Prediction Model for Severe Thrombocytopenia Induced by Gemcitabine Plus Cisplatin Combination Therapy in Patients with Urothelial Cancer.

BACKGROUND: Chemotherapy-induced thrombocytopenia is often a use-limiting adverse reaction to gemcitabine and cisplatin (GC) combination chemotherapy, reducing therapeutic intensity, and, in some cases, requiring platelet transfusion. OBJECTIVE: A retrospective cohort study was conducted on patients with urothelial cancer at the initiation of GC combination therapy and the objective was to develop a prediction model for the incidence of severe thrombocytopenia using machine learning. METHODS: We performed receiver operating characteristic analysis to determine the cut-off values of the associated factors. Multivariate analyses were conducted to identify risk factors associated with the occurrence of severe thrombocytopenia. The prediction model was constructed from an ensemble model and gradient-boosted decision trees to estimate the risk of an outcome using the risk factors associated with the occurrence of severe thrombocytopenia. RESULTS: Of 186 patients included in this study, 46 (25%) experienced severe thrombocytopenia induced by GC therapy. Multivariate analyses revealed that platelet count ≤ 21.4 (×104/µL) [odds ratio 7.19, p < 0.01], hemoglobin ≤ 12.1 (g/dL) [odds ratio 2.41, p = 0.03], lymphocyte count ≤ 1.458 (×103/µL) [odds ratio 2.47, p = 0.02], and dose of gemcitabine ≥ 775.245 (mg/m2) [odds ratio 4.00, p < 0.01] were risk factors of severe thrombocytopenia. The performance of the prediction model using these associated factors was high (area under the curve 0.76, accuracy 0.82, precision 0.68, recall 0.50, and F-measure 0.58). CONCLUSIONS: Platelet count, hemoglobin level, lymphocyte count, and gemcitabine dose contributed to the development of a novel prediction model to identify the incidence of GC-induced severe thrombocytopenia.

Association of clinical factors with thrombocytopenia in patients receiving linezolid treatment: a retrospective study.

INTRODUCTION: Linezolid (LZD) plays an important role in the treatment of severe infections caused by Gram-positive bacteria. Thrombocytopenia is regarded as one of the most common side effects of linezolid, which results from the destruction of platelets or myelosuppression. The study aimed to identify the risk factors associated with the development of thrombocytopenia in Vietnamese patients. METHODOLOGY: This retrospective, descriptive cross-sectional study was performed on adult patients who received parenteral LZD therapy (1,200 mg/day) in at least 3 days between January 2020 and June 2021 at a tertiary referral hospital in Vietnam. Thrombocytopenia was defined as either a final platelet count of less than 100 G/L or a 25% decrease in platelet count from baseline. Multivariate logistic regression analysis was applied to predict risk factors associated with LZD-induced thrombocytopenia. RESULTS: In the 208 patients included in the study, the average age was 69 and males accounted for 73.1%. LZD-induced thrombocytopenia occurred in 37% of patients. LZD-induced thrombocytopenia was significantly associated with shock (HR = 8.26, 95% CI 3.82 - 17.84, p < 0.001), baseline creatinine clearance (HR = 1.02, 95% CI [1.01 - 1.03], p = 0.002), and duration of LZD treatment of at least 14 days (HR = 4.45, 95% CI [1.83 - 11.05], p = 0.001). CONCLUSIONS: The results showed that thrombocytopenia was fairly common in patients using linezolid. Shock, renal failure, and duration of linezolid therapy of at least 14 days were significant risk factors for the incidence of linezolid-induced thrombocytopenia.

Risk and adverse clinical outcomes of thrombocytopenia among patients with solid tumors-a Danish population-based cohort study.

BACKGROUND: Knowledge about thrombocytopenia among patients with solid tumors is scarce. We examined the risk of thrombocytopenia among patients with solid tumors and its association with adverse outcomes. METHODS: Using Danish health registries, we identified all patients with incident solid tumors from 2015-2018 (n = 52,380) and a platelet count measurement within 2 weeks prior to or on their cancer diagnosis date. The risk of thrombocytopenia was categorized as grades 0 (any platelet count × 109/L): <150; 1: <100; 2: <75; 3: <50; 4: <25, and 5: <10. To study the outcomes, each patient with thrombocytopenia was matched with up to five cancer patients without thrombocytopenia by age, sex, cancer type, and stage. Cox regression was used to compute hazard ratios (HRs) of bleeding, transfusion, or death, adjusting for confounding factors. RESULTS: The 1-year risk of thrombocytopenia was 23%, increasing to 30% at 4 years. This risk was higher in patients receiving chemotherapy (43% at 1 year and 49% at 4 years). Overall, patients with thrombocytopenia had higher 30-days rates of bleeding (HR = 1.72 [95% confidence interval, CI: 1.41-2.11]). Thrombocytopenia was also associated with an increased rate of transfusion, and death, but some of the risk estimates were imprecise. CONCLUSIONS: The risk of thrombocytopenia was substantial among patients with solid tumors and associated with adverse outcomes.

Incidence rates of thrombosis with thrombocytopenia syndrome (TTS) among adults in United States commercial and Medicare claims databases, 2017-2020.

BACKGROUND: Increased risk of thrombosis with thrombocytopenia syndrome (TTS) following adenovirus vector-based COVID-19 vaccinations has been identified in passive surveillance systems. TTS incidence rates (IRs) in the United States (U.S.) are needed to contextualize reports following COVID-19 vaccination. METHODS: We estimated annual and monthly IRs of overall TTS, common site TTS, and unusual site TTS for adults aged 18-64 years in Carelon Research and MarketScan commercial claims (2017-Oct 2020), CVS Health and Optum commercial claims (2019-Oct 2020), and adults aged ≥ 65 years using CMS Medicare claims (2019-Oct 2020); IRs were stratified by age, sex, and race/ethnicity (CMS Medicare). RESULTS: Across data sources, annual IRs for overall TTS were similar between Jan-Dec 2019 and Jan-Oct 2020. Rates were higher in Medicare (IRs: 370.72 and 365.63 per 100,000 person-years for 2019 and 2020, respectively) than commercial data sources (MarketScan IRs: 24.21 and 24.06 per 100,000 person-years; Optum IRs: 32.60 and 31.29 per 100,000 person-years; Carelon Research IRs: 24.46 and 26.16 per 100,000 person-years; CVS Health IRs: 30.31 and 30.25 per 100,000 person-years). Across years and databases, common site TTS IRs increased with age and were higher among males. Among adults aged ≥ 65 years, the common site TTS IR was highest among non-Hispanic black adults. Annual unusual site TTS IRs ranged between 2.02 and 3.04 (commercial) and 12.49 (Medicare) per 100,000 person-years for Jan-Dec 2019; IRs ranged between 1.53 and 2.67 (commercial) and 11.57 (Medicare) per 100,000 person-years for Jan-Oct 2020. Unusual site TTS IRs were higher in males and increased with age in commercial data sources; among adults aged ≥ 65 years, IRs decreased with age and were highest among non-Hispanic American Indian/Alaska native adults. CONCLUSION: TTS IRs were generally similar across years, higher for males, and increased with age. These rates may contribute to surveillance of post-vaccination TTS.

Characteristics and outcomes of COVID-19 in Chinese immune thrombocytopenia patients: A prospective cohort study.

The coronavirus disease 2019 (COVID-19) pandemic has a significant impact on the immune system. This is the first and largest study on pre-existing immune thrombocytopenia (ITP) patients infected with COVID-19 in China. We prospectively collected ITP patients infected with COVID-19 enrolled in the National Longitudinal Cohort of Hematological Diseases (NICHE, NCT04645199) and followed up for at least 1 month after infection. One thousand and one hundred forty-eight pre-existing ITP patients were included. Two hundred and twelve (18.5%) patients showed a decrease in the platelet (PLT) count after infection. Forty-seven (4.1%) patients were diagnosed with pneumonia. Risk factors for a decrease in the PLT count included baseline PLT count <50 × 109/L (OR, 1.76; 95% CI, 1.25-2.46; p = 0.001), maintenance therapy including thrombopoietin receptor agonists (TPO-RAs) (OR, 2.27; 95% CI, 1.60-3.21; p < 0.001) and previous splenectomy (OR, 1.98; 95% CI, 1.09-3.61; p = 0.03). Risk factors for pneumonia included age ≥40 years (OR, 2.45; 95% CI, 1.12-5.33; p = 0.02), ≥2 comorbidities (OR, 3.47; 95% CI, 1.63-7.64; p = 0.001), maintenance therapy including TPO-RAs (OR, 2.14; 95% CI, 1.17-3.91; p = 0.01) and immunosuppressants (OR, 3.05; 95% CI, 1.17-7.91; p = 0.02). In this cohort study, we described the characteristics of pre-existing ITP patients infected with COVID-19 and identified several factors associated with poor outcomes.

Impact of heart failure and preoperative platelet count on the postoperative short-term outcome in infective endocarditis patients.

BACKGROUND: Heart failure (HF) and platelet count are often considered risk factors for mortality in patients with infective endocarditis (IE); however, their effects on various complications have not been elucidated. HYPOTHESIS: We speculated that HF and platelet count have significant impact on the short-term outcomes of IE. METHODS: This single-center retrospective study analyzed data from 320 IE patients who underwent surgery. A multivariate Cox proportional hazards model was used to identify the risk factors for adverse outcomes. The effect of the platelet count on the prognosis of patients with HF was determined by subgroup analysis and Kaplan-Meier analysis. RESULTS: The study population was divided into the HF group (n = 102) and the non-HF group (n = 218). The median age of the total population was 44.5 years (31-56 years), of which 227 (70.94%) patients were male. The incidence rates of 1-year all-cause mortality, cardiac outcomes, and composite outcomes were respectively almost sixfold, fourfold, and threefold higher in the HF group than in the non-HF group (all p < 0.001). In multivariate Cox regression analysis, HF was an independent risk factor for 1-year all-cause mortality, cardiac outcomes, cerebral outcomes, and composite outcomes. The Kaplan-Meier survival curves revealed that the patients with both HF and thrombocytopenia demonstrated the worst composite outcomes than the patients of the other groups (log-rank p < 0.001). In the HF group, the platelet count was significantly associated with mortality and composite outcomes. CONCLUSIONS: HF and preoperative platelet count are significantly associated with 1-year all-cause mortality and adverse outcomes postoperatively in IE patients. Patients with HF and thrombocytopenia have the worst short-term prognosis.

Bleeding Risk of Acupuncture for Patients with Hematological Malignancies Accompanying Thrombocytopenia: A Retrospective Chart Review.

Introduction: In recent years, it has been reported that acupuncture is useful for alleviating the symptoms of patients with hematological malignancies, but the safety of acupuncture for such patients has not been established. This study evaluated the risk of bleeding from acupuncture in patients with hematological malignancies accompanying thrombocytopenia. Methods: The authors performed a retrospective investigation of the medical records of patients with hematological malignancies who received acupuncture during hospitalization at the hematology department of a single medical center in Japan. The bleeding risk at the acupuncture site was evaluated in the following four groups according to the platelet count measured on the day of acupuncture treatment: (1) <20 × 103/µL, (2) 20-49 × 103/µL, (3) 50-99 × 103/µL, and (4) 100 × 103/µL or more. Occurrence of grade 2 or higher bleeding according to the Common Terminology Criteria for Adverse Events, version 5.0, within 24 h from the acupuncture session or before the next session was defined as an event, and the risk of occurrence of bleeding was examined in each group. Results: Of 2423 acupuncture sessions conducted on 51 patients with hematological malignancies, 815 were included in the analysis. Ninety sessions were performed in the <20 × 103/µL platelet count group, 161 in the 20-49 × 103/µL group, 133 in the 50-99 × 103/µL group, and 431 in the 100 × 103/µL or more group. No bleeding event according to the authors' definition occurred in any of these groups. Conclusions: This study is the largest to date to assess the bleeding risk of acupuncture in patients with hematological malignancies accompanying thrombocytopenia. The authors considered that acupuncture could be safely performed without causing serious bleeding for patients with hematological malignancies accompanying thrombocytopenia.

Hematological Toxicity of PARP Inhibitors in Metastatic Prostate Cancer Patients with Mutations of BRCA or HRR Genes: A Systematic Review and Safety Meta-analysis.

BACKGROUND: PARP inhibitors (PARPis) are effective treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC) as single agents or in combination with androgen receptor-targeted agents (ARTA). However, a clinically relevant adverse effect of these agents is hematological toxicity, a typical class adverse event (AE), which can lead to treatment modifications and discontinuations. OBJECTIVE: We aimed to analyze the risk of hematological AEs, including anemia, neutropenia, and thrombocytopenia secondary to PARPi treatments in mCRPC. PATIENTS AND METHODS: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. We systematically searched the PubMed, EMBASE, and Cochrane databases, the American Society of Clinical Oncology (ASCO), and the European Society of Medical Oncology (ESMO) meeting abstracts for clinical trials concerning the use of PARPis, both as single agents and in combination, in patients with mCRPC. The search deadline was 30 June, 2023. We analyzed the pooled incidence of all grades of and ≥ G3 anemia, neutropenia, and thrombocytopenia. We subsequently calculated risk ratios (RRs) for all grades of and ≥ G3 AEs of PARPis versus non-PARPis from randomized clinical trials (RCTs). RESULTS: Eleven phase 2/3 trials with olaparib, niraparib, rucaparib, and talazoparib administered as single agents or combined with ARTA were selected. Anemia was the most common all grades (38.6%) and ≥ G3 AE (24.9%). In the analysis of relative risk, six RCTs were included. The administration of PARPis significantly increased the risk of developing all grades of anemia (RR = 2.44), neutropenia (RR = 3.15), and thrombocytopenia (RR = 4.66) compared with non-PARPis. Similarly, a significant increase in the risk of ≥ G3 anemia (RR = 5.73) and thrombocytopenia (RR = 5.44), and a not significant increased risk of neutropenia (RR = 3.41), were detected. CONCLUSIONS: In mCRPC, PARPis increase the risk of hematological toxicity compared with other treatments, both as single agents or combined with ARTA (high-quality evidence). Clinicians should be aware of this risk and the correct management, especially with the expected increased PARPis use in mCRPC.

Risk factors of rituximab-induced thrombocytopenia in patients with autoimmune bullous diseases.

Rituximab has been the mainstay treatment for autoimmune bullous diseases (AIBDs). Among the side effects of rituximab, rituximab-induced thrombocytopenia (RIT) is a rare but critical complication. However, there have been no reports or identification of risk factors for RIT in patients with AIBD. In our retrospective study, we compared rituximab-treated AIBD in patients with and without thrombocytopenia to explore the risk factors. In addition, we compared two different rituximab protocols (rheumatoid arthritis [RA] and lymphoma) in terms of the incidence and severity of thrombocytopenia. A total of 222 patients were enrolled, and 46 patients (20.7%) developed RIT. Multivariate logistic regression analysis identified age and chronic kidney disease (CKD) as significant factors for RIT. We also found that patients treated with the lymphoma protocol demonstrated a significantly higher mean post-rituximab platelet count compared with those on the RA protocol. This was the first analysis, to our knowledge, of risk factors for RIT in patients with AIBD. Individuals aged 70 or older and those with multiple comorbidities, particularly CKD, should be closely monitored for thrombocytopenia. For patients with CKD, it may be safer to use the lymphoma protocol for rituximab administration as it results in a lesser reduction in post-rituximab platelet count.

The addition of tislelizumab to gemcitabine and cisplatin chemotherapy increases thrombocytopenia in patients with urothelial carcinoma: A single-center study based on propensity score matching.

PURPOSE: Whether the addition of tislelizumab to gemcitabine and cisplatin (GC) chemotherapy increases the incidence of myelosuppression has not been well established. This study identified the risk factors for the development of myelosuppression in patients with urothelial carcinoma (UC) after receiving GC chemotherapy with or without tislelizumab. MATERIALS AND METHODS: We enrolled 192 UC patients who received GC with or without tislelizumab at the Affiliated Hospital of Xuzhou Medical University between July 2014 and November 2022. Patient baseline characteristics were included in the statistical analyses after adjusting for previously reported risk factors affecting survival using propensity score matching (1:1). Binary logistic regression analysis was used to identify the risk factors associated with posttreatment myelosuppression. RESULTS: A total of 192 patients were enrolled, of whom 96 were treated with tislelizumab plus gemcitabine and cisplatin (T + GC) and 96 with GC alone. The incidence of leukopenia, anemia, and thrombocytopenia of any grade was 50.0%, 70.8%, and 42.7%, respectively, in the T + GC group and 41.7%, 72.9%, and 20.8%, respectively, in the GC group. In multivariate analysis, patients aged over 70 years (OR = 2.486, 95% CI: 1.067-5.792, p = 0.035) and those who received T + GC (OR = 3.119, 95% CI: 1.576-6.173, p = 0.001) were more likely to develop thrombocytopenia. Patients aged over 70 years (OR = 3.213, 95% CI: 1.254-8.237, p = 0.015) were more likely to develop anemia, and patients with renal insufficiency (OR = 2.105, 95% CI: 1.035-4.280, p = 0.040) were more likely to develop leukopenia. Eventually, 99 (51.6%) patients with UC successfully completed all the treatment cycles. CONCLUSIONS: This study demonstrates that the addition of tislelizumab to GC chemotherapy led to a considerable increase in the occurrence of thrombocytopenia, whereas no significant changes were observed regarding anemia or leukopenia. It is crucial to fully inform patients at increased risk for myelosuppression of potential risks and closely monitor changes in their blood routines.

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU).

PURPOSE: Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. METHODS: We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. RESULTS: We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4-46.1) had thrombocytopenia; 23.4% (20-26) had thrombocytopenia at ICU admission, and 19.8% (17.6-22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19-2.42). CONCLUSION: Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.

The risk factors for coagulation disorder of chimeric antigen receptor-T cell therapy in patients with hematological tumors: A systematic review and meta-analysis.

BACKGROUND: Currently, the frequency of coagulation dysfunction associated with chimeric antigen receptor-T cell (Car-T) therapy cannot yet be determined. OBJECTIVE: We performed a systematic review and meta-analysis to examine the prevalence of abnormal laboratory tests related to coagulation disorders in patients receiving Car-T therapy and provide a reference for future risk assessment mechanisms. METHODS: We searched PubMed, Embase, and Web of Science for relevant studies and evaluated their quality using the methodology index of non-random research (MINORS). 2672 quotations were retrieved via systematic searches. After screening of titles, abstracts and full-text, 45 trials involving 2541 patients were ultimately included. 41 studies reported the incidence of thrombocytopenia, 8 studies reported the rate of low fibrin, 4 trials reported the rate of APTT or PT abnormalities and only 3 trials reported the incidence of venous thromboembolism (VTE). We performed a quantitative meta-analysis to explore the incidence of thrombocytopenia following Car-T treatment. The incidence of hypofibrinogenemia, VTE, and abnormal APTT or PT was only qualitatively assessed, as fewer reports were included in this study. RESULTS: The overall incidence of thrombocytopenia associated with Car-T therapy was 45.8% (95%[CI], 0.384-0.533). The highest rates of thrombocytopenia occurred in patients with multiple myeloma (60.1%, 95%[CI], 0.507-0.688) and aged between 18 to 60 (50%, 95%[CI], 0.367-0.633). There was greater prevalence of thrombocytopenia in BCMA-Car-T therapy of 58.7% (95%[CI], 0.482-0.685). Thrombocytopenia occurred most frequently in Car-T patients treated with a dosage of 1 × 105-1 × 106 cell/kg, at a rate of 66.2% (95%[CI], 0.561-0.749). CONCLUSION: Overall, 45.8 percent of patients receiving Car-T treatment suffered from thrombocytopenia. Multiple myeloma patients, ages between 18-60, a dose of 1 × 105-1 × 106 cell/kg and BCMA-Car-T therapy are all considered high-risk factors.

Thrombosis with thrombocytopenia syndrome: A database review of clinical trial and post-marketing experience with Ad26.COV2.S.

BACKGROUND: Thrombosis with thrombocytopenia syndrome (TTS) is a very rare disorder described after vaccination with adenoviral vector-based COVID-19 vaccines. Co-occurring thrombosis with thrombocytopenia reported after vaccination can be a proxy for identification of TTS. METHODS: Descriptive database review of all cases of co-occurring (within 42 days) thrombosis with thrombocytopenia in participants in Ad26.COV2.S clinical trials or recipients of Ad26.COV2.S in real-world clinical practice. Cases were retrieved from Janssens' clinical trial and Global Medical Safety databases. RESULTS: There were 34 cases of co-occurring thrombosis with thrombocytopenia in Ad26.COV2.S recipients (46 per 100,000 person-years) and 15 after placebo (75 per 100,000 person-years) in clinical trials. Among Ad26.COV2.S recipients, mean age at the time of the event was 63 years (range 25-85), 82 % were male, mean time-to-onset 112 days (range 8-339) post-last Ad26.COV2.S dose, 26 events occurred post-dose-1, and 7 within a 28-day risk window post-vaccination. Diagnostic certainty was evaluated using Brighton Collaboration, US Centers for Disease Control and Prevention, and European Medicines Agency Pharmacovigilance Risk Assessment Committee case definitions. One case met the highest level of diagnostic certainty for all 3 definitions. There were 355 spontaneous reports of co-occurring thrombosis with thrombocytopenia in the Global Medical Safety database, 47 % males, 85 % within 28-days after vaccination. Twenty-seven cases met the highest level of diagnostic certainty for all definitions, 21 female, 19 with cerebral venous sinus thrombosis, age-range 18-68 years. Time-to-onset was 7-14 days post-vaccination in 20 cases. There were 8 fatalities. CONCLUSION: TTS induced by Ad26.COV2.S is very rare. Most co-occurring thrombosis with thrombocytopenia does not constitute TTS.

Re-evaluation of the risk of venous thromboembolism after COVID-19 vaccination using haematological criteria.

An elevated risk of venous thromboembolism (VTE) following a first dose of the ChAdOx1 adenovirus-vectored vaccine was found in a national epidemiological study in England using routine discharge diagnosis codes. Separately, the syndrome of vaccine-induced immune thrombotic thrombocytopenia (VITT) was identified using haematological criteria based on presence of thrombocytopenia, significantly elevated D-dimers and development of anti-PF4 antibodies. To re-evaluate risk estimates using haematological criteria, we obtained the haematology results for hospital admitted patients aged 18-64 years in 43 National Health Service trusts in England who were included in the national epidemiological study. Diagnoses were confirmed and haematological parameters obtained from local records without knowledge of vaccination status. The haematological parameters in patients admitted for a confirmed VTE following ChAdOx1 or BNT162b2 mRNA vaccination were then compared with those in a randomly selected 40% sample of unvaccinated patients with VTE. Overall, 12 (14%) of the 84 vaccinated cases had a diagnosis compatible with VITT, 11 after a first dose of ChAdOx1 and one after a first dose of BNT162b2. Thrombocytopenia (platelet count <150 × 109/L) occurred in 17 vaccinated (20%) and 4 (4%) of 108 unvaccinated patients, with all 6 cases of severe thrombocytopenia (<50 × 109/L) occurring within 42 days of a first dose of ChAdOx1. The attributable risk estimates for a cerebral venous thrombosis (CVT) or other VTE with thrombocytopenia after a first dose of ChAdOx1 vaccine were 2.82 and 9.62 per million doses respectively. However, elevated risks were also found after a first dose of ChAdOx1 for VTE without thrombocytopenia with relative incidences for CVT and other VTE of 2.67 (1.77-3.77) and 1.93 (1.57-2.35) respectively. While we identified a distinct population with features of VITT within 42 days of receiving ChAdOx1 vaccination, confirming current diagnostic criteria, we also found evidence of an increased risk of a VTE without thrombocytopenia after ChAdOx1 vaccine.

Responsiveness to Platelet Transfusions in Pediatric Patients with Thrombocytopenia: Incidence, Clinical Variables.

BACKGROUND: Refractoriness to platelet transfusion has not been adequately studied in pediatric patients with thrombocytopenia. Our objectives were: (1) to describe the practice of platelet transfusion in pediatric patients with thrombocytopenia of various etiologies; (2) to assess the responsiveness to platelet transfusions and clinical variables affecting platelet transfusions response; and (3) to evaluate incidence of PTR. METHODS: A retrospective study included pediatric patients with thrombocytopenia admitted to a tertiary children's hospital who received ≥ 1 platelet transfusion during hospitalization. Responsiveness was measured by corrected count increment (CCI), poor platelet transfusion response (PPTR), and platelet transfusion refractoriness (PTR). RESULTS: A total of 334 patients were eligible for the study and received 1,164 transfusions, with a median of 2 (IQR: 1 - 5) platelet transfusions. Patients admitted with hematologic malignancies had the highest median number of platelet transfusions (5, IQR: 4 - 10). The median CCI of 1,164 platelet post-transfusions was 17.0 (IQR: 9.4 - 24.6) and the incidence of PPTR was 11.9%. Patients admitted with ITP had the lowest median CCI (7.6, IQR: 1.0 - 12.5) and the highest incidence of PPTR (36.4%, 8/22). Older age of platelet components, low doses of platelet transfusion, increasing number of platelet transfusions (≥ 5), splenomegaly, bleeding, DIC, shock, ECMO supported, and HLA antibody-positive were independent risk factors for PPTR. Finally, the incidence of PTR was 11.4%. CONCLUSIONS: Practical experience of clinicians regarding the use of apheresis platelets in pediatric patients is determined. Highlight that PTR is not a low probability event when apheresis platelets are received in pediatric patients.

Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia in middle-income countries.

BACKGROUND: Adenovirus-based COVID-19 vaccines are extensively used in low- and middle-income countries (LMICs). Remarkably, cases of cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) have rarely been reported from LMICs. AIMS: We studied the frequency, manifestations, treatment, and outcomes of CVST-VITT in LMICs. METHODS: We report data from an international registry on CVST after COVID-19 vaccination. VITT was classified according to the Pavord criteria. We compared CVST-VITT cases from LMICs to cases from high-income countries (HICs). RESULTS: Until August 2022, 228 CVST cases were reported, of which 63 were from LMICs (all middle-income countries [MICs]: Brazil, China, India, Iran, Mexico, Pakistan, Turkey). Of these 63, 32 (51%) met the VITT criteria, compared to 103 of 165 (62%) from HICs. Only 5 of the 32 (16%) CVST-VITT cases from MICs had definite VITT, mostly because anti-platelet factor 4 antibodies were often not tested. The median age was 26 (interquartile range [IQR] 20-37) versus 47 (IQR 32-58) years, and the proportion of women was 25 of 32 (78%) versus 77 of 103 (75%) in MICs versus HICs, respectively. Patients from MICs were diagnosed later than patients from HICs (1/32 [3%] vs. 65/103 [63%] diagnosed before May 2021). Clinical manifestations, including intracranial hemorrhage, were largely similar as was intravenous immunoglobulin use. In-hospital mortality was lower in MICs (7/31 [23%, 95% confidence interval (CI) 11-40]) than in HICs (44/102 [43%, 95% CI 34-53], p = 0.039). CONCLUSIONS: The number of CVST-VITT cases reported from LMICs was small despite the widespread use of adenoviral vaccines. Clinical manifestations and treatment of CVST-VITT cases were largely similar in MICs and HICs, while mortality was lower in patients from MICs.

Association between Area under the Curve Estimated from Carboplatin Dose and Incidence of Severe Thrombocytopenia in Patients with Non-Hodgkin's Lymphoma on DeVIC Therapy.

BACKGROUND: The degrees of adverse effects with carboplatin (CBDCA) are influenced by interindividual differences in the area under the curve (AUC), whereas renal function is not considered in the CBDCA dose design for dexamethasone, etoposide, ifosfamide, and CBDCA (DeVIC) therapy. We conducted this study to evaluate the association between the AUC and incidence of severe thrombocytopenia in patients treated with DeVIC with or without rituximab (DeVIC ± R). METHODS: We retrospectively analyzed clinical data for 36 patients with non-Hodgkin's lymphoma who received DeVIC ± R between May 2013 and January 2021 at the National Hospital Organization Hokkaido Cancer Center. The AUC of CBDCA (AUCactual) was calculated backward using a variant of the Calvert formula. RESULTS: The median AUCactual was 4.6 (interquartile range: 4.3-5.3) min mg/mL and AUCactual was negatively correlated with the nadir platelet count (r = -0.45; P < 0.01). Multivariate analysis showed that AUCactual ≥ 4.3 versus < 4.3 was an independent factor predictive of severe thrombocytopenia (odds ratio: 19.3, and 95% confidence interval: 1.45-258; P = 0.02). CONCLUSION: This study suggests that the CBDCA dosing design considering renal function can reduce the risk of severe thrombocytopenia in DeVIC ± R therapy.

Causes of thrombocytopenia in dogs in the United Kingdom: A retrospective study of 762 cases.

BACKGROUND: Thrombocytopenia is a common laboratory abnormality in dogs, and numerous diseases have been associated with its development. Estimates for the sensitivity and specificity of the degree of reduction of platelet concentration for the diagnosis of primary immune-mediated thrombocytopenia (pITP) have not been reported. OBJECTIVES: To report the prevalence of different causes of thrombocytopenia in dogs in the United Kingdom and to investigate the utility of platelet concentration to differentiate causes of thrombocytopenia. METHODS: Medical records of 762 dogs with thrombocytopenia presented to seven referral hospitals from January 2017 to December 2018 were retrospectively reviewed. Cases were assigned into the following categories: pITP, infectious diseases, neoplasia, inflammatory/other immune-mediated disorders and miscellaneous causes. The prevalence of the different categories was estimated, and platelet concentrations were compared. Receiver-operating characteristic (ROC) curves were used to investigate the utility of platelet concentration to differentiate between causes of thrombocytopenia. RESULTS: The most common disease category associated with thrombocytopenia was neoplasia (27.3%), followed by miscellaneous causes (26.9%), pITP (18.8%), inflammatory/immune-mediated disorders (14.4%) and infectious diseases (12.6%). Dogs with pITP had significantly lower platelet concentrations (median 8 × 109 /L, range: 0-70 × 109 /L) than dogs in the other four categories. Platelet concentration was useful for distinguishing pITP from other causes of thrombocytopenia (area under ROC curve = 0.89, 95% confidence interval 0.87, 0.92), with a platelet concentration ≤12 × 109 /L being 60% sensitive and 90% specific. CONCLUSIONS: Severe thrombocytopenia was highly specific for a diagnosis of pITP, which was more prevalent in this UK population of thrombocytopenic dogs compared with previous epidemiological studies. Conversely, the proportion of dogs with infectious diseases was lower than in previous reports from other locations.

Incidence, consequences, and predictors of serious chemotherapy-induced thrombocytopenia in nasopharyngeal carcinoma.

OBJECTIVES: This study aimed to investigate the incidence, consequences, and predictors of serious chemotherapy-induced thrombocytopenia (CIT) in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: We retrospectively reviewed the clinical records of patients with NPC between 2013 and 2015. Multivariate Cox proportional hazards regression model and propensity score matching were used to estimate the effect of serious CIT on overall survival. Univariate and multivariate logistic regression analyses were applied to identify the predictors of serious CIT. RESULTS AND CONCLUSION: The incidence of serious CIT was 5.21% in patients with NPC. Patients who experienced serious thrombocytopenia had a worse long-term prognosis, while the difference in short-term survival rate was slight. Chemotherapy regimens of gemcitabine and platinum, 5-fluorouracil and platinum, taxane and platinum, serum potassium ion concentration, serum lactate dehydrogenase levels, platelet count, red blood cell count, and estimated glomerular filtration rate were predictors of serious CIT.

Association between postoperative thrombocytopenia and outcomes after traumatic brain injury surgery: A cohort study.

BACKGROUND: It is well known that thrombocytopenia occurs in patients with traumatic brain injury (TBI), and its incidence increases with the severity of injury. We aimed to determine whether postoperative thrombocytopenia in patients with TBI is associated with poor clinical outcomes. METHODS: This was a retrospective cohort study of a large international database called the Medical Information Mart for Intensive Care III (MIMIC-III), which included 1093 patients who underwent TBI surgery. Hospital mortality was the primary endpoint of this study. RESULTS: Multivariate logistic regression analysis revealed non-thrombocytopenia was significantly associated with a decreased hospital mortality (adjusted odds ratio [OR] 0.49; 95% confidence interval [CI] 0.33-0.75; p = .01). In addition, platelet counts increased over time in both survivors and non-survivors, according to generalized additive mixed model (GAMM). However, the platelet count increased more noticeably in the survivors than in the non-survivors and the difference in platelet count between the two groups showed a trend toward increasing within 7 days after surgery. This difference increased by 7.97 per day on average. CONCLUSIONS: Patients with TBI who experienced postoperative thrombocytopenia were more likely to have a poor short-term prognosis. In addition, we found that the rate of platelet growth over time varied significantly between the survival and non-survival groups. Patients with TBI who experienced a greater early increase in platelet count had a lower mortality rate.