Effect of CYP2C9, VKORC1, CYP4F2, and GGCX gene variants and patient characteristics on acenocoumarol maintenance dose: Proposal for a dosing algorithm for Moroccan patients

Frequencies of VKORC1-1639G>A and rs397509427 in Patients on Warfarin and Healthy Syrian Subjects

Background

Vitamin K epoxide reductase complex subunit 1 (VKORC1) gene encodes a key enzyme with multiple cellular activities, namely, the reduction of vitamin K to its active form. VKORC1-1639G>A (rs9923231) is a common single nucleotide polymorphism with a crucial impact on warfarin dosing and possibly other physiological functions. This study aimed at investigating the frequencies of VKORC1-1639G>A alleles and genotypes in Syrian healthy subjects and patients on warfarin for different indications.

Methods

A total of 138 individuals were enrolled in this cross-sectional study. Genomic DNA was extracted from both patients on warfarin and healthy subjects, and polymerase chain reaction (PCR) specific amplicons were genotyped via standard sequencing which also allowed the detection of rs397509427. Comparisons of -1639G>A frequency with other populations were drawn.

Results

Of 94 patients on warfarin, 53 (56.38%) were with idiopathic venous thromboembolism (VTE). Despite comparable frequencies of the -1639A allele (47% and 50%), the AA and GA genotypes were at disparate frequencies of 93.2% versus 79.8% in the healthy subjects (n = 44) versus patients on warfarin, respectively. Carriers of the GG genotype were at a four-fold increased risk of VTE in comparison with those of the AA and GA genotypes (odds ratio (OR) = 4, 95% CI = 1.105 - 13.6, P = 0.0469). All study subjects were wild-type for the rs397509427 variant.

Conclusions

Our results prove a high -1639A prevalence in Syrian healthy subjects and patients on warfarin at frequencies comparable to other Mediterranean and Middle Eastern populations. The A allele carriers are at a lower VTE risk, whereas a global prevalence gradient of the G allele is suggested to be associated with VTE risk.

Warfarin pharmacogenomics in African populations: the importance of ethnicity-based algorithms

Tweetable abstract It is well accepted that pharmacogenomics (PGx) information from Asia and Europe should not be applied to Africa. More work is needed on different ethnic groups to generate population-specific algorithms that can be used effectively and safely.

Establishment of predicting equation for individual sufentanil dosage postoperatively based on gene polymorphisms

BACKGROUND

Postoperative analgesia is widely used for patients undergoing major surgeries. Individual differences in genetic polymorphisms may be obstructive factors for accurately anesthetics using. However, the equation for predicting sufentanil dosage postoperatively based on genetic design has been established yet. Our aim was to establish sufentanil dosage postoperatively prediction equation based on patients' genetic polymorphisms.

METHODS

One hundred forty patients with total gastrectomy and radical resection of pulmonary carcinoma were included. To establish sufentanil dosage postoperatively for patients with gastric cancer, we collected patients' basic information and CYP3A4*1G, COMTVal158Met, OPRM1A118G, and ABCB1C3435T gene sequencing results. To verify this equation, we put patients' with lung cancer surgeries information into it.

RESULTS

The sufentanil dosage prediction equation postoperatively was y = 4.104 - 0.222 × (gender) + 0.021 × (OPRM1A118G) + 0.249 × (ABCB1C3435T). Patients' with lung cancer surgeries information were substituted into it. The results showed no significant differences between predicted and actual sufentanil dosage (p > 0.05).

CONCLUSION

We established the prediction equation for individual sufentanil dosage postoperatively based on gene polymorphisms. The results showed this prediction equation was valid, which might be used for different types of surgeries. We established an equation for individual dosage of sufentanil for postoperative analgesia based on gene polymorphisms. The results show that the prediction equation is valid, the information might be used for different types of postoperative analgesia, and the painful patients will have great potential safe and personalized pain control after analgesic therapy. It might also have potential as a clinical tool.

Efficacy and Safety of Genotype-Guided Warfarin Dosing in the Chinese Population: A Meta-analysis of Randomized Controlled Trials

AIMS

To evaluate the efficacy and safety of using genetic information to guide warfarin dosing in the Chinese population.

METHODS

This meta-analysis was conducted among the published, randomized, controlled trials (RCTs) in the Chinese population comparing genotype-guided warfarin dosing (PG group) with clinical or standard warfarin dosing (STD group). RCTs published on or before January 2018 were identified using the PubMed, Embase, Cochrane Library, CNKI, Chinese VIP database, and Chinese Wanfang database.

RESULT

Intotal, 2137 participants from 14 RCTs were included in the meta-analysis. Primary analysis showed that both bleeding events [odds ratio (OR) = 0.24; 95% confidence interval (CI), 0.11-0.52; P = 0.0003] and adverse events (OR = 0.60; 95% CI, 0.43-0.83; P = 0.002) were significantly lower in the genotype-guided group than in the clinical or standard group. The percentage of patients who received a warfarin-stable therapeutic dose during follow-up was increased in the genotype-guided group compared with the percentage in the clinical or standard group (OR = 2.68; 95% CI, 1.82-3.95; P < 0.00001). In the genotype-guided group, the time to a stable therapeutic dose (mean difference = -7.98; 95% CI, -9.08 to -6.87; P < 0.00001) and the time to the first target value (mean difference = -1.87; 95% CI, -3.41 to -0.32; P = 0.02) were shortened compared with those of the clinical or standard group, but there was no difference for international normalized ratio >4, between the 2 groups (OR = 0.42; 95% CI, 0.14-1.25; P = 0.12).

CONCLUSIONS

Genotype-guided warfarin-dosing algorithms could improve the efficacy and safety of warfarin anticoagulation in the Chinese population.