FcγRIIA Genotypes and Its Association with Anti-C1q Autoantibodies in Lupus Nephritis (LN) Patients from Western India

[摘要] To identify FcγRIIA genotypes in Systemic Lupus Erythematosus (SLE) patients and their association with anti-C1q antibodies.Methods. FcγRIIA genotyping was done in eighty Indian SLE patients and eighty healthy controls using allele-specific PCR. Anti-C1q antibodies were measured by ELISA.Results. LN patients showed higher SLEDAI (6–32) as compared to SLE patients without renal manifestations and had SLEDAI between 6–23. FcγRIIA polymorphic frequency in SLE patients was R131/H131 (67.5%), R131/R131 (20%) and H131/ H131 (12.5%) as against that of normal population (62.5%, 10%, and 27.5%), respectively. Sixty two patients (77.5%) showed positivity for anti-C1q antibodies. LN patients showed elevated levels of anti-C1q antibodies (258.2 u/ml±38.5 U/mL) as compared to SLE patients without nephritis (134.6±24.6 U/mL). Among anti-C1q positive patients, 71% had R131/H131 genotype, 22.6% had R131/R131 and remaining 6.4%, patients had H131/H131 genotype. All anti-C1q positive patients with R131/R131 genotype had elevated levels of anti-C1q antibodies (>100 U/ml), whereas among anti-C1q negative patients, none had R131/R131 genotype.Conclusion. This first report on Indian SLE patients supports the hypothesis that FcγRIIA R131 variant over expression may constitute a susceptibility factor for development of severe SLE manifestations in LN patients.

[学科分类] 内科医学