Association of a transmembrane polymorphism of Fcgamma receptor IIb (FCGR2B) with systemic lupus erythematosus in Taiwanese patients.
OBJECTIVE
To investigate the possible association of the Fcgamma receptor IIb (FcgammaRIIb) Ile/Thr187 transmembrane domain polymorphism, which significantly affects receptor signaling, with susceptibility to systemic lupus erythematosus (SLE) in Taiwanese patients.


METHODS
We used matrix-assisted laser desorption ionization-time-of-flight mass spectrometry to genotype 351 Taiwanese SLE patients and 372 age- and sex-matched healthy individuals from the same geographic area. Allele frequencies and genotype distributions were compared between the patients and controls, both as an aggregate and as stratified by sex, autoantibody profile, and clinical parameters. A combined analysis was conducted to assess the FCGR2B Thr187 allele as a common risk factor in different ethnic populations.


RESULTS
The minor Thr187 allele was significantly associated with SLE in Taiwanese subjects (P = 0.017, odds ratio [OR] 1.989 [95% confidence interval (95% CI) 1.119-3.553]). Interestingly, male SLE patients showed enrichment of the Thr/Thr187 genotype (24%; 7 of 29) as compared with female SLE patients (10%; 32 of 322) (P = 0.043, OR 2.884 [95% CI 1.028-7.839]). Additionally, SLE patients with Thr/Thr187 and Ile/Thr187 genotypes were more likely to have pleural effusions (P = 0.038, OR 1.874 [95% CI 1.033-3.411]) and anti-SSA/Ro antibody production (P = 0.046, OR 2.221 [95% CI 1.013-4.897]). Combined analysis of 4 groups of Asian patients strongly supported the association of the FCGR2B Thr187 allele with the lupus phenotype (P = 0.000159).


CONCLUSIONS
The FcgammaRIIb transmembrane polymorphism is a strong disease susceptibility candidate in epistasis with other genetic effects in Taiwanese and other Asian populations. It may also play a more prominent role in male patients with SLE.
Chen
Ji-Yih
JY
Department of Medicine, Chang Gung Memorial Hospital, Taiwan, Republic of China. jmwu@uab.edu
Wang
Chin Man
CM
Ma
Chung-Chun
CC
Luo
Shue-Fen
SF
Edberg
Jeffrey C
JC
Kimberly
Robert P
RP
Wu
Jianming
J
D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics; D004843:Epistasis, Genetic; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D017452:Receptors, IgG / Q000097:blood / Q000235:genetics*; D012307:Risk Factors; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013624:Taiwan
C499173:FCGR2B protein, human; D017452:Receptors, IgG