ABSTRACT
Objective To evaluate the copy number variation of FCGR3B gene in Henan Han systemic lupus erythematosus (SLE) patients and healthy controls,and explore the association between FCGR3B gene copy number variants (CNVs) and lupus nephritis (LN) susceptibility in Henan Han population.Methods FCGR3B CNVs was investigated in 142 SLE patients with nephritis,187 SLE patients without nephritis and 328 healthy controls.A modified methodology based on competitive PCR named Multiplex AccuCopyTM Kit was used to detect FCGR3B copy number.Clinical and laboratory data were collected retrospectively from the medical record.Logistic regression analysis was used to determine the association of FCGR3B copy number variants with LN susceptibility.Rank correlation was used to determine the correlations between FCGE3B copy number variants and clinical phenotypes of LN.Results No significant difference was detected in the copy number variations of FCGR3B in different groups.Low copy number of FCGR3B was more commonly seen in patients with nephritis (P=0.042),and was a risk factor for LN (OR=2.059; 95％ CI:1.081-3.921; P=0.028).However,high copy number (＞ 2) had no effect on SLE patients without nephritis(OR=1.152; 95％CI:0.711-1.866; P=0.565) and LN patients (OR=0.838; 95％ CI:0.529-1.329; P=0.454).There were no associations between FCGR3B copy number variants and clinical phenotypes and immunologic characteristics of LN.Conclusion The low copy number of FCGR3B is a risk factor for LN in Henan Han population.