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Background: Patients with hematological malignancies (HM) frequently present thrombocytopenia and higher risk of bleeding. Although transfusion is associated with higher risk of adverse events and poor outcomes, prophylactic transfusion of platelets is a common practice to prevent hemorrhagic complications. Thromboelastometry has been considered a better predictor for bleeding than isolated platelet counts in different settings. In early stages of sepsis, hypercoagulability may occur due to higher fibrinogen levels. Objectives: To evaluate the behavior of coagulation in patients with HM who develop sepsis and to verify whether a higher concentration of fibrinogen is associated with a proportional increase in maximum clot firmness (MCF) even in the presence of severe thrombocytopenia. Methods: We performed a unicentric analytical cross-sectional study with 60 adult patients with HM and severe thrombocytopenia, of whom 30 had sepsis (sepsis group) and 30 had no infections (control group). Coagulation conventional tests and specific coagulation tests, including thromboelastometry, were performed. The main outcome evaluated was MCF. Results: Higher levels of fibrinogen and MCF were found in sepsis group. Both fibrinogen and platelets contributed to MCF. The relative contribution of fibrin was significantly higher (60.5 ± 12.8% vs 43.6 ± 9.7%; P < .001) and that of platelets was significantly lower (39.5 ± 12.8% vs 56.4 ± 9.7%; P < .001) in the sepsis group compared with the control group. Conclusion: Patients with sepsis and HM presented higher concentrations of fibrinogen than uninfected patients, resulting in greater MCF amplitudes even in the presence of thrombocytopenia.

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BACKGROUND AND OBJECTIVES: This study describes the use of the Epvix platform for virtual cross-matching (VC) of human leucocyte antigen (HLA)-compatible platelets for patients with immune platelet refractoriness, and demonstrates effectiveness of the selected platelets. MATERIALS AND METHODS: A prospective cohort of haematological patients was evaluated from 2018 to 2022. HLA-typed donor bank profile was previously uploaded to the Epvix platform. Each patient's antibody reactivity panel (PRA) was included in the platform. Then, search, selection and VC were performed, and 24-h-corrected count increment (CCI) platelet transfusion was calculated (reference ≥2500). RESULTS: Six patients were included (four female, two male), with mean age of 61 years. HLA antibodies were detected as the cause of immunity for all patients, whereas four patients also had non-immune causes. High percentage of alloimmunization was detected in all studied patients (mean PRA: 85.7%). Thirty different donors were able to schedule and perform platelet donations. The mean 24-h CCI count was 9882. All platelet transfusions achieved a satisfactory CCI count except for two transfusion events. Presence of non-immune causes identified in these two cases could account for the unsatisfactory CCI. CONCLUSION: Epvix is a free application hosted on the Web and uses the HLAMatchmaker algorithm to generate histocompatibility reports. This study demonstrates the efficiency of VC performed by Epvix. However, physical cross-matching will still be necessary in some instances, as the platform does not support human platelet antigen polymorphism.

Assuntos

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ABSTRACT Introduction: Immune dysfunction and thrombocytopenia are common features in liver cirrhosis. Platelet transfusion is the most widely used therapeutic approach for thrombocytopenia when indicated. The transfused platelets are prone to lesions during their storage that empower their interaction with the recipient leucocyte. These interactions modulate the host immune response. The impact of platelet transfusion on the immune system in cirrhotic patients is little understood. Therefore, this study aims to investigate the impact of platelet transfusion on neutrophil function in cirrhotic patients. Methods: This prospective cohort study was implemented on 30 cirrhotic patients receiving platelet transfusion and 30 healthy individuals as a control group. EDTA blood samples were collected from cirrhotic patients before and after an elective platelet transfusion. Flowcytometric analysis of neutrophil functions (CD11b expression and PCN formation) was performed. Results: There was a significant increase in expression of CD11b on neutrophils and Frequency of platelet-complexed neutrophils (PCN) in patients with cirrhosis compared with controls. Platelet transfusion increased level of CD11b and the frequency of PCN even more. There was a significant positive correlation between change in PCN Frequency pefore and after transfusion and the change in expression of CDllb among cirrhotic patients. Conclusions: Elective platelet transfusion appears to increase level of PCN in cirrhotic patients, moreover, exacerbate the expression of activation marker CDllb on both neutrophils and PCN. More research and studies are needed to corroborate our preliminary findings.

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BACKGROUND: Thrombocytopenia is common in critically ill patients with cancer. However, the association of platelet count with spontaneous bleeding is controversial in critically ill patients and the association with cancer-related characteristics is unknown. METHODS: This observational study includes patients with active cancer and severe thrombocytopenia. A logistic regression model adjusted for confounders was used to evaluate the association of daily platelet count and cancer-related characteristics (type of cancer and presence of metastasis) with spontaneous bleeding. Confounders were identified using directed acyclic graphs. RESULTS: We screened 5822 patients, 255 (4.4%) met eligibility criteria resulting in 1401 daily observations. Fifty-three patients (20.8%) had spontaneous bleeding during the intensive care unit stay, 64% presenting minor, and 36% major bleeding. The adjusted odds ratio (OR) for spontaneous bleeding with platelet count between 49 and 20 × 109 /L was 4.6 (1.1-19.6), with platelet count between 19 and 10 × 109 /L was 14.2 (3.1-66.2), and with platelet count below 10 × 109 /L was 39.6 (6.9-228.5). The adjusted OR for spontaneous bleeding in patients with hematologic malignancies was 0.6 (0.4-1.2), and 4.3 (2.0-9.0) for patients with metastatic tumor. CONCLUSIONS: In critically ill patients with active cancer and severe thrombocytopenia, lower counts of platelets and presence of metastasis are associated with increased risk of spontaneous bleeding, while hematologic malignancy is not associated with increased risk of spontaneous bleeding.

Assuntos

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ABSTRACT Introduction: The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies. Objective: In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil. Methods: Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed. Main results: Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%. Conclusion: Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

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OBJECTIVES: To evaluate whether implementing more restrictive neonatal intensive care unit (NICU) platelet transfusion guidelines following the Platelets for Neonatal Transfusion - Study 2 randomized controlled trial (transfusion threshold changed from 50 000/µL to 25 000/µL for most neonates) was associated with fewer NICU patients receiving a platelet transfusion, without adversely affecting outcomes. STUDY DESIGN: Multi-NICU retrospective analysis of platelet transfusions, patient characteristics, and outcomes during 3 years before vs 3 years after revising system-wide guidelines. RESULTS: During the first period, 130 neonates received 1 or more platelet transfusions; this fell to 106 during the second. The transfusion rate was 15.9/1000 NICU admissions in the first period vs 12.9 in the second (P = .106). During the second period, a smaller proportion of transfusions was administered when the platelet count was in the 50 000-100 000/µL range (P = .017), and a larger proportion when it was <25 000/µL (P = .083). We also saw a fall in the platelet counts that preceded the order for transfusion from 43 100/µL to 38 000/µL (P = .044). The incidence of adverse outcomes did not change. CONCLUSIONS: Changing platelet transfusion guidelines in a multi-NICU network to a more restrictive practice was not associated with a significant reduction in number of neonates receiving a platelet transfusion. The guideline implementation was associated with a reduction in the mean platelet count triggering a transfusion. We speculate that further reductions in platelet transfusions can safely occur with additional education and accountability tracking.

Assuntos

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INTRODUCTION AND OBJECTIVES: It is challenging to adopt a policy of ABO identical platelet transfusion in hemato-oncological patients because of the high demand. Moreover, there are no global standards for the management of ABO non-identical platelet transfusions due to limited evidence. The current study compared the impact of dose and storage duration of platelets on percent platelet recovery (PPR) at 1 h and 24 h between ABO identical and ABO non-identical platelet transfusions in hemato-oncological conditions. The other objectives were to assess the clinical efficacy and compare adverse reactions between the two groups. METHODS: A total of 130 random donor platelet transfusion episodes (81 ABO identical and 49 ABO non-identical) were evaluated in 60 eligible patients with different malignant, as well as non-malignant, hematological conditions. All analysis was performed using two-sided tests, and p-values <0.05 were considered significant. RESULTS: The PPR at 1 h and 24 h was significantly higher in ABO identical platelet transfusion. Platelet recovery and survival were not affected by the gender, dose or storage duration of platelet concentrate. Aplastic anemia and myelodysplastic syndrome (MDS) disease conditions were observed to be independent risk predictors for 1-h post-transfusion refractoriness. CONCLUSION: ABO identical platelets have higher platelet recovery and survival. Both ABO identical and ABO non-identical platelet transfusions have similar efficacy in controlling bleeding episodes up to World Health Organization (WHO) grade two. Assessment of other factors, such as platelet functional properties in the donor, anti-HLA and anti-HPA antibodies, may be needed to better understand the platelet efficacy of platelet transfusions.

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INTRODUCTION: Immune dysfunction and thrombocytopenia are common features in liver cirrhosis. Platelet transfusion is the most widely used therapeutic approach for thrombocytopenia when indicated. The transfused platelets are prone to lesions during their storage that empower their interaction with the recipient leucocyte. These interactions modulate the host immune response. The impact of platelet transfusion on the immune system in cirrhotic patients is little understood. Therefore, this study aims to investigate the impact of platelet transfusion on neutrophil function in cirrhotic patients. METHODS: This prospective cohort study was implemented on 30 cirrhotic patients receiving platelet transfusion and 30 healthy individuals as a control group. EDTA blood samples were collected from cirrhotic patients before and after an elective platelet transfusion. Flowcytometric analysis of neutrophil functions (CD11b expression and PCN formation) was performed. RESULTS: There was a significant increase in expression of CD11b on neutrophils and Frequency of platelet-complexed neutrophils (PCN) in patients with cirrhosis compared with controls. Platelet transfusion increased level of CD11b and the frequency of PCN even more. There was a significant positive correlation between change in PCN Frequency pefore and after transfusion and the change in expression of CD11b among cirrhotic patients. CONCLUSIONS: Elective platelet transfusion appears to increase level of PCN in cirrhotic patients, moreover, exacerbate the expression of activation marker CD11b on both neutrophils and PCN. More research and studies are needed to corroborate our preliminary findings.

RESUMO

INTRODUCTION: The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies. OBJECTIVE: In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil. METHODS: Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed. MAIN RESULTS: Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%. CONCLUSION: Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

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INTRODUCTION: Collecting high-dose (HD) or double-dose (DD) apheresis platelets units from a single collection offers significant benefit by improving inventory logistics and minimizing the cost per unit produced. Platelet collection yield by apheresis is primarily influenced by donor factors, but the cell separator used also affects the collection yield. OBJECTIVES: To predict the cutoff in donor factors resulting in HD and DD platelet collections between Trima/Spectra Optia and MCS+ apheresis equipment using Classification and Regression Trees (CART) analysis. METHODS: High platelet yield collections (target ≥ 4.5 × 1011 platelets) using MCS+, Trima Accel and Spectra Optia were included. Endpoints were ≥ 6 × 1011 platelets for DD and ≥ 4.5 to < 6 × 1011 for HD collections. The CART, a tree building technique, was used to predict the donor factors resulting in high-yield platelet collections in Trima/Spectra Optia and MCS+ equipment by R programming. RESULTS: Out of 1,102 donations, the DDs represented 60% and the HDs, 31%. The Trima/Spectra Optia predicted higher success rates when the donor platelet count was set at ≥ 205 × 103/µl and ≥ 237 × 103/µl for HD and DD collections. The MCS+ predicted better success when the donor platelet count was ≥ 286 × 103/µl for HD and ≥ 384 × 103/µl for DD collections. Increased donor weight helped counter the effects of lower donor platelet counts only for HD collections in both the equipment. CONCLUSIONS: The donor platelet count and weight formed the strongest criteria for predicting high platelet yield donations. Success rates for collecting DD and HD products were higher in the Trima/Spectra Optia, as they require lower donor platelet count and body weight than the MCS+.