Association of a polymorphism of the Fcγ-receptor 2A (FCGR2A) gene with chronic periaortitis

OBJECTIVES: Chronic periaortitis (CP) is an inflammatory disease associated in 20-60% of the cases with IgG4 related disease. Current evidence supports an autoimmune nature for CP. Fc gamma receptors (FcγRs) are involved in several immune system activities and are associated with autoimmunity in general. We explored the influence of genetic variants within this region on susceptibility to CP. METHODS: Genotyping of 4 candidate single nucleotide polymorphisms (SNPs) of the FCGR region was performed in CP patients and controls. RESULTS: One hundred and eighty-three cases and 181 controls were included. An association between the SNP rs1801274 of the FCGR2A and CP was detected (OR 1.6, 95%CI 1.18-2.16;corrected p-value, pcorr=0.0085). After stratification of the population according to clinical characteristics, the association was restricted to cases of idiopathic retroperitoneal fibrosis (OR 1.66, 95%CI 1.21-2.29;pcorr=0.028), without involvement of the thoracic aorta (OR 1.77, 95%CI 1.21-2.57;pcorr=0.043), with deep vein thrombosis at onset (OR 3.96, 95%CI 1.81-8.66;pcorr=0.0021) and with normal IgG4 levels (OR 2.67, 95%CI 1.39-5.12;pcorr=0.031). CONCLUSIONS: In the largest candidate gene approach study performed so far in CP, we demonstrated an association for CP with a gene hallmark of autoimmunity. The association appears restricted to typical cases of CP without increase of IgG4 levels.