Phenytoin-Induced Severe Thrombocytopenia: A Case Report.

Phenytoin is a commonly prescribed antiepileptic medication for the prevention and treatment of tonic-clonic or partial seizures. Thrombocytopenia is a rare and serious adverse effect of phenytoin. This case report presents the case of a patient with severe thrombocytopenia induced by phenytoin for the treatment of tonic-clonic seizures. A 63-year-old male received 300 mg/day of phenytoin for the treatment of tonic-clonic seizures. Seven days after receiving the first dose of phenytoin, he was diagnosed with severe thrombocytopenia (platelet count 44 x 109/L) without hemorrhage. Phenytoin was discontinued, and seizures were controlled with levetiracetam. Seven days after stopping phenytoin, his daily platelet count improved from 44 to 177 x 109/L. The Naranjo algorithm score of 7 was at a probable level for phenytoin-induced thrombocytopenia. Thrombocytopenia is a serious adverse drug reaction that can result in life-threatening bleeding. Phenytoin-induced thrombocytopenia commonly begins 1-90 days after administration, and the recovery time is 3-21 days. The potential mechanism of phenytoin-induced thrombocytopenia is drug-induced immune thrombocytopenia. Drugs that enhance the concentration of phenytoin epoxide may be a contributing factor in phenytoin-induced thrombocytopenia. Phenytoin-induced thrombocytopenia is a rare but serious hematological complication. It should be recognized early, particularly in patients with a high risk of hemorrhage or concurrently with medications that increase phenytoin epoxide. Regularly consecutive complete blood count tests may be essential in order to detect an early decrease in platelet count in these patients.

Trends in Anticoagulant Utilization and Clinical Outcomes for Cancer-Associated Thrombosis: A Multicenter Cohort Study in Thailand's Upper-Middle-Income Country Setting.

PURPOSE: To evaluate anticoagulant trends and clinical outcomes in the management of cancer-associated thrombosis (CAT) within Thailand, an upper-middle-income country (UMIC). METHODS: This multicenter retrospective cohort study included adult patients with cancer diagnosed with venous thromboembolism (VTE) hospitalized in Thailand from 2017 to 2021. Anticoagulants were classified as low-molecular-weight heparin (LMWH), direct oral anticoagulants (DOACs), and warfarin. Prescription trends were assessed, and patients were followed for 1 year, or until 2022 to evaluate outcomes. The primary effectiveness outcome was recurrent VTE, whereas the primary safety outcome was major bleeding. Secondary outcomes included net clinical benefit and all-cause mortality. Treatment effects were examined using inverse probability of treatment weighting (IPTW) Cox proportional hazards models. RESULTS: Among 1,611 patients (61.3% female; mean age, 58.8 years; standard deviation, 13.1 years), 86% received LMWH, 10% warfarin, and 4% DOACs. In the study cohort, LMWH prescriptions remained consistent, warfarin use declined, and DOAC prescriptions notably increased. In IPTW analysis, DOACs showed comparable rates of VTE recurrence (weighted hazard ratio [HR], 0.77 [95% CI, 0.22 to 2.70]; P = .679) and major bleeding (weighted HR, 0.62 [95% CI, 0.15 to 2.55]; P = .506) with LMWH. Warfarin had a higher risk of major bleeding (weighted HR, 2.74 [95% CI, 1.12 to 6.72]; P = .028) but a similar rate of VTE recurrence (weighted HR, 1.46 [95% CI, 0.75 to 2.84]; P = .271) compared with LMWH. Secondary outcomes were consistent across groups. CONCLUSION: LMWH remains the primary treatment for CAT, in line with current guidelines. The study highlights the challenges faced in these settings with the continuous use of warfarin. The comparable efficacy and safety of DOACs with LMWH suggest a potential shift in CAT management within UMICs.

Predictive model for diagnostic yield of bone marrow examination in patients with HIV infection having fever of unknown origin.

OBJECTIVE: Bone marrow examination is valuable for identifying the cause of fever of unknown origin (FUO) in HIV-infected patients. Based on the outcomes of bone marrow examination of patients with FUO, we aimed to develop a predictive model for identifying the factors that can increase the diagnostic yield of bone marrow examination. DESIGN: For this retrospective cohort study, we enrolled HIV-infected patients, aged more than 15 years and diagnosed with FUO, at Songklanakarind Hospital in Southern Thailand, between January 2009 and December 2019. METHODS: Evaluations were based on bone marrow aspiration, biopsy, and culture; any missing data were imputed with regression imputation. RESULTS: Among the final 108 included patients, 44 (40.74%) showed positive bone marrow results. The diagnoses mainly comprised histoplasmosis, penicilliosis, and tuberculosis. Bone marrow examination led to treatment modifications in approximately 33% patients. Platelet count less than 150 000 cells/µl, alkaline phosphatase (ALP) level at least 200 U/l, and no previous antibiotic treatment were significantly associated with higher diagnostic yields. The HIV bone marrow (HIVBM) model, comprising of spleen size, hematocrit (Hct), platelet count before bone marrow examination, ALP level at admission, and previous antibiotic treatment, was generated as a nomogram to predict the diagnostic yield of bone marrow examination in HIV-infected patients with FUO. CONCLUSION: The results of this study indicate that the HIVBM model can be used to predict the diagnostic yield of bone marrow examination, and therefore assist in clinical decision-making regarding bone marrow procedures, to be performed for identifying the origin of fever in HIV-infected patients.

Real-World Costs and Cost-Effectiveness Analysis of Rabbit-Antithymocyte Globulin Versus Oxymetholone in Acquired Aplastic Anemia in Thailand.

OBJECTIVES: This study aimed to compare rabbit-antithymocyte globulin and cyclosporine (rATG/CsA) with oxymetholone in terms of direct medical expenditures and economic evaluation in severe acquired aplastic anemia (SAA) and very severe acquired aplastic anemia (vSAA) patients. METHODS: Patients with SAA/vSAA who initiated treatment with rATG/CsA or oxymetholone between 2004 and 2018 were included. Trial-based cost-effectiveness evaluation in healthcare provider perspective was performed. Direct medical costs were retrieved from hospital database, inflated, and converted to 2020 US dollar (30.01 Baht per US dollar). One-way sensitivity analysis and probabilistic sensitivity analysis by nonparametric bootstrap was performed. RESULTS: After 2-year follow-up, the total mean (SD) direct medical expenditures per patient for oxymetholone and rATG/CsA group were $8 514.48 ($12 595.67) and $41 070.88 ($22 084.04), respectively. Nevertheless, oxymetholone had significant lower survival rate than rATG/CsA (P=.001) but higher in second-year blood transfusion need (71.4% vs 18.2%) and hospitalization (14.3% vs 0%). The incremental cost-effectiveness ratio was $45 854.08 per life-year gained when rATG/CsA was used instead of oxymetholone (95% CI $24 244.03-$143 496.67 per life-year gained). The probabilistic sensitivity analysis indicated that rATG/CsA had no chance of being cost-effective for SAA/vSAA when willingness to pay threshold of one to 3 times of national gross domestic product per capita was applied. CONCLUSIONS: Oxymetholone remains a viable alternative in resource-limited country. Despite its high cost, the rATG/CsA is a preferred treatment option because of the significant advantages on reducing mortality, treatment complications, and hospitalization.

Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy. METHODS: This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes. RESULTS: From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 109/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS. CONCLUSION: This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 109/L contributed to a worse outcome. ABBREVIATIONS: APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Risk of thrombosis in essential thrombocythemia according to three prediction models: an external validation study.

BACKGROUND: Thrombosis is a major complication of essential thrombocythemia (ET). There are three well-known prediction models for thrombotic risk in ET patients. However, only few external validation studies for the performance of these models in Asian populations have been conducted. Thus, we aimed to evaluate the performance of these models for predicting the risk of thrombosis in Thai patients with ET. METHODS: We retrospectively evaluated the clinical characteristics and thrombotic risk of 149 Thai ET patients in a university hospital in Southern Thailand between 2002 and 2019. Thrombotic risk variables were evaluated using Cox proportional hazard regression. The Brier score, calibration plot, and Harrel concordance index (C-index) were used to evaluate the performance of the three models. RESULTS: With a median follow-up of 5.2 years, there were a total of 28 thrombotic events in 26 patients. Age > 60 years was a significant prognostic factor for thrombosis in the multivariate Cox regression analysis. The Brier scores were 0.251, 0.273, and 0.276 in the conventional, IPSET-thrombosis, and revised IPSET-thrombosis models, respectively. The conventional model had optimal calibration and good discrimination (C-index, 0.67; 95%CI:0.55-0.79). The IPSET thrombosis (C-index 0.33; 95%CI:0.20-0.49) and revised IPSET thrombosis (C-index 0.31; 95%CI:0.18-0.44) models showed poor discrimination. CONCLUSION: The conventional model, which is based on age and history of thrombosis, is the best model to predict thrombotic risk in Thai ET patients. Further studies with a larger number of patients with thrombotic events are needed to validate the IPSET-thrombosis and revised IPSET-thrombosis models.

Efficacy of Oxymetholone in Severe and Nonsevere Acquired Aplastic Anemia: A Propensity Score Matching Analysis.

Background: Bone marrow transplantation, antithymocyte globulin/cyclosporine and eltrombopag are recommended as first-line therapy of severe aplastic anemia (SAA). However, androgens could be considered as front-line treatment among any patients ineligible for better methods although unsatisfactory efficacy is presented. Objective: This retrospective study aimed to evaluate response and survival rate of practical-based treatment with oxymetholone. Patients and Methods: This constituted an analysis of patients receiving a diagnosis of acquired aplastic anemia (AA) at the age of 15 or over and receiving oxymetholone between January 2004 and December 2018. Propensity Score Analysis (PSA) 1:1 matching was performed, according to sex, age and interval from first symptom to treatment. The primary outcome was one-year overall response (OR). Results: Seventy-four patients were successfully matched by PSA. The 1-year OR of oxymetholone in the nonsevere AA (nSAA) and SAA/very severe AA (vSAA) groups was 54.1 and 13.5%, respectively (P <0.001). With median follow-up 2.7 years, the overall survival was 59.5% in nSAA and 37.8% in SAA/vSAA (P = 0.051). Median survival in nSAA and SAA/vSAA were 7.0 years and 1.8 years, respectively (P = 0.045). However, the responders of SAA/vSAA had longer survival than nonresponders of the nSAA group. Conclusion: These results revealed longer survival among the responders of patients with AA, even in the SAA/vSAA group. However, close monitoring of therapeutic responses is still performed. Switching therapy is necessary when remission is undetected after 6 months of oxymetholone treatment.

Characteristics and Outcomes of Secondary Acute Myeloid Leukemia and Acute Myeloid Leukemia With Myelodysplasia-Related Changes: Multicenter Study From the Thai Acute Leukemia Study Group.

BACKGROUND: Secondary acute myeloid leukemia (sAML) and AML with myelodysplasia-related changes (AML-MRC) both result in dismal outcomes. This retrospective study aimed to determine whether these features are poor prognostic factors independent of older age and adverse cytogenetics, which are commonly associated with a poor prognosis. METHODS: The characteristics and real-world outcomes of sAML and AML-MRC from the Thai AML registry database were investigated. RESULTS: From a total of 992 newly diagnosed AML patients, 315 (31.8%) patients were classified into sAML or AML-MRC subtypes. Older age, low white blood cell (WBC) count, low bone marrow blast, and adverse cytogenetic risk were commonly present in sAML and AML-MRC compared to de novo AML. Complete remission after 7 + 3 induction therapy occurred in 42.3% of patients with sAML or AML-MRC and 62.4% of de novo AML (P < .001). The median overall survival (OS) of sAML, AML-MRC, and de novo AML were 6.9, 7.0, and 12.2 months, respectively (P < .001). The independent prognostic factors for inferior OS were older age, intermediate-risk or adverse-risk cytogenetics, WBC count > 100 × 109/L, poor performance status, and a subgroup of AML-MRC with the morphologic criteria of multilineage dysplasia (AML-MRC-M). In addition, sAML, AML-MRC, and a WBC count > 100 × 109/L were pre-treatment prognostic factors associated with poor relapse-free survival (P = .006, P = .017, and P < .001, respectively). CONCLUSION: Both sAML and AML-MRC are independently associated with poor outcomes in Thai patients. Our study supports AML-MRC-M as an adverse prognostic factor for OS.

Comparison of Three Doses of Cytarabine Consolidation for Intermediate- and Adverse-risk Acute Myeloid Leukemia: Real World Evidence From Thai Acute Myeloid Leukemia Registry.

BACKGROUND: Intermediate or high doses of cytarabine (IDAC or HiDAC) were recommended as postremission chemotherapy for acute myeloid leukemia (AML). This retrospective study investigated the real-world outcomes of 3-different cytarabine doses from the multicenter Thai AML registry database. PATIENTS AND METHODS: The intermediate- and adverse-risk AML patients (N = 258) who achieved complete remission and proceeded to single-agent cytarabine consolidation were enrolled. RESULTS: The median relapse-free survival (RFS) using IDAC 1.5 g/m2, high-dose cytarabine (HiDAC) 2 g/m2, and HiDAC 3 g/m2 were 12.6, 11.7, and 13 months, respectively. The median overall survival (OS) using IDAC 1.5 g/m2, HiDAC 2 g/m2, and HiDAC 3 g/m2 were 34.9, 22.7, and 23.7 months, respectively. No significant difference in RFS and OS was detected between the 3 doses. Secondary AML, white blood cell > 100×109/L and the adverse-risk AML were independent prognostic factors for inferior survival (P= .008, P < .001, P= .014). Patients who completed 3 to 4 cycles of consolidation had significantly superior RFS and OS (P< .001, P< .001). Febrile neutropenia occurred in 72.9% of IDAC, 73.8% of HiDAC 2 g/m2, and 78.1% of HiDAC 3 g/m2 without statistical significance. However, the incidence of septic shock was significantly higher after HiDAC 3 g/m2 compared to IDAC regimen (8% vs. 3%, P= .037). CONCLUSION: IDAC is an appropriate regimen for postremission chemotherapy for intermediate- and adverse-risk AML. The higher dosing levels may not produce any benefits to patients and may increase incidence of septic shock. The number of consolidation cycles may impact on survivals rather than the intensity of cytarabine.

Types, Clinical Features, and Survival Outcomes of Patients with Acute Myeloid Leukemia in Thailand: A 3-Year Prospective Multicenter Study from the Thai Acute Leukemia Study Group (TALSG).

BACKGROUND: Acute myeloid leukemia (AML) is a common, challenging hematologic malignancy worldwide. Thai data on its characteristics and outcomes have never been systematically reported, to our knowledge. The objective of this study was to determine the clinical features and outcomes of Thai patients with AML. PATIENTS AND METHODS: This was a prospective observational study of nine academic hospitals. Patients with newly diagnosed AML were invited to register online. RESULTS: A total of 679 patients with AML were included. The presence of circulating peripheral blood blasts was correlated with a high white blood cell count. Acute promyelocytic leukemia (APL) had predominantly lower white blood cell counts and higher proportions without peripheral blood blasts compared with non-APL AML. Disseminated intravascular coagulation was commonly presented in APL (37.7%). Splenomegaly and normal platelet count were more frequently seen in patients with Philadelphia chromosome-positive AML. The median follow-up time for those who survived more than 1 year was 28.0 months. One-year overall survival rates for non-APL AML and APL were 31.9% and 88.2%, respectively; 2-year overall survival rates were 29.6% and 88.2%, respectively. Hematopoietic stem cell transplantation could improve survival in non-APL AML. CONCLUSION: APL should be considered despite absence of peripheral blood blast. This study demonstrates poor outcome of Thai AML and more research to improve outcomes are underway. Expanding access to hematopoietic stem cell transplantation should be considered in Thailand.

Effects of Drug Concentration, Rate of Infusion, and Flush Volume on G-CSF Drug Loss When Administered Intravenously.

Purpose: This study evaluated factors that affect granulocyte-colony stimulating factor (G-CSF) adsorption in the infusion tube by measuring the G-CSF concentration, rate of G-CSF infusion, and volume of flush solution. Methods: The concentrations of G-CSF in all samples were measured by an enzyme-linked immunosorbent assay (ELISA) using human G-CSF Quantikine® ELISA kits. The concentration of G-CSF, the rate of administration, and the volume of flush solution were studied respectively. The concentration of G-CSF and the rate of administration that had a significantly lower G-CSF percent recovery after the infusion via the infusion set were used for further investigation in the study. All samples were diluted with 5% dextrose in water (D5W) to the final concentration within the standard concentration range. All experiments were performed in triplicate. Results: The concentration of G-CSF that was administered through the infusion tube at 20 µg/mL was a significantly higher G-CSF percent recovery compared with the G-CSF concentrations of 5, 10, and 15 µg/mL. The infusion rate of 15 and 20 mL/h percent recovery of G-CSF adsorption was significantly higher than the infusion rates of 30 and 40 mL/h. The concentration of G-CSF at 15 µg/mL and an infusion rate of 30 mL/h were selected to investigate the flush volumes of D5W on G-CSF adsorption. The D5W flush volume of 40 mL dramatically decreased the G-CSF adsorption with a recovery of 103 ± 1.73%. Conclusion: The G-CSF concentration of 20 µg/mL with an infusion rate of 20 mL/h, using a 40 mL D5W flush, was appropriate for intravenous G-CSF administration.

Improved Survival of Elderly-fit Patients With Acute Myeloid Leukemia Requiring Intensive Therapy: 3-Year Multicenter Analysis From TALWG.

BACKGROUND: Elderly patients with acute myeloid leukemia (AML) have a poorer prognosis than younger ones. Several factors contribute to the poor outcomes for this patient group. PATIENTS AND METHODS: This study investigated the epidemiology, clinical characteristics, treatment, and clinical outcomes of elderly Thai patients with AML. This 3-year, prospective, multicenter study was focused on Thai patients with AML aged over 60 years who were diagnosed between 2014 and 2016. RESULTS: Of 680 patients with AML, 235 elderly patients with AML (34.6%) were identified, with a mean age of 70 ± 8 years. Using a 3-group cytogenetic risk classification (favorable, intermediate, and adverse risk), the proportions of patients in each category were 3.6%, 73.8%, and 22.6%, respectively. The median follow-up time for surviving patients was 846 days. The median overall survival (OS) of the patients was 128.2 days (range, 0-1205 days), with a 1-year OS of 13%. From a multivariate analysis, the significant factors associated with an improved long-term OS were patients with an Eastern Cooperative Oncology Group performance status 0 to 2 and those receiving intensive therapy. CONCLUSION: Our study confirms the high prevalence of AML in elderly patients with generally poor outcomes. Selected patients with a good performance status and those who received intensive induction treatment could have a long-term survival.