Delayed donor red cell chimerism and pure red cell aplasia following major ABO-incompatible nonmyeloablative hematopoietic stem cell transplantation

Bidirectional ABO Mismatch Is Associated With Elevated Mortality in Hematopoietic Stem Cell Transplantation: Insights From a Single-Center Experience

Background Hematopoietic stem cell transplantation (HSCT) is a promising therapy for various disorders and provides new opportunities for patients. ABO incompatibility in allogeneic HSCT (allo-HSCT) remains a topic of debate because of its potential impact on clinical outcomes. This study aimed to analyze the survival outcomes of patients who underwent ABO-incompatible HSCT and evaluate the occurrence of pure red cell aplasia. Methods This retrospective study included 20 patients who underwent ABO-incompatible HSCT. Data on patient characteristics, transplant details, and follow-ups were collected. Conditioning regimens and graft-versus-host disease (GVHD) prophylaxis strategies were employed. Results Neutrophil and platelet engraftment durations did not differ significantly between major and bidirectional mismatches. Pure red cell aplasia occurred in 4 patients (20%) with major mismatches, all of whom responded well to bortezomib treatment. Patients with a bidirectional mismatch exhibited a 3.57-fold increase (hazard ratio [HR]: 0.28; p<0.05) in the risk of mortality compared to those in the major mismatch group. Conclusion The results indicate that ABO mismatch, whether bidirectional or major, does not significantly affect neutrophil and platelet engraftment duration, suggesting that ABO incompatibility may not be a major factor influencing hematological recovery in allo-HSCT. Interestingly, patients with bidirectional mismatch exhibited a significantly higher mortality rate than those with major mismatch. This finding suggests that a bidirectional ABO mismatch may have an unfavorable prognosis in terms of overall survival in allo-HSCT patients.

Incidence and risk factors for secondary graft failure in uniformly treated patients with severe aplastic anemia receiving fludarabine and cyclophosphamide for conditioning and matched sibling bone marrow graft as stem cell source

BACKGROUND AIMS

Graft failure after allogeneic transplant for aplastic anemia is problematic. The risk of graft failure depends on multiple variables, including the preparative regimen, donor type, stem cell dose and source among other variables.

METHODS

We performed a retrospective analysis of patients with aplastic anemia who underwent matched-sibling allogeneic transplant at a single center.

RESULTS

We identified 82 patients who fit the inclusion criteria. One had primary graft failure and was excluded from this analysis. The recipient median age was 22 years. The donor median age was 23 years. The median time from diagnosis to transplant was 1.6 months. The median number of red cell transfusions before transplant was nine. The median number of platelet transfusions before transplant was 18. Thirteen patients developed secondary graft failure, with a cumulative incidence at 5 years of 16% and median time to develop secondary graft failure of 129 days. All patients engrafted with a median time for neutrophil engraftment of 19 days and a median time for platelet engraftment of 22 days. The survival of patients with or without secondary graft failure was not different. Major or bidirectional ABO incompatibility and older recipient age were statistically significantly associated with greater risk of secondary graft failure.

CONCLUSIONS

Secondary graft failure is a significant complication after allogeneic transplant for SAA. Identification of recipients at risk and mitigating the potential risks of this complication is warranted.

The Impact of ABO Incompatibility on the Outcomes of Hematopoietic Stem Cell Transplantation: A Single-Center Study From Pakistan

Background and objective Allogeneic hematopoietic stem cell transplantation (alloHSCT) provides curative treatment for several hematological illnesses. In this study, we evaluated the impact of ABO compatibility and incompatibility on outcomes and complications related to hematopoietic stem cell transplantation (HSCT) performed for various hematological disorders at our center. Methodology This was a retrospective, single-center, cohort study in which patients were categorized according to the ABO match and mismatch status. The mismatch group was further subcategorized into major, minor, and bidirectional groups. Results A total of 117 patients underwent alloHSCT, out of which 82 (70.1%) were male and 35 (30%) were female. The median age of the patients was 9.5 years (range: 46 years). The most common indications for stem cell transplant were beta-thalassemia major (BTM; n=58, 49%) and aplastic anemia (AA; n=42, 35.8%). However, the outcomes in match and mismatch groups showed significant results for positive direct Coombs test (DCT), indicating the occurrence of hemolysis. Despite the increased need for blood transfusions, ABO blood group incompatibility (ABOi) had no negative impact on the clinical results. Conclusion Based on our findings, ABO incompatibility does not affect the outcomes in patients undergoing alloHSCT. Patient monitoring can aid in early detection and treatment, thereby minimizing the frequency of fatal events.

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.

[Graft failure, poor graft function erythroblastopenia: Actualization of definitions, diagnosis and treatment: Guidelines from the SFGM-TC]

In this article, we discuss again the definition, the risk factor and guideline to treat the graft failure, the poor graft function and erythrobalstopenia. Graft failure is a severe but rare complication after hematopoietic cell transplantation (HCT). Despite disparity in the literature, we defined this complication and discussed the factor risks and recommendation for treatment based on new studies. Poor graft function is also a more frequent complication after HCT. New studies will soon be available to prove or not the current recommendation suggested in this article based on therapeutics medicine or cellular therapy. Erythroblastopenia, is a rarer complication post HCT. Despite anticipation for a better choice of compatibility donor/recipient, some patients still suffer from this complication.

Prevalence of adsorbed A antigen onto donor-derived group O red cells in children following stem cell transplantation: A single-centre evaluation

BACKGROUND AND OBJECTIVES

A group AB D-positive child presented 1 year after haematopoietic stem cell transplant (HSCT) from a group O D-negative donor as group A D-negative. Engraftment remained at 100% in white cell lineages. The reason for the unusual result was explored, and the scarcely reported phenomenon of adsorption of secreted antigen was considered. This study also investigated the prevalence of secreted antigen adsorbed onto donor-derived group O red blood cells (RBCs) in children after HSCT and defined a process for laboratory management.

MATERIALS AND METHODS

Retrospective data analysis of HSCTs carried out over 19 months at Great Ormond Street Hospital was conducted to identify cases of adsorbed A antigen after HSCT. Investigation of RBC reactions with different clones of anti-A and in vitro experiments was performed to recreate adsorption.

RESULTS

Nineteen A to O HSCTs were conducted over 19 months, of which six (31%) displayed weak A antigen on RBCs despite full myeloid engraftment. Negative reactions with anti-A were obtained when run on an alternative clone. Laboratory protocols for the future management of these cases have been developed.

CONCLUSION

Passive adsorption of secreted antigen is responsible for these results and is more widespread than previously reported, as a third of A to O HSCTs at our centre demonstrated this phenomenon. A process has been implemented into the laboratory to manage this cohort, ensuring component groups compatible with both donor and recipient are given, and the shared care centres are aware of these requirements.

Anti-Thymocyte Globulin (ATG)-Free Nonmyeloablative Haploidentical PBSCT Plus Post-Transplantation Cyclophosphamide Is a Safe and Efficient Treatment Approach for Pediatric Acquired Aplastic Anemia

Most cases of acquired aplastic anemia (AA) arise from autoimmune destruction of hematopoietic stem and progenitor cells. Human leukocyte antigen (HLA)-haploidentical nonmyeloablative hematopoietic stem cell transplantation (HSCT) plus post-transplantation cyclophosphamide (PTCy) is increasingly applied to salvage AA using bone marrow as graft and anti-thymocyte globulin (ATG) in conditioning. Herein, we characterize a cohort of twelve AA patients clinically and molecularly, six who possessed other immunological disorders (including two also carrying germline SAMD9L mutations). Each patient with SAMD9L mutation also carried an AA-related rare BCORL1 variant or CTLA4 p.T17A GG genotype, respectively, and both presented short telomere lengths. Six of the ten patients analyzed harbored AA-risky HLA polymorphisms. All patients recovered upon non-HSCT (n = 4) or HSCT (n = 8) treatments. Six of the eight HSCT-treated patients were subjected to a modified PTCy-based regimen involving freshly prepared peripheral blood stem cells (PBSC) as graft and exclusion of ATG. All patients were engrafted between post-transplantation days +13 and +18 and quickly reverted to normal life, displaying a sustained complete hematologic response and an absence of graft-versus-host disease. These outcomes indicate most AA cases, including of the SAMD9L-inherited subtype, are immune-mediated and the modified PTCy-based regimen we present is efficient and safe for salvage.

Pure red cell aplasia after hematopoietic stem cell transplantation - experimental therapeutic approaches

Not relevant.

Kinetics of disappearance and appearance of isoagglutinins A and B after ABO-incompatible hematopoietic stem cell transplantation

ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT) can be complicated by poor red cell engraftment and hemolysis, both mediated by isoagglutinins. Anecdotally, isoagglutinins indicates an activation of donor’s immunity or even relapse. Consequently, the routine monitoring of isoagglutinins could help physicians to predict the risk of complications. The purpose of this study is to investigate the time to disappearance and appearance of isoagglutinins after ABO-incompatible allogeneic HSCT. In a one-year follow-up, data of 136 ABO-incompatible hematopoietic stem cell (HSC) allogeneic transplanted patients were studied, of which 60 had major, 61 minor and 15 bidirectional incompatibility. Survival analyses were conducted and association with hematological diseases, HLA-compatibility and transplantation strategy was investigated. We observed a disappearance of isoagglutinin A in 82.0% of cases at one year with a median and 75th percentile of 38.4 and 138.6 days, respectively. For isoagglutinin B, these same values were 96.4%, 15.9 and 29.1 days, respectively. The appearance of isoagglutinin A occurred in 10.7% of cases. Disappearance of isoagglutinin A was significantly slower in patients with myeloid diseases compared to other diseases. The results of this study provide useful values to detect early risks of preventable immunohematological complications and possibly, in exceptional cases, relapse.

Prevalence of Pure Red Cell Aplasia Following Major ABO-Incompatible Hematopoietic Stem Cell Transplantation

Background

Pure red cell aplasia (PRCA) is one of the important complications in major ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT). The established pathogenic factor of PRCA is the persistence of high anti-donor isohemagglutinins. As previously verified, the conditioning regimen and donor type were the factors associated with the development of PRCA in the small-sized studies. Currently, the prevalence, risk factors, and prognosis of PRCA are still worth studying to provide evidence.

Methods

We conducted a prospective nested case-control study to determine the prevalence, donor-related factors, and the outcomes of PRCA following major ABO-incompatible transplantation. A total of 469 patients who underwent ABO-incompatible grafts were observed.

Results

None of the patients were diagnosed with PRCA with minor or bidirectional ABO-incompatible HSCT. Thirteen of the187 patients (7%; 95% confidence interval [CI], 3.9%–11.9%) developed PRCA following major ABO-incompatible HSCT. Eleven of the 13 patients with PRCA recovered entirely. Donor type was an independent factor associated with post-HSCT PRCA (odds ratio [OR]=0.030; 95% CI, 0.003–0.321; P=0.004). The cumulative incidence rates of post-HSCT PRCA in the context of major ABO-incompatible HSCT were 0.8%, 13.1%, and 27.2% for the haploidentical donor (HID), unrelated donor, and matched related donor, respectively. No significant influence of PRCA on transplantation outcomes was observed.

In conclusion, post-HSCT PRCA is a rare and less threatening complication in major ABO-incompatible HSCT. The majority of patients with PRCA could recover. Additionally, HIDs for recipients may have a low risk of post-HSCT PRCA. This trial was registered at www.chictr.org.cn (#ChiCTR2000041412).

Post-Hematopoietic Stem Cell Transplantation Immune-Mediated Anemia: A Literature Review and Novel Therapeutics

Anemia after allogeneic hematopoietic stem cell transplantation (HSCT) can be immune or non–immune mediated. Auto- or alloimmunity resulting from blood group incompatibility remains an important cause in post-HSCT immune-mediated anemia. ABO incompatibility is commonly encountered in HSCT and may lead to serious clinical complications, including acute hemolysis, pure red cell aplasia, and passenger lymphocyte syndrome. It remains controversial whether ABO incompatibility may affect HSCT outcomes, such as relapse, nonrelapse mortality, graft-versus-host disease, and survival. Non-ABO incompatibility is less frequently encountered but can have similar complications to ABO incompatibility, causing adverse clinical outcomes. It is crucial to identify the driving etiology of post-HSCT anemia in order to prevent and treat this condition. This requires a comprehensive understanding of the mechanism of anemia in blood group–incompatible HSCT and the temporal association between HSCT and anemia. In this review, we summarize the literature on post-HSCT immune-mediated anemia with a focus on ABO and non-ABO blood group incompatibility, describe the underlying mechanism of anemia, and outline preventive and treatment approaches.

ABO Mismatch in Allogeneic Hematopoietic Stem Cell Transplant: Effect on Short- and Long-term Outcomes

Supplemental Digital Content is available in the text.

Background.

The impact of ABO incompatibility (ABO-I) on hematopoietic stem cell transplant outcomes is still debated.

Methods.

We retrospectively investigated 432 consecutive transplants performed at our center (2012–2020). All patients but 6 were affected by hematologic malignancies. The effect of different ABO match combinations on engraftment rate, transfusion support, acute and chronic graft-versus-host disease incidences, nonrelapse mortality (NRM), disease-free survival, and overall survival was assessed in univariate and multivariate analysis. Significance was set at P < 0.05.

Results.

ABO match distribution among transplants was as follows: 223 ABO-compatible, 94 major ABO-I, 82 minor ABO-I, and 33 bidirectional ABO-I. At univariate analysis, major ABO-I delayed the engraftment of neutrophils, platelets, and erythroid cells. At multivariate analysis, major ABO-I transplants displayed delayed erythroid engraftment (odds ratio [OR], 0.51; 95% confidence intervals [CIs], 0.38-0.70; P < 0.0001) and hindered transfusion independence for both red blood cells (OR, 0.52; 95% CI, 0.37-0.72; P = 0.0001) and platelets (0.60; 95% CI, 0.45-0.86; P = 0.0048). Moreover, major ABO-I transplants received greater amounts of blood products (P < 0.0001 for red blood cells and P = 0.0447 for platelets). In comparison with other ABO matches, major ABO-I was associated with an increased NRM (OR, 1.67; 95% CI, 1.01-2.75; P = 0.0427). No effects of ABO-mismatch were found on graft-versus-host disease, disease-free survival, and overall survival.

Conclusions.

Major ABO mismatch delays multilineage engraftment hinders transfusion independence and increases NRM. The prognostic impact of transfusion burden in hematopoietic stem cell transplantation deserves to be explored.

Daratumumab: Beyond Multiple Myeloma

Daratumumab (DARA) is the biological name of an Immunoglobulin G1k human monoclonal antibody. DARA the first-in-class therapy targeting CD38 expressing- plasma cells (PC) and plasma blasts. It has been approved for the treatment of multiple myeloma. It is also being examined in the setting of other hematologic malignancies. As DARA targets PCs, it could potentially be used to treat many other disease processes that are antibody mediated. In fact, several case reports and case series report experiences of using DARA to treat a variety of antibody-mediated disorderss. The aim of this review is to present a summary of the literature thus far regarding the application of DARA beyond its uses in multiple myeloma and other hematologic diseases. Specifically, we address uses of DARA as an immunologic modulator in various antibody mediated processes.

Selective ABO immunoadsorption in hematopoietic stem cell transplantation with major ABO incompatibility

OBJECTIVE

ABO mismatch between donor and recipient occurs in 40% of allogeneic hematopoietic stem cell transplantations (HCT). Different strategies have been described to reduce isohemagglutinins (IHA) before HCT. We describe the effect of selective ABO immunoadsorption (ABO IA) on erythrocyte transfusion rate and the development of post-transplant pure red cell aplasia (ptPRCA).

METHODS

63 patients with major ABO incompatibility were retrospectively analyzed. Nine patients with major ABO incompatibility and high-IHA titer were treated by ABO IA before HCT. We analyzed the need for transfusion and the occurrence of ptPRCA. We compared the outcome with patients treated by other methods to reduce IHA.

RESULTS

In all nine patients treated by ABO IA, IHA decreased in a median four times. PtPRCA occurred in one patient. The median number of transfusions was 8 (range: 0-36) between d0 and d100. In 25 patients with high-IHA titer without treatment or treated by other methods to reduce IHA, the need for transfusions was comparable. No difference in the incidence of ptPRCA was observed.

CONCLUSIONS

Selective ABO IA is a feasible, safe, and effective method to reduce IHA before HCT in major ABO incompatibility. No effect on transfusion rate or ptPRCA compared to other strategies could be observed.

Investigation of risk factors associated with erythrocyte engraftment after ABO-incompatible hematopoietic stem cell transplantation

ABO-incompatible hematopoietic stem cell transplantations (HSCTs) are widely practiced; however, the delay in erythrocyte engraftment can be problematic. While erythrocyte engraftment is usually indicated by an increase in reticulocyte levels without the need for erythrocyte transfusions, the disappearance of recipient-derived anti-A/B isoagglutinin and detection of donor-derived A/B antigens can also be used as other parameters. We conducted a retrospective analysis of 68 ABO-incompatible HSCTs, focusing on major and bidirectional mismatch. We analyzed known clinical risk factors associated with delayed erythrocyte engraftment using the three parameters (disappearance of anti-A/B isoagglutinin in recipient, detection of donor-derived A/B antigen, and reticulocyte levels >1%). Although the three parameters were well correlated, the results showed heterogeneity when analyzing the associated risk factors for delayed erythrocyte engraftment. In the analysis of all cases, the requirement for an HLA-matched platelet transfusion was a common risk factor. Furthermore, erythrocyte engraftment was slower in adults than in children. In adults, cytomegalovirus antigenemia was a risk factor for two parameters; however, in children, underlying disease was a common risk factor for all parameters. There is a complex relationship between erythrocyte engraftment and various factors related to HSCTs. Our results suggest that greater accuracy is possible by using analysis methods other than the measurement of reticulocyte levels.

How I manage acquired pure red cell aplasia in adults

Pure red cell aplasia (PRCA) is a rare hematological disorder with multiple etiologies. The multifaceted nature of this disease is emphasized by the variety of concomitant clinical features. Classic idiopathic presentation aside, prompt recognition of pathogenetic clues is important because of their diagnostic and therapeutic implications. As a consequence, treatment of PRCA is diverse and strictly dependent on the presented clinical scenario. Here, we propose a series of clinical vignettes that showcase instructive representative situations derived from our routine clinical practice. Using these illustrative clinical cases, we review the diagnostic workup needed for a precise diagnosis and the currently available therapeutic options, discussing their applications in regard to the various PRCA-associated conditions and individual patients' characteristics. Finally, we propose a treatment algorithm that may offer guidance for personalized therapeutic recommendations.

Treatment for pure red cell aplasia after major ABO-incompatible allogeneic stem cell transplantation: a multicentre study

Pure red cell aplasia (PRCA) following allogeneic haematopoietic stem cell transplantation (aHSCT) with major ABO incompatibility is responsible for transfusion dependent anaemia, impaired quality of life and iron overload. We conducted a retrospective study, over a 10-year period, which included all consecutive patients who received a major ABO mismatched aHSCT, to assess the impact of specific treatment on PRCA. We did not observe any PRCA in the 57 aHSCT issued from cord blood. Among the remaining 631 patients, cumulative incidence of PRCA was 10·5% [range 8·2-13.0]. The median duration of resolved PRCA was 171 days [IQR 116; 261]. Pre-transplant high isohaemagglutinins titre was associated with an increased risk of PRCA (P < 10^-4 ). PRCA did not affect overall survival (P = 0·95). Twenty-two patients (33·3%) received at least one specific treatment. The most commonly used treatments were rituximab (17 patients) and donor lymphocyte infusion (DLI; seven patients). Regarding PRCA resolution, we did not observe a significant difference between treated or untreated subjects (HR = 0·93, 95% confidence interval (CI) 0·48- 1·80; P = 0·82). Similar results were observed with erythropoietin treatment (22 patients, HR = 0·86 95% CI: [0·47-1·57] P = 0·62). Our data do not support the use of erythropoietin, rituximab or DLI for the treatment of PRCA.

Immune cytopenia after allogeneic haematopoietic stem-cell transplantation: challenges, approaches, and future directions

Immune-mediated cytopenia after allogeneic haematopoietic stem-cell transplantation is rare. The pathophysiology of immune-mediated anaemia, thrombocytopenia, and neutropenia, which occur alone or in combination with other cytopenias, is unclear and most probably a consequence of immune dysregulation. Risk factors for this complication have been identified in retrospective studies but these should be interpreted with caution and should not be generalised to this heterogeneous patient population. Diagnosis is challenging, requires awareness of such complications, and has to be differentiated from a multitude of other, and sometimes overlapping, possible complications. The clinical course of immune-mediated cytopenia is highly variable. Treatment requires an interdisciplinary approach and ranges from observation to symptomatic measures and directed therapies. Intensive immunosuppression is associated with an increased risk of infections and relapse, and current treatments are based on approaches in patients who have not undergone transplantation. Plasma cell-directed therapies, immunomodulation, and receptor-stimulating agents can be used to treat immune-mediated cytopenia.

BSHI guideline: HLA matching and donor selection for haematopoietic progenitor cell transplantation

A review of the British Society for Histocompatibility and Immunogenetics (BSHI) Guideline 'HLA matching and donor selection for haematopoietic progenitor cell transplantation' published in 2016 was undertaken by a BSHI appointed writing committee. Literature searches were performed and the data extracted were presented as recommendations according to the GRADE nomenclature.

Pure red cell aplasia after major or bidirectional ABO incompatible hematopoietic stem cell transplantation: to treat or not to treat, that is the question

Pure red cell aplasia (PRCA) is a complication related to major or bidirectional ABO mismatched hematopoietic stem cell transplantation. This disorder is characterized by anemia, reticulocytopenia, and the absence or virtual absence of erythroid progenitors, other causes such as infections, hemolysis, disease relapse, or drug toxicity having been excluded. Patients with PRCA may become RBC transfusion dependent for long periods, suffering an important long-term iron overload, alloimmunization, and transfusion reactions. The persistence of recipient isoagglutinins against donor ABO antigens produced by host residual plasmatic cells has been considered as the immunological cause of the prolonged erythroid aplasia. PRCA behaves in many cases as a self-limited condition and resolution may occur spontaneously within weeks, months, and even years. Many different therapeutic approaches have been reported for posttransplant PRCA as plasmapheresis, high doses of erythropoietin, donor lymphocyte infusions, anti-thymocyte globulin, Rituximab and steroids, among others. However, to date there is no standard of care and the question if patients with PRCA should be treated and at which point remains. The objective of this article is to review the natural evolution of PRCA, and the treatments that have been used over time focusing on their suitability and efficacy.

Antigen-Specific Immunoadsorption With the Glycosorb® ABO Immunoadsorption System as a Novel Treatment Modality in Pure Red Cell Aplasia Following Major and Bidirectional ABO-Incompatible Allogeneic Hematopoietic Stem Cell Transplantation

Pure red cell aplasia (PRCA) after ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT) is caused by persisting host-derived isohemagglutinins directed against donor red blood cell (RBC) antigens. ABO antigen-specific immunoadsorption (ABO-IA) with Glycosorb®, commonly used for desensitization therapy in ABO-incompatible living donor renal transplantation, specifically eliminates circulating isohemagglutinins and might represent a novel treatment option for post-HSCT PRCA. In this prospective observational (n = 3) and retrospective (n = 3) analysis of six adult HSCT-recipients with PRCA, ABO-IA was initiated at 159 (range: 104–186) days following HSCT. The median treatment frequency was 4.5 (range: 3.9–5.5) sessions/week. ABO-IA-treatment led to a continuous decrease in isohemagglutinin titers. Reticulocytes increased to ≥30 G/L after 17.5 (range: 4–37) immunoadsorption sessions over 28.5 (range: 6–49) days and continued to rise after that. By the end of the 3-month follow-up period after discontinuation of ABO-IA, all patients showed a sustained remission of PRCA and were independent of erythropoietin-stimulating agents and transfusions. No case of infection or graft-versus-host disease was observed. After a median follow-up of 22.03 (range: 6.08–149.00) months after ABO-IA-treatment, all patients were alive and showed a stable RBC engraftment of the donor blood group. Our data provide the first evidence for ABO-IA as an effective treatment for post-HSCT PRCA.

Transfusion support for stem cell transplant recipients

Hematopoietic stem cell patients regularly require transfusion support. Indications for transfusion in this population are similar to other patients being treated with chemoradiation; however, special considerations must be made in regards to pretransfusion testing, ABO compatibility, product modifications, and anticipated challenges while patients undergo engraftment. Additionally, infusion of hematopoietic stem cells requires acute understanding of product collection, modification, and potential side effects. As these patients often require numerous platelet transfusions, platelet refractoriness may be encountered and practice options are discussed. We review current indications and guidelines for transfusion in hematopoietic stem cell patients and make recommendations for best practice based on current literature.

Poor graft function after T cell-depleted allogeneic hematopoietic stem cell transplant

PGF implies persistent cytopenia in the presence of predominant donor chimerism. We examined contributors to PGF in 104 HCT recipients who survived ≥100 days without relapse or major complications. Surrogate parameters for PGF were: Hg <10 g/dl, RBC transfusion dependence, platelet count <20 × 10⁹/L or ANC < 0.5 × 10⁹/L. All patients received T cell depletion with alemtuzumab or ATG. The 2-year OS and PFS probabilities were 66%, 95%CI (56 - 75%) and 51%, 95%CI (41-60%) respectively. Fifty-four patients (52%) met one or more PGF criteria. There was significant association between major ABO incompatibility and platelet <20 × 109/L (OR = 4.7, 95%CI 1.05-21.26, p = .043), acute GVHD and Hg <10 g/dl (OR 3.7, 95%CI 1.4-9.6, p = .005) and CMV viremia and ANC < 0.5 × 10⁹/L (OR 3.0, 95% CI 1.0, 8.7, p = .043). NRM was significantly higher in the PGF group compared to patients with adequate graft function (45.5% vs 16.7%, p = .014).

Daratumumab for pure red cell aplasia post ABO incompatible allogeneic hematopoietic stem cell transplant for aplastic anemia

Pure red cell aplasia is a known complication after ABO incompatible stem cell transplant. Due to rarity of disease, no established treatment guidelines are available for PRCA. Daratumumab is a monoclonal antibody against CD38 expressed by plasma cells. In this report we present our experience of successfully managing a patient of post-transplant PRCA with daratumumab. Our patient had failed multiple lines of therapy prior to receiving daratumumab. Response was seen after the 3rd weekly dose of daratumumab.

Impact of ABO incompatibility on outcomes after haploidentical hematopoietic stem cell transplantation for severe aplastic anemia

The impact of ABO incompatibility on transplantation outcomes in severe aplastic anemia (SAA) patients receiving haploidentical hematopoietic stem cell transplantation (HSCT) remains controversial without published data. A total of 199 SAA patients receiving haploidentical HSCT from ABO-matched (n = 114), minor ABO-incompatible (n = 47), or major ABO-incompatible donors (n = 38) were included in this study. The median time and cumulative incidences of both myeloid and platelet engraftment in the ABO-compatible and ABO-incompatible groups were similar, and pure red cell aplasia was absent. Minor ABO incompatibility increased the rate of grade III-IV acute graft-versus-host disease (aGVHD) (ABO compatible: 6.14 ± 0.05%, minor incompatible: 19.15 ± 0.34%, and major incompatible: 10.53 ± 0.25%; P = 0.051), but did not influence the rates of grade II-IV aGVHD or chronic GVHD (cGVHD). Minor ABO-incompatibility was identified as an independent risk factor for grade III-IV aGVHD by multivariate analysis (hazard ration (HR) = 4.00 (1.48-10.80), P = 0.006). Chronic GVHD, mortality, and treatment failure were not increased in the minor ABO-incompatible group. For SAA patients receiving haploidentical HSCT, ABO compatible donors are better than ABO minor incompatible donors if several haploidentical donors are available.

Modeling Long-Term Erythropoietic Recovery After Allogeneic Stem Cell Transplants in Pediatric Patients

Long term erythropoietic reconstitution after allogeneic hematopoietic stem cell transplantation (alloHSCT) has not been extensively studied. We aimed to describe erythropoietic reconstitution as an indicator of long-term graft function by modeling hemoglobin levels during the first 3 years post HSCT in pediatric patients. We retrospectively included 414 patients and 11,957 measurements. The largest hemoglobin increase was at day 45 and levels reached a steady state at day 648 with a level of 7.48 mmol/L. In patients transplanted for hematological malignancies hemoglobin levels normalized faster (p < 0.0001). Increasing patient age correlated with faster recovery (p < 0.0001), while donor age had no influence. Conditioning, donor type and graft source did not influence recovery significantly. In the ABO mismatched group there was a transient negative effect on hemoglobin levels, and a delay in reticulocyte recovery (21 vs. 19 days; p = 0.012). In contrast, hemoglobin levels reached a higher plateau beyond 9 months in these patients (p < 0.0001). After alloHSCT, experiencing a CMV reactivation negatively affected reconstitution (p = 0.034), while EBV reactivations and acute graft vs. host disease did not. In summary, erythropoietic recovery was mainly influenced by patient factors and primary disease, and less influenced by donor factors.

Successful treatment of refractory red cell aplasia after allogeneic hematopoietic cell transplantation with daratumumab

Pure red cell aplasia (PRCA) is an uncommon complication secondary to ABO mismatched allogeneic stem-cell transplantation (allo-HSCT). The best approach for PRCA after allo-HSCT remains unclear. We aim to report a single case with refractory PRCA post-ABO mismatched allo-HSCT resolved with daratumumab. A 34-year-old male diagnosed with aplastic anemia in March 2014 received a peripheral blood reduced-intensity allo-HSCT from an HLA-matched related donor in July 2016. Donor and recipient blood groups were AB positive and 0 positive, respectively, indicating a major ABO incompatibility. The patient was diagnosed with PRCA 2 months after allo-HSCT. After failing multiple standard lines of treatment, compassionate treatment with daratumumab was requested. After receiving six doses of daratumumab, the patient had a marked reticulocyte response and consecutively become transfusion independent. In conclusion, Daratumumab is a human IgG1κ monoclonal antibody targeting CD38 and is used to treat multiple myeloma. The use of anti-CD38 therapy with daratumumab to target residual host plasma cells is safe and effective, and it can be considered in refractory recipients with PRCA after allo-HSCT secondary to ABO incompatibility.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Characterization of reemergent anti-B red blood cell antibodies in a patient with recurrent acute myeloid leukemia with ABO-incompatible allogeneic peripheral blood stem cell transplantation

BACKGROUND

Isohemagglutinins against ABO antigens absent on both recipient and donor red blood cells (RBCs) increase or decrease after ABO-incompatible hematopoietic stem cell transplantation (HSCT). However, few reports have described the changes in the isohemagglutinin titers and the characteristics in patients with recurrent hematologic conditions after ABO-incompatible HSCT.

CASE REPORT

A 59-year-old female with acute erythroid leukemia received a peripheral blood stem cell transplant from her HLA-haploidentical daughter. The patient was typed as group O with anti- A (4+) and B (4+) isohemagglutinins, while the donor was typed as group B. The bone marrow cells achieved complete donor cell chimerism on Day 13 after HSCT. On Day 120, the patient showed 97% B RBC type with persistent anti-A (3+) and without anti-B antibodies. On Day 375, her leukemia relapsed, and recipient type O RBCs and anti-B antibodies sequentially reemerged. However, clinicolaboratory hemolysis and erythroid aplasia were not detected in the patient.

RESULTS

The post-HSCT sera agglutinated the allo B RBCs, but not the donor B RBCs, while the pre-HSCT sera agglutinated both RBCs. The burst-forming/colony-forming units of erythroid formation from the donor peripheral blood stem cells were impaired by only the pre-HSCT sera and not by the post-HSCT sera.

CONCLUSION

To our knowledge, this is the first report investigating the characteristic changes of isohemagglutinins between the pre- and post-HSCT sera in a patient with recurrent acute myeloid leukemia. The present study suggests that the plasma cells producing anti-donor B RBCs in the patient have been selectively eliminated or induced into an anergic state by the post-HSCT immunologic reconstruction.

Immune Cytopenias after Ex Vivo CD34+-Selected Allogeneic Hematopoietic Cell Transplantation

Immune-mediated cytopenias (ICs), such as immune thrombocytopenia and immune hemolytic anemia, are among the adverse events after allogeneic hematopoietic cell transplantation (allo-HCT). Previous reports suggest that in vivo T cell depletion may increase the incidence of IC after allo-HCT. We evaluated whether a strategy that reduces functional donor T cells via ex vivo CD34⁺-selection associates with the development of IC in a cohort of 408 patients who underwent allo-HCT for hematologic malignancy. The cumulative incidence of IC at 6, 12, and 36 months after the 30-day landmark post-HCT was 3.4%, 4.9%, and 5.8%, respectively. Among 23 patients who developed IC, 7 died of relapse-related mortality and 4 of nonrelapse mortality. A median 2 types of treatment (range, 1 to 5) was required to resolve IC, and there was considerable heterogeneity in the therapies used. In univariable analyses, a hematologic malignancy Disease Risk Index (DRI) score of 3 was significantly associated with an increased risk of IC compared with a DRI of 1 or 2 (hazard ratio [HR], 4.12; P = .003), and IC (HR, 2.4; P = .03) was associated with increased risk of relapse. In a multivariable analysis that included DRI, IC remained significantly associated with increased risk of relapse (HR, 2.4; P = .03). Our findings show that IC events occur with relatively similar frequency in patients after ex vivo CD34⁺-selected allo-HCT compared with unmodified allo-HCT, suggesting that reduced donor T cell immunity is not causative of IC. Moreover, we noted a possible link between its development and/or treatment and increased risk of relapse.

Transfusion support for matched sibling allogeneic hematopoietic stem cell transplantation (1993-2010): factors that predict intensity and time to transfusion independence

BACKGROUND

Patients undergoing allogeneic hematopoietic stem cell transplant require variable, often extensive transfusion support. Identification of factors that predict urgent, intensive, or special needs should improve management of these patients.

STUDY DESIGN AND METHODS

This is a retrospective study of red blood cell (RBC) and platelet transfusion support provided for sequential matched sibling donor allogeneic transplants conducted at the Clinical Center, National Institutes of Health, from 1993 through 2010. Factors potentially important for predicting quantity of RBC and platelet transfusions, and time to transfusion independence through Day 200 following hematopoietic stem cell transplantation were evaluated.

RESULTS

Subjects (n = 800) received 10,591 RBC and 10,199 platelet transfusions. Multivariable analysis demonstrated that the need for RBC pretransplant, CD34+ dose, transplant year, diagnostic category, and ABO match were significantly independently associated with quantity of RBC transfusions during Days 0 through 30. Only pretransplant need for RBCs, CD34+ dose, and transplant year had significance during Days 0 through 100. Similar analyses for quantity of platelet transfusions demonstrated that for both Days 0 through 30 and 0 through 100 significant factors were need for platelet support before transplant, CD34+ dose, transplant year, and transplant regimen. Of note, long term, during Days 101 through 200, only CD34+ dose remained significant for quantity of RBC and platelet transfusions. Analysis of time to transfusion independence demonstrated that patients with ABO major mismatches required longer to achieve freedom from RBC transfusion support compared to identical matches or those with minor mismatches.

CONCLUSION

Patient-specific factors including CD34+ dose and ABO match of the graft should be given particular consideration by transfusion services when planning support of patients receiving allogeneic hematopoietic stem cell transplant.

Donor-type fresh frozen plasma is effective in preventing hemolytic reaction in major ABO incompatible allogeneic stem cell transplant

BACKGROUND

Hemolysis at the time of graft infusion is one of the immediate complications in major ABO-incompatible allogeneic hematopoietic stem cell transplants (HSCTs). We conducted a retrospective analysis to evaluate the efficacy of donor-type fresh frozen plasma (FFP) in reducing isohemagglutinin titer and preventing hemolysis, as well as its effect on delayed red cell engraftment.

MATERIALS AND METHODS

This is a single-center study on a series of 380 allogeneic HSCT between 2005 and 2015; of which 99 were either major (n = 74) or bidirectional (n = 25) ABO mismatched. Pre-transplant infusion of FFP, post-transplant complications and transfusion requirements were determined by retrospective review of individual medical records. Laboratory results were also reviewed for evidence of hemolysis and pure red cell aplasia (PRCA).

RESULTS

Clinical manifestation of hemolysis attributable to ABO mismatch was present in one recipient of major ABO-incompatible peripheral blood stem cell (PBSC) with a titer of 64. Another recipient of major ABO-incompatible PBSC with a titer of 64 showed biochemical evidence of hemolysis. Both patients recovered with supportive treatment. Hemolysis did not occur in any patients with titer of 32 or less at the time of stem cell infusion. We were unable to demonstrate the influence of any variables on the incidence of PRCA.

CONCLUSION

Our experience demonstrated that donor-type FFP is safe and effective in preventing acute hemolysis in major ABO-mismatched HSCT. We have also established the titer of 64 as the threshold that may cause hemolysis and therefore efforts should be made to reduce titer to below this level.

Daratumumab for Delayed Red-Cell Engraftment after Allogeneic Transplantation

Daratumumab, a human IgG1κ monoclonal antibody targeting CD38, is used to treat multiple myeloma. We describe successful treatment with daratumumab in a case of treatment-refractory pure red-cell aplasia after ABO-mismatched allogeneic stem-cell transplantation. The patient was a 72-year-old man with the myelodysplastic syndrome who received a transplant from an HLA-matched, unrelated donor with a major ABO incompatibility (blood group A in the donor and blood group O in the recipient). The patient had persistent circulating anti-A antibodies and no red-cell recovery 200 days after transplantation. Standard treatments had no effect. Within 1 week after the initiation of treatment with daratumumab, he no longer required transfusions.

Assessing the impact of ABO incompatibility on major allogeneic hematopoietic stem cell transplant outcomes: a prospective, single-center, cohort study

Background

ABO blood group incompatibility between donor and recipient is associated with a number of immunohematological complications, but is not considered a major contraindication to allogeneic hematopoietic stem cell transplantation. However, available evidence from the literature seems to be conflicting as to the impact of incompatibility on overall survival, event-free survival, transplant-related mortality, graft-versus-host disease, and time to neutrophil and platelet engraftment.

Methods

This single-center, prospective, cohort study included patients with hematological malignancies who underwent a first allogeneic hematopoietic stem cell transplantation between 2008 and 2014. Patients receiving umbilical cord blood as the stem cell source were excluded from this analysis. The impact of ABO incompatibility was evaluated in respect to overall survival, event-free survival, transplant-related mortality, acute graft-versus-host disease and engraftment.

Results

A total of 130 patients were included of whom 78 (60%) were males. The median age at transplant was 36 (range: 2–65) years, 44 (33%) presented ABO incompatibility, 75 (58%) had acute leukemia, 111 (85%) had a related donor, 100 (77%) received peripheral blood hematopoietic stem cells as graft source and 99 (76%) underwent a myeloablative conditioning regimen. There was no statistically significant association between ABO incompatibility and overall survival, event-free survival, transplant-related mortality, grade II–IV acute graft-versus-host disease, neutrophil or platelet engraftment in multivariate analysis.

Conclusion

These results show that ABO incompatibility does not seem to influence these parameters in patients undergoing allogeneic hematopoietic stem cell transplantation.

Immunohaematological complications in patients with sickle cell disease after haemopoietic progenitor cell transplantation: a prospective, single-centre, observational study

BACKGROUND

Haemopoietic progenitor cell (HPC) transplantation can cure sickle cell disease. Non-myeloablative conditioning typically results in donor-derived erythrocytes and stable mixed chimerism of recipient-derived and donor-derived leucocytes. Exposure to donor antigens from the HPC graft and new red cell antibodies induced by transfusion can lead to immunohaematological complications. We assessed the incidence of such complications among HPC transplant recipients with sickle cell disease.

METHODS

The study population was all patients with sickle cell disease enrolled before March 31, 2015, in the three clinical trials of non-myeloablative HPC transplantation at the National Institutes of Health. We assessed formation of new red cell antibodies after transplantation and red cell incompatibility between donors and recipients.

FINDINGS

61 patients were enrolled, 42 were HLA matched and 19 were haploidentical. Nine (15%) had immunohaematological complications. Before HPC transplantation, three patients had antibodies incompatible with their donors. After HPC transplantation, new red cell antibodies were seen in six patients (11 alloantibodies and two autoantibodies), among whom three developed antibodies incompatible with donor or recipient red cells and three developed compatible antibodies. The clinical course of complications was highly variable, from no severe effects attributable to antibodies, to sustained reticulocytopenia, to near-fatal haemolysis. We found no significant correlation between immunohaematological complications and graft failure, graft rejection, or death.

INTERPRETATION

Clinical effects ranged from seemingly not clinically important to potentially fatal. In patients with sickle cell disease, donor and recipient red cell phenotypes should be carefully assessed before transplantation to minimise and manage the risk of immunohaematological complications.

FUNDING

Intramural Research Program and National Institutes of Health.

Successful treatment of pure red cell aplasia with high-dose dexamethasone after ABO-incompatible allogeneic hematopoietic stem cell transplantation

The literature reports an incidence of Pure Red Cell Aplasia (PRCA) ranging from 6-30% of all cases of ABO-incompatible HSCT. Although most patients resolve spontaneously after withdrawal immunosuppression, some of them require more aggressive treatment to manage this condition.

[Is transplantation an alternative to the transfusional impasse in sickle cell disease?]

Sickle cell disease is the most frequent genetic disease in France, concerning 400 newborns each year. The management of these Afro-Caribbean patients requires frequent transfusions from Caucasian donors. Due to important erythroid antigenic differences between Caucasian and African, the prevalence of allo-immunization is high in this population with a risk of transfusional impasse. Allogeneic stem cell transplantation is the only curative treatment for this disease and the replacement of red cells and lymphocytes of the sickle cell patient by those of the donor can also resolve the transfusional impasse. However, a close consultation between physicians from the blood bank and transplantation unit will be required for the choice of conditioning regimen and GvH prophylaxis in order to ensure the transition from a mixed chimerism to the full donor curative graft.

Haemolysis, pure red cell aplasia and red cell antibody formation associated with major and bidirectional ABO incompatible haematopoietic stem cell transplantation

BACKGROUND

Acute and delayed haemolysis, alloimmunisation and pure red cell aplasia (PRCA) are potential complications after ABO incompatible haematopoietic stem cell transplantation (HSCT). The aims of this study were to investigate acute and delayed red blood cell (RBC) antibody-associated complications, including haemolysis, PRCA and alloimmunisation in major and bidirectional ABO incompatible HSCT.

MATERIALS AND METHODS

We retrospectively examined the transplant courses of 36 recipients of bone marrow or peripheral blood stem cells from ABO incompatible donors and evaluated the current practice of performing plasmapheresis in patients with higher isoagglutinin titres. We investigated the role of ABO incompatibility in haematopoietic recovery, transfusion requirements, alloimmunisation and PRCA.

RESULTS

Laboratory signs of acute haemolysis were noted in five (14%) patients, one (3%) of whom had clinically overt haemolysis. Patients with haemolysis had IgM titres ≥1:8 and received >16 mL of RBC in the HSCT. In patients with higher titres, plasmapheresis performed prior to the transplant prevented acute haemolysis. Delayed haemolysis was not recorded in the follow up. Haematopoietic recovery and transfusion requirements did not differ notably between patients with and without haemolysis. De novo RBC antibodies were detected in two (5.5%) patients after HSCT, and PRCA was noted in one (3%) patient.

DISCUSSION

Carried out with adequate graft processing, plasmapheresis and blood component support, haemolysis is not a common complication after HSCT. Our results confirm that the occurrence of haemolysis depends on larger RBC volumes and higher isoagglutinin titres. Despite the reduction of patients' isoagglutinin titres by plasmapheresis, we still noted a critical combination for the development of laboratory signs of haemolysis (IgM titre ≥1:8 and RBC volume >16 mL). De novo immunisation to RBC antigens and PRCA are rare events following ABO incompatible HSCT.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.