OBJECTIVETo investigate the impact of novel P2Y(12) receptor inhibitors including prasugrel or ticagrelor on platelet reactivity in patients with acute coronary syndrome (ACS) receiving percutaneous coronary intervention (PCI), and provide clinical data for novel oral P2Y(12) receptor inhibitors use among Chinese patients.

METHODSBetween October 2011 to February 2014, 174 consecutive patients (135 males; (67.8±11.8) years old) with ACS undergoing PCI in Kiang Wu Hospital, Macau were prospectively enrolled in this study. Oral aspirin and one P2Y(12) receptor inhibitor were administered for 5 days or above after PCI, patients were divided into clopidogrel, prasugrel and ticagrelor groups in accordance with the agent administered. Platelet reactivity of the patients was detected by VerifyNow P2Y(12) reaction unit (PRU); and the high on-treatment platelet reactivity (HPR) and non-HPR were defined as PRU≥208 and PRU<208 respectively. Patients with HPR during clopidogrel therapy were switched either to prasugrel or ticagrelor, or continued the same treatment; and then the platelet reactivity was monitored again.

RESULTSThere were 113 clopidogrel cases (64.9%), 20 prasugrel cases (11.5%) and 41 ticagrelor cases (23.6%). Fifty-seven cases (32.8%) were defined as HPR post P2Y(12) receptor inhibitor use, in which 55 cases (55/113, 48.7%) were treated with clopidogrel. The degree of inhibition of platelet reactivity was significantly different in patients on clopidogrel, prasugrel and ticagrelor therapy, percent inhibition assayed by the VerifyNow P2Y(12) system was 28.2%±23.5%, 61.4%±26.7% and 81.3%±19.8% respectively (P<0.05). Different degree of platelet reactivity was achieved by the 3 P2Y(12) receptor inhibitors at multiple time points. The among-group differences in platelet reactivity became apparent at the early treatment stage (P<0.05). Platelet aggregation decreased significantly in patients switched from clopidogrel to prasugrel or ticagrelor (P<0.05).

CONCLUSIONNovel oral P2Y(12) receptor inhibitors are more effective in inhibiting platelet reactivity in ACS patients, and our results show that novel oral P2Y(12) receptor inhibitors provide a new option for ACS patients with HPR post clopidogrel or high-risk features of ischemic complications, including stent thrombosis and post-PCI ischemic events.

Acute Coronary Syndrome ; Adenosine ; analogs & derivatives ; Aged ; Aspirin ; Blood Platelets ; Female ; Humans ; Male ; Percutaneous Coronary Intervention ; Platelet Aggregation ; Platelet Aggregation Inhibitors ; Platelet Function Tests ; Prasugrel Hydrochloride ; Prospective Studies ; Ticlopidine ; analogs & derivatives

Purinergic P2Y Receptor Antagonists ; Consensus ; Cardiovascular System ; Cardiology ; Asia

Objectives. Polymorphisms in metabolic genes which alter rates of bioactivation and detoxification have been shown to modulate susceptibility to colorectal cancer. This study sought to evaluate the colorectal cancer risk from environmental factors and to do polymorphism studies on genes that code for Phase I and II xenobiotic metabolic enzymes among Filipino colorectal cancer patients and matched controls. Methods. A total of 224 colorectal cancer cases and 276 controls from the Filipino population were genotyped for selected polymorphisms in GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subject participants.Results. Univariate logistic regression of non-genetic factors identified exposure to UV (sunlight) (OR 1.99, 95% CI: 1.16-3.39) and wood dust (OR 2.66, 95% CI: 1.21-5.83) and moldy food exposure (OR 1.61, 95% CI:1.11-2.35) as risk factors; while the NAT2*6B allele (recessive model OR 1.51, 95% CI :1.06-2.16; dominant model OR 1.87, 95% CI: 1.05-3.33) and homozygous genotype (OR 2.19, 95% CI: 1.19-4.03) were found to be significant among the genetic factors. After multivariate logistic regression of both environmental and genetic factors, only UV radiation exposure (OR 2.08, 95% CI: 1.21-3.58) and wood dust exposure (OR 2.08, 95% CI: 0.95-5.30) remained to be significantly associated with increasing colorectal cancer risk in the study population.Conclusion. This study demonstrated that UV sunlight and wood dust exposure play a greater role in influencing colorectal cancer susceptibility than genotype status from genetic polymorphisms of the GST and the NAT` genes.
Colorectal Neoplasms ; Polymorphism, Genetic

Objectives: The highly polymorphic nature of the CYP2D6 gene and its central role in the metabolism of commonly used drugs make it an ideal candidate for pharmacogenetic screening. This study aims to determine the prevalence of CYP2D6 polymorphisms among Filipinos and their association to lung cancer. Method: Forty seven single nucleotide polymorphisms (SNPs) of the CYP2D6 gene were genotyped from DNA samples of 115 cases with lung cancer and age- and sex-matched 115 controls. Results: Results show that 18 out of 47 polymorphisms have significant genotypic variability (>1% for at least 2 genotypes). No variant is associated with lung cancer. However, rs1135840, rs16947 and rs28360521, were found to be highly variable among Filipinos. Conclusion This study demonstrated that CYP2D6 polymorphisms are present among Filipinos, which, although not found to be associated with lung cancer, can be useful biomarkers for future pharmacogenetic studies. The SNP rs16947 is found to be associated with cancer and timolol-induced bradycardia; the SNP rs1135840, on the other hand, is only shown to be linked with cancer. The genetic variant rs28360521 is known to be associated with low-dose aspirin-induced lower gastrointestinal bleeding.
Pharmacogenetics ; Cytochrome P-450 CYP2D6 ; Lung Neoplasms ; Biomarkers