clinical manifestations of severity rather than susceptibility to this vasculitis.
炎性细胞因子与巨细胞动脉炎（GCA）和风湿性多肌痛（PMR）的发病机制有关。在本研究中，我们检测了干扰素γ（IFN-γ）基因第一内含子中CA重复多态性与这些疾病易感性及临床表型之间的潜在关联。
对来自西班牙西北部卢戈的79例孤立性PMR患者、59例经活检证实的GCA患者以及129名种族匹配的对照者进行研究。采用分子方法对患者和对照者的IFN-γ基因第一内含子中的微卫星二核苷酸（CA）重复进行基因分型。
未发现GCA患者、孤立性PMR患者及对照者之间IFN-γ基因多态性等位基因分布有显著差异。然而，与孤立性PMR患者（46.2%）相比，GCA患者中IFN-γ等位基因4（128 bp）的频率降低（33.1%）。此外，有视觉缺血表现的GCA患者中IFN-γ等位基因4的频率显著低于无视觉表现的患者（17.9%对42.5%；p = 0.05 [OR：0.36，95% CI：0.13 - 1.00]）。而且，等位基因*3（126 bp）在有视觉缺血表现的GCA患者中占比过高（71.4%对其余GCA患者中的44.4%；p = 0.01 [OR = 3.13，95% CI：1.27 - 7.68]）。
在GCA中，IFN-γ功能多态性与该血管炎的严重程度临床表现相关，而非易感性相关。
