Platelet Transfusion Refractoriness in Single-Unit Cord Blood Transplantation for Adults: Risk Factors and Clinical Outcomes

Impact of platelet transfusion refractoriness in the first 30 days post-hematopoietic stem cell transplantation on outcomes of patients with myelodysplastic syndrome

Introduction

Currently, no study has determined whether platelet transfusion refractoriness (PTR) post-hematopoietic stem cell transplantation (HSCT) before engraftment in patients with myelodysplastic syndrome (MDS) would impacts clinical outcomes.

Methods

We performed a MDS-specific retrospective analysis to determine whether PTR in one-month post-HSCT in patients with MDS could influence outcomes.

Results and discussion

Among the 315 patients enrolled, 110 (34.9 %) had PTR from stem cell infusion to one-month post-HSCT. Baseline characteristics of the PTR and non-PTR groups were similar. We found that patients with PTR had a slower and lower rate of platelet engraftment by day 28, as well as a slower recovery of neutrophils. The median days of neutrophil and platelet engraftment were 14 days (9-23) and 17 days (8-28) in the PTR groups versus 13 days (9-23) and 15 days (7-28) in the non-PTR group (P<0.001). By day 28, 84 of 110 patients (76.4%) with PTR achieved platelet engraftment compared with 181 of 205 patients (88.3%) without PTR achieving platelet engraftment (P=0.007). In addition, patients in the PTR group received significantly more red blood cell (median, 17 units vs. 10 units, P<0.001) and platelet transfusions (median, 13 units vs. 7 units, P<0.001). However, the overall survival was similar between the two groups. PTR in one-month post-HSCT, haploidentical donor, and ferritin level>1041ng/ml (median level) were independent adverse factors of platelet engraftment.

Levels of C-Reactive Protein and Body Temperature Elevation During Neutropenia Predict Engraftment and Non-Relapse Mortality for Unrelated Single-Unit Cord Blood Transplantation in Adults

Cord blood transplantation (CBT) presents unique challenges related to inflammation during neutropenia, such as mucosal damage, infections, and the potential development of pre-engraftment syndrome or pre-engraftment immune reaction. These factors can contribute to significant inflammation and infection shortly after CBT. However, the effect of severe inflammation during neutropenia, specifically elevated C-reactive protein (CRP) level and body temperature, on post-transplant outcomes after CBT remains unclear. This retrospective study aimed to investigate the association between maximum CRP level, maximum body temperature during neutropenia, and post-transplantation outcomes in adult patients undergoing single-unit CBT. We retrospectively evaluated the impact of maximum CRP level and maximum body temperature during neutropenia on post-transplantation outcomes in adults who underwent single-unit unrelated CBT between 1998 and 2023 at our institution. A total of 336 adult patients were included in this study. The median maximum CRP level before neutrophil recovery was 7.75 mg/dL (interquartile range [IQR], 4.70 to 12.05 mg/dL) at a median of 14 d (IQR, 8 to 16 d). The median maximum body temperature before neutrophil recovery was 39.5°C (IQR, 39.0 to 40.0°C) at a median of 15 d (IQR, 12 to 17 d). In the multivariate analysis, a maximum CRP level≥20 mg/dL was significantly associated with lower neutrophil recovery (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.23 to 0.59; P < .001), lower platelet recovery (HR, 0.28; 95% CI, 0.16 to 0.48; P < .001), and a higher incidence of veno-occlusive disease/sinusoidal obstruction syndrome (HR, 16.42; 95% CI, 4.11 to 65.54; P < .001), which resulted in higher non-relapse mortality (NRM) (HR, 5.16; 95% CI, 2.62 to 10.15; P < .001) and worse overall survival (HR, 2.81; 95% CI, 1.66 to 4.78; P < .001). Similarly, a maximum body temperature≥40.5°C was significantly associated with lower neutrophil recovery (HR, 0.51; 95% CI, 0.33 to 0.79; P = .002), lower platelet recovery (HR, 0.55; 95% CI, 0.38 to 0.79; P = .001), higher incidence of grades III to IV acute GVHD (HR, 2.93; 95% CI, 1.24 to 6.88; P = .013), and extensive chronic GVHD (HR, 2.47; 95% CI, 1.22 to 4.97; P = .011), which resulted in higher NRM (HR, 3.43; 95% CI, 1.53 to 7.67; P = .002). Maximum CRP level and maximum body temperature during neutropenia were significantly associated with lower hematopoietic recovery and higher NRM following single-unit CBT in adults. Further studies are warranted to explore early intervention strategies aimed at preventing severe inflammation and improving post-transplant outcomes in single-unit CBT.

Pretransplantation EASIX Score Predicts Nonrelapse and Overall Mortality of Adult Patients Undergoing Single-Unit Unrelated Cord Blood Transplantation

The Endothelial Activation and Stress Index (EASIX) is a laboratory-based score used to estimate endothelial damage occurring after hematopoietic cell transplantation (HCT). The EASIX score exhibits dynamic changes during the course of transplantation and has been identified as a predictor of nonrelapse mortality (NRM) and worse overall survival (OS) in studies focused mainly on patients who received matched related or unrelated donor allogeneic HCT. However, the role of EASIX score in the setting of cord blood transplantation (CBT) is unclear. This study examined the association between pretransplant EASIX score and post-transplantation outcomes in adult patients undergoing single-unit CBT. We retrospectively evaluated the impact of EASIX score at different time points on post-transplantation outcomes in adults following single-unit unrelated CBT between 1998 and 2022 at our institution. EASIX scores were calculated at the start of conditioning (EASIX-PRE), at day 30 post-CBT (EASIX-d30), at day 100 post-CBT (EASIX-d100), and at the onset of grade II-IV acute graft-versus-host disease (GVHD) (EASIX-GVHD II-IV). A total of 317 patients were included in this study. In the multivariate analysis, log2-EASIX-PRE (continuous variable) was significantly associated with lower risks of neutrophil engraftment (hazard ratio [HR], .87; 95% confidence interval [CI], .80 to .94; P < .001) and platelet engraftment (HR, .91; 95% CI, .83 to .99; P = .047), lower risk of grade II-IV acute GVHD (HR, .85; 95% CI, .76 to .94; P = .003), and higher risk of veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) (HR, 1.44; 95% CI, 1.03 to 2.02; P = .032). Log2-EASIX-PRE also was significantly associated with higher NRM (HR, 1.42; 95% CI, 1.08 to 1.86; P = .011) and worse OS (HR, 1.26; 95% CI, 1.08 to 1.46; P = .003), but not with relapse (HR, 1.02; 95% CI, .88 to 1.18; P = .780). Similarly, log2-EASIX-d30 (HR, 1.60; 95% CI, 1.26 to 2.05; P < .001), and log2-EASIX-d100 (HR, 2.01; 95% CI, 1.63 to 2.48; P < .001) were also significantly associated with higher NRM, but log2-EASIX-GVHD II-IV was not (HR, 1.15; 95% CI, .85 to 1.55; P = .360). Pretransplantation EASIX score is a powerful predictor of engraftment, VOS/SOS, NRM, and OS in adult patients undergoing single-unit unrelated CBT who mainly received intensified conditioning regimens. EASIX is an easily evaluable and dynamic prognostic score for accurately predicting post-transplantation outcomes in patients at any time during the course of allogeneic HCT, particularly for CBT.

Comparison of platelet antibody screen, crossmatching and HLA antibody testing in patients refractory to platelet transfusions

Patients undergoing recurrent platelet transfusions can become refractory to these transfusions. Platelet antibody screens (Immucor), platelet crossmatching assays (Immucor), and HLA antibody testing are commonly used to test these patients. The relative effectiveness of these tests has not been determined. A higher incidence of strongly positive screen results that did not predict crossmatch results was anecdotally noted. Therefore, the results of the platelet antibody screens and crossmatches were systematically compiled over a 12-year period from 2010 to 2021. Of note, the Immucor Capture-P Ready Screen (platelet antibody) had a recall in March 2013 after which the performance of the test appears to have changed. The positivity rate of the platelet antibody screen increased over the course of the study, and this was statistically significant when analyzing year as a continuous variable and when grouping years by four-year periods (2010-13,2014-17,2018-21). In contrast, platelet crossmatch reactivity decreased slightly throughout this period. During the 2018-21 period, HLA antibody testing was commonly performed and correlated well with the crossmatch testing but not with the screen. These results suggest that the drastic increase in positivity we observed in the platelet antibody screen over this period is due to increased analytic sensitivity (with possible reduced specificity) of the screen and not a change in our patient population. Based on these results, the platelet antibody screen has little clinical utility and directly performing platelet crossmatching or HLA antibody testing is recommended for patients suspected to be refractory to platelet transfusions due to alloimmune-mediated factors.

A meta-analysis of risk factors associated with platelet transfusion refractoriness

BACKGROUND

Platelet transfusion refractoriness (PTR) remains an intractable issue in clinical practice, and is common in hematological patients. At present, it is believed that both immune and non-immune factors play a role. We conducted a meta-analysis of various risk factors which may contribute to PTR.

METHODS

PubMed, Embase, Cochrane library, and Web of Science were selected as research database platforms. Citations included were further assessed for quality and bias using the Newcastle-Ottawa Scale. All analyses were performed using Review Manager Version 5.4 and STATA 16.0.

RESULTS

The preliminary search revealed 1069 publications, and 17 (5929 patients in total) were ultimately included in the quantitative analysis. The following variables were associated with the occurrence of PTR: fever (OR = 2.26, 95%CI 2.00-2.55, p < 0.00001), bleeding (OR = 2.10, 95%CI 1.36-3.24, p = 0.0008), female sex (OR = 2.06, 95%CI 1.13-3.75, p = 0.02), antibiotic use (OR = 2.94, 95%CI 1.54-5.59, p = 0.001), and infection (OR = 2.19, 95%CI 1.20-4.03, p = 0.01). Antibodies involved in immune activation were a higher risk factor (OR = 4.17, 95%CI 2.36-7.36, p < 0.00001), and splenomegaly was nearly significant (OR = 1.73, 95%CI 0.97-3.07, p = 0.06).

CONCLUSIONS

We identified some important risk factors for PTR, but further research is needed to identify the many other possible elements that may contribute to or mediate PTR.

[Incidence and clinical significance of platelet transfusion refractoriness after allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia]

Objective: To retrospectively analyze the incidence and clinical significance of platelet transfusion refractoriness (PTR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with chronic myelomonocytic leukemia (CMML) . Methods: A cohort of 55 CMML patients received allo-HSCT at Peking University Institute of Hematology during 2004-2021 were retrospectively assessed. The incidence of PTR within 30 days after allo-HSCT was retrospectively analyzed, and the impact on clinical outcomes and bleeding event were compared between patients with platelet transfusion refractoriness (PTR) or effective platelet transfusion (EPT) . Results: The incidence of PTR after allo-HSCT in CMML patients was 25.5% (14/55) . PTR patients had a lower rate of platelet engraftment than EPT patients (28.6% vs 100%) , and the median time of engraftment was 67 (33-144) days and 21 (9-157) days respectively (P<0.010) . There was no significant difference between two groups in acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) (P=0.183, P=0.455) . After following-up a median of 684 (24-3978) days, the 1-year overall survival (OS) and 1-year leukemia free survival (LFS) in PTR and EPT patients were (35.4±13.9) % vs (75.1±7.8) % (P=0.037) and (28.1±13.3) % vs (65.3±8.2) % (P=0.072) , respectively. The transplant-related mortality (TRM) were (48.2±2.4) % and (9.0±0.25) %, respectively (P=0.009) . Bleeding events occurred in five patients (35.7%) of PTR and 2 patients (4.9%) of EPT (P=0.009) . Conclusion: In CMML patients with allo-HSCT, the incidence of PTR is 25.5%, which was associated with delayed platelet engraftment, increased bleeding events, inferior OS and increased TRM.

Pre-Transplant Platelet Refractoriness and Alternative Donors Are Associated With Cytomegalovirus Retinitis in Hematopoietic Stem Cell Transplantation for Severe Aplastic Anemia

Background

Cytomegalovirus retinitis is a severe, vision-threatening opportunistic infection in an immunodeficient population. Reports on cytomegalovirus retinitis in hematopoietic stem cell transplant recipients due to severe aplastic anemia have been scant. This study assessed the risk of cytomegalovirus retinitis in relation to the pre-transplant status of severe aplastic anemia patients.

Methods

We conducted a retrospective nested case-control study of cytomegalovirus retinitis among severe aplastic anemia patients receiving allogeneic hematopoietic stem cell transplants in a tertiary care institution that attends severe aplastic anemia patients from southern China from January 1, 2013 to December 31, 2018. Each cytomegalovirus retinitis case was matched with four controls without cytomegalovirus retinitis by age and gender. Thirteen pre-transplant parameters were chosen to compare the risk factor levels between the cases and controls. Multivariable logistic regressions were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs).

Results

A total of 361 severe aplastic anemia patients received hematopoietic stem cell transplants in the study period 2013–2018 in our medical institution, and 31 (8.58%) developed cytomegalovirus retinitis. Cytomegalovirus retinitis was diagnosed in the median of 148 days after transplantation. We confirmed platelet refractoriness more frequently in cases than in controls (p = 0.0005). Compared with human leukocyte antigen-matched sibling donors, alternative donors were significantly more prone to cytomegalovirus retinitis (p = 0.0009). After stepwise selection in multivariate logistic regression, platelet refractoriness (OR 5.41, 95% CI 1.98–15.39), haploidentical donor (OR 7.46, 95% CI 2.19–34.87), and unrelated donor (OR 8.38, 95% CI 2.30–41.34) were associated with an increased risk of cytomegalovirus retinitis.

Conclusions

Pre-transplant platelet refractoriness and alternative donors were significant predictors of cytomegalovirus retinitis in severe aplastic anemia recipients. These results highlight the importance of accounting for existing risks while developing prevention strategies and preemptive treatment for severe aplastic anemia recipients. We recommend that the platelet count be closely monitored and thrombopoietin be properly applied during the period when cytomegalovirus retinitis is prone to occur.

Cytokine Release Syndrome Is an Independent Risk Factor Associated With Platelet Transfusion Refractoriness After CAR-T Therapy for Relapsed/Refractory Acute Lymphoblastic Leukemia

Background: Chimeric antigen receptor T cell (CAR-T) therapy is successful in improving treatment outcomes for relapsed/refractory acute lymphoblastic leukemia (R/R ALL). However, toxicities associated with CAR-T therapy are being increasingly identified. Pancytopenia is one of the most common complications after CAR-T therapy, and platelet transfusions are an essential part of its supportive care. Study Design and Methods: This study aimed to assess the effectiveness of platelet transfusions for R/R ALL patients at our single center and identify associated risk factors. Overall, 44 R/R ALL patients were enrolled in this study, of whom 26 received CAR-T therapy and 18 received salvage chemotherapy. Result: Patients in the CAR-T group had a higher incidence of platelet transfusion refractoriness (PTR) (15/26, 57.7%) than those in the chemotherapy group (3/18, 16.7%) (p = 0.007). For patients receiving CAR-T therapy, multivariate analysis showed that the grade of cytokine release syndrome (CRS) was the only independent risk factor associated with PTR (p = 0.007). Moreover, higher peak serum IL-6 and IFN-γ levels suggested a higher risk of PTR (p = 0.024 and 0.009, respectively). Patients with PTR received more platelet infusion doses than those without PTR (p = 0.0426). Patients with PTR had more grade 3-4 bleeding events than those without PTR (21.4 vs. 0%, p = 0.230), and the cumulative incidence of grade 3-4 bleeding event was different (p = 0.023). Conclusion: We found for the first time that PTR is associated with the CRS grade. Improved knowledge on the mechanisms of PTR after CAR-T therapy is needed to design a rational therapeutic strategy that aims to improve the efficiency of transfusions.

Human leukocyte antigen (HLA)-incompatible mean fluorescence intensity-selected platelet products have corrected count increments similar to HLA antigen-matched platelets

BACKGROUND

Donor specific antibody sum mean fluorescence intensity (MFI) values have been successfully used in transplant medicine to assess risk for organ rejection. However, little is known regarding whether MFI values could be similarly used to aid in platelet product selection. We have developed a novel protocol where MFI values are used to offer human leukocyte antigen (HLA)-incompatible platelet products when HLA antigen-matched products are not available. We aimed to evaluate the efficacy of this protocol.

METHODS

We performed a 4-year retrospective chart review for all patients who received at least one MFI-selected platelet product. A corrected count increment (CCI) was calculated for each transfusion event. A mixed effects model was used to investigate the association between CCIs for MFI-selected, HLA antigen matched, and random donor platelet transfusions. A random effects expectation-maximization regression tree was used to define the extent to which other patient variables, such as age, sex, and diagnosis impacted the CCI for each platelet transfusion.

RESULTS

Twenty highly HLA alloimmunized patients received a total of 591 platelets. MFI-selected platelet (low MFI) transfusions had a significantly higher median CCI 0-6 hour post-transfusion (13,559, interquartile range [IQR]: 8275-18,736) compared to random donor platelets (2121, IQR: 0-10,368, p < 0.0001). There was no significant difference in median CCI between HLA antigen matched and MFI selected platelet transfusions (p = 0.2). Mixed effects and regression modeling revealed that MFI-selected platelet products had a significantly higher CCI than non-matched platelets, even when accounting for other significant patient variables.

CONCLUSION

MFI-selected HLA-incompatible platelet products could provide a comparable alternative to traditional HLA antigen-matched platelet products.

Clinical and immunological features of platelet transfusion refractoriness in young patients with de novo acute myeloid leukemia

Platelet transfusion is important in the prevention and treatment of bleeding in patients with acute myeloid leukemia (AML) after receiving intensive chemotherapy. However, platelet transfusion refractoriness (PTR) is an intractable clinical issue occurred in these patients. And its clinical and immunological features remain largely unknown. The potential causes and clinical features of PTR were retrospectively analyzed in 560 patients who were diagnosed as de novo AML in Tongji Hospital from June 2012 through June 2018. A high‐throughput antibody screening for the detection of human leukocyte antigen (HLA) and its serotypes was performed in 133 newly diagnosed AML patients. PTR occurred in 11.8% of the de novo AML patients. The median age for patients with PTR was 46 years (range, 15‐70). It frequently manifested in female patients and in patients with splenomegaly, M4 subtype, c‐Kit gene mutation, and rearrangements of RUNX1‐RUNX1T1 or CBFB‐MYH11, commonly referred to as core binding factor AML (CBF‐AML). Notably, CBF‐AML was independently associated with the occurrence of PTR. PTR predominantly developed in patients who had CBF‐AML (P < .001) and in patients who further had better minimal residual disease (MRD) reduction (≥3‐log) before the second consolidation chemotherapy (P = .007). HLA‐I antibodies were detected in the serum of 9.0% of AML patients and markedly enriched in patients with PTR (P < .001) and in patients with CBF‐AML (P = .018). HLA‐B was the most frequently identified serum epitope in PTR patients. Patients with CBF‐AML had higher tendency to develop HLA‐I antibodies and PTR, which depicted novel features of PTR in AML and might provide insights into its efficient managements.

Platelet Transfusion: And Update on Challenges and Outcomes

Platelet transfusion is a common practice in onco-hematologic patients for preventing or treating hemorrhages. Platelet concentrates can be transfused with therapeutic or prophylactic purposes. With the aim to help clinicians to take the decisions on platelet transfusion, some guidelines have been developed based on the current scientific evidence. However, there are some controversial issues and available scientific evidence is not enough to solve them. There is little information about what is the best platelet product to be transfused: random platelets or single donor apheresis platelets, and plasma-suspended or additive solution suspended platelets. Platelets are often transfused without respecting the ABO compatibility, but influence of this practice on platelet transfusion outcome is not well established. In the prophylactic platelet transfusion set there are some questions unsolved as the platelet threshold to transfuse prior to specific procedures or surgery, and even if platelet transfusion is necessary for some specific procedures as autologous hematopoietic stem cell transplantation. A challenging complication raised from multiple platelet transfusions is the platelet transfusion refractoriness. The study and management of this complication is often disappointing. In summary, although it is a widespread practice, platelet transfusion has still many controversial and unknown issues. The objective of this article is to review the current evidence on platelet transfusion practices, focusing on the controversial issues and challenges.