Incidence of anti-platelet factor4/polyanionic antibodies, thrombocytopenia, and thrombosis after COVID-19 vaccination with ChAdOx1 nCoV-19 in Thais

BACKGROUND

The prevalence of anti-platelet factor 4 (PF4)/polyanionic antibodies occurring after vaccination with ChAdOx1 nCoV-19 is low. Most of these antibodies are not associated with vaccine-induced thrombotic thrombocytopenia. It remains unknown whether these antibodies are preexisting or occur as a result of vaccination. In this study, we demonstrated the incidence of anti-PF4/polyanionic antibodies, thrombocytopenia, and thrombosis after vaccination with ChAdOx1 nCoV-19 in a large cohort of Thais.

METHODS

We conducted a prospective study in a cohort of health care workers and members of the general population who received COVID-19 vaccination with ChAdOx1 nCoV-19. Blood collection for complete blood count, D-dimer, and anti-PF4/polyanionic antibodies was performed before vaccination (day 0), day 10, and day 28 after vaccination. Anti-PF4/polyanionic antibodies were detected using enzyme-link immunosorbent assay (ELISA). Functional assay was performed for all positive ELISA tests.

RESULTS

A total of 720 participants were included in the study. 214 participants received both the first and second doses, 91 participants received only the first, 51 received only the second, and 364 received the third booster dose of ChAdOx1 nCoV-19. Median age was 42 years (IQR, 34-53). 67% of participants were female. Three participants developed seroconversion, yielding an incidence of vaccination-induced anti-PF4/polyanionic antibodies of 0.42% (95% confidence interval 0.08, 1.23). Fourteen (1.9%) participants had preexisting anti-PF4/polyanionic antibodies before the vaccination but their optical density of anti-PF4/polyanionic antibodies did not significantly increase over time. None of the anti-PF4/polyanionic positive sera induced platelet aggregation. Abnormal D-dimer levels following vaccination were not different among the positive and negative anti-PF4/polyanionic groups (11.8% vs. 13.2%, p = 0.86). Thrombocytopenia occurred in one person with negative anti-PF4/polyanionic antibodies. No clinical thrombosis or bleeding occurred.

CONCLUSION

We found a low incidence of seroconversion of anti-PF4/polyanionic antibodies after vaccination with ChAdOx1 nCoV-19 in Thais. Most of the anti-PF4/polyanionic antibodies were preexisting and did not significantly increase after vaccination with ChAdOx1 nCoV-19. Following vaccination, some participants with anti-PF4/polyanionic antibodies had elevated D-dimer levels, while only one developed thrombocytopenia and no thrombotic events were observed.

Effectiveness and Safety of Direct Oral Anticoagulants in Thai Patients with Atrial Fibrillation: A Real-World Retrospective Cohort Study

Background

Direct oral anticoagulants (DOACs) are commonly used to prevent stroke and systemic embolism in patients with atrial fibrillation (AF). However, studies into their effectiveness and safety in the Thai population have so far been limited.

Objectives

To study the effectiveness and safety of warfarin and DOACs among Thai AF patients

Methods

A retrospective cohort study was conducted on AF patients at Ramathibodi Hospital from 2013 to 2018. All patients were followed for at least 1 year. Relevant clinical information was collected and compared between AF patient groups receiving warfarin, dabigatran, rivaroxaban, and apixaban. The primary outcome was a composite of major bleeding, ischemic stroke, and systemic thromboembolism. The secondary outcomes were all-cause mortality and disease-specific mortality caused by major bleeding, ischemic stroke, and systemic thromboembolism.

Results

A total of 1680 AF patients were enrolled in the study (warfarin 1193, apixaban 140, dabigatran 193, rivaroxaban 114). The estimated incidence of composite outcome was 16% [95% CI, 14−18%] and 12.4% [95% CI, 9.4−15.3%] in the warfarin and DOAC group, respectively, given a number needed to treat of 28 [95% CI, 3−52]. Compared with warfarin, DOACs were associated with both lower rate of all-cause mortality (4.9% [22/447] vs 8% [98/1193]) and lower disease-specific mortality (0.4% [2/447] and 1% [12/1193]).

Conclusions

This study suggests DOACs were associated with a lower risk of major bleeding, ischemic stroke, and systemic thromboembolism compared to warfarin in Thai patients with AF. Patients receiving DOAC also had a lower rate of all-cause mortality and disease-specific mortality.

Vaccine-induced immune thrombotic thrombocytopenia with ChAdOx1 nCoV-19 is rare in Asia

BACKGROUND

Vaccination with ChAdOx1 n-CoV-19 is associated with a rare syndrome called vaccine-induced immune thrombotic thrombocytopenia (VITT). VITT has been reported mainly in Western countries, whereas the report of VITT in Asians is sparse.

OBJECTIVES

To report a case series of VITT following ChAdOx1 n-CoV-19 in Thailand and to estimate the incidence of VITT among Asian countries.

METHODS

We retrieved the number of VITT patients and the total inoculation doses from the database of the Thai Ministry of Public Health. We performed a literature search including published articles and gray literature to estimate the incidence of VITT. The incidences of VITT by countries and respective confidence intervals were calculated.

RESULTS

By the end of August 2021, five VITT cases occurred after 15 million doses of ChAdOx1 n-CoV-19 in Thailand. The median age was 31 years, and 60% were women. The incidence of VITT is estimated at 1 in 3 million. In other Asian countries, only a few cases of VITT have been reported. The incidence of VITT is much lower than in those of Western countries, which is estimated at 1 in 100, 000. The fatality rate was 44% in this study.

CONCLUSIONS

Although the incidence of VITT in Asians is low, the mortality rate is substantially higher. We urge that public awareness of this syndrome be raised, as early recognition and appropriate treatment of this syndrome following ChAdOx1 n-CoV-19 are crucial to improve the outcome.

Treatment Outcomes and Clinical Relevance in Patients with Double Expressor DLBCL

BACKGROUND

Double-expressor lymphoma (DEL) was found to account for 20-30% of DLBCL. We conducted this study to analyze the survival, the clinical presentation, and the factors associated with treatment outcomes in DEL-DLBCL.

METHODS

A retrospective study of 291 patients diagnosed with DLBCL during January 2015 - December 2018 was conducted.

RESULTS

Of the 291 patients, the median age was 63 years, germinal center B cell-like DLBCL (GCB) and non-GCB subtypes were found in 32% and 68%, respectively. DEL was found in 46% of 264 patients with available immunohistochemistry staining for MYC protein. Patients with DEL was significantly more common in elderly patients (p= 0.017) and non-GCB subtype (p= 0.006). High serum lactate dehydrogenase (LDH) levels and high Ki-67 index were significantly found in DEL patients than non-DEL patients (p= 0.024 and p= 0.04, respectively). The 3y-OS rate was shorter in the DEL group than in the non-DEL group, 58.7% versus 78.9% (p=0.026), whereas no significant difference in 3y-DFS was identified between these groups (58.4% versus 67.7%, p= 0.343). Independent factors affecting OS and DFS in DEL patients were ECOG 3-4, high LDH levels, extranodal involvement> 1 site, high IPI, and stage III-IV in univariate analysis.

CONCLUSIONS

High incidence of DEL was observed in this study, especially in patients aged 60 years or older and non-GCB subtype. Patients with DEL showed dismal DFS and OS.

Prevalence of anti-platelet factor 4/polyanionic antibodies after COVID-19 vaccination with ChAdOx1 nCoV-19 and CoronaVac in Thais

INTRODUCTION

Vaccine-induced thrombotic thrombocytopenia (VITT) has been reported after vaccination with the adenoviral vector coronavirus disease 2019 (COVID-19) vaccine ChAdOx1 nCoV-19 in European countries. To date, two cases of VITT have been reported in Thais after COVID-19 vaccination. We determined the frequency of anti-platelet factor 4 (PF4)/polyanionic antibodies in the Thai population receiving the COVID-19 vaccines.

METHODS

We conducted a cross-sectional study to evaluate the prevalence of anti-PF4/polyanionic antibodies in health care workers who received COVID-19 vaccination with ChAdOx1 nCoV-19 or CoronaVac within 7 to 35 days. A control population who had not been vaccinated was also included. Anti-PF4/polyanionic antibodies were detected using ELISA. Functional assay with platelet aggregation was performed for all positive anti-PF4/polyanionic antibody ELISA tests.

RESULTS

A total of 646 participants were included in the study; 221 received ChAdOx1 nCoV-19, 232 received CoronaVac, and 193 participants were in the control group. The prevalence of anti-PF4 antibodies was 2.3% (95% confidence interval [CI], 0.7-5.2), 1.7% (95% CI, 0.5-4.4) in the ChAdOx1 nCoV-19 and CoronaVac groups, respectively. There was no positive test in the control group. None of the PF4/polyanionic positive sera induced platelet aggregation.

CONCLUSION

We found a low prevalence of anti-PF4 antibodies in Thais after vaccination with ChAdOx1 nCoV-19 and CoronaVac. None of the antibodies were functional and lacked an association with VITT.

A quality-of-life questionnaire for heavy menstrual bleeding in Thai women receiving oral antithrombotics: Assessment of the translated Menstrual Bleeding Questionnaire

BACKGROUND

Heavy menstrual bleeding (HMB) is common among reproductive-aged women receiving oral antithrombotics and frequently results in a negative impact on quality of life.

METHODS

We translated the Menstrual Bleeding Questionnaire (MBQ) into Thai by forward translation, back-translation, pretesting, and cognitive interviewing. The translated questionnaire was content validated by a gynecologist. A validation study was conducted for the translated MBQ and defined the optimal score for the diagnosis of HMB. We then performed a cross-sectional study to determine the prevalence of HMB using the translated MBQ. Reproductive-aged Thai women who visited outpatient clinics receiving oral antithrombotics were asked to assess menstrual characteristics after receiving antithrombotics. The impact of menstruation on quality of life was assessed by using the MBQ.

RESULTS

The translated MBQ had excellent reliability (intraclass correlation coefficient = 0.93) and discriminated between women with and without HMB (area under the receiver operating characteristic curve = 0.93). A score of 21.5 had 82.9% sensitivity and 83.1% specificity in the diagnosis of HMB. The mean (standard deviation) of the score was significantly higher in the HMB group than in the normal menstrual bleeding group (30.4 [9.4] vs 15.4 [5.6]; P < .001, respectively). Of the 49 women, the prevalence of HMB in patients receiving warfarin (n = 29), direct oral anticoagulants (n = 4), or antiplatelet agents (n = 16) was 27.6%, 25.0%, and 25.0%, respectively.

CONCLUSIONS

MBQ is a simple and valid tool that can be applied to screen women experiencing HMB. One-fourth of reproductive-aged women who received oral antithrombotics experienced HMB that impacted their quality of life.

Comparison between blood hemoglobin concentration determined by point-of-care device and complete blood count in adult patients with dengue

Background

Hematocrit measurement has been an indispensable tool for monitoring plasma leakage and bleeding in dengue patients. However, hematocrit measurement by automated methods is hampered by frequent venipunctures. Utility of point-of-care hemoglobin (POC-Hb) test for monitoring dengue patients has not been established. We evaluated the relationship between hemoglobin measured by POC-Hb testing and hematocrit measured by the automated method in adult dengue patients.

Methodology and principal findings

Adult dengue patients were recruited at two university hospitals in Thailand from October 2019 to December 2020. POC-Hb test was performed using capillary blood simultaneously with venipuncture to obtain whole blood for an automated complete blood count (CBC) analysis. The correlation of hemoglobin and hematocrit measurement was evaluated. A total of 44 dengue patients were enrolled. Twenty-nine patients (65.9%) were female, with a median age of 31 years (interquartile range 22–41). Of the enrolled patients, 30 (68.2%), 11 (25.0%), and 3 (6.8%) were classified as dengue without warning signs, with warning signs, and severe dengue, respectively. Seven patients (15.9%) had hemoconcentration, and five patients (11.3%) had bleeding. A total of 216 pairs of POC-Hb and CBC were evaluated. A significant positive correlation was observed between hemoglobin measured by POC-Hb testing and hematocrit measured by an automated CBC (r = 0.869, p <0.001). Bland-Altman analysis between hemoglobin measured by POC-Hb testing and an automated CBC showed a bias of -0.43 (95% limit of agreement of -1.81 and 0.95). Using the cutoff of POC-Hb ≥20% as a criteria for hemoconcentration, the sensitivity and specificity of hemoconcentration detected by POC-Hb device were 71.4% and 100.0%, respectively.

Conclusions

Hemoglobin measurement by POC-Hb testing has a strong correlation with hematocrit in adult patients with dengue fever. However, the sensitivity in detecting hemoconcentration is fair. The adjunct use of capillary POC-Hb testing can decrease the frequency of venipuncture. Further study in children is encouraged.

The natural history of dengue has the unique characteristic of plasma leakage that results in hemoconcentration as well as vasculopathy and thrombocytopenia that result in bleeding. Therefore, hematocrit monitoring is a crucial tool to guide management in dengue patients. Microhematocrit adjunct with a complete blood count (CBC) to monitor dengue patients were traditionally performed to decrease the frequency of venipuncture. However, microhematocrit is currently less preferred to the point-of-care hemoglobin monitoring tools to measure red cells in other diseases. There has been no study investigating the feasibility of using point-of-care hemoglobin (POC-Hb) to monitor dengue patients. We studied the correlation of hemoglobin measured by POC-Hb testing and hematocrit measured by an automated CBC in adult dengue patients. We were able to show a strong positive correlation between the two measurements (r = 0.869, p <0.001). Using the rise of POC-Hb value of ≥20% above the convalescent value as the criteria for detecting hemoconcentration by POC-Hb testing, measurement of hemoglobin using POC-Hb has a sensitivity of 71.4% for detecting hemoconcentration compared to the traditional hematocrit criteria. Our findings support the use of POC-Hb testing adjunct with a complete blood count to guide fluid management in dengue patients.

MYH9 disorder: Identification and a novel mutation in patients with macrothrombocytopenia

The diagnosis of MYH9 disorder is guided by recognizing granulocyte Döhle body-like inclusion bodies and large/giant platelets in the peripheral blood smear. Immunofluorescence study of nonmuscle myosin heavy chain IIA is a sensitive screening method for diagnosis of MYH9 disorder. The diagnosis can then be confirmed by genetic analysis. A total of 67 patients with macrothrombocytopenia were included, of which 11 patients (16%), aged 4 months to 22 years, were ultimately diagnosed with MYH9 disorder. One novel mutation in exon 30 at c.4338T>C (p.F1446A) was detected. This mutation was associated with nonhematologic manifestations presenting in late adolescence with cataracts, hearing loss, and hematuria.

Heavy menstrual bleeding in women on anticoagulant treatment for venous thromboembolism: Comparison of high- and low-dose rivaroxaban with aspirin

BACKGROUND

Rivaroxaban may induce heavy menstrual bleeding. It is unknown if this effect is dose related or if rivaroxaban is associated with more menstrual bleeding than aspirin.

OBJECTIVES

To demonstrate and compare menstrual patterns and actions taken among women receiving aspirin and two doses of rivaroxaban.

METHODS

The EINSTEIN-CHOICE trial compared once-daily rivaroxaban 20 mg, rivaroxaban 10 mg, and aspirin 100 mg for extended treatment of venous thromboembolism in patients who had completed 6 to 12 months of anticoagulant therapy. In 362 women with menstrual cycles, menstrual flow duration and intensity assessed at days 30, 90, 180, and 360 were compared with those before starting anticoagulant therapy.

RESULTS

Menstrual flow duration increased in 12%-18% of the 134 women given 20-mg rivaroxaban, in 6% to 12% of 120 women given 10-mg rivaroxaban, and in 9% to 12% of 108 women given aspirin. Corresponding increases in flow intensity were 19% to 24%, 14% to 21%, and 13% to 20%. The odds ratios (ORs) for increased menstrual flow duration were 1.36 (95% confidence interval [CI], 0.62-2.96) for rivaroxaban 20 mg versus aspirin, 0.77 (95% CI, 0.33-1.81) for rivaroxaban 10 mg versus aspirin, and 0.57 (95% CI, 0.26-1.25) for rivaroxaban 10 mg versus 20 mg. The ORs for increased menstrual flow intensity were 1.41 (95% CI, 0.67-2.99), 1.07 (95% CI, 0.49-2.34), and 0.76 (95% CI, 0.37- 1.57), respectively.

CONCLUSIONS

There were no statistically significant differences in menstrual hemorrhage patterns between women treated with 10 or 20 mg of rivaroxaban and aspirin. Compared with 10-mg rivaroxaban or aspirin, 20-mg rivaroxaban showed numerically more often increased menstrual flow duration and intensity.

Saliva sample as a non-invasive specimen for the diagnosis of coronavirus disease 2019: a cross-sectional study

OBJECTIVES

Amid the increasing number of pandemic coronavirus disease 2019 (COVID-19) cases, there is a need for a quick and easy method to obtain a non-invasive sample for the detection of this novel coronavirus (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2). We aimed to investigate the potential use of saliva samples as a non-invasive tool for the diagnosis of COVID-19.

METHODS

From 27 March to 4 April 2020, we prospectively collected saliva samples and a standard nasopharyngeal and throat swab in persons seeking care at an acute respiratory infection clinic in a university hospital during the outbreak of COVID-19. Real-time polymerase chain reaction (RT-PCR) was performed, and the results of the two specimens were compared.

RESULTS

Two-hundred pairs of samples were collected. Sixty-nine (34.5%) individuals were male, and the median (interquartile) age was 36 (28-48) years. Using nasopharyngeal and throat swab RT-PCR as the reference standard, the prevalence of COVID-19 diagnosed by nasopharyngeal and throat swab RT-PCR was 9.5%. The sensitivity and specificity of the saliva sample RT-PCR were 84.2% (95% CI 60.4%-96.6%), and 98.9% (95% CI 96.1%-99.9%), respectively. An analysis of the agreement between the two specimens demonstrated 97.5% observed agreement (κ coefficient 0.851, 95% CI 0.723-0.979; p < 0.001).

CONCLUSIONS

Saliva might be an alternative specimen for the diagnosis of COVID-19. The collection is non-invasive, and non-aerosol generating. This method could facilitate the diagnosis of the disease, given the simplicity of specimen collection and good diagnostic performance.

Incidence of thromboembolism in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, the incidence of thromboembolism has been increasingly reported. The aim of this systematic review was to explore the incidence of venous and arterial thromboembolism among COVID-19 patients requiring hospitalization.

METHODS

Medline, Embase, Scopus, and grey literature were searched until June 2020. Observational studies reported on the incidence of venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT) or arterial thromboembolism (ATE) were included. The pool incidences and their 95% confidence intervals (CI) were calculated using the random-effects model.

RESULTS

A total of 36 studies were included. In the intensive care unit (ICU) setting, the pooled incidence of VTE was 28% (95% CI, 22-34%). Subgroups based on compression ultrasound (CUS) screening revealed a higher incidence of DVT in the CUS screening group than in the no CUS screening group (32% [95% CI, 18-45%] vs. 6% [95% CI, 4-9%]). The pooled incidence of ATE in ICU was 3% (95% CI, 2-5%). In the non-ICU setting, the pooled incidence of VTE was 10% (95% CI, 6-14%,).

CONCLUSIONS

The incidence of VTE in COVID-19 patients was higher in the ICU setting than in the non-ICU setting, and also significantly higher in studies that incorporated the CUS screening protocol. The incidence of ATE in the ICU setting was low. VTE prophylactic measures should be given to all hospitalized patients diagnosed with COVID-19.

Saliva sample as a non-invasive specimen for the diagnosis of coronavirus disease 2019: a cross-sectional study

Objectives

Amid the increasing number of pandemic coronavirus disease 2019 (COVID-19) cases, there is a need for a quick and easy method to obtain a non-invasive sample for the detection of this novel coronavirus (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2). We aimed to investigate the potential use of saliva samples as a non-invasive tool for the diagnosis of COVID-19.

Methods

From 27 March to 4 April 2020, we prospectively collected saliva samples and a standard nasopharyngeal and throat swab in persons seeking care at an acute respiratory infection clinic in a university hospital during the outbreak of COVID-19. Real-time polymerase chain reaction (RT-PCR) was performed, and the results of the two specimens were compared.

Results

Two-hundred pairs of samples were collected. Sixty-nine (34.5%) individuals were male, and the median (interquartile) age was 36 (28–48) years. Using nasopharyngeal and throat swab RT-PCR as the reference standard, the prevalence of COVID-19 diagnosed by nasopharyngeal and throat swab RT-PCR was 9.5%. The sensitivity and specificity of the saliva sample RT-PCR were 84.2% (95% CI 60.4%–96.6%), and 98.9% (95% CI 96.1%–99.9%), respectively. An analysis of the agreement between the two specimens demonstrated 97.5% observed agreement (κ coefficient 0.851, 95% CI 0.723–0.979; p < 0.001).

Conclusions

Saliva might be an alternative specimen for the diagnosis of COVID-19. The collection is non-invasive, and non-aerosol generating. This method could facilitate the diagnosis of the disease, given the simplicity of specimen collection and good diagnostic performance.

Treatment outcome and prognostic factors in PCNSL

Objectives

Standard treatment with a thiotepa-based regimen in countries with a limited resource is less feasible. Aims of the study were to evaluate the treatment outcome, and identify the prognostic factors in patients with primary central nervous system lymphoma (PCNSL).

Methods

We conducted a retrospective study of 43 patients diagnosed with PCNSL, DLBCL subtype, who were treated with either HDMTX-based regimen, whole brain radiotherapy (WBRT), or both between 2010 and 2017.

Results

There were 43 patients with a median age of 65 years (range 34–89 years). Protein expression of CD10, Bcl6, MUM1, Bcl2 and MYC were found in 19, 86, 91, 91 and 23%, respectively. Both germinal center B cell (GCB) and double-expressor (MYC+/Bcl2+) lymphomas were found in 21%. Multiple brain lesions and maximum tumor diameter (MTD) ≥5 cm were seen in 27 and 10 patients, respectively. Chemotherapy combined with WBRT, chemotherapy and WBRT were given to 20, 14 and 9 patients, respectively. Overall complete remission (CR) rate was 55.8%. Those receiving a combined-modality therapy had a higher CR rate than those treated with either chemotherapy (75% versus 36%, p = 0.036) or WBRT (75% versus 44%, p = 0.109). Median follow-up time was 17 months, and a 7-year overall survival (OS) was 40%. Features associated with a prolonged OS were an ECOG score ≤ 2 (p = 0.001), multiple brain lesions (p = 0.010), multiple area of brain involvement (p = 0.023), MTD < 5 cm (p = 0.004), GCB subtype (p = 0.003) and positive CD10 staining (p = 0.007). Expression of Bcl2 protein was associated with a significantly worse OS in the non-GCB DLBCL patients.

Discussion

The factors affecting treatment outcomes in PCNSL were cell of origin of DLBCL, lesion characteristics, patients’ status and treatment regimen.

Cytogenetics and FLT3-ITD mutation predict clinical outcomes in non transplant patients with acute myeloid leukemia

Background

Cytogenetic abnormalities and mutated genes indicate the role of consolidation therapy with hematopoietic stem cell transplantation (HSCT) or chemotherapy in acute myeloid leukemia (AML). In this study, we conducted a retrospective study in adult AML patients with newly diagnosed with de novo AML who did not undergo HSCT, to study long term relapse free survival (RFS) and overall survival (OS) after consolidation chemotherapy.

Methods

We recruited 141 consecutive AML patients during January 2010–June 2017, the patients received induction chemotherapy with standard dose Ara-C and Idarubicin (7 + 3 or 5 + 2 regimen) followed by intermediate (IDAC) or high dose Ara-c (HiDAC) consolidation therapy.

Results

Normal karyotype, complex, favorable, intermediate and adverse chromosomal aberrations were found in 59%, 16%, 5%, 14% and 6%, respectively. Mutated NPM1, FLT3-ITD and CEBPA genes in CN-AML were seen in 33%, 18% and 19%, respectively. A 5 year follow up, 5y-RFS was 16% and 5y-OS was 14% in the whole study population. 5y-RFS and 5y-OS in patients completed 4 cycles of consolidation therapy were 25% and 40%, respectively. Adverse cytogenetic risk and mutated FLT3-ITD were significantly associated with poor RFS (9 and 15 months, respectively) and OS (14 and 16 months, respectively), whereas patients with mutant NPM1 had favorable outcomes (RFS/OS = 51/63 months). Patients receiving 4 cycles of consolidation therapy had significantly impacts on median RFS and OS compared with those treated with 1 or 2 cycles; 15 versus 11 months (p = 0.006) and 31 versus 15 months (p < 0.001), respectively.

Conclusions

Cytogenetic and mutation tests for FLT3-ITD, NPM1 and CEBPA genes were meaningful for predicting outcomes in adult AML patients. Adverse cytogenetic abnormalities and FLT3-ITD mutation showed dismal RFS and OS.

Reduced-dose direct oral anticoagulants in the extended treatment of venous thromboembolism: a systematic review and meta-analysis

Essentials In venous thromboembolism (VTE), benefits of extended treatment are balanced by bleeding risks. This is a meta-analysis of reduced-dose direct oral anticoagulants (DOACs) in extended treatment. Reduced-dose DOACs are as effective as full anticoagulation with bleeding risks similar to placebo. Reduced-dose DOACs are an attractive option for patients in the extended phase of VTE treatment.

SUMMARY

Background Extended-duration anticoagulation is beneficial for preventing recurrent venous thromboembolism (VTE). Reduced-dose direct oral anticoagulants (DOACs) may be preferable if they preserve efficacy and cause less bleeding. We conducted a systematic review and meta-analysis of trials comparing reduced-dose DOACs with full-dose DOACs and aspirin or placebo in the extended phase of VTE treatment. Methods A literature search was conducted by use of the MEDLINE, EMBASE and CINAHL databases, supplemented by hand-searching. One thousand three hundred and ninety-nine titles were screened, with data from accepted studies being extracted by two independent reviewers. Major outcomes analyzed included recurrent VTE and major and clinically relevant non-major bleeding events, presented as risk ratios (RRs) and 95% confidence intervals (CI). Results Two trials met the prespecified inclusion criteria. Data from 5847 patients were analyzed for efficacy outcomes, and from 5842 patients for safety outcomes. Reduced-dose DOACs were as effective as full-dose treatment in preventing recurrent VTE at 1 year (RR 1.12 [95% CI 0.67-1.87]), and more effective than aspirin or placebo (RR 0.26 [95% CI 0.14-0.46]). Rates of major or clinically relevant non-major bleeding events were similar between patients receiving reduced-dose DOACs and and those receiving aspirin or placebo (RR 1.19 [95% CI 0.81-1.77]). There was a trend towards less bleeding when reduced-dose and full-dose DOACs were compared (RR 0.74 [95% CI 0.52-1.05]). Conclusions Extended-duration treatment of VTE with reduced-dose DOACs may be as efficacious as full-dose treatment, with rates of major bleeding being similar to those in patients receiving treatment with aspirin or placebo, but further long-term studies are needed.

Association of body weight with efficacy and safety outcomes in phase III randomized controlled trials of direct oral anticoagulants: a systematic review and meta-analysis

Essentials The association of body weight and patient-important outcomes remains unknown. Phase III randomized controlled trials of direct oral anticoagulants (DOACs) were searched. Risk of outcomes varying among body weight subgroups is not attributable to anticoagulant type. Dose adjustment of DOACs, outside that recommended, is unlikely to improve the outcomes. Click to hear Dr Braunwald's perspective on antithrombotic therapy in cardiovascular disease SUMMARY: Background Concerns have arisen in direct oral anticoagulant (DOAC)-treated patients about safety and efficacy in extremes of body weight. The aims of this systematic review were to investigate the association of body weight and patient-important outcomes in patients treated with DOACs or warfarin, and to demonstrate the fixed-dose effect of DOACs. Methods MEDLINE and EMBASE were searched until November 2016. Phase III randomized controlled trials (RCTs) using DOACs in atrial fibrillation (AF) and acute venous thromboembolism (VTE) were included. Relative risk and 95% confidence interval were calculated. The pooled estimates were performed using a Mantel-Haenszel random effects model. Results A total of 11 phase III RCTs were included. Low body weight was associated with increased risk of thromboembolism compared with non-low body weight (relative risk [RR], 1.57; 95% confidence interval [CI], 1.34-1.85). High body weight was not associated with risk of thromboembolism compared with non-high body weight (RR, 0.88; 95% CI, 0.63-1.23). The subgroup of AF patients with high body weight had a lower risk of thromboembolism compared with non-high body weight (RR, 0.43; 95% CI, 0.28-0.67). Bleeding outcomes were comparable for all body weight comparisons. There were no clear interactions between types of anticoagulant in all outcomes. Conclusion The pooled effect of both the DOAC and comparison arms was likely to be attributable to differences in baseline thrombotic risk in each body weight category, rather than an effect of the type or dose of DOAC used for each indication. Dose adjustment of DOACs, outside that recommended in the package insert, is unlikely to improve safety or efficacy.

The effect of low-dose oral vitamin K supplementation on INR stability in patients receiving warfarin. A randomised trial

The anticoagulant effect of warfarin is influenced by variations in vitamin K intake. Concomitant use of daily low-dose oral vitamin K (LDVK) and warfarin may improve INR stability. We hypothesise that administration of LDVK improves INR control. To test this hypothesis we performed a multi-centre, placebo-controlled, randomised trial conducted at four university-affiliated hospitals in Canada. Patients on chronic warfarin therapy received oral vitamin K 150 mcg daily or a matching placebo for a total of six months after a one-month run in period. The primary outcome was a comparison of mean time in therapeutic range (TTR) in LDVK and placebo group during a six-month-period. The secondary outcome was number of INR excursions <1.5 or >4.5. There was no significant difference in the final TTR between the two groups (65.1 % vs 66 %, p =0.8). Mean TTR in both LDVK and placebo groups were statistically increased compared with prior to the study. The number of INR excursions were significantly decreased in the LDVK group (9.4 % and 5.4 %, absolute difference [pre- minus post-] = 4 %, 95 % CI, 2 to 6 %, p-value <0.001). We conclude that LDVK administration did not increase mean TTR, but did decrease the number of INR excursions. The observed improvement in mean TTR in both groups suggests that more attentive monitoring of warfarin therapy, rather than LDVK, was responsible for the improvement in TTR observed. The reduced excursions suggest that LDVK did reduce extreme INR variation. The study is registered at www.ClinicalTrial.gov# NCT00990158.

Hemodialysis for the treatment of dabigatran-associated bleeding: a case report and systematic review

BACKGROUND

Dabigatran, a direct thrombin inhibitor, is effective for the treatment of venous thromboembolism and the prevention of stroke and systemic embolism resulting from atrial fibrillation. The most effective way of reversing the anticoagulant effect of dabigatran in patients who have bleeding complications is unknown.

OBJECTIVES

To document the clinical outcomes of patients undergoing renal replacement therapy (RRT) for dabigatran-associated bleeding.

METHODS

We searched MEDLINE and EMBASE up to May 2015. Articles were selected if the patients presented with dabigatran-associated bleeding, underwent RRT for dabigatran removal, and reported an effect on bleeding.

RESULTS

The search yielded 22 studies representing 35 unique patient cases. The median patient age was 74.1 years (range, 56-94 years). Thirteen patients (37.1%) were female, and 32 (91.4%) patients received dabigatran for atrial fibrillation. Twenty-three patients (65.7%) underwent intermittent hemodialysis, 10 patients (28.6%) underwent continuous RRT (CRRT), and two patients underwent both intermittent hemodialysis and CRRT. Following RRT, there were significant reductions in dabigatran concentrations (P = 0.001). Rebound of the dabigatran concentration was reported in 12 (57.1%) patients following cessation of RRT. Hemostasis was reportedly achieved in 24 patients (70.6%), and 10 patients (29.4%) died because of bleeding.

CONCLUSIONS

In patients with dabigatran-associated bleeding, RRT appears to be effective in reducing dabigatran concentrations, and in case reports this has been associated with a reduction in the duration and/or severity of bleeding. However, a rebound in concentrations may be seen following withdrawal of RRT, suggesting that a prolonged course of RRT may be more effective.

Venous Thromboembolism Prophylaxis in Critically Ill Patients

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is recognized as a common complication in critically ill patients. Risk factors including critical illness, mechanical ventilation, sedative medications, and central venous catheter insertion are major contributing factors to the high risk of VTE. Because of their impaired cardiopulmonary reserve, PE arising from thrombosis in the deep veins of the calf that propagates proximally is poorly tolerated by critically ill patients. Pharmacologic prophylaxis with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) has been shown to decrease the incidence of VTE in medical, surgical, and critically ill patients. As a result, over the past decades, VTE prophylaxis had become a standard of preventive measure in the intensive care unit (ICU). In clinical practice, the rate of VTE prophylaxis varies and may be inadequate in some centers. A perception of a high bleeding risk in critically ill patients is a major concern for most physicians that may lead to inadequate prophylaxis.

Low prevalence of heparin-induced thrombocytopenia after cardiac surgery in Thai patients

INTRODUCTION

Heparin induced-thrombocytopenia (HIT) has been well recognized in Western countries. However, there are no data in the Thai population. We therefore investigated the prevalence of anti-platelet factor 4 (PF4)/heparin antibodies, HIT, and its thrombotic complications in Thai patients undergoing cardiac surgery using unfractionated heparin.

MATERIALS AND METHODS

Seventy-three consecutive patients were prospectively enrolled in this study. Blood samples before operation and week 1, week 2, and week 3 after operation were collected from each patient for HIT antibody screening by enzyme-linked immunosorbent assay using IgG antibody specific to the PF4/heparin complex. Positive samples were further analyzed by (14)C-serotonin release assay. Complete blood count was performed daily during the first week, then weekly for 3 weeks.

RESULTS

No patient had detectable anti-PF4/heparin antibodies at baseline. Five patients sero-converted during the course of the study for anti-PF4/heparin IgG: 3 (4.1%) at week 1, 4 (5.5%) at week 2, and 5 (6.8%) at week 3 after surgery. However, none of these patients had anti-PF4/heparin antibodies that resulted in (14)C-serotonin release to be considered clinically significant antibodies. Post-operative thrombocytopenia after the operation was found in 35 patients (47.9%), but was not considered to be caused by HIT. Thromboembolic events occurred in 3 patients (4.1%) during follow up; however, none of these patients had positive PF4/heparin antibody tests.

CONCLUSIONS

Our study represents the first study to examine Thai patients exposed to heparin in the context of cardiac surgery. We found a lower prevalence of positive anti-PF4/heparin antibodies and clinical HIT than previously published studies.

Hydroxyurea and colonic ulcers: a case report

Background

Hydroxyurea at a relatively low dose is frequently prescribed to induce hemoglobin F production in patients with sickle cell and β-thalassemia diseases because of its good efficacy and safety profiles. However, a potentially fatal gastrointestinal ulceration was recently found and herein reported.

Case presentation

A thirty-seven-year-old man with transfusion dependent hemoglobin E/β-thalassemia disease was treated with hydroxyurea to induce hemoglobin F production since 2007 without incident. From 2008 to April 2010, episodes of hematochezia, mucous diarrhea and epigastric pain intermittently manifested. Four colonoscopies done during the period repeatedly showed ulcerative lesions from the terminal ileum to the ascending colon with a non-specific histo-pathologic finding. Subsequently, ulcerative lesions also developed at the pharynx, histo-pathologic findings of which were not different from those in the colon. These ulcerative lesions resolved within a month after discontinuing hydroxyurea in April 2010 and have not recurred since.

Conclusion

The findings suggested role of hydroxyurea in the pathogenesis of these ulcers, and that it must be immediately discontinued to prevent further damage to the digestive mucosa.

The added-up albumin enhances the diuretic effect of furosemide in patients with hypoalbuminemic chronic kidney disease: a randomized controlled study

Background

Chronic kidney disease (CKD) with edema is a common clinical problem resulting from defects in water and solute excretion. Furosemide is the drug of choice for treatment. In theory, good perfusion and albumin are required for the furosemide to be secreted at the tubular lumen. Thus, in the situation of low glomerular filtration rate (GFR) and hypoalbuminemia, the efficacy of furosemide alone might be limited. There has been no study to validate the effectiveness of the combination of furosemide and albumin in this condition.

Methods

We conducted a randomized controlled crossover study to compare the efficacy of diuretics between furosemide alone and the combination of furosemide plus albumin in stable hypoalbuminemic CKD patients by measuring urine output and sodium. The baseline urine output/sodium at 6 and 24 hours were recorded. The increment of urine output/sodium after treatment at 6 and 24 hours were calculated by using post-treatment minus baseline urine output/sodium at the corresponding period.

Results

Twenty-four CKD patients (GFR = 31.0 ± 13.8 mL/min) with hypoalbuminemia (2.98 ± 0.30 g/dL) were enrolled. At 6 hours, there were significant differences in the increment of urine volume (0.47 ± 0.40 vs 0.67 ± 0.31 L, P < 0.02) and urine sodium (37.5 ± 29.3 vs 55.0 ± 26.7 mEq, P < 0.01) between treatment with furosemide alone and with furosemide plus albumin. However, at 24 hours, there were no significant differences in the increment of urine volume (0.49 ± 0.47 vs 0.59 ± 0.50 L, P = 0.46) and urine sodium (65.3 ± 47.5 vs 76.1 ± 50.1 mEq, P = 0.32) between the two groups.

Conclusion

The combination of furosemide and albumin has a superior short-term efficacy over furosemide alone in enhancing water and sodium diuresis in hypoalbuminemic CKD patients.

Trial registration

The Australian New Zealand Clinical Trials Registration (ANZCTR12611000480987)