Association of ABCB1 gene polymorphisms rs1128503, rs2032582, rs4148738 with anemia in patients receiving dabigatran after total knee arthroplasty.

PURPOSE: Dabigatran is usually prescribed in recommended doses without monitoring of the blood coagulation for the prevention of venous thromboembolism after joint arthroplasty. ABCB1 is a key gene in the metabolism of dabigatran etexilate. Its allele variants are likely to play a pivotal role in the occurrence of hemorrhagic complications.

METHODS: The prospective study included 127 patients with primary knee osteoarthritis undergoing total knee arthroplasty. Patients with anemia and coagulation disorders, elevated transaminase and creatinine levels as well as already receiving anticoagulant and antiplatelet therapy were excluded from the study. The association of ABCB1 gene polymorphisms rs1128503, rs2032582, rs4148738 with anemia as the outcome of dabigatran therapy was evaluated by single-nucleotide polymorphism analysis with a real-time polymerase chain reaction assay and laboratory blood tests. The beta regression model was used to predict the effect of polymorphisms on the studied laboratory markers.

RESULTS: For all polymorphisms there was no association with the level of platelets, protein, creatinine, alanine transaminase, prothrombin, international normalized ratio, activated partial thromboplastin time and fibrinogen. Carriers of rs1128503 (TT) had a significant decrease of hematocrit (p = 0.001), red blood count and hemoglobin (p = 0.015) while receiving dabigatran therapy during the postoperative period compared to the CC, CT. Carriers of rs2032582 (TT) had a significant decrease of hematocrit (p = 0.001), red blood count and hemoglobin (p = 0.006) while receiving dabigatran therapy during the postoperative period compared to the GG, GT phenotypes. These differences were not observed in carriers of rs4148738.

CONCLUSION: It might be necessary to reconsider thromboprophylaxis with dabigatran in carriers of rs1128503 (TT) or rs2032582 (TT) polymorphisms in favor of other new oral anticoagulants. The long-term implication of these findings would be the reduction of bleeding complications after total joint arthroplasty.