TRANSPLANTATION AND CELLULAR ENGINEERING: Prolonged isolated red blood cell transfusion requirement after allogeneic blood stem cell transplantation: identification of patients at risk

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.

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.

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.

Allogeneic peripheral blood stem cell transplantation using reduced-intensity conditioning in an outpatient setting in ABO-incompatible patients: are survival and graft-versus-host disease different?

BACKGROUND

Graft-versus-host disease (GVHD) is a major cause of morbimortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Minor ABO incompatibility has been associated with an increased risk of GVHD. We analyzed the impact of ABO matching on patient outcome after peripheral blood, reduced-intensity allo-HSCT in an outpatient setting, and its relationship with GVHD.

STUDY DESIGN AND METHODS

Data of 121 patients were included. All patients received allo-HSCT from HLA-identical siblings as outpatients using a reduced-intensity conditioning regimen. Influence of ABO matching as a risk factor for the development of GVHD and survival was analyzed using logistic regression and Cox proportional hazards regression, respectively.

RESULTS

Median age was 36 years (range, 1-71 years); 88 patients were ABO identical: 13 presented major mismatch and 20 minor mismatch, with an ABO incompatibility rate of 27.3%. The median follow-up period was 54 months (range, 0.3-120 months). Minor ABO incompatibility patients presented the highest rate of acute GVHD (aGVHD; 25%), in comparison with ABO-identical (20.5%) and major ABO incompatibility patients (15.4%; p = 0.79). The highest incidence of chronic GVHD (cGVHD) occurred in the context of minor ABO incompatibility (35%), in contrast to ABO-identical (30.8%) and major ABO incompatibility (15.4%). Survival was higher for patients in the minor ABO mismatch group; however, there was no significant correlation between ABO matching status and survival (p = 0.45).

CONCLUSION

Using this type of peripheral blood stem cell transplantation, minor ABO-mismatched allo-HSCT was associated with a higher incidence of aGVHD and cGVHD and with increased survival, albeit with no significance.

Fatal immune hemolytic anemia following allogeneic stem cell transplantation: report of 2 cases and review of literature

Immune hemolytic anemia is a well-recognized complication after allogeneic hematopoietic stem cell transplantation (HSCT). There are 4 possible causes for this complication. First, antibodies present in the recipient destroy donor cells. Second, donor red cell antibodies at the time of stem cell infusion are transferred to the recipient. Third, sometimes, engrafted donor lymphocytes cause active production of red cell antibodies. Fourth, another cause of hemolysis after allogeneic HSCT is autoimmune hemolytic anemia (AIHA). It is thought to be due to antibodies produced by the donor's immune system against antigens on red cells of donor origin. Autoimmune hemolytic anemia after allogeneic HSCT is rare, it is still not well characterized, and it represents a life-threatening situation. We describe 2 patients with acute myeloid leukemia treated with intensive chemotherapy and umbilical cord blood stem cell transplantation (UCBT). One patient developed AIHA at day +182 and the other at day +212 after receiving UCBT. Patients received 5 and 7 line treatment options, respectively, including continuous corticosteroids, intravenous immunoglobulin, splenectomy, cyclophosphamide, plasma exchange, rituximab, bortezomib, and eculizumab. However, both patients died because of massive hemolysis after 85 and 106 days of intensive treatment, respectively. These cases reflect the extreme difficulty in the therapeutic management of patients with AIHA following UCBT. After an extensive review of the literature, the exact physiopathologic mechanisms of AIHA after allogeneic HSCT in general, and after UCBT in particular, and therefore an effective treatment remain unknown.

Incidence and natural history of pure red cell aplasia in major ABO-mismatched haematopoietic cell transplantation

Major ABO mismatching is not considered a contraindication to allogeneic haematopoietic stem cell transplantation (HSCT). Modern reduced-intensity conditioning and reduced-toxicity regimens cause much less myeloablation than conventional myeloablative regimens, such as cyclophosphamide with busulfan or total body irradiation, which may affect the incidence of pure red cell aplasia (PRCA). We estimated the incidence and described the natural history of PRCA in patients with major ABO-mismatched donor stem cells. Between 2007 and 2008, 161 (27% of all patients undergoing HSCT) underwent allogeneic HSCT with major ABO-mismatched stem cells and 12 (7·5%) of these patients developed PRCA. Thirty and ninety day T-cell and myeloid cell chimerism and neutrophil and platelet engraftment did not differ between patients who developed PRCA and those who did not. The only risk factor associated with PRCA was the use of a fludarabine/busulfan conditioning regimen. All patients with PRCA needed red cell transfusion for several months after HSCT resulting in significant iron overload. Pure red cell aplasia resolved spontaneously in the majority (seven patients) but only resolved after stopping tacrolimus in three patients. Hence, after major ABO-mismatched HSCT, the incidence of PRCA was 7·5% and it resolved spontaneously or after withdrawal of immunosuppression in the majority of patients.

Cytopenias after day 28 in allogeneic hematopoietic cell transplantation: impact of recipient/donor factors, transplant conditions and myelotoxic drugs

BACKGROUND

Secondary cytopenias are serious complications following hematopoietic cell transplantation. Etiologies include myelotoxic agents, viral infections, and possibly transplant-related factors such as the intensity of the conditioning regimen and the source of stem cells.

DESIGN AND METHODS

We retrospectively analyzed data from 2162 hematopoietic cell transplant recipients to examine the effect of these factors on overall cytopenias occurring after 28 days in hematopoietic cell transplantation.

RESULTS

Advanced age of the patient, recipient cytomegalovirus seropositivity, unrelated donor status, human leukocyte antigen mismatch and lower doses of transplanted CD34(+) cells (≤ 6.4×10(6)/kg) significantly increased the risk of cytopenias after day 28. Non-myeloablative hematopoietic cell transplantation had protective effects on anemia and thrombocytopenia after day 28 (adjusted odds ratio 0.76, probability value of 0.05 and adjusted odds ratio 0.31, probability value of <0.0001, respectively) but not on overall or ganciclovir-related neutropenia. This lack of protection appeared to be due to the use of mycophenolate mofetil in the majority of recipients of non-myeloablative hematopoietic cell transplants. Peripheral blood stem cells did not confer protection from cytopenias when compared to bone marrow.

CONCLUSIONS

Elderly patients appear to be more prone to cumulative toxicities of post-transplant drug regimens, but non-myeloablative conditioning, optimized human leukocyte antigen matching, and higher doses of CD34(+) cell infusions may reduce the risk of cytopenia after day 28.