Early atherosclerosis and IgG2 to bacteria are associated with FcgammaRIIa genotype in non-smokers.
BACKGROUND
Involvement of low density lipoprotein (LDL) immune complexes (ICs) in atherogenesis has been proposed. Human FcgammaRIIa receptor (CD32) plays a crucial role in the phagocytosis of IgG(2) ICs and a functional point mutation 131His/Arg diminishes IgG(2) binding to the receptor.


METHODS
We examined FcgammaRIIa-131His/Arg polymorphism, IgG(2) antibody titres to oxidized low-density lipoprotein (OxLDL) and Streptococcus pneumoniae cell wall polysaccharide (CWPS) and subclinical atherosclerosis in a large cohort of Finnish subjects (n = 1041).


RESULTS
Non-smoking subjects with homozygous 131His/His genotype had more premature atherosclerosis (P = 0.004) and higher IgG(2) to bacterial CWPS (P = 0.002) compared with other genotypes. Smoking subjects had significantly higher intima-media thickness (IMT) than that of non-smokers (P < 0.001) and genotype-dependent associations were indistinct. There was no association between FcgammaRIIa genotype and antibody titres to OxLDL.


CONCLUSIONS
Our data demonstrate that FcgammaRIIa 131His/Arg polymorphism is associated with subclinical atherosclerosis in non-smoking subjects. Furthermore, FcgammaRIIa genotype is associated with IgG(2) titres to bacterial CWPS, but not to OxLDL. These data propose possible involvement of FcgammaRIIa receptor in atherogenesis.
Sämpi
M
M
University of Oulu, Oulu, Finland.
Ukkola
O
O
Päivänsalo
M
M
Kesäniemi
Y A
YA
Hörkkö
S
S
D050197:Atherosclerosis / Q000235:genetics* / Q000276:immunology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics* / Q000276:immunology; D008077:Lipoproteins, LDL / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics* / Q000276:immunology
C080568:Fc gamma receptor IIA; D007074:Immunoglobulin G; D008077:Lipoproteins, LDL; D017452:Receptors, IgG