A review of transfusion practice before, during, and after hematopoietic progenitor cell transplantation

Patient Blood Management after Hematopoietic Stem Cell Transplantation in a Pediatric Setting: Starting Low and Going Lower

Despite the substantial transfusion requirements, there are few studies on the optimal transfusion strategy in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Our study aimed to retrospectively analyze red blood cell (RBC) and platelet (PLT) transfusion practices during the first 100 days after HSCT at the pediatric hematology/oncology unit of our hospital between 2016 and 2019, due to a more restrictive approach adopted after 2016. We also evaluated the impact on patient outcomes. A total of 146 consecutive HSCT patients were analyzed. In patients without hemorrhagic complications, the Hb threshold for RBC transfusions decreased significantly from 2016 to 2017 (from 7.8 g/dL to 7.3 g/dL; p = 0.010), whereas it remained the same in 2017, 2018, and 2019 (7.3, 7.2, and 7.2 g/dL, respectively). Similarly, the PLT threshold decreased significantly from 2016 to 2017 (from 18,000 to 16,000/μL; p = 0.026) and further decreased in 2019 (15,000/μL). In patients without severe hemorrhagic complications, the number of RBC and PLT transfusions remained very low over time. No increase in 100-day and 180-day non-relapse mortality or adverse events was observed during the study period. No patient died due to hemorrhagic complications. Our preliminary observations support robust studies enrolling HSCT patients in patient blood management programs.

A retrospective study to assess the impact of ABO incompatibility on outcomes of allogeneic peripheral blood stem cell transplants at a tertiary care hospital in Western Maharashtra

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) has emerged as a curative measure for life-threatening hematological disorders. It can be autologous or allogeneic depending on the disease characteristics. Providing transfusion support to the transplant patients can be challenging, especially in AB-mismatched allogeneic HSCT. In this study, we investigated the impact of ABO incompatibility in patients undergoing allogeneic HSCT.

MATERIALS AND METHODS

A retrospective review was conducted in 76 patients with hematological diseases who underwent allogeneic HSCT. Transfusion requirements, engraftment profile, incidence of graft versus host disease (GvHD), and mortality for a period of 1 year were analyzed.

RESULTS

ABO incompatibility between donor and the patient did not significantly affect the neutrophil and platelet (PLT) engraftment time (P = 0.389, 0.349, respectively), packed red blood cells transfusion requirement, and duration of initial hospital stay. However, patients of ABO-incompatible HSCT received more PLT transfusions posttransplant which was statistically significant. 29.1% of ABO compatible and 16.7% incompatible HSCT patients developed GVHD. Mortality rates in the two groups were 16.7% and 8.3%, respectively. However, differences in both the parameters were not statistically significant.

CONCLUSION

Our study showed that ABO incompatibility does not significantly affect the outcome and should not be a limiting factor for selection of donor. Donor availability and human leukocyte antigen (HLA) matching remain the critical selection criteria.

Blood components utilization in hematopoietic stem cell transplantation: Thirteen-year analysis from an apex oncology center of India

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment modality for a range of hematological disorders including malignancies. The increasing volumes of HSCTs impact transfusion services and the requirement of blood products vary depending on the primary disease, type and phase of transplant, and the HSCT donor type.

MATERIALS AND METHODS

This study analyzed the factors affecting blood component requirements in patients undergoing HSCT. The authors studied the transfusion requirement of packed red blood cells (PRBC) and platelets (PLT) up to 100 days post-transplant among 617 adult patients undergoing HSCT during the study period (2007-2019).

RESULTS

Requirement of PRBC and PLT was significantly higher (P < 0.05) in allogenic HSCT cases across all three phases of transplant compared to autologous HSCT. Unlike PRBC requirement, the PLT requirement was significantly higher during peri-transplant period for haploidentical HSCT and major ABO-incompatible HSCT group compared to matched related donor HSCT and ABO identical HSCT, respectively. In subset analysis based on diagnosis with leukemia as reference, the multiple myeloma group required less while the anemia group required more PRBC and PLT transfusions. The leukemia group required more PRBC than lymphoma group, while the PLT requirement was vice-versa.

CONCLUSION

Factors such as allogeneic HSCT, haploidentical donor type, major ABO-incompatible HSCT, and primary diagnosis as leukemia or anemia were the predictors for increased need of blood products. As higher transfusion requirements may translate into increased costs of treatment, a study like this can help in managing blood component inventory and planning treatment costs of a HSCT program.

Transfusion Burden in Allogeneic Hematopoietic Stem Cell Transplantation over Time: Experience from a Single Institution

INTRODUCTION

Transfusion plays a main role in supportive treatment for patients who receive an allogeneic hematopoietic stem cell transplantation (HSCT). In this study, we compare the transfusion requirements of patients undergoing different modalities of HSCT according to different time periods. The objective is to assess the evolution of HSCT transfusion requirements over time, from a single institution.

METHODS

The clinical charts and transfusion records of patients who underwent HSCT of different modalities at La Fe University Hospital during a twelve-year period were reviewed (2009-2020). For analysis, we divided the overall time into three periods: 1 from 2009 to 2012, 2 from 2013 to 2016 and 3 from 2017 to 2020. The study included 855 consecutive adult HSCT: 358 HLA-matched related donors (MRD), 134 HLA-matched unrelated donors (MUD), 223 umbilical cord blood transplantation (UCBT) and 140 haploidentical transplants (Haplo-HSCT).

RESULTS

There were no significant differences in RBC and PLT requirements or transfusion independence among the three time periods for MUD and Haplo-HSCT. However, the transfusion burden increased significantly for MRD HSCT during the 2017-2020 period.

CONCLUSION

despite HSCT modalities having evolved and changed over time, overall transfusion requirements have not significantly decreased and continue to be a cornerstone of transplantation-supportive care.

Related donor platelet transfusion improves platelet transfusion refractoriness in hematological patients

Objective

Transfusion of HLA-matched platelets can reduce the effect of alloimmune responses on platelet transfusion efficacy; however, finding HLA-matched platelets in the population is nearly impossible. Almost all HLA-matched platelets from related are half-matched, but the hemostatic efficacy of related donor platelets is unclear. Our goal was to compare the hemostatic effect of related donated platelets and unrelated donors platelets.

Methods

In this retrospective cohort study, we included acute leukemia and myelodysplastic syndrome patients with thrombocytopenia after chemotherapy. These patients were all transfused with platelets. This study excluded patients younger than 16 years and older than 65 years, or patients with abnormal coagulation parameters during platelet transfusion. We compared the hemostatic effect of related donated platelets and unrelated donors platelet. The primary outcome was transfusion efficacy after platelet transfusion, and the number of platelet counts and corrected count increments at 24 h after platelet transfusion.

Result

We analyzed 31 patients who received platelet transfusions from related donors (Treatment group) and 35 patients who received platelet transfusions from unrelated donors (Comparator group). Except for the relatively small proportion of patients with myelodysplastic syndrome in the treatment group, baseline clinical and laboratory characteristics were similar between the two groups. Hemostasis and prevention of bleeding in the treatment group showed significant superiority; the number of platelets increased 24 h after platelet transfusion in the treatment group was significantly higher than that in the comparator group. After 24 h, the corrected count increments treatment group was also higher than the comparator group; in the treatment group, the transfusion effect was better when the three sites of HLA-A, B, and C were identical, and the different blood types of platelet donors and recipients did not affect the transfusion effect.

Conclusion

Related donated platelets have better hemostasis and prevention effects, and no increase in adverse blood transfusion reactions. It may be a better transfusion strategy for platelet refractoriness patients in emergency situations.

Analysis of ABO grouping discrepancies among patients from a tertiary hospital in Korea

BACKGROUND

Accurate ABO typing is essential for preventing ABO incompatibility reactions. However, the causes of ABO grouping discrepancy has not been sufficiently studied, and it may vary among different ethnic populations. Thus, the aim of this retrospective study was to investigate the causes of ABO discrepancy in the East Asian population.

MATERIALS AND METHODS

A retrospective observational study on ABO typing discrepancy among patients in a tertiary hospital was carried out using the electronic medical record database of Samsung Medical Center (Seoul, Korea) between July 2016 and May 2019.

RESULTS

ABO grouping was performed on 551,959 blood samples during the study period; 1468 events of serologic ABO discrepancy were determined from 1334 (0.24 %) samples. A total of 134 samples (0.02 %) presented multiple causes of ABO discrepancy. Weak/missing serum reactivity (594, 40.5 %) was the most frequent reason for ABO discrepancy, followed by extra serum reactivity (370, 25.2 %), weak/missing red cell reactivity (267, 18.2 %), mixed-field red cell reactivity (176, 12.0 %), and extra red cell reactivity (61, 4.2 %). In the category of weak/missing red cell reactivity, ABO subgroup was the most common reason, and using ABO genotyping, 26.2 % of the cases genotyped were found to be related to the cis-AB allele.

CONCLUSIONS

Our results suggest that the incidence and cause of ABO typing discrepancies vary among institutes and ethnic groups. Our data helps to better understand and facilitate the resolution of ABO typing discrepancies in patients.

Predictive Value of 3 Clinical Criteria for Sepsis (Quick Sequential Organ Failure Assessment, Systemic Inflammatory Response Syndrome, and National Early Warning Score) With Respect to Short-term Mortality in Allogeneic Hematopoietic Cell Transplant Recipients With Suspected Infections

BACKGROUND

Sepsis disproportionately affects allogeneic hematopoietic cell transplant (HCT) recipients and is challenging to define. Clinical criteria that predict mortality and intensive care unit end-points in patients with suspected infections (SIs) are used in sepsis definitions, but their predictive value among immunocompromised populations is largely unknown. Here, we evaluate 3 criteria among allogeneic HCT recipients with SIs.

METHODS

We evaluated Systemic Inflammatory Response Syndrome (SIRS), quick Sequential Organ Failure Assessment (qSOFA), and National Early Warning Score (NEWS) in relation to short-term mortality among recipients transplanted between September 2010 and July 2017. We used cut-points of ≥ 2 for qSOFA/SIRS and ≥ 7 for NEWS and restricted to first SI per hospital encounter during patients' first 100 days posttransplant.

RESULTS

Of the 880 recipients who experienced ≥ 1 SI, 58 (6.6%) died within 28 days and 22 (2.5%) within 10 days of an SI. In relation to 10-day mortality, SIRS was the most sensitive (91.3% [95% confidence interval {CI}, 72.0%-98.9%]) but least specific (35.0% [95% CI, 32.6%-37.5%]), whereas qSOFA was the most specific (90.5% [95% CI, 88.9%-91.9%]) but least sensitive (47.8% [95% CI, 26.8%-69.4%]). NEWS was moderately sensitive (78.3% [95% CI, 56.3%-92.5%]) and specific (70.2% [95% CI, 67.8%-72.4%]).

CONCLUSIONS

NEWS outperformed qSOFA and SIRS, but each criterion had low to moderate predictive accuracy, and the magnitude of the known limitations of qSOFA and SIRS was at least as large as in the general population. Our data suggest that population-specific criteria are needed for immunocompromised patients.

Platelet transfusion refractoriness: how do I diagnose and manage?

Platelet refractoriness continues to be a problem for thrombocytopenic patients because the risk of a major spontaneous or life-threatening bleed significantly increases when platelet counts drop below 10 × 109/L. The majority of patients have nonimmune causes driving the refractoriness, such as bleeding, medications, or diffuse intravascular coagulation; however, this article is dedicated to the diagnosis and support of patients with immune-based platelet refractoriness. Antibodies to class I HLA molecules (A and B alleles) are responsible for most immune-based refractory cases, with antibodies to platelet antigens seen much less frequently. Patients may be supported with either crossmatch-compatible or HLA-matched/compatible platelet units. When trying to select HLA units it can be difficult to find a perfect "4 of 4" match for the patient's class IA and IB alleles. In these cases, it is better to use the antibody specificity prediction method, which identifies compatible units that lack antigens recognized by the patient's anti-HLA antibodies. For an algorithmic approach to the patient with platelet refractoriness, see Visual Abstract.

Pre-transplant thrombocytopenia predicts engraftment time and blood products requirement in allogeneic hematopoietic stem cell transplantation patients

INTRODUCTION

Thrombocytopenia is a common consequence of leukemia that affects the outcome of hematopoietic stem cell transplantation (HSCT). The stromal damage of bone marrow following pre-HSCT conditioning regimens can delay the hematopoietic engraftment and increased blood product transfusions. We tried to define threshold based on pre-transplant platelet count as a biomarker to predict engraftment time and blood product requirements in allogeneic HSCT patients.

METHODS

This retrospective study was performed on 194 patients who received allogeneic HSCT. The median for platelet (PLT) count of patients at the admission day was considered as a cut off value. The association of platelet count with white blood cell (WBC) and PLT engraftment time and also the requirement of packed red blood cell or PLT transfusions as outcomes of interest were investigated.

RESULTS

164 patients (84.5 %) had successful WBC engraftment, and PLT engraftment was seen in 155 patients (79.9 %) in 30 and 50 days after HSCT, respectively. The patients with PLT count higher than 154,000/μL had better PLT engraftment (P = 0.060), and WBC engraftment (P = 0.014) than those with PLT count lower than this cut off. The pre-transplant PLT count had negative relations with SD platelet requests after HSCT (P = 0.008).

CONCLUSION

The thrombocytopenia before HSCT might delay the platelet and WBC engraftment time, which should be taken into account before transplantation. Since the blood product transfusion is one of the factors associated with engraftment, the pre-transplant platelet count can be used as a predictive biomarker to manage the blood product requirement during the HSCT until engraftment occurs.

Overview of Plasma and Platelet Transfusions in Critically Ill Children

Critically ill children are a unique population who frequently receive plasma and platelet transfusions for both active bleeding and mitigation of bleeding risk. While these products are frequently administered, transfusion indications in this population remain unclear, and practice varies across institutions and providers. In this manuscript, we will outline the current evidence regarding plasma and platelet transfusions for hemostasis in the pediatric intensive care setting. For both products, we will describe the product composition, epidemiology, and product indications and discuss the potential risks and benefits involved with the transfusion. We will also discuss knowledge gaps and future areas of research.

Aplastic Anemia Preconditioned with Fludarabine, Cyclophosphamide, and Anti-Thymocyte Globulin

Background

Graft rejection and graft versus host disease (GvHD) have impeded the success of hematopoietic cell transplantation for severe aplastic anemia (SAA) patients. There is no sufficient data to identify the outcomes of peripheral blood stem cell transplantation (PBSCT) in SAA patients, especially for adult SAA patients. The aim of this study was to evaluate the outcomes of adult SAA patients undergoing PBSCT with the FCA regimen. The FCA regimen includes fludarabine, cyclophosphamide, and anti-thymocyte globulin (ATG).

Material/Methods

We report our experience with 46 adult SAA patients who underwent PBSCT with the FCA regimen. Thirty SAA patients who received only cyclophosphamide and ATG (CA) regimen were used as controls. Complications and survival outcomes were evaluated and compared.

Results

There was a significantly higher percentage of patients who achieved >95% donor chimerism by day 30 in the FCA group. The 5-year event-free survival (EFS) rate in the FCA group was higher than that in the CA group (95.4% versus 73.3%). In addition, the 5-year rejection rate (RR) in the FCA group was lower than that in the CA group (4.6% versus 23.6%). A multivariable model identified the FCA regimen as an independent factor affecting EFS and RR. However, GvHD and serious infection did not differ between the 2 groups. For patients with an unrelated donor, the FCA regimen had a higher EFS and a lower RR than the CA regimen.

Conclusions

The FCA regimen for PBSCT in adult SAA patients compared favorably to the CA regimen. It can improve EFS and reduce graft rejection, especially for unrelated donor PBSCT.

ABO-mismatched marrow processing for transplantation: Comparative results of 80 procedures performed with Cobe Spectra and Spectra Optia

BACKGROUND

removal of incompatible red blood cells (RBCs) or plasma is usually required to avoid hemolysis during infusion of ABO incompatible bone marrow (BM) allogeneic transplants. This process often involves separation of buffy coat (BC) by centrifugation in automated devices. We have evaluated the Spectra Optia™ (Optia) apheresis system to determine its effectiveness in BC concentration, volume reduction and RBCs depletion of ABO-incompatible BM compared with our previous method using Cobe Spectra™ (Cobe).

MATERIALS AND METHODS

28 processes were performed with Optia and 52 with Cobe. We compared volume reduction, RBCs depletion, and recovery of total nucleated cells (TNCs), mononuclear cells (MNCs), CD34+ and CD3+ cells in the final product. Hematopoietic engraftment was ascertained. We used Saphiro-Wilks and Kolmorgorov- Smirnov tests to test normality and Mann-Whitney's U test to compare means between both groups.

RESULTS

We found statistically significant differences favoring Optia versus Cobe in TNCs recovery (62% vs. 37%), CD34+ cell recovery (98 vs 84%), volume reduction (91 vs 84%), and RBCs depletion (99 vs. 97%), but not in processing time or time to engraftment.

CONCLUSION

Optia achieves high RBCs and volume depletion of BM, while providing excellent CD34+ recovery in clinical routine. Some parameters compare favorably with Cobe Spectra.

Is surgical volume still the most accurate indicator of blood usage in the United States?

BACKGROUND

Estimates of blood collection and use in the United States derived from the National Blood Collection and Utilization Survey (NBCUS) call for application of robust statistical methods in the analysis of survey data. Since 1993, annual inpatient surgical volume has been used as the main stratification variable for sampling and estimation. However, recent NBCUS results have shown a decrease in blood use in surgical settings, raising the possibility that inpatient surgical volume may no longer be the optimal stratification variable. The objective of this study is to explore factors affecting hospital blood utilization.

STUDY DESIGN AND METHODS

A multivariate generalized linear regression with a negative binomial distribution was used to determine which hospital characteristics best explained allogeneic red blood cell (RBC) use, using data from the 2015 NBCUS to determine hospital blood use and the 2013 annual American Hospital Association database to identify hospital characteristics.

RESULTS

Annual inpatient surgical volume explained the most variation in allogeneic RBC use among hospitals (pseudo-R² of 70.8%). Additional variables, such as presence of an oncology service, were also statistically significant in the models but explained little additional variability in blood use.

CONCLUSION

These findings suggest that annual inpatient surgical volume is an appropriate indicator for estimating blood utilization in the United States. As trends in blood utilization continue to evolve, ongoing analytic efforts to understand indicators of blood use are necessary.

Transfusion-associated graft-versus-host disease: A concise review

Transfusion-associated graft-versushost disease (TA-GVHD) represents a rare fatal event observed in immunocompromised patients and immunocompetent individuals. The main clinical features of this transfusion reaction are pancitopenia and multiorgan failure (skin, liver, gut). The possible pathogenesis includes donor T lymphocyte proliferation in blood, their engraftment and host tissue attack. The purpose of this narrative review was analyzing the international guidelines for irradiation of cellular blood components to prevent TA-GVHD. A literature search was conducted using PubMed articles published between January 2000 to July 2018. American, Australian, British and Japanese transfusion guidelines have been compared regarding clinical indications. The contribution of manuscripts has been focused on recipients of Haematopoietic Stem Cell Transplantation, severe cellular immunodeficient patients, fetuses and neonates, immunocompentent individuals. Furthermore, 348 cases of TA-GVHD in the last five decades have been documented according to a recent systematic review. The standard of care to prevent this complication is gamma or x irradiation of cellular blood products. New treatments with pathogen inactivation appear safe and effective against proliferating white blood cells and T cells. Further clinical and biological studies are necessary to better characterize immunocompetence of T cells and select alternative preventive strategies.

The role of collateral related donors in haploidentical hematopoietic stem cell transplantation

A key issue in the haploiedntical hematopoietic stem cell transplantation (haplo-HSCT) setting is the search for the best donor, because donor selection can significantly impact the clinical outcomes. We aimed to identify the role of collateral related donors (CRDs) in donor selection for haplo-HSCT through comparing the clinical outcomes between CRDs (n = 60) and maternal donors (MDs, n = 296), which were the last choice of donor selection in immediate related donors (IRDs). The cumulative incidence of graft-versus-host disease was comparable between CRDs and MDs. The 5-year cumulative incidence of relapse and non-relapse mortality was 22.0% (95% CI, 11.3%-32.7%) versus 17.4% (95% CI, 13.0%-21.8%) (P = 0.455) and 25.0% (95% CI, 13.9%-36.1%) versus 23.1% (95% CI, 18.2%-28.0%) (P = 0.721) for the CRDs and MDs, respectively. The 5-year probabilities of disease-free survival and overall survival was 53.2% (95% CI, 40.4%-66.0%) versus 59.5% (95% CI, 53.8%-65.2%) (P = 0.406) and 56.5% (95% CI, 43.8%-69.2%) versus 61.8% (95% CI, 56.1%-67.5%) (P = 0.458) for the CRDs and MDs, respectively. Female donor/male recipient (FDMR) CRDs were associated with the poorest clinical outcomes, and the clinical outcomes of non-FDMR CRDs were comparable to those of MDs. In summary, our results showed that CRDs did not showed superiority over MDs. Thus, IRDs should be the first choice of donor selection, and CRDs could only be the donors for those without IRDs.

Bone marrow harvest in donors with anaemia

BACKGROUND

Bone marrow harvest (BMH) for haematopoietic stem cell transplantation is a well-established procedure. The guidelines of World Marrow Donor Association provide information on donor selection. However, some of the guidelines regarding donors with anaemia prior to harvest lack in supporting data from clinical studies. With this study, we aimed to provide such data.

MATERIAL AND METHODS

In this retrospective, single-centre study, we analysed the interplay between haemoglobin levels and BMH and BMH impact on haemoglobin levels in a cohort of 149 unrelated BM donors, including 13 subjects with mild anaemia.

RESULTS

The BMH led to significantly lower decrease in haemoglobin levels in donors with anaemia than in control group (1·79 g/dl vs. 2·56 g/dl, P < 0·0001). The following parameters: BMH volume (ml), BMH volume/donor body weight (ml/kg), total nucleated cells (TNC) in product (×10⁸ ) and TNC/kg recipient body weight in product (×10⁸ /kg) did not differ significantly between those two analysed groups (P > 0·05). Median BM volume harvested from anaemic donors was 16·34 ml/kg; none of them required blood transfusion after BMH.

CONCLUSION

Mild anaemia prior to BMH does not significantly impact the collection results. The BMH is safe and feasible in donors with mild anaemia.

Safety of hematopoietic cell infusion in children with malignant and non-malignant diseases

HPC infusions have been associated with a variety of adverse events related to either patient or HPC product-related factors. Studies documenting infusion-related AEs in children are limited. We reviewed HPC infusion records in 354 children. Infusion-related adverse events were classified as follows: grade 0-absent, grade I-mild, grade II-moderate, grade III-severe, grade IV-life-threatening, and grade V-death. The percentage of patients with grade 0, I, and II-IV AEs was as follows: 0 = 67%, I = 23.4%, and II-V = 9.6% (one patient had fatal anaphylactic reaction to dimethyl sulfoxide). The incidence of grade II-IV hypertension was 7.1%. There was a higher incidence of AEs with infusion of allogeneic bone marrow versus allogeneic PBSCs (47.4% vs 25.3%, P = .001). Cryopreserved products had a lower incidence of infusion-associated AEs compared with fresh HPC products (24% vs 39.4%, P = .003). Allogeneic HPC infusion volume (>100 mL) was a significant risk factor for infusion-associated AEs (P < .001). Patients >10 years who received autologous HPC infusions had higher risk of AEs when compared to patients <10 years (P = .01). Our study demonstrated that despite a high incidence of infusion-associated hypertension, HPC infusion is relatively safe in children. Investigating strategies to optimize management of hypertension in the setting of HPC infusion is warranted.

Integration of red cell genotyping into the blood supply chain: a population-based study

BACKGROUND

When problems with compatibility arise, transfusion services often use time-consuming serological tests to identify antigen-negative red cell units for safe transfusion. New methods have made red cell genotyping possible for all clinically relevant blood group antigens. We did mass-scale genotyping of donor blood and provided hospitals with access to a large red cell database to meet the demand for antigen-negative red cell units beyond ABO and Rh blood typing.

METHODS

We established a red cell genotype database at the BloodCenter of Wisconsin on July 17, 2010. All self-declared African American, Asian, Hispanic, and Native American blood donors were eligible irrespective of their ABO and Rh type or history of donation. Additionally, blood donors who were groups O, A, and B, irrespective of their Rh phenotype, were eligible for inclusion only if they had a history of at least three donations in the previous 3 years, with one donation in the previous 12 months at the BloodCenter of Wisconsin. We did red cell genotyping with a nanofluidic microarray system, using 32 single nucleotide polymorphisms to predict 42 blood group antigens. An additional 14 antigens were identified via serological phenotype. We monitored the ability of the red cell genotype database to meet demand for compatible blood during 3 years. In addition to the central database at the BloodCenter of Wisconsin, we gave seven hospitals online access to a web-based antigen query portal on May 1, 2013, to help them to locate antigen-negative red cell units in their own inventories.

FINDINGS

We analysed genotype data for 43,066 blood donors. Requests were filled for 5661 (99.8%) of 5672 patient encounters in which antigen-negative red cell units were needed. Red cell genotyping met the demand for antigen-negative blood in 5339 (94.1%) of 5672 patient encounters, and the remaining 333 (5.9%) requests were filled by use of serological data. Using the 42 antigens represented in our red cell genotype database, we were able to fill 14,357 (94.8%) of 15,140 requests for antigen-negative red cell units from hospitals served by the BloodCenter of Wisconsin. In the pilot phase, the seven hospitals identified 71 units from 52 antigen-negative red cell unit requests.

INTERPRETATION

Red cell genotyping has the potential to transform the way antigen-negative red cell units are provided. An antigen query portal could reduce the need for transportation of blood and serological screening. If this wealth of genotype data can be made easily accessible online, it will help with the supply of affordable antigen-negative red cell units to ensure patient safety.

FUNDING

BloodCenter of Wisconsin Diagnostic Laboratories Strategic Initiative and the NIH Clinical Center Intramural Research Program.

Payment and Care for Hematopoietic Cell Transplantation Patients: Toward a Specialized Medical Home for Complex Care Patients

Patient-centered medical home models are fundamental to the advanced alternative payment models defined in the Medicare Access and Children's Health Insurance Plan Reauthorization Act (MACRA). The patient-centered medical home is a model of healthcare delivery supported by alternative payment mechanisms and designed to promote coordinated medical care that is simultaneously patient-centric and population-oriented. This transformative care model requires shifting reimbursement to include a per-patient payment intended to cover services not previously reimbursed such as disease management over time. Payment is linked to quality measures, including proportion of care delivered according to predefined pathways and demonstrated impact on outcomes. Some medical homes also include opportunities for shared savings by reducing overall costs of care. Recent proposals have suggested expanding the medical home model to specialized populations with complex needs because primary care teams may not have the facilities or the requisite expertise for their unique needs. An example of a successful care model that may provide valuable lessons for those creating specialty medical home models already exists in many hematopoietic cell transplantation (HCT) centers that deliver multidisciplinary, coordinated, and highly specialized care. The integration of care delivery in HCT centers has been driven by the specialty care their patients require and by the payment methodology preferred by the commercial payers, which has included bundling of both inpatient and outpatient care in the peritransplant interval. Commercial payers identify qualified HCT centers based on accreditation status and comparative performance, enabled in part by center-level comparative performance data available within a national outcomes database mandated by the Stem Cell Therapeutic and Research Act of 2005. Standardization across centers has been facilitated via voluntary accreditation implemented by Foundation for the Accreditation of Cell Therapy. Payers have built on these community-established programs and use public outcomes and program accreditation as standards necessary for inclusion in specialty care networks and contracts. Although HCT centers have not been described as medical homes, most HCT providers have already developed the structures that address critical requirements of MACRA for medical homes.

Donor and recipient age, gender and ABO incompatibility regardless of donor source: validated criteria for donor selection for haematopoietic transplants

Prior data indicate similar outcomes after transplants from human leukocyte antigen (HLA)-haplotype-matched relatives, HLA-identical siblings and HLA-matched unrelated donors. We used our prospective data set to answer a clinically important question: who is the best donor for a person with acute leukaemia transplanted in first complete remission. Patients were randomly divided into training (n=611) and validation (n=588) sets. A total of 1199 consecutive subjects received a transplant from an HLA-haplotype-matched relative using granulocyte colony-stimulating factor and anti-thymocyte globulin (n=685) or an HLA-identical sibling (n=514); 3-year leukaemia-free survivals (LFSs) were 75 and 74% (P=0.95), respectively. The multivariate model identified three major risk factors for transplant-related mortality (TRM): older donor/recipient age, female-to-male transplants and donor-recipient ABO major-mismatch transplants. A risk score was developed based on these three features. TRMs were 8%, 15% and 31% for subjects with scores of 0-1, 2 and 3, respectively, (P<0.001). Three-year LFSs were 78%, 74% and 58%, respectively, (P=0.003). The risk score was validated in an independent cohort. In conclusion, our data confirm donor source is not significantly correlated with transplant outcomes. Selection of the best donor needs to consider donor-recipient age, matching for gender and ABO incompatibility among persons with acute leukaemia receiving related transplants under our transplant modality.

GM-CSF and IL-4 Fusion Cytokine Induces B Cell-Dependent Hematopoietic Regeneration

Hematopoietic stem cells (HSCs) have the capacity to self-renew and differentiate into hematopoietic cells and have been utilized to replace diseased bone marrow for patients with cancers and blood disorders. Although remarkable progress has been made in developing new tools to manipulate HSCs for clinic use, there is still no effective method to expand HSCs in vivo for quick repopulation of hematopoietic cells following sublethal irradiation. We have recently described a novel synthetic cytokine that is derived from the fusion of granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin 4 (IL-4; named as GIFT4), and we have now discovered that GIFT4 fusokine promotes long-term hematopoietic regeneration in a B cell-dependent manner. We found that GIFT4 treatment triggered a robust expansion of endogenous bone marrow HSCs and multipotent progenitors in vivo. Delivery of GIFT4 protein together with B cells rescued lethally irradiated mice. Moreover, adoptive transfer of autologous or allogeneic GIFT4-treated B cells (GIFT4-B cells) enhanced long-term hematopoietic recovery in radiated mice and prevented the mice from irradiation-induced death. Our data suggest that GIFT4 as well as GIFT4-B cells could serve as means to augment HSC engraftment in the setting of bone marrow transplantation for patients with hematological malignancy.

Transfusion challenges in hematology oncology and hematopoietic stem cell transplant - Literature review and local experience

Transfusion medicine plays a vital role in the supportive care of patients receiving therapy for hematology, oncology and hematopoietic stem cell transplants (HSCT). With advances in therapy with more intensive chemotherapy or radiotherapy, patients usually develop cytopenias and need frequent transfusion support with packed red blood cells, granulocyte transfusion or platelets to support them until they recover from the effect of therapy. HSCT poses unique challenges for transfusion medicine, since transplant recipients may require substantial transfusion support due to cytopenias associated with toxic medications, decreased marrow reserve, infection or their malignancy. Transfusion support has many complications, mainly immune mediated and infectious complications. Jehovah's Witness patients deny transfusions of blood products as a therapeutic option and, consequently, management of their disease with chemotherapy and stem cell transplant after myeloablative therapy is quite challenging. This review describes the challenges of transfusion support in managing hemato-oncology and stem cell transplant patients and highlights a local experience in transplanting two Jehovah's Witness patients.

Newly established stem cell transplant program: 100 days follow-up of patients and its comparison with published Indian literature

Background:

Hematopoietic progenitor stem cell transplantation (HPSCT) is used as a standard treatment option to improve outcome in hematological and nonhematological disorders. It is important for new HPSCT program to look at its patient outcome data and compare it with the published data to evaluate the efficacy of program.

Aims:

The aim was to compile and collate the patient outcome data of HPSCT and compare with published reports.

Materials and Methods:

Patient demographics, indications, stem cell harvest by apheresis, dose collected, infusion, engraftment, and follow-up data were collected from hospital information system from 2010 to 2013 in a tertiary care hospital. HPSCs were mobilized with granulocyte colony-stimulating factor, and harvests were done on the 5^th day. Engraftment was decided for neutrophil when counts were 0.5 × 10⁹/L and for platelets when counts were 20 × 10⁹/L on two consecutive days without any transfusion support.

Results:

There were 133 harvests for 95 patients with various disorders; multiple myeloma was most common in autologous and acute lymphoblastic leukemia in allogeneic group. One hundred harvests were done for autologous and 33 for allogeneic HPSCT. In autologous group, of 66 patients, 60 (90.9%) received stem cell infusion at median dose of 4.63 × 10⁶ CD34⁺ cells/kg. Similarly, in allogeneic group, of 29 patients, 27 (93.10%) received infusion at median dose of 5.8 × 10⁶ CD34⁺ cells/kg. 58 (96.9%) patients and 25 (92.6%) engrafted in autologous and allogeneic group, respectively. The median time for neutrophils engraftment was 11 days in autologous group and 12 days in allogeneic group. The median time for platelet engraftment was 11.5 days in autologous group and 13 days in allogeneic group. The 100-day survival rate was 95% (n = 57) in autologous group and 77.8% (n = 21) in allogeneic group.

Conclusion:

This data analysis shows reasonably good results of HPSCTs with majority of patients surviving at 100-day follow-up.

Complex Transfusion Issues in Pediatric Hematopoietic Stem Cell Transplantation

Advances in the fields of pediatric transfusion medicine and hematopoietic stem cell transplant have resulted in improved outcomes but also present new questions for research. The diagnostic capabilities involved in transfusion medicine have improved in recent times, now including methods for determination of red blood cell minor antigens, detection of anti-human leukocyte antigen antibodies, and noninvasive iron quantification. At the same time, transplants are being performed for more indications including nonmalignant disease and with less intense conditioning regimens that allow some recipient blood cells to persist after transplant. We are therefore faced with new opportunities to understand the implications of transfusion medicine testing and to develop data-driven guidelines relevant to the current-day approach to transfusion and transplantation.

An update on ABO incompatible hematopoietic progenitor cell transplantation

Hematopoietic progenitor cell (HPC) transplantation has long been established as the optimal treatment for many hematologic malignancies. In the setting of allogenic HLA matched HPC transplantation, greater than 50% of unrelated donors and 30% of related donors demonstrate some degree of ABO incompatibility (ABOi), which is classified in one of three ways: major, minor, or bidirectional. Major ABOi refers to the presence of recipient isoagglutinins against the donor's A and/or B antigen. Minor ABOi occurs when the HPC product contains the isoagglutinins targeting the recipient's A and/or B antigen. Bidirectional refers to the presence of both major and minor ABOi. Major adverse events associated with ABOi HPC transplantation includes acute and delayed hemolysis, pure red cell aplasia, and delayed engraftment. ABOi HPC transplantation poses a unique challenge to the clinical transplantation unit, the HPC processing lab, and the transfusion medicine service. Therefore, it is essential that these services actively communicate with one another to ensure patient safety. This review will attempt to globally address the challenges related to ABOi HPC transplantation, with an increased focus on aspects related to the laboratory and transfusion medicine services.

How do we choose the best donor for T-cell-replete, HLA-haploidentical transplantation?

In haploidentical stem cell transplantations (haplo-SCT), nearly all patients have more than one donor. A key issue in the haplo-SCT setting is the search for the best donor, because donor selection can significantly impact the incidences of acute and chronic graft-versus-host disease, transplant-related mortality, and relapse, in addition to overall survival. In this review, we focused on factors associated with transplant outcomes following unmanipulated haplo-SCT with anti-thymocyte globulin (ATG) or after T-cell-replete haplo-SCT with post-transplantation cyclophosphamide (PT/Cy). We summarized the effects of the primary factors, including donor-specific antibodies against human leukocyte antigens (HLA); donor age and gender; killer immunoglobulin-like receptor-ligand mismatches; and non-inherited maternal antigen mismatches. We also offered some expert recommendations and proposed an algorithm for selecting donors for unmanipulated haplo-SCT with ATG and for T-cell-replete haplo-SCT with PT/Cy.

Anemia of Central Origin

Hypoproliferative anemia results from the inability of bone marrow to produce adequate numbers of red blood cells. The list of conditions that cause hypoproliferative anemia is long, starting from common etiologies as iron deficiency to rarer diagnoses of constitutional bone marrow failure syndromes. There is no perfect diagnostic algorithm, and clinical data may not always clearly distinguish "normal" from "abnormal", yet it is important for practicing clinicians to recognize each condition so that treatment can be initiated promptly. This review describes diagnostic approaches to hypoproliferative anemia, with particular emphasis on bone marrow failure syndromes.

Sustained Delivery of Chemokine CXCL12 from Chemically Modified Silk Hydrogels

A delivery platform was developed using silk-based hydrogels, and sustained delivery of the cationic chemokine CXCL12 at therapeutically relevant doses is demonstrated. Hydrogels were prepared from plain silk and silk that had been chemically modified with sulfonic acid groups. CXCL12 was mixed with the silk solution prior to gelation, resulting in 100% encapsulation efficiency, and both hydrated and lyophilized gels were compared. By attaching a fluorescein tag to CXCL12 using a site-specific sortase-mediated enzymatic ligation, release was easily quantified in a high-throughput manner using fluorescence spectroscopy. CXCL12 continually eluted from both plain and acid-modified silk hydrogels for more than 5 weeks at concentrations ranging from 10 to 160 ng per day, depending on the gel preparation method. Notably, acid-modified silk hydrogels displayed minimal burst release yet had higher long-term release rates compared to those of plain silk hydrogels. Similar release profiles were observed over a range of loading capacities, allowing dosage to be easily varied.

Micro gel column technique is fit for detecting mixed fields post ABO incompatible hematopoietic stem cell transplantation

How to choose suitable serologic method for assessment of the actual stages of ABO chimera is more important to establish transfusion strategy for patients post-ABO incompatible hematopoietic stem cell transplantation. We reported ABO phenotypes of a patient post-ABO minor incompatible hematopoietic stem cell transplantation from 1+ weak agglutination by tube method was obviously reaffirmed to mixed fields with 4+ positive reaction by micro gel column card. Hence, blood bank technologists must continually work together with hematologist to establish appropriate transfusion strategy, and micro gel column technique can be more appropriate for detecting mixed fields during the whole period of transplantation.

Transfusions for anemia in adult and pediatric patients with malignancies

Anemia is present in over two-thirds of patients with malignant hematological disorders. The etiology of anemia predominates from ineffective erythropoiesis from marrow infiltration, cytokine related suppression, erythropoietin suppression, and vitamin deficiency; ineffective erythropoiesis is further exacerbated by accelerated clearance due to antibody mediated hemolysis and thrombotic microangiopathy. As the anemia is chronic in nature, symptoms are generally well tolerated and often non-specific. Transfusion of red blood cells (RBCs) is a balance between providing benefit for patients while avoiding risks of transfusion. Conservative/restrictive RBC transfusion practices have shown equivalent patient outcomes compared to liberal transfusion practices, and meta-analysis has shown improved in-hospital mortality, reduced cardiac events, re-bleeding, and bacterial infections. The implications for a lower threshold for transfusion in patients with malignancies are therefore increasingly being scrutinized. Alternative management strategies for anemia with IV iron and erythropoietin stimulating agents (ESAs) should be considered in the appropriate settings.

Management of hemolytic anemia following allogeneic stem cell transplantation

Hemolytic anemia (HA) is a frequent condition with variable pathophysiology. Hematopoietic stem cell transplantation (HSCT) is unique because it is performed across the ABO blood group barrier. Thereby, there is a transfer of plasma, red blood cells, and immunocompetent cells from the donor to the recipient, possibly leading to HA, due to red blood cell incompatibility. The underlying disease, drugs (particularly those used for conditioning and immunosuppressants), infections, graft-versus-host disease, and autoimmune diseases may all contribute to the clinical and laboratory picture of HA. Additionally, transplantation-associated thrombotic microangiopathy (TA-TMA) may occur and is associated with significant morbidity and mortality. This review highlights the current knowledge on HA after allogeneic HSCT, particularly due to ABO incompatibility. We follow the timeline of the transplantation process and discuss investigations, differential diagnosis, and prophylactic measures including graft processing to avoid hemolysis in case of ABO incompatibility. Finally, current therapeutic approaches for both TA-TMA and post-HSCT autoimmune HA, which are associated with high morbidity and mortality, are discussed.

Using HLA typing to support patients with cancer

BACKGROUND

The human leukocyte antigen (HLA) system plays a crucial role in immune function, and HLA testing is often needed in the support of patients with cancer.

METHODS

We briefly review the published literature to clarify the nomenclature of the HLA system, currently available methods for HLA testing, and commonly used HLA assays. The uses of HLA testing in pharmacogenomics, disease association, platelet transfusion support, and in the management of both solid organ and hematopoietic stem cell transplantation are also reviewed.

RESULTS

HLA testing is commonly performed for select patient populations, including patients with cancer and in those requiring solid organ and hematopoietic stem cell transplantation.

CONCLUSION

Newer molecular typing methods have helped improve patient outcomes following hematopoietic stem cell transplantation.

Erythropoiesis-stimulating agents in allogeneic and autologous hematopoietic stem cell transplantation

INTRODUCTION

Erythropoiesis-stimulating agents (ESAs) are used in treating cancer- and chemotherapy-induced anemia with the aim of accelerating the recovery of red blood cells (RBCs), reduce the risks associated with RBC transfusions and improve quality of life.

AREAS COVERED

A systematic review has been conducted to examine the current evidence for the efficacy and safety of using ESAs in hematopoietic stem cell transplants (HSCTs).

EXPERT OPINION

Despite the international recommendations for the use of ESAs in treating different malignancies, there is a lack of guidelines for their use in patients undergoing HSCT. An evaluation of published clinical trials shows that there are no available powerful studies concerning the use of ESAs in this setting, with only heterogeneous and small numbers of patients reported so far. Nevertheless, the more robust and intriguing of these data suggest that the ESA's administration at an appropriate time after the infusion of stem cells may be effective both in autologous and allogeneic HSCTs. New guidelines are required, overseen by an expert in the in the field of stem cell transplantation.

Prevention of Transfusion-Transmitted Cytomegalovirus Infections: Which is the Optimal Strategy?

Traditionally, leukoreduction and selection of blood products from seronegative donors have been used as alternative strategies to reduce the risk of transfusion-transmitted cytomegalovirus infections (TT-CMV) in atrisk patients. After the introduction of universal leukoreduction for red blood cell and platelet concentrates in Germany, a controversy evolved as to whether the additional selection of blood products from seronegative donors would reduce or even increase the risk of TT-CMV. This review summarizes the current knowledge about CMV infections in blood donors and the implications of this information on the effect of potential transfusion strategies. Even though there are conflicting data about the incidence of TT-CMV remaining after the introduction of leukodepletion, it has been clearly shown that both prevalence and concentration of CMV DNA in peripheral blood are highest in newly seropositive donors. Therefore, avoidance of blood products from these donors is the most important goal of any transfusion strategy. This goal can be reached by: i) selection of blood products from seronegative donors, ii) provision of CMV DNA-negative blood products, or iii) provision of blood from long-term seropositive donors. In cases of suspected TT-CMV, all implicated donors should be investigated carefully to gather further knowledge on which donors confer the lowest risk for TT-CMV.

Fludarabine and exposure-targeted busulfan compares favorably with busulfan/cyclophosphamide-based regimens in pediatric hematopoietic cell transplantation: maintaining efficacy with less toxicity

Busulfan (Bu) is used as a myeloablative agent in conditioning regimens before allogeneic hematopoietic cell transplantation (allo-HCT). In line with strategies explored in adults, patient outcomes may be optimized by replacing cyclophosphamide (Cy) with or without melphalan (Mel) with fludarabine (Flu). We compared outcomes in 2 consecutive cohorts of HCT recipients with a nonmalignant HCT indication, a myeloid malignancy, or a lymphoid malignancy with a contraindication for total body irradiation (TBI). Between 2009 and 2012, 64 children received Flu + Bu at a target dose of 80-95 mg·h/L, and between 2005 and 2008, 50 children received Bu targeted to 74-80 mg·h/L + Cy. In the latter group, Mel was added for patients with myeloid malignancy (n = 12). Possible confounding effects of calendar time were studied in 69 patients receiving a myeloablative dose of TBI between 2005 and 2012. Estimated 2-year survival and event-free survival were 82% and 78%, respectively, in the FluBu arm and 78% and 72%, respectively, in the BuCy (Mel) arm (P = not significant). Compared with the BuCy (Mel) arm, less toxicity was noted in the FluBu arm, with lower rates of acute (noninfectious) lung injury (16% versus 36%; P = .007), veno-occlusive disease (3% versus 28%; P = .003), chronic graft-versus-host disease (9% versus 26%; P = .047), adenovirus infection (3% versus 32%; P = .001), and human herpesvirus 6 infection reactivation (21% versus 44%; P = .005). Furthermore, the median duration of neutropenia was shorter in the FluBu arm (11 days versus 22 days; P < .001), and the patients in this arm required fewer transfusions. Our data indicate that Flu (160 mg/m(2)) with targeted myeloablative Bu (90 mg·h/L) is less toxic than and equally effective as BuCy (Mel) in patients with similar indications for allo-HCT.

Analysis of donor and recipient ABO incompatibility and antibody-associated complications after allogeneic stem cell transplantation with reduced-intensity conditioning

Allogeneic hematopoietic stem cell transplantation (HSCT) can be performed across the ABO blood group barrier. The impact of ABO incompatibility on clinical outcome is controversial. A retrospective analysis of 310 patients who underwent HSCT with reduced-intensity conditioning between 1998 and 2011 was performed to investigate the frequency and clinical implications of anti-RBC antibodies in passenger lymphocyte syndrome (PLS) after minor ABO mismatch (mm), persistent or recurring recipient type ABO antibodies (PRABO) after major ABO mm HSCT, and autoimmune hemolytic anemia (AIHA). Transplantation characteristics and clinical outcome were analyzed by univariate and multivariate analysis for groups with or without anti-RBC antibodies. ABO blood group incompatibility did not affect clinical outcome despite an increased requirement of blood transfusion. Twelve patients with AIHA, 6 patients with PLS, and 12 patients with PRABO post-HSCT were identified. AIHA did not affect overall survival (OS) or transplant-related mortality (TRM), but patients with AIHA had a lower incidence of grades II to IV acute graft-versus-host disease (P = .05). OS in the PLS group was 0% compared with 61% in the whole group receiving minor ABO mm transplants (P < .001). Comparing PRABO patients with those receiving a major ABO mm HSCT, the OS was 17% versus 73% (P = .002) and TRM was 50% versus 21% (P = .03). At our center, PLS after minor ABO mm and PRABO antibodies after major ABO mm HSCT are significant risk factors for decreased OS and TRM. Our results suggest that occurrence of unexpected ABO antibodies after HSCT warrant a wider investigation individual to find the underlying cause.

ABO chimerism determined by real-time polymerase chain reaction analysis after ABO-incompatible haematopoietic stem cell transplantation

BACKGROUND

The dynamic alteration of ABO blood group in ABO-incompatible haematopoietic stem cell transplantation can be well defined by ABO chimerism analysis. In view of the intrinsic difference in ABO phenotypes or genotypes between donor and recipient in ABO incompatible transplantation, ABO allele-associated nucleotide polymorphic sites could theoretically be used as available informative markers for chimerism analysis.

MATERIALS AND METHODS

We chose nucleotide polymorphism sites (261, 467, 802, 803 and 1,061) of common ABO alleles to use as markers from 76 randomly chosen donors and assessed the limit of linear detection of a specifically designed real-time quantitative polymerase chain reaction using SYBR Green I dye with these sites for a chimerism assay.

RESULTS

We successfully established the real-time quantitative polymerase chain reaction for detecting 261, 467(mutated) and 803 sites and their limits of linear detection, which were at least 10(-3), 10(-2) and 10(-2), respectively. The limits of linear detection between heterozygous DNA and homozygous DNA with 261 or 803 sites were not significantly different.

DISCUSSION

ABO chimerism can be well analysed by real-time polymerase chain reaction with ABO gene-associated nucleotide polymorphic sites. This strategy could be very beneficial for the early and accurate judgement of the crucial point of transition in order to plan a safe transfusion strategy following ABO-incompatible transplantation.

Clinical factors affecting engraftment and transfusion needs in SCT: a single-center retrospective analysis

Successful utilization of SCT modalities often requires utilization of both red cell and platelet transfusions. In this retrospective evaluation of clinical factors affecting transplant engraftment and transfusion utilization at a single transplant center in 505 patients from 2005 through 2009, we found that graft type, donor type and the conditioning regimen intensity significantly affected both the neutrophil engraftment time (P<0.001) and the platelet engraftment time (P<0.001). SCT patients required an average of 6.2 red cell units, and 7.9 platelet transfusions in the first 100 days with a wide s.d. Among auto-SCT patients, 5% required neither RBC nor platelet transfusions. Some reduced-intensity transplants were also associated with no transfusion need, and in allogeneic transplants, conditioning regimen intensity was positively correlated with platelet transfusion events as assessed by multivariate analysis. Other patient characteristics such as gender, graft type, donor type, underlying disease and use of TBI were all independently associated with transfusion needs in SCT patients. Further studies are required to understand the means to minimize transfusions and potential related complications in SCT patients.

Donor selection in T cell-replete haploidentical hematopoietic stem cell transplantation: knowns, unknowns, and controversies

Multiple donors are generally available for haploidentical hematopoietic stem cell transplantation. Here we discuss the factors that should be considered when selecting donors for this type of transplantation according to the currently available evidence. Donor-specific anti-HLA antibodies (DSAs) increase the risk of graft failure and should be avoided whenever possible. Strategies to manage recipients with DSAs are discussed. One should choose a full haplotype mismatch rather than a better-matched donor and maximize the dose of infused hematopoietic cells. Donor age and sex are other important factors. Other factors, including predicted natural killer cell alloreactivity and consideration of noninherited maternal alleles, are more controversial. Larger studies are needed to further clarify the role of these factors for donor selection in haploidentical hematopoietic stem cell transplantation.