To investigate the associations between gout tophus and polymorphisms 869T/C and -509C/T in TGF-beta1 gene.
The polymorphisms 869T/C and -509C/T were determined in 73 gout patients and 114 healthy controls among male Taiwanese using the PCR-restriction fragment length polymorphism method. Each patient was matched with 1-2 controls by age within 1-2 yrs. The tophus number was measured from all the patients' arms and legs.
Neither 869T/C nor -509C/T showed a significant association between patients and controls in the proportions of genotypes, allele frequency or dominant and recessive models. The mean number of tophi for all patients was 1.53 +/- 3.44, showing a significant difference in distribution among the genotypes at polymorphism 869T/C (P = 0.006), but not those in polymorphism -509C/T (P > 0.05). Those carrying genotype CC at polymorphism 869T/C have a mean number of tophi 0.35 (+/- 1.11), which is significantly lower than those carrying genotype TT (3.73 +/- 4.67; P < 0.05). Those with genotype TT at polymorphism 869T/C also had 11.06 times the likelihood of having at least one tophus compared with the genotype CC after adjustment of hyperuricaemia (95% CI = 1.84, 66.36; P = 0.009). However, except for the tophus number, these two polymorphisms did not show any significant association with the clinical characteristics or biochemical markers.
The polymorphism 869T/C in TGF-beta1 gene has a significant association with the occurrence of tophus in gout patients.