ABO mismatch may affect engraftment in multiple myeloma patients receiving nonmyeloablative conditioning

Seven-years post allogeneic hematopoietic stem cell transplantation pure red cell aplastic anemia cured with daratumumab: A case report and review of literature

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is currently the only viable method of curing patients with acute myeloid leukaemia. In 30% to 50% of patients, donors and recipients have some level of ABO blood group incompatibility. ABO blood group incompatibility can cause antibodies against the donor's red blood cells to persist in the recipient's body, resulting in a delay of several months in the recovery of red blood cells. A number of different treatments have been reported for post-transplant pure red cell aplastic anaemia (PRCA), such as plasmapheresis, donor lymphocyte infusions, anti-thymocyte globulin, rituximab and steroids.

CASE SUMMARY

A 41-year-old female diagnosed with acute myeloid leukaemia underwent peripheral blood allogeneic haematopoietic stem cell transplantation in November 2013 from an HLA matched unrelated donor. The donor was AB-positive and the recipient was O-positive. The patient was diagnosed with PRCA three months after receiving the donor stem cell transplant. After failing multiple lines of therapy, the patient applied for daratumumab. After receiving three doses of daratumumab, the patient developed a reticulocyte response and no longer required blood transfusions.

CONCLUSION

The use of daratumumab anti-CD38 for the remove of plasma cells is safe and effective and may be tried for refractory patients with PRCA after undergoing allo-HSCT for ABO incompatibility.

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.

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.

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.

Impact of Graft-Recipient ABO Compatibility on Outcomes after Umbilical Cord Blood Transplant for Nonmalignant Disease

Existing literature shows mixed conclusions regarding the impact of ABO incompatibility on outcomes after hematopoietic stem cell transplantation. Because the future for umbilical cord blood (UCB) expansion technologies is bright, we assessed whether this typically overlooked graft characteristic impacted various outcomes after UCB transplantation (UCBT) for nonmalignant disorders (NMDs). A prospectively maintained institutional blood and marrow transplant program database was queried for all patients undergoing first UCBT for NMDs. UCB and recipient ABO compatibility was considered as matched, major mismatched, minor mismatched, or bidirectional mismatched. The impact of ABO incompatibility was assessed on overall survival, graft failure, acute and chronic graft-versus-host disease (GVHD), time to neutrophil and platelet recovery, day 0 to day 100 RBC transfusion burden, and donor hematopoietic chimerism. Through December 2014, 270 patients have undergone first UCBT for various NMDs. In both univariable and multivariable analyses, ABO compatibility status did not appear to impact any outcomes assessed, although a trend toward increased grades III to IV acute GVHD was seen in recipients of major mismatched units. When considering UCBT for treatment of NMDs, ABO compatibility between the donor unit and intended recipient does not appear to be an important consideration in the UCB unit choice.

Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning

Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34(+) selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as <5% cord blood chimerism at day 60 in the myeloid and CD3 compartments, irrespective of neutrophil and platelet counts. CGF occurred in 14 of 94 assessable patients (15%). Median survival after CGF was 12.7 months with haploidentical or mixed haploidentical-autologous hematopoiesis persisting in the 7 surviving. Median progression-free survival after CGF was 7.7 months and was not statistically different from those without CGF (10.47 months; P = .18). In univariate analyses, no UCB factors were associated with CGF, including cell dose, cell viability, recipient major ABO mismatch against the UCB unit, or degree of HLA match. We also found no association of CGF with recipient cytomegalovirus serostatus, haploidentical donor age, or day 30 haploidentical chimerism. However, higher haploidentical total nucleated and CD34(+) cell doses and day 30 UCB chimerism < 5% in either the myeloid or CD3 compartments were associated with greater risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

ABO blood group incompatibility as an adverse risk factor for outcomes in patients with myelodysplastic syndromes and acute myeloid leukemia undergoing HLA-matched peripheral blood hematopoietic cell transplantation after reduced-intensity conditioning

BACKGROUND

ABO incompatibility is not a contraindication to hematopoietic cell transplantation (HCT), but it has been associated with additional risks including delayed engraftment, pure red cell aplasia (PRCA), and higher transfusion needs. Data on these events and on patient survival after reduced-intensity conditioning (RIC) HCT are limited.

STUDY DESIGN AND METHODS

A total of 127 consecutive patients, 86 with acute myeloid leukemia and 41 with myelodysplastic syndromes, who underwent HLA-matched peripheral blood RIC allogenic HCT between 2005 and 2014 were retrospectively analyzed.

RESULTS

Eighty ABO-compatible, 26 major/bidirectional, and 21 minor-ABO-mismatch HCT were identified. Compared to the ABO-compatible group, major/bidirectional mismatches had increased red blood cell (RBC) transfusion requirement during the first 100 days (p = 0.009), delayed RBC and PLT engraftment (p = 0.0011 and p = 0.005, respectively), and higher incidence of grade II to IV acute graft-versus-host disease (aGVHD; p = 0.037). In multivariable analysis, major/bidirectional mismatches had significantly higher non-relapse mortality (NRM) and inferior disease-free survival (DFS) and overall survival (OS) compared with ABO-compatible patients (p = 0.01, p = 0.04, and p = 0.035, respectively). Minor ABO mismatch had no impact on survival (p = 0.99). Four (15%) of 26 major/bidirectional mismatches developed PRCA. There was a significant association between fludarabine plus busulfan conditioning and PRCA (p = 0.0046).

CONCLUSION

Major/bidirectional ABO mismatch is associated with higher NRM and shortened DFS and OS in the setting of RIC HCT. Increased transfusion need, delayed RBC and platelet engraftment, PRCA, and increased severity of aGVHD are additional complications contributing to the morbidity.

The role of rituximab in autologous and allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

The addition of rituximab to chemotherapy has substantially changed the treatment strategies for patients with B-cell lymphomas. Rituximab, combined with standard chemotherapy regimens, shows consistently improved results compared with chemotherapy alone and has been extensively employed in both newly diagnosed and relapsed patients with B-cell lymphoma. Because of its low toxicity profile and its potent antilymphoma activity mediated through direct apoptotic and indirect effector mechanisms, rituximab also has been actively incorporated into stem cell transplantation (SCT) protocols to attain a state of minimal disease, provide a safe and effective method for in vivo purging prior to autologous SCT, and promote graft-versus-lymphoma effects in allogeneic SCT. This review compiles the still immature but rapidly growing data on this combined modality.

The impact of donor type and ABO incompatibility on transfusion requirements after nonmyeloablative haematopoietic cell transplantation

We retrospectively analyzed transfusion requirements within the first 100 d among allogeneic haematopoietic cell transplantation (HCT) recipients with haematological malignancies given either myeloablative (n = 1353) or nonmyeloablative conditioning (n = 503). We confirmed that myeloablative recipients required more platelet and red blood cell (RBC) transfusions than nonmyeloablative recipients (P < 0.0001 for both). Myeloablative patients given peripheral blood stem cells required less platelet transfusions (P < 0.0001) than those given marrow while RBC transfusion requirements did not differ significantly. Subsequent analyses were restricted to nonmyeloablative recipients. Platelet and RBC transfusions were less frequent among related compared to unrelated recipients (P < 0.0001 for both), with comparable median numbers of transfused units. Major/bidirectionally ABO-mismatched recipients required more RBC transfusions than ABO-matched recipients (P = 0.006). Rates of graft rejection/failure, grades II-IV acute and chronic graft-versus-host-disease (GVHD), 2-year relapse, 3-year survivals and non-relapse mortality were comparable among ABO-matched, minor-mismatched, and major/bidirectionally mismatched recipients (P = 0.93, 0.72, 0.57, 0.36, 0.17 and 0.79, respectively). Times to disappearance of anti-donor IgG and IgM isohemagglutinins among major/bidirectionally ABO-mismatched recipients were affected by magnitude of pre-HCT titres (P < 0.001 for both) but not GVHD (P = 0.71 and 0.78, respectively). In conclusion, nonmyeloablative recipients required fewer platelet and RBC transfusions and among them, both unrelated and major/bidirectionally ABO-mismatched recipients required more RBC transfusions. ABO incompatibility did not affect nonmyeloablative HCT outcomes.

Prevention of pure red cell aplasia after major or bidirectional ABO blood group incompatible hematopoietic stem cell transplantation by pretransplant reduction of host anti-donor isoagglutinins

BACKGROUND

Persistent anti-donor isoagglutinins after major ABO blood group incompatible hematopoietic stem cell transplantation may cause delayed red blood cell engraftment and post-transplant pure red cell aplasia.

DESIGN AND METHODS

We investigated the effect of pretransplant anti-donor isoagglutinin reduction by in vivo absorption and/or plasmapheresis on the incidence of pure red cell aplasia and the time to red blood cell engraftment in 153 hematopoietic stem cell transplant recipients with major ABO incompatibility.

RESULTS

Twelve patients (8%) developed pure red cell aplasia, 3/98 (3%) with, and 9/55 (16%) without prior isoagglutinin reduction (p=0.009). Red blood cell engraftment was faster in patients with isoagglutinin reduction; in addition, peripheral blood hematopoietic stem cell transplantation, acute graft-versus-host disease, and younger age were associated with faster red blood cell engraftment in Cox regression analysis. In patients with pure red cell aplasia the mean red blood cell engraftment occurred after 225 days (p<0.001) and was associated with a simultaneous decrease of anti-donor isoagglutinins. Patients with pure red cell aplasia had higher pretransplant anti-donor isoagglutinin titers (p=0.001) and received more post-transplant red blood cell transfusions (p<0.001).

CONCLUSIONS

Following major ABO incompatible hematopoietic stem cell transplantation, pure red cell aplasia and delayed red blood cell engraftment depend on the levels of anti-donor isoagglutinins and are efficiently prevented by the pretransplant removal of these isoagglutinins. The benefits of reducing the time of transfusion-dependency and transfusion-associated risks must be carefully balanced against the potential side effects of isoagglutinin reduction.

Significance of donor-derived isoagglutinins in ABO-Incompatible hematopoietic stem cell transplantation

Changes in isoagglutinin titers may have implications in the occurrence of hematological complications such as pure red cell aplasia or immune-mediated hemolysis. Furthermore, isoagglutinin titers could reflect immunohematological reconstitution after transplantation. The objective of this study was to examine the relationship between donor-derived isoagglutinins (DDIs) and graft-versus-host disease (GVHD). In total, 114 patients who underwent ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT) were analyzed. Among these patients, 27.7% demonstrated increased donor-derived isoagglutinins (IDDIs) against red blood cells (RBCs) of the recipient, and 32.8% of the patients showed DDIs that were not against RBCs of the recipient. Patients with acute GVHD and DDIs against RBCs of the recipient tended to have higher incidences of IDDIs that occurred before posttransplant day 60 compared with patients without acute GVHD (17.3 vs. 3.9%, P=0.058). In patients with acute GVHD, IDDIs occurred significantly earlier (mean, day 32 vs. 181, P=0.046), the period of elevation was shorter (mean, day 36 vs. 134, P=0.033), and the donors were younger (mean, 28 vs. 36 years, P=0.01) than those without GVHD. Moreover, significant correlations were found between IDDIs and acute GVHD. Taken together, these data underscore a possible role for humoral immunity in GVHD after HSCT.

Post-hematopoietic stem cell transplantion immune-mediated cytopenias

Immune-mediated cytopenias after allogeneic stem cell transplantation can be categorized as either alloimmune when host or donor immunity reacts against donor or host elements, respectively, or autoimmune when donor immunity reacts against donor hematopoietic tissue, owing to poorly understood mechanisms that result in severe impairment of central and peripheral tolerance. Immune cytopenias are manifested as monolineage or more rarely as bilineage cytopenias, and are usually mediated through humoral immune mechanisms. On the contrary, immune-mediated pancytopenia is a rare event with only few cases reported in the literature. The exact pathogenesis of immune pancytopenia is not well known although it is possible that cellular immunity may play a significant role. The importance of these syndromes lies in the fact that they can cause severe morbidity and mortality. Differential diagnosis from other causes of post-transplant pancytopenia is of extreme value because these disorders can respond to various treatment modalities.

Mesenchymal stem cells for the treatment of refractory pure red cell aplasia after major ABO-incompatible hematopoietic stem cell transplantation

Pure red cell aplasia (PRCA) is a well-known, although infrequent, hematological complication after allogeneic hematopoietic stem cell transplantation (HSCT). PRCA occurs in cases of major ABO mismatch between donor and recipient and is believed to be due to inhibition of donor erythroid progenitors by residual host isohemagglutinins. The purpose of our study was to further evaluate the efficacy of human adipose tissue-derived mesenchymal stem cells (AMSC) as the salvage therapy for refractory PRCA after major ABO-incompatible HSCT. Two patients with refractory pure red cell aplasia received intravenous infusions of AMSC at a dose of 1.5 x 10(6)/kg of the patients' weight, and rapid recovery from PRCA without any side effects was observed. We conclude that AMSC seems to be a promising therapeutic option in patients with PRCA after ABO-mismatched HSCT, in whom conventional treatment fails.

ABO incompatibility is associated with increased non-relapse and GVHD related mortality in patients with malignancies treated with a reduced intensity regimen: a single center experience of 221 patients

The effect of ABO-incompatibility on transplantation outcome remains a controversial issue, with many of the reported studies showing conflicting results. In this study, we evaluate: the association between ABO-incompatibility and myeloid engraftment; the incidence and severity of acute and chronic graft-versus-host disease (GVHD); non-relapse mortality (NRM); GVHD-associated mortality, relapse and overall survival (OS). Our study includes 221 patients with malignant diseases treated in the same institution with the same reduced intensity regimen. Other variables known to affect the transplantation outcome such as age, disease, disease risk, and donor characteristics were well-balanced between ABO-matched and ABO-mismatched transplants. Analysis of our data shows increased incidence of NRM during the first months after transplantation in the groups of patients with major and minor ABO-incompatibility. Although neither incidence nor severity of GVHD differed significantly among the different groups, we found increased mortality associated with GVHD in the major ABO-incompatible groups. Long-term OS and relapse rate were not different, although we observed a trend for decreased OS during the first year post transplantation in the group of patients with major ABO-incompatibility. Our study showed that ABO-incompatibility has an adverse impact on the transplantation outcome.

ABO incompatible stem cell transplantation in children does not influence outcome

BACKGROUND

Although delayed red cell engraftment and/or hemolysis have been thoroughly documented in association with ABO incompatibility between donor and recipient in patients undergoing hematopoietic stem cell transplantation (HSCT), there are no studies defining the general, long term clinical outcome in a large group of pediatric patients.

METHODS

We undertook a retrospective single center analysis of children undergoing pediatric allogeneic stem cell transplantation to determine the influence of ABO donor/recipient incompatibility. Outcome was analyzed according to donor type and included survival, graft versus host disease (GvHD), relapse, days of infection, antibiotic use, transfusion requirement and duration of hospital stay.

RESULTS

Two hundred and sixteen children (136 males; 80 females, aged 0-19) transplanted between January 1992 and December 2003 were included in the study. Indications for transplantation were hematological malignancies (n=179) and aplastic conditions (n=37). ABO compatibility was documented in 121 donor/recipient pairs. ABO incompatibility was documented in 95 donor/recipient pairs with 40 major, 40 minor and 15 bi-directional incompatible pairs. ABO incompatibility did not influence survival rate (P=0.3762), the incidence of GvHD (P=0.253) or rate of relapse (P=0.930). Recovery of leucocytes was influenced by ABO incompatibility (P=0.0493), but the rate of infection, transfusion requirements and duration of hospital stay are not.

CONCLUSION

In the pediatric setting, ABO major and/or minor mismatch between donor and recipient did not significantly influence the outcome of HSCT. The choice of donor should be determined by the degree of HLA match and CMV status in preference to ABO blood group compatibility.

Impact of ABO incompatibility on engraftment and transfusion requirement after unrelated cord blood transplantation: a single institute experience in Japan

The impact of ABO incompatibility between donor and recipient on engraftment and transfusion requirement was studied in 95 adults who underwent unrelated cord blood transplantation (CBT). The patients included 27 ABO-identical, 29 minor, 21 major and 18 bidirectional ABO-incompatible recipients. Neutrophil engraftment did not differ between ABO-identical/minor ABO-incompatible and major/bidirectional ABO-incompatible recipients (hazard ratio (HR) 1.17, P=0.48). Cumulative incidence of platelet engraftment in ABO-identical/minor ABO-incompatible recipients was higher than in major/bidirectional ABO-incompatible recipients (HR 1.88, P=0.013). In addition, fewer platelet transfusions were required during the first 60 days after CBT in ABO-identical/minor ABO-incompatible recipients (HR 0.80, P=0.040). RBC engraftment did not differ between the two groups (HR 1.25, P=0.33). However, fewer RBC transfusions were required in ABO-identical/minor ABO-incompatible recipients than in major/bidirectional ABO-incompatible recipients (HR 0.74, P<0.005). No patients developed pure red-cell aplasia after CBT. These results indicate that ABO incompatibility affected platelet engraftment and transfusion requirement of RBC and platelet in CBT recipients. Further studies including larger patient numbers are required to elucidate the impact of ABO incompatibility on the clinical outcome of CBT.

[ABO incompatibility and non myeloablative allogeneic stem cell transplantation]

ABO incompatibility is not a barrier for allogeneic hematopoietic stem cell transplantation but is associated with specific complications. Major ABO incompatibility is associated with delayed erythroid engraftment, increased transfusion requirement and cases of pure red cell aplasia. Minor ABO incompatibility may be responsible for acute haemolytic reactions in the first months following transplantation. The widely used non myeloablative conditioning regimens might modify the management of ABO incompatibility. They could favour pure red cell aplasia development in the setting of major ABO mismatch since they are associated with a prolonged persistence of host anti-donor isohemagglutinins after allogeneic hematopoietic stem cell transplantation. In the setting of minor ABO incompatibility, the use of peripheral blood stem cells and the nature of graft-versus-host disease prophylaxis regimen may have an impact on the incidence of haemolytic reactions. In that review, the clinical and therapeutic aspects of ABO incompatibility are studied, especially regarding the impact of the conditioning regimen intensity.

Major ABO blood group mismatch increases the risk for graft failure after unrelated donor hematopoietic stem cell transplantation

Two hundred twenty-four patients with leukemia transplanted with an unrelated donor between 1991 and 2003 at the Karolinska University Hospital were analyzed according to association between graft failure and ABO, RhD, MNSs, and Kidd blood group antigen compatibility. Median age was 29 years (range: 0-55). Conditioning consisted of total-body irradiation or busulfan-based myeloablative conditioning. A bone marrow graft was given to 152 patients, and 72 patients received peripheral blood stem cells. Most patients received graft-versus-host disease prophylaxis with cyclosporine and MTX. Graft failure (GF) was seen in 6 (2.7%) patients. In the multivariate analysis major ABO mismatch (odds ratio [OR] 14.9, 95% confidence interval [CI] 2.01-110, P = .008) and HLA-allele mismatch (6.42, 1.19-34.8, P = .03) was significantly associated to GF. In patients with and without major ABO mismatch the incidence of GF was 7.5% and 0.6% (P = .02), respectively. Using an ABO major mismatched graft increases the risk for GF after unrelated donor hematopoietic stem cell transplantation.

Impact of nonmyeloablative conditioning regimens on the occurrence of pure red cell aplasia after ABO-incompatible allogeneic haematopoietic stem cell transplantation

BACKGROUND AND OBJECTIVES

In the setting of major ABO-incompatible allogeneic haematopoietic stem cell transplantation (HSCT), pure red cell aplasia (PRCA) is linked to the persistence of host residual plasma cells secreting antidonor isohaemagglutinins (HA) after transplantation. There are conflicting results regarding the impact of the intensity of conditioning regimen on the occurrence of PRCA after major ABO-mismatched HSCT.

MATERIAL AND METHODS

To address this question, we compared two cases occurring after nonmyeloablative (NMA) and myeloablative (MA) HSCT and reviewed previous cases reported in the NMA setting.

RESULTS AND CONCLUSIONS

We observed a delayed disappearance of antidonor HAs in the NMA setting, associated to a more prolonged period of red blood cells transfusion dependence than in the MA setting. In our case as in several others, the disappearance of antidonor HAs and resolution of PRCA were observed after reinforcement of the graft-versus-host effect (i.e. immunosuppression removal or donor leukocytes infusion).

Lack of effect of donor–recipient ABO mismatching on outcome following allogeneic hematopoietic stem cell transplantation

Several recently published studies have suggested that patients who undergo ABO mismatched hematopoietic stem cell transplantation may be at increased risk for relapse, graft-versus-host disease, transplant-related mortality, and/or all-cause mortality. To investigate this issue further, we analyzed potential associations between the donor-recipient ABO mismatch pattern and the above outcome measures among 240 consecutive patients who underwent allogeneic hematopoietic stem cell transplantation at our institution. Our analyses uncovered no significant associations between donor-recipient ABO mismatch pattern and overall survival, event-free survival, transplant-related mortality, incidence of acute graft-versus-host disease (GVHD), or incidence of chronic GVHD. Our data do not support recent assertions that donor-recipient ABO mismatching is a major risk factor for patients undergoing allogeneic transplant, nor do they support recent assertions that ABO matching should be an important consideration in selecting allogeneic hematopoietic stem cell donors.

Resistant pure red cell aplasia after allogeneic bone marrow transplantation with major ABO mismatch treated by purified CD34+ cell infusion

We report a case of pure red cell aplasia (PRCA) subsequent to an allogeneic bone marrow transplantation with a major ABO mismatch, which was resistant to the standard treatment options such as plasma exchange, erythropoietin and changes in the immunosuppressive treatment. Accordingly, two cycles of Rituximab therapy were administered without success. The patient had a chronic graft-vs.-host disease of the liver, which meant that an additional donor leukocyte infusion could not be introduced. Instead, purified CD34(+) cells were administered after fludarabine and antithymocyte globulin therapy. As a result, the PRCA was resolved and the antidonor isohemagglutinin titer became undetectable.

Determinants of ABH expression on human blood platelets

Platelets express ABH antigens, which can adversely effect platelet transfusion recovery and survival in ABH-incompatible recipients. To date, there has been no large, comprehensive study comparing specific donor factors with ABH expression on platelet membranes and glycoconjugates. We studied ABH expression in 166 group A apheresis platelet donors by flow cytometry, Western blotting, and thin layer chromatography relative to donor age, sex, A1/A2 subgroup, and Lewis phenotype. Overall, A antigen on platelet membranes, glycoproteins, and glycosphingolipids was linked to an A1 red blood cell (RBC) phenotype. Among A1 donors, platelet ABH varied significantly between donors (0%-87%). Intradonor variability, however, was minimal, suggesting that platelet ABH expression is a stable, donor-specific characteristic, with 5% of A1 donors typing as either ABH high- or low-expressers. Group A2 donors, in contrast, possessed a Bombay-like phenotype, lacking both A and H antigens. Unlike RBCs, ABH expression on platelets may be determined primarily by H-glycosyltransferase (FUT1) activity. Identification of A2 and A1 low expressers may increase the availability and selection of crossmatched and HLA-matched platelets. Platelets from group A2 may also be a superior product for patients undergoing A/O major mismatch allogeneic progenitor cell transplantation.

Recovery from and consequences of severe iatrogenic lymphopenia (induced to treat autoimmune diseases)

To ascertain the consequences of severe leukopenia and the tempo of recovery, we studied the immunity of 56 adult patients treated for multiple sclerosis or systemic sclerosis with autologous CD34 cell transplantation using extremely lymphoablative conditioning. NK cell, monocyte, and neutrophil counts recovered to normal by 1 month; dendritic cell and B cell counts by 6 months; and T cell counts by 2 years posttransplant, although CD4 T cell counts remained borderline low. Initial peripheral expansion was robust for CD8 T cells but only moderate for CD4 T cells. Subsequent thymopoiesis was slow, especially in older patients. Importantly, levels of antibodies, including autoantibodies, did not drop substantially. Infections were frequent during the first 6 months, when all immune cells were deficient, and surprisingly rare (0.21 per patient year) at 7-24 months posttransplant, when only T cells (particularly CD4 T cells) were deficient. In conclusion, peripheral expansion of CD8 but not CD4 T cells is highly efficient. Prolonged CD4 lymphopenia is associated with relatively few infections, possibly due to antibodies produced by persisting pretransplant plasma cells.

Resistant pure red cell aplasia after allogeneic stem cell transplantation with major ABO mismatch treated by escalating dose donor leukocyte infusion

We report a case of pure red cell aplasia (PRCA) following allogeneic stem cell transplantation (SCT) with major ABO mismatch which proved resistant to all standard treatment options such as change in immunosuppressive treatment, high-dose erythropoietin (EPO) or plasma exchange. We therefore proceeded to administer five cycles of Rituximab therapy, without success. Finally, escalating doses of donor-derived leukocyte infusion (DLI) resolved the PRCA of our patient 415 d after bone-marrow transplantation (BMT) and 140 d after the first infusion of donor leukocytes. A review of the literature shows the efficacy of various treatments; the role of DLI and other treatment options are discussed. Furthermore, the underlying pathophysiological mechanisms especially with regard to the role of NK cells in alloreactivity after allogeneic SCT are explained.

Impact of ABO incompatibility on allogeneic peripheral blood progenitor cell transplantation after reduced intensity conditioning

BACKGROUND

Most studies indicate that ABO incompatibility has no effect on the clinical outcome after allogeneic peripheral blood progenitor cell (PBPC) transplantation (allo-PBPCT). However, it carries additional risks of hemolytic reactions, delayed red blood cell (RBC) engraftment, and pure red cell aplasia (PRCA). Data on these events after reduced intensity conditioning (RIC) regimens are limited, but recent studies have suggested a higher transplant-related mortality (TRM) and morbidity in this setting.

STUDY DESIGN AND METHODS

We investigated the impact of ABO-matching on the outcome of 77 patients included in a prospective RIC allo-PBPCT protocol, focusing on engraftment, transfusion requirements, graft-versus-host disease, TRM, and survival.

RESULTS

There were 17 (22%) minor and 8 (10%) major ABO-incompatible transplants. No graft failures were observed. After major ABO-incompatible grafts, RBC engraftment was delayed, longer thrombocytopenia periods were documented, and transfusion requirements increased. A transient mild hemolysis occurred in 10 patients, 7 (41%) minor and 3 (37%) major ABO-mismatched. A PRCA was observed in a O+ patient with a pretransplant anti-Jka, grafted from an A + Jka+ donor. Graft-versus-host disease, disease progression, and TRM were not affected by ABO matching.

CONCLUSION

ABO incompatibility was not associated with clinically relevant hemolysis after the RIC protocol used and did not impair the clinical outcome. PRCA was only observed in one patient, with a non-ABO RBC allo-antibody.

Pure Red Cell Aplasia After ABO Major-Mismatched Allogeneic Peripheral Blood Stem Cell Transplantation Successfully Treated with Plasma Exchange and Low-Dose Steroid: Two Case Reports

Pure red cell aplasia (PRCA) is a complication of ABO-incompatible allogeneic stem cell transplantation. The mechanism is not well known, although the isoagglutinin titer before transplantation or cyclosporine use is considered to be the cause. Patients with this complication require more blood transfusions than those without it. There is no standard treatment. We report two cases of PRCA after allogeneic peripheral blood stem cell transplantation that were successfully treated with plasma exchange and low-dose steroid.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of multiple myeloma: an evidence-based review

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of multiple myeloma (MM) is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published medical literature and for grading the quality of the evidence, the strength of the evidence, and the strength of the treatment recommendations. Treatment recommendations based on the evidence presented in the review were made unanimously by a panel of MM experts. Recommendations for SCT as an effective therapy for MM include the following: SCT is preferred to standard chemotherapy as de novo therapy; SCT is preferred as de novo rather than salvage therapy; autologous peripheral blood stem cell transplantation (PBSCT) is preferred to bone marrow transplantation (BMT); and melphalan is preferred to melphalan plus total body irradiation as the conditioning regimen for autologous SCT. Recommendations that SCT is not effective include the following: current purging techniques of bone marrow. Recommendations of equivalence include the following: PBSCT using CD34+ selected or unselected stem cells. No recommendation is made for indications or transplantation techniques that have not been adequately studied, including the following: SCT versus standard chemotherapy as salvage therapy, tandem autologous SCT, autologous or allogeneic SCT as a high-dose sequential regimen, allogeneic BMT versus PBSCT, a preferred allogeneic myeloablative or non-myeloablative conditioning regimen, and maintenance therapy post-autologous SCT with interferon alpha post-SCT. The priority area of needed future research is maintenance therapy posttransplantation with nothing versus interferon alpha versus other agents such as corticosteroids or thalidomide or its derivatives.