高原人群CYP2C9和VKORC1基因多态性及其与华法林用药剂量的相关性研究

Study on CYP2C9 and VKORC1 gene polymorphisms and their correlation with warfarin dosage in high altitude population

摘要:

目的 探讨高原人群基于中国人群华法林用药剂量计算公式（PRC模型）和国际华法林遗传药理学协会推荐的亚裔人群华法林剂量计算公式（IWPC模型）两种模型预测剂量的准确性及其临床应用价值。方法 回顾性分析曲靖市第一人民医院2016年10月—2020年1月375例行华法林代谢基因多态性检测患者的临床资料。通过qRT-PCR检测CYP2C9和VKORC1基因多态性，记录患者基本信息和临床用药情况，采用两种模型计算预测剂量并分析其与维持剂量［国际标准化比值（INR）稳定维持在2.0～3.0范围内时所服用的华法林剂量］的相关性，评估两模型预测的准确性。结果 在实际治疗过程中患者是否选择服用华法林进行抗凝，通常与患者的性别、身高、吸烟史、是否合并房颤、是否注射低分子肝素钙无关，而与患者年龄、体重、体表面积（BSA）、初INR、是否置换主动脉瓣膜、是否服用阿司匹林、利伐沙班或氯吡格雷相关。375例患者CYP2C9和VKORC1基因频率符合Hardy-Weinberg遗传平衡定律，其中CYP2C9基因*1/*1（AA）、*1/*3（AC）及*3/*3（CC）基因型频率分别为93.07%（349/375）、6.93%（26/375）和0.00%（0/375），VKORC1-1639基因AA、AG和GG基因型频率分别为82.66%（310/375）、16.27%（61/375）和1.07%（4/375）。无论是使用PRC还是IWPC模型，除CYP2C9*1/*1 & VKORC1AA（n =289）组与CYP2C9*1/*3 & VKORC1AG（n =5）组预测剂量的差异无统计学意义（P >0.05）外，其他所有基因型组预测剂量两两比较均有差异（P <0.05）。在收集到维持剂量的174例患者中，CYP2C9*1/*1 & VKORC1 AG和CYP2C9*1/*1 & VKORC1 GG组维持剂量分别为［（3.41±1.01）mg，n =30］和［（4.75±0.35）mg，n =2］，均高于CYP2C9*1/*1 & VKORC1 AA组［（2.59±0.73）mg，n =136］（P <0.05）；CYP2C9*1/*3 & VKORC1 AA组维持剂量为［（2.00±0.53）mg，n =5］，低于其他基因型组合（P <0.05）。PRC和IWPC模型预测准确性分别为72.99%（127/174）和62.64%（109/174）；Pearson相关系数（r₁ =0.546，r₂ =0.567）；决定系数（R₁²=0.298，R₂²=0.322）。两个模型预测剂量间无差异（r =0.839，P >0.05）。结论 携带CYP2C9*3等位基因的患者对华法林更敏感，所需华法林剂量较低，而携带VKORC1-1639 G等位基因的患者需要更高剂量的华法林才可以获得有效的抗凝疗效。基因组学预测剂量可为临床使用华法林剂量提供依据，提高抗凝治疗的安全性和有效性。

Abstract:

Objective To explore the accuracy and clinical value of dose prediction based on warfarin dose calculation formula (PRC model) in Chinese population and warfarin dose calculation formula (IWPC model) in Asian population recommended by the International Association of warfarin genetics and pharmacology.Methods The clinical data of 375 patients with warfarin metabolic gene polymorphism in Qujing first people's Hospital from October 2016 to January 2020 were analyzed retrospectively. The gene polymorphisms of CYP2C9*3 and VKORC1 were detected by qRT-PCR, and the basic information and clinical medication of patients were recorded. The predicted dose was calculated by two models, and its correlation with the maintenance dose (warfarin dose taken when the international standardized ratio (INR) was stably maintained in the range of 2.0 to 3.0) was analyzed to evaluate the accuracy of the prediction of the two models.Results Whether patients choose to take warfarin for anticoagulation in the actual treatment process is usually not related to the patient's gender, height, smoking history, atrial fibrillation, and low molecular weight heparin calcium injection, but related to the patient's age, weight, body surface area (BSA), initial INR, aortic valve replacement, aspirin, rivaroxaban, and clopidogrel. The frequencies of CYP2C9 and VKORC1 genes in 375 patients were in accordance with Hardy Weinberg's law of genetic balance. The frequencies of CYP2C9 gene *1/*1 (AA), *1/*3 (AC), and *3/*3 (CC) genotypes were 93.07% (349/375), 6.93% (26/375), and 0.00% (0/375) respectively, and the frequencies of VKORC1-1639 gene AA, AG, and GG genotypes were 82.66% (310/375), 16.27% (61/375), and 1.07% (4/375) respectively. No matter using the PRC or IWPC model, there was no significant difference in the predicted dose between CYP2C9*1/*1 & VKORC1 AA (n = 289) group and CYP2C9*1/*3 & VKPRC1 AG (n =5) (P >0.05). Among 174 patients with maintenance dose, the maintenance dose of CYP2C9*1/*1 & VKORC1 AG and CYP2C9*1/*1 & VKORC1 GG group were[(3.41±1.01) mg, n = 30] and [(4.75 ± 0.35) mg, n = 2], respectively, which were higher than that of CYP2C9*1/*1 & VKORC1 AA group [(2.59 ± 0.73) mg, n = 136] (P < 0.05); the maintenance dose of CYP2C9*1/*3 & VKORC1 AA group was [(2.00 ± 0.53) mg, n = 5], which was lower than that of other genotype combinations (P < 0.05). The prediction accuracy of PRC and IWPC models were 72.99% (127/174) and 62.64% (109/174), respectively; Pearson correlation coefficient (r₁ = 0.546, r₂ = 0.567); determination coefficient (R₁² = 0.298, R₂² = 0.322). There was no difference between the predicted doses of the two models (r = 0.839, P > 0.05).Conclusion Patients with CYP2C9*3 allele are more sensitive to warfarin and required lower warfarin dosage, while patients carrying the VKORC1-1639 G allele required a higher warfarin dosage to reach target effective anticoagulant therapy. The detection results of CYP2C9 and VKORC1 gene polymorphisms can provide the basis for warfarin dosage adjustment and improve the safety and effectiveness of warfarin anticoagulant therapy.