Cytokine gene variants and venous thrombotic risk in the BRATROS (BRAZILIAN THROMBOSIS STUDY)

INTRODUCTION: Venous thrombosis (VT) and inflammation are two closely related entities. In the present investigation we assessed whether there is a relation between genetic modifiers of the inflammatory response and the risk of VT. MATERIALS AND METHODS: 420 consecutive and unrelated patients with an objective diagnosis of deep VT and 420 matched controls were investigated. The frequencies of the following gene polymorphisms were determined in all subjects: TNF-alpha-308 G/A, LT-alpha+252 A/G, IL-6-174 G/C, IL1-ra 86 bp VNTR, IL-10-1082 A/G and CD-31 125 C/G. RESULTS: Overall odds ratio (OR) for VT related to TNF-alpha-308 G/A, LT-alpha+252 A/G, IL-6-174 G/C, A1 allele (4 bp repeat) of the IL1-ra 86 bp VNTR, IL-10-1082 A/G and CD-31 125 C/G were respectively: 1.0 (CI95: 0.8-1.5), 1.3 (CI95: 1.0-1.7), 1.1 (CI95: 0.9-1.5), 1.6 (CI95: 1-2.5), 1.2 (CI95: 0.8-1.7) and 0.8 (CI95: 0.6-1.1). A possible interaction between polymorphisms was observed only for the co-inheritance of the mutant alleles of the LT-alpha+252 A/G and IL-10-1082 G/A polymorphisms (OR=2; CI95: 1.1-3.8). The risk of VT conferred by factor V Leiden and FII G20210A was not substantially altered by co-inheritance with any of the cytokine gene polymorphisms. CONCLUSIONS: Cytokine gene polymorphisms here investigated did not significantly influence venous thrombotic risk.