Prediction of bleeding and prophylactic platelet transfusions in cancer patients with thrombocytopenia

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.

Impact of anemia and thrombocytopenia on postpartum hemorrhage risk among women with term singleton pregnancy

Both thrombocytopenia (platelet count < 150 × 10³/µL) and anemia have been associated with postpartum hemorrhage (PPH). However, the impact of thrombocytopenia on PPH risk among women with mild and severe anemia is unknown. We sought to evaluate the association between thrombocytopenia and anemia in increasing risk of PPH. We performed a secondary analysis of a retrospective cohort of pregnant women from 19 hospitals across the United States from 2016 to 2021. Women who had a term singleton pregnancy and hematocrit (Hct) ≤ 33% at delivery were included in the study. The primary outcome was PPH (defined as blood loss ≥ 1000 mL or blood transfusion). We also analyzed the effect of severe anemia (Hct < 28%) on the association between PPH and thrombocytopenia. Chi-squared tests and Fisher's exact tests were used for categorical variables and an independent t-test was used for continuous variables. There were 20,808 women who met our inclusion criteria, of which 1793 (8.6%) had platelet count < 150 × 10³/µL. The prevalence of PPH was 6.4%. Compared with women with normal platelet count, those with thrombocytopenia had 1.3-fold higher odds of PPH [6.8% vs. 4.5%, adjusted OR 1.3 (1.1-1.7)]. Platelet count ≥ 150 × 10³/µL was associated with decreased odds of PPH among patients with hct between 28 and 33% and hct < 28%. In conclusion, anemic women with term singleton pregnancies who delivered with thrombocytopenia had a higher frequency of PPH. Normal platelet count at delivery was protective against PPH in the setting of anemia regardless of severity.

EHA Guidelines on Management of Antithrombotic Treatments in Thrombocytopenic Patients With Cancer

In cancer patients, thrombocytopenia can result from bone marrow infiltration or from anticancer medications and represents an important limitation for the use of antithrombotic treatments, including anticoagulant, antiplatelet, and fibrinolytic agents. These drugs are often required for prevention or treatment of cancer-associated thrombosis or for cardioembolic prevention in atrial fibrillation in an increasingly older cancer population. Data indicate that cancer remains an independent risk factor for thrombosis even in case of thrombocytopenia, since mild-to-moderate thrombocytopenia does not protect against arterial or venous thrombosis. In addition, cancer patients are at increased risk of antithrombotic drug-associated bleeding, further complicated by thrombocytopenia and acquired hemostatic defects. Furthermore, some anticancer treatments are associated with increased thrombotic risk and may generate interactions affecting the effectiveness or safety of antithrombotic drugs. In this complex scenario, the European Hematology Association in collaboration with the European Society of Cardiology has produced this scientific document to provide a clinical practice guideline to help clinicians in the management of patients with cancer and thrombocytopenia. The Guidelines focus on adult patients with active cancer and a clear indication for anticoagulation, single or dual antiplatelet therapy, their combination, or reperfusion therapy, who have concurrent thrombocytopenia because of either malignancy or anticancer medications. The level of evidence and the strength of the recommendations were discussed according to a Delphi procedure and graded according to the Oxford Centre for Evidence-Based Medicine.

Analysis of preplatelets and their barbell platelet derivatives by imaging flow cytometry

Circulating large "preplatelets" undergo fission via barbell platelet intermediates into two smaller, mature platelets. In this study, we determine whether preplatelets and/or barbells are equivalent to reticulated/immature platelets by using ImageStream flow cytometry and super-resolution microscopy. Immature platelets, preplatelets, and barbells were quantified in healthy and thrombocytopenic mice, healthy human volunteers, and patients with immune thrombocytopenia or undergoing chemotherapy. Preplatelets and barbells were 1.9% ± 0.18%/1.7% ± 0.48% (n = 6) and 3.3% ± 1.6%/0.5% ± 0.27% (n = 12) of total platelet counts in murine and human whole blood, respectively. Both preplatelets and barbells exhibited high expression of major histocompatibility complex class I with high thiazole orange and Mitotracker fluorescence. Tracking dye experiments confirmed that preplatelets transform into barbells and undergo fission ex vivo to increase platelet counts, with dependence on the cytoskeleton and normal mitochondrial respiration. Samples from antibody-induced thrombocytopenia in mice and patients with immune thrombocytopenia had increased levels of both preplatelets and barbells correlating with immature platelet levels. Furthermore, barbells were absent after chemotherapy in patients. In mice, in vivo biotinylation confirmed that barbells, but not all large platelets, were immature. This study demonstrates that a subpopulation of large platelets are immature preplatelets that can transform into barbells and undergo fission during maturation.

Feasibility of a mean platelet volume standard: an international council for standardization in hematology (ICSH) inter-laboratory study

We have evaluated a commercial-fixed porcine platelet preparation (with and without added fixed human red blood cells (RBC)) for the potential standardization of mean platelet volume (MPV) measurements. The standards (Biotechne) were distributed internationally to 19 laboratories including all major hematology instrument manufacturers and academic/pathology laboratories. Overall, the standards demonstrated excellent stability up to 1 month within both MPV values and platelet counts when stored at 4°C. The presence of RBC significantly increased the platelet count and MPV values compared to platelets alone. However, as expected, there were differences in MPV values between different instruments and manufacturers. MPV values were also significantly higher in the whole blood standard compared to the platelet standard in the majority of instruments except with some instruments, where MPV values were significantly higher in the platelet only preparation. To further investigate this phenomenon, two different Platelet MPV preparations (with low and high MPV) in combination with 3 different RBC MCV preparations (with low, normal or high MCVs) were tested to try and further elucidate how RBC populations may impact upon platelet analysis (count, MPV, and PDW) using a single impedance analyzer. Both MPV and MCV values showed good stability over the course of the study for up to 50 days. As expected, the RBC preparation with the lowest MCV had the greatest impact on the MPV. However, this was not observed with an increase in MCV of the RBC or by a larger MPV of the platelet population. To further understand how different gating strategies may also influence results, we investigated the effect of either fixed or floating gate strategies upon MPV raw data from patient samples in a single impedance analyzer. Overall, it was clear that floating and fixed gate strategies also significantly impact upon MPV values. In conclusion, we have demonstrated the potential of an MPV standard with good stability characteristics for calibrating and comparing full blood counters that use different analysis principles, gating and MPV calculations. This may facilitate future instrument calibration and harmonization of results between different technologies.

Investigation of patient factors associated with the number of transfusions required during chemotherapy for high-risk neuroblastoma

BACKGROUND

Blood transfusion is an important supportive care for high-risk neuroblastoma. When the number of transfusions increases, transfusion-associated adverse reactions may be more problematic. However, the factors determining the degree of myelosuppression and the number of transfusions during chemotherapy for high-risk neuroblastoma remain unclear.

MATERIALS AND METHODS

We investigated patient factors determining the number of required transfusions in 15 high-risk neuroblastoma patients who received five courses of chemotherapy. Clinical data, cytokine profile and colony-forming assay with bone marrow samples at diagnosis were analysed.

RESULTS

The required number of transfusions of both platelets and erythrocytes decreased once in the second course and then increased as the course progressed. The variability among cases increased as the chemotherapy course progressed. In cases of low peripheral blood platelet count and lower fibrinogen level at diagnosis, the number of platelet transfusions was higher during chemotherapy. In contrast, there was a negative correlation between the forming ability of granulocyte-macrophage or erythroid colonies and the number of erythrocyte transfusions in the latter period.

CONCLUSION

In the early stages of chemotherapy, bone marrow infiltration in neuroblastoma and/or coagulopathy complication may cause thrombocytopenia and requirement of platelet transfusion; conversely, in the later stages, the number of erythrocyte transfusions may be defined by the patient's inherent hematopoietic ability. These factors may be useful in predicting the required number of transfusions.

Platelets in aging and cancer-"double-edged sword"

Platelets control hemostasis and play a key role in inflammation and immunity. However, platelet function may change during aging, and a role for these versatile cells in many age-related pathological processes is emerging. In addition to a well-known role in cardiovascular disease, platelet activity is now thought to contribute to cancer cell metastasis and tumor-associated venous thromboembolism (VTE) development. Worldwide, the great majority of all patients with cardiovascular disease and some with cancer receive anti-platelet therapy to reduce the risk of thrombosis. However, not only do thrombotic diseases remain a leading cause of morbidity and mortality, cancer, especially metastasis, is still the second cause of death worldwide. Understanding how platelets change during aging and how they may contribute to aging-related diseases such as cancer may contribute to steps taken along the road towards a "healthy aging" strategy. Here, we review the changes that occur in platelets during aging, and investigate how these versatile blood components contribute to cancer progression.

The role of platelets in bleeding in patients with thrombocytopenia and hematological disease

This review evaluates the role of platelets in bleeding risk among patients with hematological disease and thrombocytopenia. Platelets are pivotal in primary hemostasis, and possess non-hemostatic properties involved in angiogenesis, tissue repair, inflammation and metastatis. Also, platelets safeguard vascular integrity in inflamed vessels. Overall, bleeding risk depends on the underlying disease, and patients with cancer and platelet count <6-10 × 109/L have a markedly increased bleeding risk, while the platelet count does not correlate with bleeding risk at higher platelet counts. Other factors might affect platelet properties and thus bleeding risk, for example, drugs, low hematocrit, coagulation system impairments or transfusion of dysfunctional donor platelets. For patients with leukemia and immune thrombocytopenia, reduced platelet activation, platelet aggregation, or thrombopoiesis, reflected by the reduced presence of reticulated platelets, are associated with bleeding phenotype. However, mechanistic insight into the cause of reduced platelet function in different thrombocytopenic conditions is sparse, except for some inherited platelet disorders. Promising tools for platelet function studies in thrombocytopenia are flow cytometry and biomarker studies on platelet constituents. An important message from this current paper is that bleeding risk assessment must be tailored to specific patient populations and cannot be applied broadly to all patients with thrombocytopenia.

Anticoagulation in thrombocytopenic patients with hematological malignancy: A multinational clinical vignette-based experiment

BACKGROUND

Thrombocytopenia in cancer patients with an indication for anticoagulation poses a unique clinical challenge. There are guidelines for the setting of venous thromboembolism but not atrial fibrillation (AF). Evidence is lacking and current practice is unclear.

OBJECTIVE

To identify patient and physician characteristics associated with anticoagulation management in hematological malignancy and thrombocytopenia.

METHODS

A clinical vignette-based experiment was designed. Eleven hematologists were interviewed, identifying 5 relevant variable categories with 2-5 options each. Thirty hypothetical vignettes were generated. Each physician received 5 vignettes and selected a management strategy (hold anticoagulation; no change; transfuse platelets; modify type/dose). The survey was distributed to hematologists and thrombosis specialists in 3 countries. Poisson regression models with cluster robust variance estimates were used to calculate relative risks for using one management option over the other, for each variable in comparison to a reference variable.

RESULTS

168 physicians answered 774 cases and reported continuing anticoagulation for venous thromboembolism or AF in 607 (78%) cases, usually with dose reduction or platelet transfusion support. Overall, management was affected by platelet count, anticoagulation indication, time since indication, type of hematological disease and treatment, and prior major bleeding, as well as physician demographics and practice setting. The CHA₂DS₂-VASc score and time since AF diagnosis affected anticoagulation management in AF.

CONCLUSION

This study indicates what the widely accepted management strategies are. These strategies, and possibly others, should be assessed prospectively to ascertain effectiveness. The decision process is intricate and compatible with current venous thromboembolism guidelines.

Prophylactic use of platelets in critically ill patients with thrombocytopaenia: A retrospective two-centre observational study

PURPOSE

We report the use and effect of prophylactic platelet transfusions in critically ill thrombocytopaenic patients, comparing patients with or without bone marrow failure as a cause of thrombocytopaenia.

METHODS

A retrospective observational study of admissions to three intensive care units (ICU) in the UK. We identified thrombocytopaenic patients who received a platelet transfusion and extracted the platelet count prior and subsequent to platelet transfusion. We grouped patients with or without suspected bone marrow failure, defined by a total white cell count ≤1.0 × 10⁹/L.

RESULTS

Of 11,757 admissions, 399 (3.4%) patients received a platelet transfusion for thrombocytopaenia. The median [IQR] platelet count prior to transfusion in patients without bone marrow failure was 42 [28-64] × 10⁹/L versus 14 [7-24] × 10⁹/L (p < .0001) in those with. The median [IQR] increment in platelets following transfusion was lower in patients with marrow failure (12 [-1-23] × 10⁹/L) compared to those without (18 [5-36] × 10⁹/L) (p = .006).

CONCLUSIONS

Platelet transfusions were given at a higher median platelet count than suggested by guidelines. Patients with bone marrow failure were transfused at a lower threshold and experienced a smaller increment in platelet count when compared to patients without marrow failure.

Is there a role for proton pump inhibitor prophylaxis in haematology patients?

While proton pump inhibitors (PPI) are widely prescribed as prophylaxis in selected haematology inpatient and outpatients, an informal survey of haematology units around Australia found wide variations in the specific indications for their use. This is consistent with a literature review which showed a paucity of robust evidence to support their use, specifically in chemotherapy-induced mucositis, thrombocytopenia or administration of high dose glucocorticosteroids in the absence of additional risk factors. Rationalising PPI prescribing is clinically important from both a cost and safety perspective, given the emerging evidence of adverse events associated with prolonged PPI administration. A review of prescribing practices at our institution over a 14-month period found that approximately 60% of myeloma, lymphoma and autograft patients received PPI prophylaxis during and beyond chemotherapy without an accepted indication. We encourage institutions to review their PPI prescribing practices with the intent of rationalising their use, and to conduct studies aiming to fill the substantial gaps in our knowledge.

Fibrinolysis in patients with chemotherapy-induced thrombocytopenia and the effect of platelet transfusion

Essentials Bleeding in chemotherapy induced thrombocytopenia (CIT) might be influenced by hyperfibrinolysis. t-PA-thromboelastography is a fast and reliable assay for hyperfibrinolysis in CIT patients. Clots of CIT patients are more susceptible to t-PA induced lysis compared to healthy individuals. Besides platelets, other factors are likely to influence clot lysis in CIT patients.

BACKGROUND

Bleeding events in chemotherapy-induced thrombocytopenic (CIT) patients with similar platelet counts might be influenced by changes in clot lysis potential.

OBJECTIVES

To investigate, in an observational study, thromboelastographic lysis parameters, alterations in clot strength and susceptibility to clot lysis in CIT patients. To identify factors associated with fibrinolytic profiles, and to evaluate the effects of platelet transfusions.

METHODS

Independent determinants of tissue-type plasminogen activator (t-PA)-ROTEM lysis parameters were identified with multivariable linear regression. Clot formation, strength and lysis parameters were compared with the results of healthy individuals. Characteristics of CIT patients with and without hyperfibrinolytic profiles were compared. t-PA-ROTEM results before, 1 hour after and 24 hours after platelet transfusion were compared.

RESULTS

A total of 72 consecutive CIT patients were included. t-PA-ROTEM lysis parameters correlated with changes in fibrinolytic proteins. Clot formation time was longer, maximum clot firmness was weaker and lysis times were shorter than in healthy individuals. CIT patients had low plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor levels, and 40% showed hyperfibrinolytic profiles. Platelet transfusions resulted in less hyperfibrinolytic profiles in many, but not all CIT patients. Patients without hyperfibrinolytic profiles had higher fibrinogen, factor VIII and α2 -antiplasmin levels.

CONCLUSIONS

t-PA-ROTEM can be used as a fast and reliable assay to detect hyperfibrinolytic profiles in CIT patients. CIT patients have weaker clots, which are more susceptible to clot lysis, than healthy individuals. Besides platelets, other factors are likely to influence clot susceptibility to fibrinolysis in CIT patients. The impact of a hyperfibrinolytic t-PA-ROTEM profile on bleeding remains to be investigated.

A comparison of global coagulation assays between normal controls and patients with thrombocytopenia

INTRODUCTION

Some patients with thrombocytopenia may be at risk of bleeding although quantitative platelet count is not always a sufficient predictive factor. Global coagulation assays such as thromboelastography (TEG^® ), calibrated automated thrombogram (CAT) and overall haemostatic potential (OHP) may provide a better assessment of an individual's haemostatic profile.

METHODS

Blood samples were collected from thrombocytopenic patients. TEG^® was performed on citrated whole blood, while CAT and OHP were performed on platelet-poor plasma. Results were compared to our previously collected normal controls.

RESULTS

Fifty-eight participants (24 immune thrombocytopenia, 34 chemotherapy/malignancy-related) with mean age of 57.5 years were recruited. Compared to normal controls, thrombocytopenic participants had comparable maximum amplitude but reduced clot lysis (0.0% vs 0.6%; P < 0.001) on TEG^® with reduced endogenous thrombin potential on CAT (1252.2 vs 1353.0 nmol/L/min; P = 0.040). No differences were seen in the OHP parameters. TEG^® showed significant difference between marked and mild thrombocytopenia groups with minimal differences seen on CAT and OHP. Those with marked thrombocytopenia showed reduced maximum amplitude (47.2 vs 57.8 mm; P = 0.002) as expected while participants with mild thrombocytopenia (platelet count 100-150 × 10⁹ /L) paradoxically demonstrated increased maximum amplitude (66.4 vs 57.8 mm; P < 0.001).

CONCLUSION

Global coagulation assays, particularly TEG^® , can detect subtle differences in coagulation in thrombocytopenic patients. While patients with marked thrombocytopenia showed reduced maximum amplitude, patients with mild thrombocytopenia appear to paradoxically show increased maximum amplitude, suggesting compensatory activity within the coagulation pathway which may in part explain why not all thrombocytopenic patients have bleeding complications.

The primary haemostasis is more preserved in thrombocytopenic patients with liver cirrhosis than cancer

: In thrombocytopenia, differences in haemostatic capacity may explain discrepancies in bleeding risk between patients with cancer and patients with liver cirrhosis. The objective was to compare the haemostatic capacity in different thrombocytopenic patient populations. We evaluated platelet aggregation using impedance aggregometry (Multiplate Analyzer), von Willebrand factor antigen (VWF:Ag), VWF:ristocetin-cofactor activity (VWF:RCo), activated partial thromboplastin time (aPTT), coagulation factor VIII, fibrinogen, and thrombin generation in adult hospitalized patients with platelet count less than 80 × 10/l. Patients either had liver cirrhosis (n = 28), or cancer (n = 169; n = 49 had haematological cancer) with no difference among patients with liver cirrhosis and cancer. Median platelet count was 48 × 10/l [interquartile range (IQR) 32-63 × 10/l]. Median platelet aggregation was higher in patients with cirrhosis than cancer, 416 AU × min (IQR 257-676) versus 145 AU × min (IQR 50-326) for collagen-induced platelet aggregation, P < 0.001. There was no difference in activated partial thromboplastin time (aPTT), coagulation factor VIII, or thrombin generation between the patient groups. Fibrinogen activity was higher in patients with cancer compared with patients with cirrhosis [12.5 μmol/L (IQR 9.9-16.5) versus 7.2 μmol/l (IQR 5.6-10.2)], P < 0.003. Patients with liver cirrhosis had a more preserved primary haemostasis compared with patients with cancer.

Big data modeling to predict platelet usage and minimize wastage in a tertiary care system

In modern hospital systems where complicated, severely ill patient populations are the norm, there is currently no reliable way to forecast the use of perishable medical resources to enable a smart and economic way to deliver optimal patient care. We here demonstrate a statistical model using hospital patient data to quantitatively forecast, days in advance, the need for platelet transfusions. This approach can be leveraged to significantly decrease platelet wastage, and, if adopted nationwide, would save approximately 80 million dollars per year. We believe our approach can be generalized to all other aspects of patient care involving timely delivery of perishable medical resources.

Maintaining a robust blood product supply is an essential requirement to guarantee optimal patient care in modern health care systems. However, daily blood product use is difficult to anticipate. Platelet products are the most variable in daily usage, have short shelf lives, and are also the most expensive to produce, test, and store. Due to the combination of absolute need, uncertain daily demand, and short shelf life, platelet products are frequently wasted due to expiration. Our aim is to build and validate a statistical model to forecast future platelet demand and thereby reduce wastage. We have investigated platelet usage patterns at our institution, and specifically interrogated the relationship between platelet usage and aggregated hospital-wide patient data over a recent consecutive 29-mo period. Using a convex statistical formulation, we have found that platelet usage is highly dependent on weekday/weekend pattern, number of patients with various abnormal complete blood count measurements, and location-specific hospital census data. We incorporated these relationships in a mathematical model to guide collection and ordering strategy. This model minimizes waste due to expiration while avoiding shortages; the number of remaining platelet units at the end of any day stays above 10 in our model during the same period. Compared with historical expiration rates during the same period, our model reduces the expiration rate from 10.5 to 3.2%. Extrapolating our results to the ∼2 million units of platelets transfused annually within the United States, if implemented successfully, our model can potentially save ∼80 million dollars in health care costs.