Hm. Dijstelbloem et al., Fc gamma receptor polymorphisms in systemic lupus erythematosus - Association with disease and in vivo clearance of immune complexes, ARTH RHEUM, 43(12), 2000, pp. 2793-2800
Objective, Fc receptors for IgG (Fc gammaR) play a prominent role in the cl
earance of immune complexes in systemic lupus erythematosus (SLE). Polymorp
hisms of Fc gammaR have been proposed as genetic factors that influence sus
ceptibility to SLE, We analyzed 3 functional Fc gammaR polymorphisms in a s
trictly Caucasian population of SLE patients, and determined the influence
of these polymorphisms on the clearance of immune complexes in vivo,
Methods. Genomic DNA was isolated from 230 Caucasian patients with SLE and
154 controls. Amplification of Fc gammaR-genomic regions in allotype-specif
ic polymerase chain reactions was used to distinguish the genotypes, In add
ition, we analyzed the Fc gammaR genotypes of 13 patients with SLE who part
icipated in a study determining the half-life of IgG-coated erythrocytes in
the blood.
Results. We found a strong trend toward skewing of Fc gamma RIIa, with an e
nrichment of the homozygous Fc gamma RIIa-R/R131 genotype in patients compa
red with controls. We did not find a correlation between this genotype and
the development of lupus nephritis, However, we established that the half-l
ife of IgG-coated erythrocytes in the blood was prolonged in patients expre
ssing the Fc gamma RIIa-R/R131 genotype, The homozygous Fc gamma RIIIa-F/F1
58 genotype was found more frequently in patients with arthritis and/or ser
ositis,
Conclusion, In Caucasian populations, the R/H polymorphism of Fc gamma RIIa
is a minor determinant in susceptibility to SLE, whereas the V/F polymorph
ism of Fc gamma RIIIa is associated with a set of disease manifestations, N
otably, the R/H polymorphism of Fc gamma RIIa affects the clearance of immu
ne complexes in vivo, which may influence the course of a disease such as S
LE.