Immunoglobulin GM genes and IgG antibodies to cytomegalovirus in patients with systemic sclerosis.Clin Exp Rheumatol. 2004 Jan-Feb; 22(3 Suppl 33):S35-7.CE
To determine the role of GM and KM genes--genetic markers of immunoglobulin gamma and kappa chains, respectively--in humoral immunity to human cytomegalovirus (HCMV) in patients with systemic sclerosis (SSc; scleroderma).
A total of 137 Caucasian patients with SSc and 145 ethnically matched controls were genotyped for GM f/3, z/17, n+/23+, n-/23-, KM 1, and KM 3 alleles by polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequencing methods. IgG antibodies to HCMV were measured by an enzyme-linked immunosorbent assay.
In SSc patients, GM f,z genotypes were strongly associated with the occurrence of anti-HCMV IgG antibodies. The frequency of the GM f homozygotes was lower (42.2 vs 62.2%; p= 0.02; OR=0.4) and the frequency of the GM f,z heterozygotes was higher (51.1 vs 26.7%; p = 0.006; OR = 2.8) in SSc patients with IgG antibodies to HCMV than in subjects who lacked these antibodies. This association was not observed in the control group. KM and GM n genotypes were not significantly associated with the prevalence of these antibodies.
GM f,z alleles or alleles in linkage disequilibrium with them influence the generation of IgG antibodies to HCMV in patients with SSc.