Susceptibility for Lupus Nephritis by Low Copy Number of the FCGR3B Gene Is Linked to Increased Levels of Pathogenic Autoantibodies
[ 摘要 ]
Low copy number (CN) of the FCGR3B gene reduces FCGR3B membrane expression on neutrophils and results in clearance of a smaller amount of immune complex. We investigated FCGR3B CN in relation to the clinical phenotype in a Caucasian SLE cohort (). FCGR3B CN was determined by three different qPCR parameter estimations (Ct−, Cy0, and cpD1) and confirmed by the FCGR2C/FCGR2A paralog ratio test. Clinical and serological data were then analyzed for their association with FCGR3B CN. Low FCGR3B CN (<2) was more frequent in SLE patients than in healthy controls () (20% versus 6%, OR 4.15, ) and associated with higher disease activity scores (SLEDAI 10.4 versus 6.1, ), lupus nephritis (LN) (25 versus 5%, ), and increased levels of antibodies against dsDNA (81 versus 37 IU, ), C1q (22 versus 6 IU, ), and ribosomal P (10 versus 5 IU, ). No such associations were seen with antibodies against extractable nuclear antigens or high FCGR3B CN (>2). In multivariate analyses, LN was independently associated with anti-C1q-Ab levels () and low FCGR3B CN (). We conclude that the susceptibility for LN in patients with low FCGR3B CN is linked to increased levels of pathogenic autoantibodies.
[ 学科分类 ] 内科医学
[ 发文字号 ] 10.1155/2013/750814