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Management of adult patients with immune thrombocytopenia (ITP) is often unsatisfactory, due to variable efficacy of treatment, risk of life-threatening bleeding if disease control is poor, and side effects associated with treatment. Lack of data on the platelet count threshold associated with bleeding and infection risk associated with ITP treatment limits risk/benefit clinical decision making. We reviewed medical records of all ITP patients who were admitted to our hospital between 2012 and 2017 to evaluate the platelet count threshold for bleeding, infection burden associated with treatment, and real-world efficacy of second-line treatment. We demonstrated fair discrimination between platelet count and occurrence of bleeding, with 15 × 109/L being the optimal cut-off for predicting any bleeding while 20 × 109/L had the highest negative predictive value for severe bleeding. In multivariable analyses, patients who were treated with corticosteroids for at least 2 months were 5.3 times as likely to have an infection. In addition, rituximab response was strongly associated with response to frontline corticosteroids and infection was associated with older age ≥ 65 years and corticosteroid dependence. If corticosteroids are initiated, physicians should aim for the shortest duration of treatment before switching to effective second-line agents for hemostatic platelet counts.

Objectives Pregnancy-associated venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is associated with increased risk of maternal mortality and morbidity. This study aimed to assess potential risk factors for pregnancy-associated VTE. Methods In this case-control study, women with pregnancy-associated VTE were identified via International Classification of Diseases codes and included if they had been objectively diagnosed with VTE during pregnancy or within six weeks postpartum, from 2004 to 2016, at KK Women’s and Children’s Hospital or Singapore General Hospital in Singapore. Controls, i.e. pregnant women without VTE, were selected from a prospective longitudinal study. The odds ratio (OR) for VTE was computed for a range of maternal and obstetric factors. Results and conclusions From 2004 to 2016, 89 cases of pregnancy-associated VTE and 926 controls were identifed and analysed using logistic regression. The most significant risk factors for pregnancy-associated VTE were smoking (OR 5.44, p=0.0002) and preterm delivery (OR 5.06, p=0.023). Malay race, multiparity, non-O blood group and caesarean section, were also identified to be of higher risk. These risk factors should be useful in the development of thromboprophylaxis strategies for pregnancy and the postpartum period, especially in Singapore.

Objective To determine the cumulative incidence, time of occurrence and risk factors of pregnancy-associated pulmonary embolism (PE) in Singapore, and to review the maternal mortality ratio of PE over the last four decades. Study design and setting In this retrospective epidemiology review, women with pregnancy-associated PE were identified via International Classification of Diseases codes and included if they had been objectively diagnosed on imaging with PE during pregnancy or within 6 weeks postpartum from 2004 to 2016 at KK Women's and Children's Hospital (KKH) and Singapore General Hospital (SGH) in Singapore. The medical records were reviewed and the time of occurrence of confirmed PE cases and risk factors for PE were noted. Results There were 18 PE cases out of 174 708 deliveries, of which two were fatal, giving a cumulative incidence of PE at 1.03 per 10 000 deliveries and a mortality rate of 11.1%. The maternal mortality ratio is 1.14 per 100 000 deliveries, the lowest compared to that of the previous three decades (2.5-4.9 per 100 000 deliveries). Majority of PE (66.7%) occurred during the first 2 weeks postpartum. Cumulative incidence of postpartum PE was four times more in caesarean section compared to vaginal delivery at 1.58 per 10 000 deliveries and 0.40 per 10 000 deliveries, respectively. Conclusion Although the cumulative incidence of pregnancy-associated PE in Singapore is low, it is comparable to the United Kingdom (UK) and United States (US). Risk assessment and thromboprophylaxis have decreased PE mortality significantly during this period.

The Universal Health Coverage goals call for access to affordable palliative care to reduce inequities in “total pain” and suffering. To achieve this, a patient-centred understanding of these inequities is required. To assess association of total pain and suffering (i.e. physical, psychological, social, and spiritual health outcomes) and perceived health care quality with financial difficulties among stage IV solid malignancy patients. Using baseline data from the COMPASS cohort study, we assessed total pain and suffering including physical (physical and functional well-being, pain, symptom burden), psychological (anxiety, depression, emotional well-being), social (social well-being), and spiritual (spiritual well-being, hope) outcomes and perceived health care quality (physician communication, nursing care, and coordination/responsiveness). Financial difficulties were scored by assessing patient perception of the extent to which their resources were meeting expenses for their treatments, daily living, and other obligations. We used multivariable linear/logistic regression to test association between financial difficulties and each patient-reported outcome. Six hundred stage IV solid malignancy patients in Singapore. Thirty-five percent reported difficulty in meeting expenses. A higher financial difficulties score was associated with worse physical, psychological, social, spiritual outcomes, and lower perceived quality of health care coordination and responsiveness (i.e. greater total pain and suffering) (all p

COVID-19 caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and other respiratory viral (non-CoV-2-RV) infections are associated with thrombotic complications. The differences in prothrombotic potential between SARS-CoV-2 and non-CoV-2-RV have not been well characterised. We compared the thrombotic rates between these two groups of patients directly and further delved into their coagulation profiles. In this single-center, retrospective cohort study, all consecutive COVID-19 and non-CoV-2-RV patients admitted between January 15th and April 10th 2020 were included. Coagulation parameters studied were prothrombin time and activated partial thromboplastin time and its associated clot waveform analysis (CWA) parameter, min1, min2 and max2. In the COVID-19 (n = 181) group there were two (1.0 event/1000-hospital-days) myocardial infarction events while one (1.8 event/1000-hospital-day) was reported in the non-CoV-2-RV (n = 165) group. These events occurred in patients who were severely ill. There were no venous thrombotic events. Coagulation parameters did not differ throughout the course of mild COVID-19. However, CWA parameters were significantly higher in severe COVID-19 compared with mild disease, suggesting hypercoagulability (min1: 6.48%/s vs 5.05%/s, P 2 vs 0.74%/s2, P = 0.033). In conclusion, the thrombotic rates were low and did not differ between COVID-19 and non-CoV-2-RV patients. The hypercoagulability in COVID-19 is a highly dynamic process with the highest risk occurring when patients were most severely ill. Such changes in haemostasis could be detected by CWA. In our population, a more individualized thromboprophylaxis approach, considering clinical and laboratory factors, is preferred over universal pharmacological thromboprophylaxis for all hospitalized COVID-19 patients and such personalized approach warrants further research.

Infections cause varying degrees of haemostatic dysfunction which can be detected by clot waveform analysis (CWA), a global haemostatic marker. CWA has been shown to predict poor outcomes in severe infections with disseminated intravascular coagulopathy. The effect of less severe bacterial and viral infections on CWA has not been established. We hypothesized that different infections influence CWA distinctively. Patients admitted with bacterial infections, dengue and upper respiratory tract viral infections were recruited if they had an activated partial thromboplastin time (aPTT) measured on admission. APTT-based CWA was performed on Sysmex CS2100i automated analyser using Dade Actin FSL reagent. CWA parameters [(maximum velocity (min1), maximum acceleration (min2) and maximum deceleration (max2)] were compared against control patients. Infected patients (n = 101) had longer aPTT than controls (n = 112) (34.37 ± 7.72 s vs 27.80 ± 1.59 s, p 2; 0.74 ± 0.16%/s2), bacterial infection has higher CWA results (6.92 ± 1.60%/s; 1.04 ± 0.28%/s2; 0.82 ± 0.24%/s2, all p 2; 0.43 ± 0.14%/s2, all p 2; 0.73 ± 0.18%/s2, all p > 0.05). CWA parameters demonstrated positive correlation with C-reactive protein levels (min1: r = 0.54, min2: r = 0.44, max2: r = 0.34; all p

Race is touted as an independent risk factor for venous thromboembolism (VTE), although the basis for this is varied and contentious. Comparison of plasma thrombin generation (TG) using calibrated automated thrombogram (CAT) across races offers a modality that objectively measures global hemostatic function to evaluate this influence. Direct comparative data across races are currently not available. Aim is to establish the influence of race on plasma TG. Sixty normal participants, matched for age and gender, equally representing 4 races—Caucasian, Chinese, Indian, and Malay—were recruited. Thrombin generation parameters (lag time, time to peak, peak, and endogenous thrombin potential [ETP]) in platelet-poor plasma were measured using CAT. The mean ETP (standard deviation) for the different races were Caucasians: 1338.18 (194.19) nM·min; Chinese, 1318.91 (108.90) nM·min; Indians, 1389.81 (182.61) nM·min; and Malays, 1436.21 (184.24) nM·min. Caucasians had the longest mean lag time of 2.59 ± 0.37 seconds; Indians had the highest mean peak of 284.22 ± 30.74 nM, and Malays had the longest mean time to peak of 5.47 ± 0.59 seconds. Analysis based on race did not demonstrate any significant difference for all TG parameters. The greatest mean difference of ETP between any 2 races (Malays and Chinese) was 117.30 nM·min (95% confidence interval: −45.86 to 280.46 nM·min) which was within the predefined limit of equivalence. In a cohort of healthy participants, TG mediated by plasma factors is not influenced by race and does not explain the reported racial differences in VTE incidence. For the 4 racial groups studied, the use of separate normal ranges for plasma TG might not be essential.

BackgroundFamily caregivers of patients with advanced cancer have been reported to provide long hours of care and be at risk for poor psychological outcomes. Although research has focused on the nature of caregiving burden, little attention has been paid to identifying protective factors that improve caregiver psychological outcomes.AimWe examined the relationship between caregivers’ time spent caregiving and the following psychological outcomes: anxiety, depression and caregiving esteem. Subsequently, we explored the main and moderating effects of caregiver-perceived self-competency and sense of meaning on caregiver psychological outcomes.Design/participantsCross-sectional analysis was conducted using the baseline data from an ongoing cohort study. Family caregivers of advanced cancer patients (n=287) were recruited from two tertiary hospitals in Singapore.ResultsTime spent caregiving was not significantly associated with caregiver anxiety, depression or caregiving esteem. However, significant main effects of self-competency on anxiety and caregiving esteem; and sense of meaning on anxiety, depression and caregiving esteem were observed. Moderator analyses further indicated that self-competency attenuated the positive relationship between time spent caregiving and anxiety, while sense of meaning attenuated the negative relationship between time spent caregiving and caregiving esteem.ConclusionGreater perceived self-competency and sense of meaning are related to better caregiver psychological outcomes, and protect caregivers from worsening outcomes as caregiving hours increase. Our findings suggest that screening caregivers for distress is an important part of care, and that supportive interventions for caregivers should aim to enhance their perceived caregiving competencies and the ability to make meaning of their caregiving role.

Introduction: A hypercoagulable state is a predisposition for venous thromboembolism (VTE). The activated partial thromboplastin time (aPTT)-based clot waveform analysis (CWA) is a global haemostatic measure but its role in assessment of hypercoagulability and thrombotic disorders is uncertain. We aimed to study the changes of CWA parameters in acute VTE. We hypothesized that patients with acute VTE would demonstrate higher CWA values than control patients without VTE and having elevated CWA parameters is associated with acute VTE. Materials and methods: Clot waveform analysis data from patients (N = 45) with objectively proven acute VTE who had an aPTT performed prior to initiation of anticoagulation were compared with controls (N = 111). The CWA parameters measured were min1, min2, max2 and delta change. Results: While the mean aPTT between VTE patients and controls did not differ (P = 0.830), the mean CWA parameters were significantly higher among VTE patients than controls (min1, P < 0.001; min2, P = 0.001; max2, P = 0.002; delta change, P < 0.001). There were significantly more cases within the VTE group exhibiting CWA values above their reference intervals than the control group (all P < 0.001), with the odds ratios for VTE of 8.0, 5.2, 4.8 and 18.6 for min1, min2, max2 and delta change, respectively (all P < 0.001). Conclusions: Patients with acute VTE had elevated aPTT-based CWA parameters than controls. Higher CWA parameters were significantly associated with acute VTE.

Non-transfusion-dependent thalassaemia (NTDT) is associated with a hypercoagulable state with thrombotic risk highest after splenectomy. Various mechanisms have been proposed. Although an antiplatelet agent is commonly recommended as thromboprophylaxis in NTDT, the role of platelets contributing to this hypercoagulable state is not well-defined. This study aims to evaluate the role of platelets contributing to hypercoagulability in NTDT patients using thrombin generation (TG). Platelet-rich (PRP) and platelet-poor plasma (PPP) were collected from NTDT patients (n = 30) and normal controls (n = 20) for TG measurement and compared. Controls had higher endogenous thrombin potential (ETP) in PPP (1204.97 nM.min vs 911.62 nM.min, p

Purpose Herbs with “blood-activating” properties by traditional medicine theory often raise concerns for their possible anti-platelet or anticoagulation effects based on reports from in vitro studies. Such herbs have been implicated for bleeding manifestations based on only anecdotal reports. In particular, the combination of such herbs with anti-platelet agents is often empirically advised against despite lack of good clinical evidence. Here we studied 3 commonly used herbal preparations Curcuma longa, Angelica sinensis and Panax ginseng on their respective anti-platelet and anticoagulation effect, alone and in combination with aspirin. Study design This is a randomized, double-blind, placebo-controlled trial involving 25 healthy volunteers for each herbal preparation. Methods Each subject underwent 3 phases comprising of herbal product alone, aspirin alone and aspirin with herbal product, where each phase lasted for 3 weeks with 2 weeks of washout between phases. PT/APTT, platelet function by light transmission aggregometry and thrombin generation assay by calibrated automated thrombogram were measured at baseline and after each phase. Information on adverse reaction including bleeding manifestations was collected after each phase. Results On the whole there was no clinically relevant impact on platelet and coagulation function. With the exception of 5 of 24 subjects in the Curcuma longa group, 2 of 24 subjects in the Angelica sinensis group and 1 of 23 subjects in the Panax ginseng group who had an inhibition in arachidonic-acid induced platelet aggregation, there was no effect of these 3 herbals products on platelet aggregation by other agonists. Combination of these herbal products with aspirin respectively did not further aggravate platelet inhibition caused by aspirin. None of the herbs impaired PT/APTT or thrombin generation. There was no significant bleeding manifestation. Conclusions This study on healthy volunteers provides good evidence on the lack of bleeding risks of Curcuma longa, Angelica sinensis and Panax ginseng either used alone or in combination with aspirin.

Aim Hereditary thrombophilic markers are commonly screened among patients diagnosed as having venous thromboembolism, but optimal patient selection and the goals of screening may differ between populations. Determining the patterns of hereditary thrombophilia may improve screening strategies. Method An unselected cohort of venous thromboembolism patients in three tertiary institutions in Singapore was prospectively tested for the prevalence of deficiencies of protein C, protein S, antithrombin III, factor V Leiden and prothrombin 20210 gene mutations. Results Among 384 patients screened, the prevalences of protein S, protein C and antithrombin III were 9.20%, 1.18% and 4.19% respectively. Only one patient was positive for the factor V Leiden mutation and none tested positive for the prothrombin 20210 gene mutation. At least 1 in 9 patients (11.52%, 95% CI 8.20 to 15.93) will test positive for one of the above markers in an unselected group of 269 patients who completed all tests. The exclusion of patients with clinical risk factors did not improve the detection rates, in comparison with those with obvious provoking clinical risk factors (11.72%, 95% CI 7.36 to 18.06 vs 11.29%, 95% CI 6.73 to 18.18). When upper age limits were set for thrombophilia screening by decades, a statistical difference in the likelihood of a positive thrombophilia screen between younger and older patient was seen for patients below 40 (p Conclusion In Singapore and countries with similar demographics, hereditary thrombophilia screening should be confined to testing for protein C, protein S and antithrombin III.

Multiple myeloma is clinically heterogeneous and risk stratification is vital for prognostication and informing treatment decisions. As bortezomib is able to overcome several high-risk features of myeloma, the validity of conventional risk-stratification and prognostication systems needs to be reevaluated. We study the survival data of 261 previously untreated myeloma patients managed at our institution, where bortezomib became available from 2004 for the treatment of relapse disease. Patient and disease characteristics, and survival data were evaluated overall, and with respect to bortezomib exposure. Overall, the international staging system (ISS), metaphase karyotyping and interphase fluorescence in situ hybridization (FISH) were discerning of survival outcomes, where the median for the entire cohort was 5.2 years. However, when stratified by bortezomib exposure, only metaphase karyotyping was still discriminating of long-term prognosis. The presence of an abnormal nonhyperdiploid karyotype overrides all other clinical and laboratory parameters in predicting for a worse outcome on multivariate analysis (median survival 2.6 years, P = 0.001), suggesting that bortezomib used at relapse is better able to overcome adverse risk related to high tumor burden (as measured by the ISS) than adverse cytogenetics on conventional karyotyping. Metaphase karyotyping provides additional prognostic information on tumor kinetics where the presence of a normal diploid karyotype in the absence of any high-risk FISH markers correlated with superior survival and could act as a surrogate for lower plasma cell proliferation.

Temporary interruption of anticoagulation therapy is usually recommended for anticoagulated patients undergoing invasive procedures to minimize their bleeding risks. We validated the current consensus recommendation on warfarin interruption which were based on Western population studies to determine if they could safely be applied to Asians. The international normalized ratios (INR) in twenty warfarinised patients with a stable INR of 2-3 were prospectively measured at days 0, 3 and 5 after stopping warfarin for procedures or at completion of treatment. The median INR at days 0, 3 and 5 were 2.30 (95% CI 2.16-2.43), 1.32 (95% CI 1.22-1.57) and 1.06 (95% CI 1.05-1.13) respectively (P < 0.001 for trend). All patients were below therapeutic INRs by day 3 with 14 patients (70%, 95% CI 49.92-90.08) achieving INR readings below 1.5. By day 5, all INRs were below 1.5 and only 2 patients (10%, 95% CI -3.15 to 23.15) had INRs above 1.2. There were no significant peri-procedure bleeding or thrombotic events in the 1 month following interruption of warfarin. Our results suggest that the current international recommendation of stopping warfarin for 5 days prior to procedure can safely be applied to Asians without compromising risk of bleeding or thrombosis.

Strokes can have a catastrophic impact on patients' health-related quality of life (HRQoL). In addition to warfarin, two novel oral anticoagulants, i.e., dabigatran and rivaroxaban, have been approved to prevent strokes. This study aimed to use direct measures to elicit patient-reported utilities (i.e., preferences) for anticoagulant-related outcomes. A cross-sectional survey was administered to 100 patients taking warfarin in an anticoagulation clinic. Utilities for six long-term and four short-term anticoagulant-related health states were elicited by the visual analogue scale (VAS) and standard gamble (SG) methods. Health states with the highest SG-derived mean utility values were "well on rivaroxaban" (mean ± SD = 0.90 ± 0.15), "well on warfarin" (0.86 ± 0.17), and "well on dabigatran" (0.83 ± 0.18). Approximately half of the patients considered major ischemic stroke (-1.57 ± 6.77) and intracranial hemorrhage (-1.99 ± 6.98) to be worse than death. The percentages of patients who considered a particular health state worse than death ranged from 0 to 55 % among various health states assessed. The VAS had similar findings. Good logical consistency was observed in both VAS- and SG-derived utility values. Ischemic stroke and intracranial hemorrhage had a significant impact on patients' HRQoL. Greater variation in patients' preferences was observed for more severely impaired health states, indicating the need for individualized medical decision-making. In this study, both long-term and short-term health states were included in the utility assessment. The findings of this study can be used in cost-utility analysis of future anticoagulation therapies.

Chronic liver disease (CLD) has been suggested to be associated with venous thromboembolism (VTE) in western populations. However, little is known about the risk effects of CLD on VTE among Asians.To compute the prevalence of VTE among hospitalised Asian patients, and to evaluate the pattern and scale of risk effects of CLD on VTE occurrence.Retrospective study of hospital discharge database from 2004 to 2011 to identify patients with VTE and CLD using International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Australian Modification (ICD-9-AM) codes.Of 199904 medically managed inpatients during the 8years, 1744 (0.9%) patients had VTE. Patients with CLD had significant higher prevalence of VTE (non-cirrhosis CLD 1.5%, cirrhosis 2.0%) than patients without CLD (0.8%, p0.001). In the logistic regression analyses, non-cirrhosis CLD (odds ratio, OR 1.4, 95% CI 1.2-1.7, p0.001) and cirrhosis (OR 1.5, 95% CI 1.2-2.0, p=0.002) were significant predictors of VTE after adjustment for age, gender, ethnicity, hospital long stayer, cancer, infectious disease, and other comorbid conditions such as diabetic mellitus, anaemia, and cardiovascular, cerebrovascular, renal and pulmonary diseases.CLD, particular liver cirrhosis, increases the risks of VTE in hospitalised Asian patients. As CLD patients are perceived to be at risks of bleeding due to the prolonged clotting times and thrombocytopenia, the results of this study brings attention to opposite end of the haemostatic pendulum in patients with chronic liver disease.

The purpose of this study was to determine the impact of these 2 reperfusion strategies (reduced-dose alteplase plus abciximab or direct angioplasty plus abciximab) on fibrinolytic and thrombin generation activities. The effect of reduced-dose alteplase plus abciximab and direct angioplasty plus abciximab on hemostatic factors is unknown. Of 70 patients with acute myocardial infarction ofor = 6 hours, 34 were randomized to reduced-dose alteplase (35 to 50 mg in 1 hour) and 36 to direct angioplasty. A standard bolus and infusion dose of abciximab was administered to all patients. Blood specimens were collected at baseline, and at 1, 4, 12, and 24 hours. The following parameters were assayed: fibrinogen, plasminogen and antiplasmin activities, tissue plasminogen activator antigen, D-dimer, prothrombin fragments F1 + 2, and thrombin/antithrombin III complexes. Among patients treated with reduced-dose alteplase plus abciximab, the fibrinogen level decreased by 28.4% in the first hour (11.7 +/- 3.4 vs 7.8 +/- 2.5 micromol/L, p0.001). Correspondingly, plasminogen and antiplasmin activities decreased by 43.8% (p0.001) and 59.1% (p0.001), respectively. Prothrombin fragments F1 + 2 increased from 2.2 +/- 1.7 to 4.2 +/- 1.6 nmol/L (1 hour) (p0.001) and thrombin/antithrombin III increased from 16.3 +/- 15.0 to 33.5 +/- 19.9 microg/L (1 hour) (p0.001). Conversely, in the direct angioplasty group, there was a marginal elevation in fibrinogen level at 1 hour (10.2 +/- 2.4 vs 10.6 +/- 2.0 micromol/L, p = 0.064) despite a significant reduction in plasminogen and an increase in tissue plasminogen activator levels. There was no significant change in prothrombin fragments F1 + 2 and thrombin/antithrombin III levels. Thus, there was considerable fibrinolytic activity with reduced-dose alteplase plus abciximab; thrombin generation was not prevented. Among patients treated with direct angioplasty, there was some endogenous fibrinolytic activity, but there was no significant thrombin generation.

Introduction A better understanding of patients’ knowledge, satisfaction and concerns can identify deficits and help develop targeted patient education. This study aimed to examine patients’ knowledge, satisfaction and concerns regarding warfarin therapy and assess their association with warfarin adherence and international normalized ratio (INR) control. Materials and methods A cross-sectional survey was conducted in a convenience sample of patients taking warfarin in an anticoagulation clinic. The questionnaire consisted of questions on patients’ knowledge, satisfaction and concerns regarding warfarin treatment. Patients’ warfarin refill records and time within the therapeutic INR range were retrieved from hospital databases. Results One hundred and eighty-three patients participated in the survey. Patients had inadequate knowledge of warfarin-diet and warfarin-drug interactions. Over 40% of the respondents were not satisfied with the waiting time to see a pharmacist. The most common concerns of taking warfarin were worries about warfarin-drug interactions (36.1%), forgetting to take warfarin (26.2%) and worries about side effects (25.7%). Higher satisfaction was associated with better knowledge (r = 0.24, p = 0.001) and fewer concerns (r s = − 0.23, p = 0.002). Better knowledge and higher satisfaction were associated with higher warfarin adherence (r s = 0.21 and 0.16; p = 0.01 and 0.046, respectively). Better knowledge, higher satisfaction, fewer concerns, and better warfarin adherence were associated with good INR control (p = 0.003, 0.02, 0.03 and 0.003, respectively). Conclusions This study highlighted patients’ concerns and deficits in knowledge regarding warfarin treatment, and also demonstrated their association with warfarin adherence and INR control.

Warfarin exhibits wide interpatient variability in dosing requirements. Recent studies have shown a novel polymorphism (rs2108622, V433M) in the CYP4F2 gene to be associated with variability in warfarin requirements in Caucasians. The purpose of this study was to evaluate the impact of rs2108622 on warfarin dose requirements in the Asian population. The mean warfarin dose was found to be significantly lower in patients carrying homozygous wild-type allele CC when compared with patients carrying variant alleles CT and TT (CC vs CT+TT: 3.0 mg/day vs 3.75 mg/day, p = 0.033). In patients harboring VKORC1 diplotypes associated with low warfarin requirements, a linear regression model which included age, weight, CYP2C9 and CYP4F2 variants accounted for 38% of the variability in warfarin dose. Approximately 11% of the dose variation was explained by CYP4F2 rs2108622 (p = 0.004). The influence of rs2108622 in patients harboring VKORC1 diplotypes associated with high warfarin requirements was not significant. This study suggests that CYP4F2 rs2108622 may significantly affect warfarin dose requirements in carriers of VKORC1 low-dose-associated diplotypes.

SummaryVenous thromboembolism (VTE) has long been considered a disease of secondary importance among Asians because of its perceived low prevalence. We studied the prevalence and patterns of deep venous thrombosis (DVT) among hospitalised patients in our tertiary referral centre. Primary and secondary DVT prevalence among hospitalised patients was 0.453%, a significant rise from reported rates of 0.079% and 0.158% in 1989–1990 and 1996–1997, respectively. Malignancies and orthopaedic surgery were the most common risk factors for DVT. Further comparisons with the two earlier Singaporean studies showed no changes in the gender and ethnic background of patients but a higher proportion of elderly patients (>80 years) was recorded in the current study (11.7% vs. 7.0%, p = 0.04). Statistically significant increases were found in all medical and surgical disciplines except among obstetrics and gynaecology patients. Orthopaedic patients had the highest increase in DVT rates between the 1989–1990 and 2002–2003 periods (0.082% vs. 0.96%, p

Point-of-care (POC) coagulometers are increasingly used by patients for self-monitoring of oral vitamin K antagonists therapy. We studied the feasibility of introducing POC international normalised ratio (INR) testing in place of standard laboratory assays in a hospital-based anticoagulation clinic with 250 active patients. The CoaguChek® XS system was first validated in 253 INR samples and found to have a correlation of r = 0.945 with standard assays. Variations increased with INR readings above 3.5 and this was chosen as the cutoff for acceptance of POC INR results. POC testing was done for 1,332 clinic visits during the subsequent 6-month study. Rate of rejections of INR over 3.5 was 4.3% (95% CI 3.3–5.5%). POC testing reduced clinic visit duration by 35 min (p

AIM OF THE STUDY This study aims to evaluate the association between hepatitis B virus (HBV) and lymphoma and to characterize HBV-related lymphomas. The efficacy of prophylactic lamivudine on HBV reactivation was also evaluated. METHODS We compared the prevalence rate of HBV infection in 556 patients with lymphoma seen over a 4-yr period with that in a group of 4698 Singapore residents aged 18-69 who participated in the National Health Survey. Next, we compared the clinic-pathologic characteristics of HBV-positive and HBV-negative lymphoma cases. RESULTS The prevalence rate of HBV infection in our study was 10.3% (57/556), higher than the prevalence rate of 4.1% (192/4698) in the general population (P < or = 0.001). The higher prevalence was observed in both sexes and across different age groups. An association was observed for non-Hodgkin's lymphoma (NHL) but not Hodgkin's lymphoma. The characteristics of HBV-infected patients with lymphoma were similar to those who were HBV-uninfected in terms of age, ECOG, extra-nodal involvement, LDH level, stage, complete remission rate and overall survival. Use of prophylactic lamivudine significantly decreased the incidence of HBV reactivation (13% vs. 38%, P = 0.02) and disruption to chemotherapy (43% vs. 4%, P = 0.02), with a trend towards improved overall survival. CONCLUSIONS Our findings suggest that an association exists between HBV infection and NHL. However, HBV infection does not appear to have a significant impact on the clinical characteristics and prognosis of NHL. Prophylactic lamivudine should be considered in all HBV-infected patients receiving antracycline and/or steroid containing chemotherapy.

Acute leukemia is an uncommon complication of patients with essential thrombocythemia (ET). We describe a patient with ET, who transformed to acute biphenotypic leukemia 4 and 1/2 years after initial ET diagnosis. She had received hydroxyurea, anagrelide, and interferon, in different combinations and varying doses, before leukemic transformation. Acute biphenotypic leukemia was confirmed on bone marrow studies and immunophenotyping. Complete remission (CR) was achieved with induction chemotherapy for acute leukemia. This was followed with consolidation chemotherapy and the patient has remained in CR 9 months after initial induction chemotherapy. To our knowledge, this is a rare event of acute biphenotypic leukemic transformation of a patient with ET.

An end-stage renal failure patient with lupus nephritis was treated with low molecular weight heparin (LMWH) and aspirin for cardiac ischemia. She was then subjected to surgery to recreate a new arteriovenous fistula for dialysis 1 day after discontinuing LMWH and aspirin. Severe postsurgical bleeding required wound reexploration and multiple transfusions of blood products, which nevertheless, failed to arrest bleeding. Recombinant factor VIIa (rFVIIa) as a bolus dose of 120 microg/kg successfully secured hemostasis. Bleeding in this patient was attributed to the accumulation of low molecular weight heparin activity from poor renal clearance as well as the antiplatelet activity of aspirin. The potential of rFVIIa in securing hemostasis for excessive bleeding after use of these agents is promising.