Objective: To analyze candidate genes, related to cardiovascular disease (CVD) in general, and potentially involved in the inflammatory process, in RA patients from northern Sweden.
Methods: Four hundred and sixty-seven individuals (345 females; 122 males) with RA (ACR criteria), having a mean age of 61.8 +/- 13.0 years and mean disease duration of 16.2 +/- 12.1 years, were consecutively recruited and followed-up for 3 years. The prevalence of CVD, [(ischemic heart disease (IHD), deep vein thromboses/pulmonary embolism (DVT/PE) and/or stroke/TIA] and hypertension was registered. Candidate genes encoding for Beta-fibrinogen (G-455A), Factor XIIIA (Val34Leu), plasminogen activator inhibitor type-1 (PAI-1 4G/5G), and tumor necrosis factor receptor (TNFR)II (M196R) were analysed. Controls (n = 672) were randomly selected according to age and gender from the Medical Biobank of Northern Sweden. Polymorphisms were genotyped using a TaqMan 9700HT and the 5'nuclease allelic discrimination assay.
Results: The genotypes, carriers and alleles did not differ in distribution between patients and controls. Carriage of the TNFRII R variant was more frequent among patients with hypertension (p = 0.018). The genotype distribution of PAI-1 in patients with IHD differed significantly (p = 0.002) because carriage of 4G was more frequent (p = 0.024). Combined carriage of TNFRII 196R variant and Beta-fibrinogen-455A was a stronger predictor for hypertension than each genotype separately. The distribution of FXIIIA genotypes deviated significantly in RA patients with DVT/PE (p = 0.028) with an increased frequency of the Leu34 variant.
Conclusion: The unusual alleles of TNFRII, PAI-1 and FXIIIA were associated with CVD in RA patients. The combination of several of the rare types further increased the predictive values for CVD.