Gh. Hong et al., ASSOCIATION OF COMPLEMENT C4 AND HLA-DR ALLELES WITH SYSTEMIC LUPUS-ERYTHEMATOSUS IN KOREANS, Journal of rheumatology, 21(3), 1994, pp. 442-447
Objective. To examine the association of complement C4 and HLA-DR to s
ystemic lupus erythematosus (SLE) susceptibility in Korea. Methods. Co
mplement C4 protein typing was carried out by immunofixation and immun
oblotting methods using EDTA-plasma from 60 patients with SLE and 72 h
ealthy controls. Restriction fragment length polymorphism analysis of
C4 genes was also carried out using TaqI or HindIII for restriction en
zymes. HLA-DR was determined by polymerase chain reaction amplificatio
n with sequence specific primers using genomic DNA from 67 patients wi
th SLE and 72 healthy controls. Results. The frequency of the C4AQ0 al
lele was significantly higher in the patients with SLE than in control
s (41.7 vs 25.0%, p < 0.05). The deletion of the C4A gene commonly fou
nd in Caucasian patients with SLE was not observed in any patients. Fo
r HLA-DR, a significant increase of the haplotype DRB1()1501-DRB5(*)0
101 was observed in the patients (26.9 vs 12.5%, p < 0.05) and DR9 was
also significantly increased (23.9 vs 11.1%, p < 0.05). An increase i
n each DR2 and DR9 was independent of an increase in C4AQ0. The freque
ncies of DR2 and DR9 were significantly decreased in patients with ren
al involvement and alopecia, respectively. Conclusion. Our data sugges
ted that the presence of C4AQ0 allele, DRB1()1501-DRB5(*)0101 haploty
pe and DR9 contributed to susceptibility to SLE in Koreans and that Ko
rean SLE is based on a different genetic background from Caucasian pat
ients.