Platelet transfusion improves clot formation and platelet function in severely thrombocytopenic haematology patients

Improving platelet function following prophylactic platelet transfusion in patients with hematological malignancies

INTRODUCTION

Platelet transfusion is a standard treatment to prevent bleeding in patients with hematological malignancies. Although transfusions can improve platelet count, their impact on platelet function remains controversial.

METHODS

We conducted flow cytometry to assess platelet function before and after transfusion and performed subgroup analyses to examine differences based on blood type, corrected count increment (CCI), and platelet microparticles.

RESULTS

Overall, 50 patients who received prophylactic platelet transfusion were enrolled. CD42b expression increased, whereas CD41 expression decreased after transfusion. Apheresis platelets exhibited the lowest expression of PAC-1 and P-selectin when exposed to agonist stimulations. PAC-1 expression increased under high adenosine diphosphate (ADP) stimulation, while P-selectin expression increased under both high ADP and thrombin receptor-activating peptide stimulation. In the subgroup analysis, patients with a CCI >4500 and those with the same blood types exhibited a more significant increase in PAC-1 and P-selectin expression under agonist stimulation. When comparing apheresis platelets collected on different days, only the percentage of platelet-derived microparticles showed a significant increase.

CONCLUSION

Prophylactic transfusion improved platelet function. Platelet function significantly improved in patients with a CCI >4500, those with the same blood types as that of apheresis platelets, or those with platelet-derived microparticle levels <4.7%. No significant improvement in platelet function was noted after the transfusion of different blood types with acceptable compatibility or the transfusion of incompatible blood types. Our results suggest that transfusing platelets with the same blood type remains the optimal choice.

Clinical efficacy of avatrombopag and recombinant human thrombopoietin in the treatment of chronic liver disease-associated severe thrombocytopenia: A real-world study

Purpose: To investigate the clinical efficacy of avatrombopag, an oral thrombopoietin receptor agonist, versus subcutaneous recombinant human thrombopoietin (rh-TPO) in the treatment of severe thrombocytopenia (TCP) associated with chronic liver disease (CLD).

Methods: Clinical data of 250 patients with severe TCP associated with CLD were collected in a single hospital from January 2019 to January 2022. The main parameters measured were the therapeutic response rate, changes in platelets (PLTs), and adverse events. Propensity score matching (PSM) was used to avoid possible selection bias.

Results: After PSM, a total of 154 patients were enrolled in the study: 77 in the avatrombopag group and 77 in the rh-TPO group. There was no statistically significant difference between the two groups in the effect of increasing the PLT count (Waldχ2 = 1.659, p = 0.198; Waldχ2 = 0.220, p = 0.639). In addition, no interaction between time and different medications was found (Waldχ2 = 0.540, p = 0.910; Waldχ2 = 1.273, p = 0.736). Interestingly, in the subgroup analysis, both before and after PSM, avatrombopag showed better clinical efficacy than rh-TPO in the treatment of TCP associated with CLD in Child‒Pugh Class A (88.89% vs. 63.41%, p =0.003; 81.33% vs. 61.76%, p = 0.043). Fewer patients reported dizziness in the avatrombopag group than in the rh-TPO group both before and after PSM (7.8% vs. 25.0%; 7.8% vs. 24.7%, p &lt; 0.05).

Conclusion: Both before and after PSM, avatrombopag showed better clinical efficacy than rh-TPO in the treatment of TCP associated with CLD in Child‒Pugh Class A and showed a lower incidence of dizziness in all patients.

Mechanism of Abnormal Coagulation Induced by Tigecycline in Cancer Patients

Tigecycline is a broad-spectrum active intravenous antibiotic that is active against methicillin-resistant staphylococcus aureus. In Phase 3 and 4 clinical trials, increased all-cause mortality was observed in patients treated with tigecycline compared to patients in the control group. The reason for the increase is unclear. In this study, we found that tigecycline cause abnormal coagulation in tumor patients, especially in patients with hematological malignancies. The main manifestations were decreased fibrinogen and prolonged activated prothrombin time (APTT), thrombin time (TT), and D-dimer. In addition, through functional studies, we found that tigecycline inhibit platelet adhesion and aggregation, and the coagulation function of patients gradually recover after discontinuation. Gene sequencing results suggested that tigecycline significantly regulate the expression of genes related to platelet function pathways and increase the incidence of single nucleotide polymorphisms and the number of alternative splices in the Chinese hamster ovary (CHO) cells treated with tigecycline. An abnormal function and low numbers of platelets are common in patients with hematological malignancies. Our study can explain the mechanism of abnormal coagulation caused by tigecycline. Additionally, doctors who apply tigecycline to cure infections in tumor patients should be warned.

Application of Rotational Thromboelastometry in Patients with Acute Promyelocytic Leukemia

Introduction

Hemorrhagic early death (HED) remains a major cause of treatment failure among patients with acute promyelocytic leukemia (APL). We aimed to investigate the prognostic potential of rotational thromboelastometry (ROTEM) for bleeding in patients with APL.

Materials and Methods

31 newly-diagnosed APL patients (median age of 40 years; 14 female/17 male) that underwent treatment at the Clinic of Hematology UCCS from 2016-2020 with all-trans retinoic acid and anthracyclines were recruited. CBCs (complete blood count), conventional coagulation tests (CCTs), and ROTEM parameters obtained before treatment initiation were evaluated.

Results

All patients demonstrated at least one ROTEM parameter out of the reference range. ROTEM parameters associated with significant hemorrhage were EXTEM clotting time (CT) (P = 0.041) and INTEM amplitude 10 (A10) (P = 0.039), however, only EXTEM CT (P = 0.036) was associated with HED. Among CBCs and CCTs, only platelets were associated with significant bleeding (P = 0.015), while D-dimer was associated with both bleeding and HED (P = 0.001 and P = 0.002, respectively).

Conclusion

Our results indicate that ROTEM parameters may reveal hypocoagulability in APL patients and have the potential to improve current hemorrhage prognostic methods. Additionally, these results suggest the combination of ROTEM and CCTs might be useful in identifying patients at risk for HED.