Hematopoietic stem cell transplantation: contrasting the outcome of transplantations from HLA-identical siblings, partially HLA-mismatched related donors, and HLA-matched unrelated donors

Pharmacokinetics and Pharmacodynamics of Systemic Corticosteroids in Autoimmune and Inflammatory Diseases: A Review of Current Evidence

BACKGROUND AND OBJECTIVE

Systemic corticosteroids have a long history of use in the treatment of autoimmune and inflammatory diseases. Both efficacy and safety show large interindividual variability (IIV), suggesting that corticosteroids may have the potential for individualised dosing strategies to optimise therapy. This systematic review aims to provide an overview of current evidence on the pharmacokinetic (PK) and pharmacodynamic (PD) relationships of systemic corticosteroids in patients with autoimmune and inflammatory diseases.

METHODS

A systematic literature search was conducted in PubMed and Embase for PK/PD studies of systemic corticosteroids in autoimmune and inflammatory diseases in humans published until December 2023. Studies were scored from 1 to 5 according to criteria for the levels of evidence, as inspired by the Oxford Centre for Evidence-Based Medicine.

RESULTS

Twelve studies (1981-2016) were included. The majority of these studies had a small sample size. The corticosteroids involved were prednisone, prednisolone, methylprednisolone and budesonide. Substantial IIV of corticosteroid PK was described in all studies. Evidence for a relationship between the PK of corticosteroids and efficacy was inconclusive and limited. However, there was some evidence for a relationship between the PK of prednisolone and the severity of Cushingoid features.

CONCLUSION

There is insufficient evidence to draw firm conclusions on the potential associations between PK and clinical outcome of systemic corticosteroid treatment in autoimmune and inflammatory diseases. This is remarkable given the many decades that steroid drugs have been used in clinical care. Prospective research is recommended with robust and well-defined cohorts to fully quantify the PK/PD associations of corticosteroids.

Lower overall survival in male patients with advanced disease undergoing allogeneic hematopoietic stem cell transplantation is associated with CYP1B1 Leu432Val polymorphism

Human cytochrome P450 1B1 (CYP1B1) is an extrahepatic key enzyme involved in estrogen metabolism, steroid synthesis, and pro-carcinogen activation. In a single-center retrospective study, 382 patients who underwent allogeneic hematopoetic stem cell transplantation and their donors were genotyped for CYP1B1 C432G polymorphism by reverse transcription polymerase chain reaction. One hundred and sixty-nine patients (44%) were homozygous wild-type (wt) gene CC, 157 (41%) heterozygous CG and 56 (15%) homozygous gene mutated GG. Of interest, mutated CYP1B1 was more common in male (62%) than in female patients (48%) P=0.006, unlike in donors. Five-year estimate for overall survival (OS) was 58±4% (CC) versus 48±3% (CG and GG), P=0.048. Surprisingly, this difference was only evident in males (P=0.024): OS 58±6% versus 42±4%, whereas it was virtually absent in females. Importantly, this difference was only evident in male patients with advanced disease (AD) (n=118, P=0.002): OS 44±8% (CC) versus 32±6% (CG) versus 6±6% (GG), whereas it was virtually absent in male patients with early disease. One-year non-relapse mortality in male patients with AD was 8±4% (CC) versus 21±5% (CG) versus 50±12% (GG), P=0.002. Three-year relapse rate in male patients with AD was 31±7% (wt) versus 42±6% (mut), P=0.04. Multivariate analysis for OS in male patients with AD revealed CYP1B1 polymorphism as the only prognostic factor: RR 1.78, P=0.001. In conclusion, these results suggest that male patients with AD and mutant CYP1B1 polymorphism have lower OS after allogeneic hematopoetic stem cell transplantation due to a higher non-relapse mortality and a higher relapse rate.

PET assessment of acute gastrointestinal graft versus host disease

Acute gastrointestinal graft versus host disease (GI-GVHD) is a common complication following allogeneic haematopoietic cell transplantation (HCT), and is characterised by severe morbidity, frequent treatment-refractoriness, and high mortality. Early, accurate identification of GI-GVHD could allow for therapeutic interventions to ameliorate its severity, improve response rates and survival; however, standard endoscopic biopsy is inadequately informative in terms of diagnostic sensitivity or outcome prediction. In an era where rapid technological and laboratory advances have dramatically expanded our understanding of GI-GVHD biology and potential therapeutic targets, there is substantial scope for novel investigations that can precisely guide GI-GVHD management. In particular, the combination of tissue-based biomarker assessment (plasma cytokines, faecal microbiome) and molecular imaging by positron emission tomography (PET) offers the potential for non-invasive, real-time in vivo assessment of donor:recipient immune activity within the GI tract for GI-GVHD prediction or diagnosis. In this article, we review the evidence regarding GI-GVHD diagnosis, and examine the potential roles and translational opportunities posed by these novel diagnostic tools, with a focus on the evolving role of PET.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Total body irradiation-free haploidentical peripheral blood stem cell transplantation compared to related and unrelated donor transplantation in pediatrics with acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most prevalent childhood cancer under the age of 15 years. Despite the recent advances in therapeutic regimens, relapse occurs in 15%-20% of pediatric patients after chemotherapy, and hematopoietic stem cell transplantation (HSCT) is the best treatment option. However, donor availability is one of the major challenges. Over the last decade, haploidentical donor (HID) transplantation has evolved as an alternative option. Herein, we aimed to compare the transplant outcomes in pediatric patients receiving total body irradiation (TBI)-free myeloablative regimens, between non-HID and HID transplant.

PATIENTS AND METHODS

The study included 60 pediatric ALL patients who had undergone HSCT from October 2016 until September 2020. Forty-three patients received non-HID HSCT, while 17 patients received HID. The sources of stem cells (SC) were peripheral blood stem cells (PBSC) for all the patients. The conditioning regimen was based on busulfan and cyclophosphamide. For graft-versus-host disease (GvHD) prophylaxis, patients received cyclosporine and methotrexate in the setting of non-HID transplantation, where HIDs received post-transplant cyclosporine and cyclophosphamide.

RESULTS

The cumulative incidences of 3-year overall survival (OS) were 73.1%, 66.6%, and 69.5%, for matched sibling donor-matched related donor (MSD-MRD), matched unrelated donor-mismatched unrelated donor (MUD-MMUD), and HID groups, respectively (p = .85). The cumulative incidences of grade II-IV acute GvHD for the MRD, MUD-MMUD, and HID groups were 29%, 41%, and 49%, respectively (p = .47). Furthermore, the 3-year cumulative incidence of chronic GvHD was MSD-MRD: 70% versus MUD-MMUD: 42% versus HID: 45% (p = .64). The 3-year cumulative incidence of relapse post transplantation was 45%, 18%, and 45%, respectively, for the MSD-MRD, MUD-MMUD, and HID groups, and the differences were not statistically significant (p = .55). There was a higher risk for cytomegalovirus (CMV) infection in patients receiving HID transplants compared to those of non-HIDs (p < .01).

CONCLUSION

Our results indicate that PBSC-HID transplant outcomes in the setting of non-TBI conditioning are comparable to those of non-HIDs in pediatric ALL patients.

Long-Term Results of Allogeneic Stem Cell Transplantation in Adult Ph- Negative High-Risk Acute Lymphoblastic Leukemia

Allogeneic hematopoietic stem cell transplantation (HCT) is standard treatment for adult high-risk (HR) acute lymphoblastic leukemia (ALL) and contributed to the overall improved outcome. We report a consecutive cohort of prospectively defined HR patients treated on German Multicenter Acute Lymphoblastic Leukemia trials 06/99-07/03 with similar induction/consolidation therapy and HCT in first remission. A total of 542 patients (15-55 years) with BCR-ABL-negative ALL were analyzed. Sixty-seven percent received HCT from matched unrelated donors (MUD) and 32% from matched sibling donors (MSD). The incidence of non-relapse mortality (NRM) was 20% at 5 years. NRM occurred after median 6.6 months; the leading cause (46%) was infection. NRM after MUD decreased from 39% in trial 06/99 to 16% in trial 07/03 (P < .00001). Patient age was the strongest predictor of NRM. The 5-year relapse incidence was 23% using MSD and 25% using MUD. Minimal residual disease (MRD) was the strongest predictor of relapse (45% for molecular failure versus 6% for molecular CR; P < .0001). The median follow-up was 67 months, and the 5-year survival rate was 58%. Age, subtype/high risk feature, MRD status, trial and acute GvHD were significant prognostic factors. We provide a large reference analysis with long follow-up confirming a similar outcome of MSD and MUD HCT and improved NRM for MUD HCT over years. MRD has a strong impact on relapse risk, whereas age was the strongest predictor of NRM. New adapted conditioning strategies should be considered for older patients combined with the goal to reduce the MRD level before stem cell transplantation.

A Prospective Trial Comparing Haploidentical Donor Transplantation With Cord Blood Versus HLA-Matched Sibling Donor Transplantation for Hematologic Malignancy Patients

Although haploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) has achieved similar survival to HLA-identical sibling donor (ISD) transplantation, the delayed hematopoietic engraftment as well as higher incidence of graft-versus-host-disease (GVHD), results in prolonged hospitalization, higher costs, and increased morbidity. In this study, a prospective, non-randomized clinical study was designed to evaluate the outcomes of patients who underwent HID HSCT supported by cord blood or ISD HSCT. Between May 2017 and November 2020, 113 patients were enrolled to undergo HID HSCT supported by cord blood (n=88) or ISD HSCT (n=25). The cumulative incidence of neutrophil and platelet engraftment at 30days was comparable in these two groups. Importantly, there was no significant difference in the cumulative incidence of grade II-IV aGVHD at 100days (20.5% [95% confidence interval [CI]: 12.2%–28.8%] versus 12.0% [95% CI: 0.2%–23.8%], P = 0.32) and cGVHD at 1 year (19.5% [95% CI: 11.2%–27.8%] versus 16.6% [[95% CI: 1.3%–31.9%] P = 0.70) between the two groups. Among the HID and ISD groups, the 2-year disease free survival was 76.8 and 80.0% (P = 0.83), the 2-year overall survival was 82.4 and 88.0% (P = 0.66), the 2-year GVHD-free, relapse-free survival was 68.9 and 75.3% (P = 0.62), respectively. Our results indicate that HID transplantation supported by cord blood may offer a good alternative to ISD HSCT for patients with hematopoietic malignancies.

Comparing transplant outcomes in ALL patients after haploidentical with PTCy or matched unrelated donor transplantation

We compared outcomes of 1461 adult patients with acute lymphoblastic leukemia (ALL) receiving hematopoietic cell transplantation (HCT) from a haploidentical (n = 487) or matched unrelated donor (MUD; n = 974) between January 2005 and June 2018. Graft-versus-host disease (GVHD) prophylaxis was posttransplant cyclophosphamide (PTCy), calcineurin inhibitor (CNI), and mycophenolate mofetil (MMF) for haploidentical, and CNI with MMF or methotrexate with/without antithymoglobulin for MUDs. Haploidentical recipients were matched (1:2 ratio) with MUD controls for sex, conditioning intensity, disease stage, Philadelphia-chromosome status, and cytogenetic risk. In the myeloablative setting, day +28 neutrophil recovery was similar between haploidentical (87%) and MUD (88%) (P = .11). Corresponding rates after reduced-intensity conditioning (RIC) were 84% and 88% (P = .47). The 3-month incidence of grade II-IV acute GVHD (aGVHD) and 3-year chronic GVHD (cGVHD) was similar after haploidentical compared with MUD: myeloablative conditioning, 33% vs 34% (P = .46) for aGVHD and 29% vs 31% for cGVHD (P = .58); RIC, 31% vs 30% (P = .06) for aGVHD and 24% vs 29% for cGVHD (P = .86). Among patients receiving myeloablative regimens, 3-year probabilities of overall survival were 44% and 51% with haploidentical and MUD (P = .56). Corresponding rates after RIC were 43% and 42% (P = .6). In this large multicenter case-matched retrospective analysis, despite the limitations of a registry-based study (ie, unavailability of key elements such as minimal residual disease testing), our analysis indicated that outcomes of patients with ALL undergoing HCT from a haploidentical donor were comparable with 8 of 8 MUD transplantations.

Haploidentical versus HLA-matched sibling transplantation for refractory acute leukemia undergoing sequential intensified conditioning followed by DLI: an analysis from two prospective data

BACKGROUND

Compared with HLA-matched sibling donor (MSD) transplant, the outcomes of haploidentical donor (HID) transplant for refractory acute leukemia need to be further explored. In this study, we compared the outcomes of HID with MSD for refractory acute leukemia.

PATIENTS AND METHODS

This study population came from two prospective multicenter trials (NCT01883180, NCT02673008). Two hundred and seventy-eight patients with refractory acute leukemia were enrolled in this study, including 119 in HID group and 132 in MSD group. Sequential intensified conditioning was employed in all patients, and donor lymphocyte infusion (DLI) was administered in patients in the absence of active GVHD and according to minimal residual disease (MRD) from day + 60 post-transplantation for preventing relapse.

RESULTS

The complete remission of leukemia by day + 30 post-transplant were 94% and 93%, respectively, in HID and MSD groups (p = .802). The 1-year incidence of grades II-IV acute GVHD was 62% and 54% (p = .025), and 3-year incidence of chronic GVHD was 55% and 55% (p = .789), respectively, in two groups. HID transplant had lower incidence of first episode of MRD positivity and relapse than MSD transplant (28% vs 45%, p = .006; 26% vs 38%, p = .034). There was higher infection-related mortality in HID than MSD (8% vs 2%, p = .049) within the first 100 days' post-transplant. The 5-year overall survival was 46% and 42% (p = .832), respectively; the 5-year disease-free survival was 43% and 39% (p = .665), in HID and MSD groups, respectively.

CONCLUSIONS

HID transplant has lower relapse, but higher infection-related mortality and similar survival rates in refractory acute leukemia by the strategy of sequential intensified conditioning followed by DLI compared with MSD transplant.

Haploidentical transplantation might have superior graft-versus-leukemia effect than HLA-matched sibling transplantation for high-risk acute myeloid leukemia in first complete remission: a prospective multicentre cohort study

This study aimed to investigate graft-versus-leukemia (GVL) of haploidentical donor (HID) compared with HLA-matched sibling donor (MSD) for high-risk acute myeloid leukemia (H-AML) in first complete remission (CR1). One hundred and eighty-nine patients with H-AML in CR1 were enrolled in this multicentre prospective cohort study. Patients were assigned to groups transplanted with HID (n = 83) or MSD (n = 106) based on donor availability (biological randomization). The primary endpoint was the incidence of MRD positivity posttransplantation (post-MRD+). All post-MRD+ patients received preemptive interventions. The cumulative incidences of post-MRD+ were 18 and 42% in HID and MSD groups, respectively, (p < 0.001). Fifty-two patients received preemptive DLI, including 13 (16%) in HID and 39 cases (37%) in MSD groups (p = 0.001). Among HID and MSD groups, the 3-year cumulative incidence of relapse were 14 and 24% (p = 0.101); the 3-year cumulative incidence of treatment-related mortality were 15 and 10% (p = 0.368); the 3-year overall survival rates were 72 and 68% (p = 0.687); the 3-year disease-free-survival were 71 and 66% (p = 0.579); the 3-year graft-versus-host disease and relapse free survival were 63 and 43% (p = 0.035), respectively. HID might have a stronger GVL than MSD in H-AML patients. HID transplantation as postremission therapy should be recommended as one of the optimal choices for H-AML patients in CR1.

Heterogeneity of antigen specificity between HLA-A*02:01 and other frequent Chinese HLA-A2 subtypes detected by a modified autologous lymphocyte-monocyte coculture

HLA-A2 is the most common serological HLA type among all ethnic groups. Through advances in DNA typing, more than 800 subtypes of HLA-A2 have been identified, and the existence of heterogeneity of antigen specificity among the HLA-A2 subtypes has been suggested by retrospective analyses of allogeneic transplantation patients and by studies of antigen amino acid structure. However, prior to this study, the antigenicity of a given subtype or the mismatch extent between two given subtypes could not be studied in vitro. Here, we used a modified autologous lymphocyte-monocyte coculture method to reveal heterogeneity of antigen specificity among HLA-A2 subtypes. The coculture was set up with HLA-A2 (non-A*02:01) lymphocytes and monocytes, and the monocytes were coated with an HLA-A*02:01/IgG1-Fc fusion protein (dimer) by high-affinity binding of the IgG1-Fc to FcgRI. Lymphocyte proliferation following coculture indicated that HLA-A*02:01 showed antigenicity against the HLA-A2 (non-A*02:01) subtype. Among the most frequent HLA-A2 subtypes in the Chinese population (HLA-A*02:01, -A*02:03, -A*02:06 and -A*02:07), we identified significant -A*02:01 antigenicity for T cells from -A*02:03 or -A*02:06 but not -A*02:07 individuals. Our findings were consistent with retrospective studies of allograft patients with a limited number of involved subtypes, indicating that this modified coculture method provides a practical and reliable means to study the antigenicity of HLA allele subtypes in vitro.

Incubation of Immune Cell Grafts With MAX.16H5 IgG1 Anti-Human CD4 Antibody Prolonged Survival After Hematopoietic Stem Cell Transplantation in a Mouse Model for Fms Like Tyrosine Kinase 3 Positive Acute Myeloid Leukemia

Despite the constant development of innovative therapeutic options for hematological malignancies, the gold-standard therapy regimen for curative treatment often includes allogeneic hematopoietic stem cell transplantation (HSCT). The graft-vs.-leukemia effect (GVL) is one of the main therapeutic goals that arises from HSCT. On the other hand, graft-vs.-host disease (GVHD) is still one of the main and most serious complications following allogeneic HSCT. In acute myeloid leukemia (AML), HSCT together with high-dose chemotherapy is used as a treatment option. An aggressive progression of the disease, a decreased response to treatment, and a poor prognosis are connected to internal tandem duplication (ITD) mutations in the Fms like tyrosine kinase 3 (FLT3) gene, which affects around 30% of AML patients. In this study, C3H/HeN mice received an allogeneic graft together with 32D-FLT3^ITD AML cells to induce acute GVHD and GVL. It was examined if pre-incubation of the graft with the anti-human cluster of differentiation (CD) 4 antibody MAX.16H5 IgG₁ prevented the development of GVHD and whether the graft function was impaired. Animals receiving grafts pre-incubated with the antibody together with FLT3^ITD AML cells survived significantly longer than mice receiving untreated grafts. The observed prolonged survival due to MAX.16H5 incubation of immune cell grafts prior to transplantation may allow an extended application of additional targeted strategies in the treatment of AML.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

Background

Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome.

Objective

To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center.

Results

Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality.

Conclusions

In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

HLA genotyping by next-generation sequencing of complementary DNA

Background

Genotyping of the human leucocyte antigen (HLA) is indispensable for various medical treatments. However, unambiguous genotyping is technically challenging due to high polymorphism of the corresponding genomic region. Next-generation sequencing is changing the landscape of genotyping. In addition to high throughput of data, its additional advantage is that DNA templates are derived from single molecules, which is a strong merit for the phasing problem. Although most currently developed technologies use genomic DNA, use of cDNA could enable genotyping with reduced costs in data production and analysis. We thus developed an HLA genotyping system based on next-generation sequencing of cDNA.

Methods

Each HLA gene was divided into 3 or 4 target regions subjected to PCR amplification and subsequent sequencing with Ion Torrent PGM. The sequence data were then subjected to an automated analysis. The principle of the analysis was to construct candidate sequences generated from all possible combinations of variable bases and arrange them in decreasing order of the number of reads. Upon collecting candidate sequences from all target regions, 2 haplotypes were usually assigned. Cases not assigned 2 haplotypes were forwarded to 4 additional processes: selection of candidate sequences applying more stringent criteria, removal of artificial haplotypes, selection of candidate sequences with a relaxed threshold for sequence matching, and countermeasure for incomplete sequences in the HLA database.

Results

The genotyping system was evaluated using 30 samples; the overall accuracy was 97.0% at the field 3 level and 98.3% at the G group level. With one sample, genotyping of DPB1 was not completed due to short read size. We then developed a method for complete sequencing of individual molecules of the DPB1 gene, using the molecular barcode technology.

Conclusion

The performance of the automatic genotyping system was comparable to that of systems developed in previous studies. Thus, next-generation sequencing of cDNA is a viable option for HLA genotyping.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4300-7) contains supplementary material, which is available to authorized users.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

Early CMV-replication after allogeneic stem cell transplantation is associated with a reduced relapse risk in lymphoma

A preventive effect of early human cytomegalovirus (HCMV) replication was evaluated in 136 non-Hodgkin lymphoma (NHL) patients with mature B-cell NHLs (n = 94), and mature T- and NK-cell NHLs (n = 42) after allogeneic stem cell transplantation (alloSCT). Most study-patients (85%) had received at least 2 cycles of chemotherapy and 60% had also received an autograft prior to alloSCT. First detection of CMV-replication by HCMV antigenemia/viremia was found at a median of day +33 after alloSCT. The cumulative incidence of relapse at 5 years after alloSCT was 38% (95% confidence interval [95%CI]: 26-49) in 82 patients without compared to 22% (95%CI: 8-37) in 54 patients with HCMV antigenemia/viremia (p = .013). A decreased relapse risk of HCMV replication was confirmed by multivariate analysis for HCMV antigenemia/viremia (Hazard ratio [HR]: 0.29, 95%CI: 0.11-0.76, p < .014). This report demonstrated a possible improvement of relapse incidence after replicative HCMV infection in patients with NHL after alloSCT.

Haploidentical Transplantation Without In Vitro T-Cell Depletion Results in Outcomes Equivalent to Those of Contemporaneous Matched Sibling and Unrelated Donor Transplantation for Acute Leukemia

The aim of the study is to determine whether HLA-haploidentical-related donor (HRD) transplant can achieve equivalent outcomes and have stronger GVL compared to HLA-matched sibling donor (MSD) and HLA-matched unrelated donor (MUD) transplants. A total of 355 consecutive patients with acute leukemia undergoing allogeneic transplant at our single institute between March 2008 and March 2014 were enrolled in this retrospective investigation. Of the 355 patients, 96 cases received HRD, 153 MSD, and 106 MUD transplants. HRD transplant was associated with higher incidences of grade II to IV aGVHD (40.6%) compared with MSD (23.5%, P = 0.002) and MUD transplants (34.0%, P = 0.049), whereas incidences of grade III to IV aGVHD (11.4%, 7.8%, 10.5%, respectively; P = 0.590) and cGVHD (29.5%, 24.0%, 29.5%, respectively; P = 0.538) did not differ among 3 groups. Five-year relapse rates were 19.2%, 26.8%, and 23.0% in 3 groups, respectively (P = 0.419). However, of 206 high-risk patients, the relapse rate in HRD transplant was lower than in MSD transplant (23.8% vs 41.9%, P = 0.026). Multivariate analysis showed that HRD had beneficial impact on relapse (for MSD: P = 0.006). Five-year transplant-related mortality was lower in MSD transplant compared with those in HRD (17.3% vs 26.4%, P = 0.041) and MUD transplants (17.3% vs 24.1%, P = 0.037). Five-year overall survival were 60.4%, 64.6%, and 61.0%, respectively, in HRD, MSD, and MUD groups (P = 0.371); 5-year disease-free survival were 59.6%, 58.8%, and 54.9%, respectively (P = 0.423). Our results suggest that HRD transplant results in outcomes equivalent to MSD and MUD transplants. HRD might carry a superior GVL effect compared to MSD for high-risk patients.

Transplantations from HLA-identical siblings versus 10/10 HLA-matched unrelated donors

The clinical outcome after allogeneic stem cell transplantation from a human leukocyte antigen (HLA)-matched sibling donor as well as an HLA-matched unrelated donor has clearly improved due in part to the progress made in the domains of HLA-typing techniques. Although HLA-matched sibling transplantation is still held as the "gold standard," transplantation from HLA-A, -B, -C, -DRB1, and -DQB1-matched unrelated donors (so called 10/10) represent the first choice for patients without a suitable related donor. Several studies have shown that unmanipulated marrow transplantation from an HLA allele-matched unrelated donor resulted in similar outcomes to those observed following sibling transplantation. However, incorporating anti-thymocyte globulin (ATG) within graft-versus-host disease (GVHD) prophylaxis should be considered for peripheral blood stem cell grafts in order to decrease the risk of developing chronic GVHD.

Hematologic Recovery after Pretransplant Chemotherapy Does Not Influence Survival after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Patients

Pretransplant remission status in patients with acute myeloid leukemia (AML) is 1 of the most important factors determining their outcomes after allogeneic hematopoietic cell transplantation (allo-HCT). Most patients are in complete remission with full hematologic recovery (CR) before undergoing allo-HCT. However, some patients achieve CR without recovery of platelet count (CRp) or a morphologic leukemia-free state (MLFS), defined as meeting all CR criteria without recovery of both neutrophil and platelet counts. Currently, there is a paucity of data regarding transplant outcomes in AML patients achieving MLFS after chemotherapy. To address this question, we evaluated transplant outcomes in 270 AML patients who received 6/6 HLA-matched sibling or 10/10 HLA-matched unrelated donor transplantation at a single institution between 2006 and 2013. Of our 270 patients, 206 were in CR, 45 were in CRp, and 19 were in MLFS before allo-HCT. Patients in CR, CRp, or MLFS had similar 3-year overall survival rates (49%, 46%, and 47%, respectively; P = .88) and 3-year event-free survival rates (45%, 36%, and 40%, respectively; P = .53). However, the cumulative incidence of nonrelapse mortality was significantly higher in patients in MLFS compared with those in CR (58% versus 22%, P = .0004), whereas the cumulative incidence of relapse in patients in MLFS was significantly lower compared with those in CR (11% versus 36%, P = .03). Our results suggest that survival outcomes in AML patients are not influenced by degree of hematologic recovery before allo-HCT.

Haploidentical hematopoietic SCT may be superior to conventional consolidation/maintenance chemotherapy as post-remission therapy for high-risk adult ALL

Only 30% of high-risk adult ALL patients in their first complete remission (CR1) are able to receive an HLA-matched sibling stem cell transplant. The role of haploidentical hematopoietic SCT (haplo-HSCT) in post-remission therapy is not well established. Recently, we developed a novel protocol for unmanipulated haploidentical transplantation. In this study, we compared haplo-HSCT with conventional consolidation and maintenance chemotherapy in adult high-risk ALL patients. Between January 2000 and December 2012, 104 patients received conventional chemotherapy and 79 patients received haplo-HSCT. Patients who underwent haplo-HSCT had significantly improved 3-year OS (72.5% vs 26.6%; P<0.001), 3-year disease-free survival (DFS) (63.9% vs 21.1%; P<0.001) and 3-year relapse (18.7% vs 60.5%; P<0.001) rates. The non-relapse mortality (NRM) rate was not different between patients treated with haplo-HSCT vs chemotherapy (19.2% vs 14.4%; P=0.80). In multivariate analysis, the only factor associated with improved OS, better DFS and low risk of relapse was haplo-HSCT. The only factor associated with high NRM was enrollment before 2006. In conclusion, haplo-HSCT may be an option for adults with high-risk ALL in CR1 who do not have an HLA-matched donor.

Protective effect of cytomegalovirus reactivation on relapse after allogeneic hematopoietic cell transplantation in acute myeloid leukemia patients is influenced by conditioning regimen

Cytomegalovirus (CMV) reactivation after allogeneic hematopoietic cell transplant (allo-HCT) has been associated with a reduced risk of relapse in patients with acute myeloid leukemia (AML). However, the influence of the conditioning regimen on this protective effect of CMV reactivation after allo-HCT is relatively unexplored. To address this, we evaluated the risk of relapse in 264 AML patients who received T cell-replete, 6/6 HLA matched sibling or 10/10 HLA matched unrelated donor transplantation at a single institution between 2006 and 2011. Of these 264 patients, 206 received myeloablative (MA) and 58 received reduced-intensity conditioning (RIC) regimens. CMV reactivation was observed in 88 patients with MA conditioning and 37 patients with RIC. At a median follow-up of 299 days, CMV reactivation was associated with significantly lower risk of relapse in patients who received MA conditioning both in univariate (P = .01) and multivariate analyses (hazard ratio, .5246; P = .006); however, CMV reactivation did not significantly affect the risk of relapse in our RIC cohort. These results confirm the protective effect of CMV reactivation on relapse in AML patients after allo-HCT reported by previous studies but suggest this protective effect of CMV reactivation on relapse is influenced by the conditioning regimen used with the transplant.

Bone marrow transplantation for thalassemia from alternative related donors: improved outcomes with a new approach

Bone marrow transplantation (BMT) performance can be limited by a lack of ideal donors, and the role of alternative donor hematopoietic cell transplantation in thalassemia is not well established. Here we used a new treatment protocol (Pc 26.1) in 16 thalassemia patients to perform BMT using phenotypically HLA-identical or 1-antigen-mismatched relatives (related donors [RDs]). We compared these results with HLA-matched sibling (matched sibling donors [MSDs]) BMT in 66 patients. The entire RD group and 88% of MSD group had sustained engraftment. Rejection incidence was 0% in the RD and 12% (95% confidence interval [95% CI], 6%-21%) in MSD groups (P = .15), with respective thalassemia-free survival probabilities of 94% (95% CI, 63%-99%) and 82% (95% CI, 70%-89%) (P = .24). Transplant-related mortality was 6% (95% CI, 1%-26%) in the RD group and 8% (95% CI, 3%-16%) in the MSD group (P = .83). The intensified new protocol was not associated with increased nonhematologic toxicity. The present data show that the Pc 26.1 preparative regimen allows thalassemia patients to safely undergo BMT from RDs who are not HLA-matched siblings, with transplant outcomes similar to patients with MSD grafts.

16(th) IHIW : review of HLA typing by NGS

Human leucocyte antigen (HLA) genes play an important role in the success of organ transplantation and are associated with autoimmune and infectious diseases. Current DNA-based genotyping methods, including Sanger sequence-based typing (SSBT), have identified a high degree of polymorphism. This level of polymorphism makes high-resolution HLA genotyping challenging, resulting in ambiguous typing results due to an inability to resolve phase and/or defining polymorphisms lying outside the region amplified. Next-generation sequencing (NGS) may resolve the issue through the combination of clonal amplification, which provides phase information, and the ability to sequence larger regions of genes, including introns, without the additional effort or cost associated with current methods. The NGS HLA sequencing project of the 16IHIW aimed to discuss the different approaches to (i) template preparation including short- and long-range PCR amplicons, exome capture and whole genome; (ii) sequencing platforms, including GS 454 FLX, Ion Torrent PGM, Illumina MiSeq/HiSeq and Pacific Biosciences SMRT; (iii) data analysis, specifically allele-calling software. The pilot studies presented at the workshop demonstrated that although individual sequencers have very different performance characteristics, all produced sequence data suitable for the resolution of HLA genotyping ambiguities. The developments presented at this workshop clearly highlight the potential benefits of NGS in the HLA laboratory.

NOD2 Polymorphisms and Their Impact on Haematopoietic Stem Cell Transplant Outcome

Haematopoietic stem cell transplantation (HSCT) is a valuable tool in the treatment of many haematological disorders. Advances in understanding HLA matching have improved prognoses. However, many recipients of well-matched HSCT develop posttransplant complications, and survival is far from absolute. The pursuit of novel genetic factors that may impact on HSCT outcome has resulted in the publication of many articles on a multitude of genes. Three NOD2 polymorphisms, identified as disease-associated variants in Crohn's disease, have recently been suggested as important candidate gene markers in the outcome of HSCT. It was originally postulated that as the clinical manifestation of inflammatory responses characteristic of several post-transplant complications was of notable similarity to those seen in Crohn's disease, it was possible that they shared a common cause. Since the publication of this first paper, numerous studies have attempted to replicate the results in different transplant settings. The data has varied considerably between studies, and as yet no consensus on the impact of NOD2 SNPs on HSCT outcome has been achieved. Here, we will review the existing literature, summarise current theories as to why the data differs, and suggest possible mechanisms by which the SNPs affect HSCT outcome.

Outcomes after matched unrelated donor versus identical sibling hematopoietic cell transplantation in adults with acute myelogenous leukemia

Approximately one-third of patients with an indication for hematopoietic cell transplantation (HCT) have an HLA-matched related donor (MRD) available to them. For the remaining patients, a matched unrelated donor (MUD) is an alternative. Prior studies comparing MRD and MUD HCT provide conflicting results, and the relative efficacy of MRD and MUD transplantation is an area of active investigation. To address this issue, we analyzed outcomes of 2223 adult acute myelogenous leukemia patients who underwent allogeneic HCT between 2002 and 2006 (MRD, n = 624; 8/8 HLA locus matched MUD, n = 1193; 7/8 MUD, n = 406). The 100-day cumulative incidence of grades B-D acute GVHD was significantly lower in MRD HCT recipients than in 8/8 MUD and 7/8 MUD HCT recipients (33%, 51%, and 53%, respectively; P < .001). In multivariate analysis, 8/8 MUD HCT recipients had a similar survival rate compared with MRD HCT recipients (relative risk [RR], 1.03; P = .62). 7/8 MUD HCT recipients had higher early mortality than MRD HCT recipients (RR, 1.40; P < .001), but beyond 6 months after HCT, their survival rates were similar (RR, 0.88; P = .30). These results suggest that transplantation from MUD and MRD donors results in similar survival times for patients with acute myelogenous leukemia.

Cellular therapies in acute lymphoblastic leukemia

ALL remains a difficult disease to treat. In the adult setting, most patients will ultimately die of their disease, whereas in the pediatric setting, relapsed and refractory disease remains a therapeutic challenge. Cellular therapy through allo-HSCT remains an option for these patients, and recent advances in alternative forms of allo-HSCT, including unrelated donor transplants, UCB transplants, and haploidentical transplants, have expanded the numbers of patients eligible for allo-HSCT but have not improved outcomes when compared with HLA-matched related allo-HSCTs. In light of this persistent failure, several novel adoptive cellular approaches are being investigated to treat patients with ALL. The use of enriched WT-1–specific donor T cells to treat patients with ALL is currently under investigation in phase I trials at several centers. Treatment of ALL with genetically modified T cells targeted to the CD19 antigen through the expression of a CD19-specific CAR also have entered phase I clinical trials at several centers. Similarly, a clinical trial treating patients with ALL with genetically modified NK cells targeted to the CD19 antigen has recently opened for accrual. Collectively, these ongoing and anticipated trials provide a promising role for adoptive cellular therapies in the treatment of ALL. What remains to be seen is whether this promise will either translate into improved outcomes for these patients or provide significant insights on which to design second-generation adoptive cell therapeutic clinical trials for ALL in the future.

Graft-versus-tumor effect according to type of graft-versus-host disease defined by National Institutes of Health consensus criteria and associated outcomes

The impact of National Institutes of Health consensus criteria (NCC) graft-versus-host disease (GVHD) on survival has rarely been investigated in a large cohort of patients with GVHD presenting before and after day 100 posttransplantation. We retrospectively investigated 775 patients who underwent allogeneic stem cell transplantation and assessed the GVHD effects on survival by the time-dependent covariates in Cox proportional hazards regression models. Using the NCC, the patients were classified into 4 groups: (1) no GVHD (n = 251); (2) acute GVHD (aGVHD) only (n = 199), including 26 patients with late aGVHD; (3) classic chronic GVHD (cGVHD; n = 232); and (4) overlap syndrome (OS; n = 93). Multivariate analyses showed that classic cGVHD (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.27-0.77) and OS (HR, 0.52; 95% CI, 0.28-0.96) were associated with significantly decreased risk of relapse, whereas aGVHD only was not associated with relapse rate (HR, 1.11; 95% CI, 0.76-1.63). All aGVHD events, including the period of aGVHD in patients who developed cGVHD after aGVHD, also did not affect the risk of relapse (HR, 0.74; 95% CI, 0.49-1.12). All types of GVHD were significantly associated with higher nonrelapse mortality in common. Finally, patients with aGVHD only had significantly lower overall survival and disease-free survival compared with those without GVHD, in contrast to favorable survival outcomes in patients with cGVHD without previous aGVHD. This study demonstrates that NCC GVHD type is associated with different graft-versus-tumor effects. Further studies are needed to investigate risk factors, pathogenesis, and biomarkers for each type of NCC GVHD.

HLA mismatch direction in cord blood transplantation: impact on outcome and implications for cord blood unit selection

Donor-recipient human leukocyte antigen mismatch level affects the outcome of unrelated cord blood (CB) transplantation. To identify possible "permissive" mismatches, we examined the relationship between direction of human leukocyte antigen mismatch ("vector") and transplantation outcomes in 1202 recipients of single CB units from the New York Blood Center National Cord Blood Program treated in United States Centers from 1993-2006. Altogether, 98 donor/patient pairs had only unidirectional mismatches: 58 in the graft-versus-host (GVH) direction only (GVH-O) and 40 in the host-versus-graft or rejection direction only (R-O). Engraftment was faster in patients with GVH-O mismatches compared with those with 1 bidirectional mismatch (hazard ratio [HR] = 1.6, P = .003). In addition, patients with hematologic malignancies given GVH-O grafts had lower transplantation-related mortality (HR = 0.5, P = .062), overall mortality (HR = 0.5, P = .019), and treatment failure (HR = 0.5, P = .016), resulting in outcomes similar to those of matched CB grafts. In contrast, R-O mismatches had slower engraftment, higher graft failure, and higher relapse rates (HR = 2.4, P = .010). Based on our findings, CB search algorithms should be modified to identify unidirectional mismatches. We recommend that transplant centers give priority to GVH-O-mismatched units over other mismatches and avoid selecting R-O mismatches, if possible.

Allogeneic haematopoietic stem cell transplantation as therapy for chronic granulomatous disease--single centre experience

Chronic granulomatous disease (CGD) is phagocytic cell metabolic disorder resulting in recurrent infections and granuloma formation. This paper reports the favourable outcome of allogeneic transplantation in six high-risk CGD patients. The following donors were used: HLA-matched, related (two) and unrelated (three), and HLA-mismatched, unrelated (one). One patient was transplanted twice using the same sibling donor because of graft rejection at 6 months after reduced-intensity conditioning transplant (fludarabine and melphalan). Myeloablative conditioning regimen consisted of busulphan and cyclophosphamide. Stem cell source was unmanipulated bone marrow containing: 5.2 (2.6-6.5) × 10(8) nucleated cells, 3.8 (2.0-8.0) × 10(6) CD34+ cells and 45 (27-64) × 10(6) CD3+ cells per kilogramme. Graft-versus-host disease prophylaxis consisted of cyclosporine A and, for unrelated donors, short course of methotrexate and anti-T-lymphocyte globulin. Mean neutrophile and platelet engraftments were observed at day 22 (20-23) and day 20 (16-29), respectively. Pre-existing infections and inflammatory granulomas resolved. With the follow-up of 4-35 months (mean, 20 months), all patients are alive and well with full donor chimerism and normalized superoxide production.

Early human cytomegalovirus replication after transplantation is associated with a decreased relapse risk: evidence for a putative virus-versus-leukemia effect in acute myeloid leukemia patients

The impact of early human cytomegalovirus (HCMV) replication on leukemic recurrence was evaluated in 266 consecutive adult (median age, 47 years; range, 18-73 years) acute myeloid leukemia patients, who underwent allogeneic stem cell transplantation (alloSCT) from 10 of 10 high-resolution human leukocyte Ag-identical unrelated (n = 148) or sibling (n = 118) donors. A total of 63% of patients (n = 167) were at risk for HCMV reactivation by patient and donor pretransplantation HCMV serostatus. In 77 patients, first HCMV replication as detected by pp65-antigenemia assay developed at a median of 46 days (range, 25-108 days) after alloSCT. Taking all relevant competing risk factors into account, the cumulative incidence of hematologic relapse at 10 years after alloSCT was 42% (95% confidence interval [CI], 35%-51%) in patients without opposed to 9% (95% CI, 4%-19%) in patients with early pp65-antigenemia (P < .0001). A substantial and independent reduction of the relapse risk associated with early HCMV replication was confirmed by multivariate analysis using time-dependent covariate functions for grades II to IV acute and chronic graft-versus-host disease, and pp65-antigenemia (hazard ratio = 0.2; 95% CI, 0.1-0.4, P < .0001). This is the first report that demonstrates an independent and substantial reduction of the leukemic relapse risk after early replicative HCMV infection in a homogeneous population of adult acute myeloid leukemia patients.

Use of matched unrelated donors compared with matched related donors is associated with lower relapse and superior progression-free survival after reduced-intensity conditioning hematopoietic stem cell transplantation

As success of reduced-intensity conditioning (RIC) hematopoietic stem cell transplantation (HSCT) relies primarily on graft-versus-leukemia (GVL) activity, increased minor HLA disparity in unrelated compared to related donors could have a significant impact on transplant outcomes. To assess whether use of unrelated donors (URD) engenders more potent GVL in RIC HSCT compared to matched related donors (MRD), we retrospectively studied 433 consecutive T-replete 6/6 HLA matched URD (n = 246) and MRD (n = 187) RIC HSCT for hematologic malignancies at our institution. Diseases included: acute myelogenous leukemia (AML) (127), non-Hodgkin lymphoma (NHL) (71), chronic lymphocytic leukemia (CLL) (68), myelodysplastic syndrome (MDS) (64), Hodgkin disease (HD) (40), chronic myeloid leukemia (CML) (25), multiple myeloma (MM) (23), myeloproliferative disorder (MPD) (12), acute lymphoblastic leukemia (ALL) (7), and other leukemia (1). All received uniform fludarabine and intravenous busulfan conditioning, and GVHD prophylaxis with tacrolimus/mini-methroxate (mini-MTX) or tacrolimus/sirolimus ± mini-MTX. Unrelated donors were younger compared to MRD (median donor age: 33 years versus 52 years, P < .0001), and provided larger CD34(+) products (median CD34(+) cells infused: 8.7 × 10(6)/kg versus 7.5 × 10(6)/kg, P = .002). Distribution of diseases, disease risk, prior transplant, and cytomegalovirus (CMV) status was similar in both cohorts. Cumulative incidence of grade II-IV acute GVHD (at day +180), 2-year chronic GVHD, and 2-year nonrelapse mortality (NRM) were 20% versus 16%, 55% versus 50%, and 8% versus 6% in URD and MRD, respectively (P = NS). Cumulative incidence of relapse at 2 years was lower in URD, 52% versus 65% (P = .005). With median follow-up of 26.5 and 35.8 months, 2-year progression-free survival (PFS) was significantly better in unrelated donor transplants, 39.5% for URD, and 29% for MRD (P = .01). Overall survival (OS) at 2 years were 56% for URD versus 50% for MRD (P = .53). In multivariable analysis, URD was associated with a lower risk of relapse (hazard ratio [HR] 0.67, P = .002) and superior PFS (HR 0.69, P = .002). These results suggest that URD is associated with greater GVL activity than MRD, and could have practice changing impact on future donor selection in RIC HSCT.

Outcomes of patients with myeloid malignancies treated with allogeneic hematopoietic stem cell transplantation from matched unrelated donors compared with one human leukocyte antigen mismatched related donors using HLA typing at 10 loci

Most candidates for hematopoietic stem cell transplantation (HSCT) lack a human leukocyte antigen (HLA)-identical sibling donor. Some patients may have a related donor with whom they are mismatched at 1 antigen/allele. It is not known whether such a match is preferable to a matched unrelated donor (MUD). We evaluated the outcomes (survival, relapse, nonrelapse mortality [NRM]) of all 28 patients with a single HLA antigen/allele mismatch identified through high-resolution HLA typing at HLA-A, -B, -C, -DRB1, and -DQB1, and all 318 patients with myeloid malignancies who received transplants from a 10/10 MUD treated during the same period of time at a single institution. Overall, outcomes for patients treated from a 1-antigen/allele mismatch related donor were significantly worse than from a MUD, primarily because of increased NRM. Overall survival (OS) rates at 3 years for 1-antigen/allele mismatched related donor and MUD transplant recipients were 19% and 45% (P = .007), and NRM rates were 40% and 26% (P = .05), respectively. Patients with class I mismatches appeared to have poorer OS than did patients with class II mismatches. A higher incidence of graft rejection was identified in the mismatched related donor group (P = .02). These results indicate that transplant outcomes are better with a MUD than with a 1 antigen/allele-mismatched related donor.

One-antigen mismatched related versus HLA-matched unrelated donor hematopoietic stem cell transplantation in adults with acute leukemia: Center for International Blood and Marrow Transplant Research results in the era of molecular HLA typing

Approximately 13% of patients lacking an HLA-identical sibling have a one-antigen-mismatched related donor (MMRD). Historically, outcomes from the use of a one-antigen MMRD were considered equivalent to those from the use of a matched unrelated donor (UD). Recent improvements in UD stem cell transplantation (SCT) resulting from better molecular HLA matching justifies investigating whether UD should be preferred over MMRD in adult patients with acute leukemia. Here, we compared the outcomes of MMRD (n = 89) and HLA-A, -B, -C, and -DRB1 allele-matched UD (n = 700) SCT reported to the Center for International Blood and Marrow Transplant Research between 1995 and 2005. The patients underwent transplantation for acute myelogenous leukemia or acute lymphoblastic leukemia in first or second complete remission. Donor type was not associated with hematologic recovery. Univariate and multivariate comparisons of MMRD versus HLA-matched UD transplants showed no statistically significant differences in overall survival, disease-free survival, treatment-related mortality, relapse, or 100-day grade III-IV acute graft-versus-host disease (GVHD). MMRD SCT was associated with a lower rate of chronic GVHD at 1 year (35% vs 47%; P = .03), which was confirmed by multivariate analysis (relative risk, 0.58; 95% confidence interval, 0.39-0.85; P < .01). According to our data, HLA-matched UD and MMRD SCT are associated with comparable survival. Given that less chronic GVHD was observed in the MMRD transplantations, this option, when available, remains the first choice in patients with acute leukemia without an HLA-identical sibling in need of allogeneic SCT.

Minor histocompatibility antigen HA-1 and HA-2 polymorphisms in Taiwan: frequency and application in hematopoietic stem cell transplantation

BACKGROUND

Minor histocompatibility antigens influence the occurrence of graft-vs.-host disease and graft-vs.-leukemia effects after hematopoietic stem cell transplantation (HSCT). We determined the population frequencies of HA-1 and HA-2 alleles in Taiwan and exploited their potential applications in allogeneic HSCT.

METHODS

HA-1 and HA-2 were genotyped using polymerase chain reaction and restriction fragment length polymorphism in healthy controls (221 for HA-1 and 306 for HA-2) and HLA-matched donor-recipient sibling pairs with HSCT (92 for HA-1 and 38 for HA-2). The association of genetic polymorphisms with HSCT outcome was evaluated by univariate and multivariate analyses.

RESULTS

The allele frequencies in controls were 35.3% and 64.7% for HA-1(H) and HA-1(R), and 89.0% and 11.0% for HA-2(V) and HA-2(M), respectively. HA-1 disparity was denoted in 16.3% of HLA-matched donor-recipient sibling pairs, while it was not associated with HSCT outcome. HA-2 disparity was not observed in the donor-recipient pairs studied. The possibilities of using HA-1 and HA-2 variabilities as molecular markers for hematopoietic chimerism after HSCT were 39.2% and 18.4%, respectively.

CONCLUSIONS

Our data provide the information on allele and genotype frequencies of HA-1 and HA-2 in a Taiwanese population, and suggest that prospective genomic typing for HA-1 and HA-2 alleles of the donor and recipient could be a useful approach for molecular identification of hematopoietic chimerism after HSCT, rather than prognosis of clinical outcome.

HLA-allele matched unrelated donors compared to HLA-matched sibling donors: role of cell source and disease risk category

To determine whether the risks of allogeneic transplantation are different when the donor is a fully matched unrelated donor (MUD; based on 10/10 HLA alleles) compared to an HLA-identical sibling, we performed a retrospective analysis of 1448 patients with high-risk or advanced hematologic malignancies given T-replete grafts after myeloablative conditioning. No statistically significant differences were found between recipients of a matched sibling donor (MSD) and 10/10 MUD in survival, disease-free survival (DFS), and nonrelapse mortality (NRM) for patients with high-risk disease or those given bone marrow as a graft source. However, for patients with intermediate-risk disease receiving peripheral blood grafts, we observed higher NRM and lower overall survival (OS) in the 10/10 MUD group compared to the MSD cohort. Graft-versus-host disease (GVHD) was higher in the MUD group compared to the MSD group. These results suggest that if a patient has high-risk disease and an MSD is not available, selection of an HLA-allele-matched MUD may provide similar OS and DFS, and therefore lack of an MSD in and of itself should not preclude such a patient from undergoing transplantation. However, for patients with intermediate-risk disease, transplantation with peripheral blood from a 10/10 MUD is associated with lower survival than an MSD.

Minor ABO-mismatches are risk factors for acute graft-versus-host disease in hematopoietic stem cell transplant patients

We investigated the impact of ABO and Rhesus (Rh) blood group matching on the outcome of hematopoietic stem cell transplantation (HSCT) of 154 patients matched at 10/10 HLA loci with unrelated donors. ABO and Rh, as potential risk factors, were modeled with the clinical outcome--acute and chronic graft-versus-host disease (aGVHD, cGVHD), relapse, treatment-related mortality (TRM), and overall survival (OS)--by simple, multiple, and competing risk analyses. We found that minor ABO-mismatches represent a significant risk factor for aGVHD (II-IV) with an estimated risk increase of almost 3-fold (hazard ratio [HR]=2.92, 95% confidence interval [CI]: 1.43-5.95, P=.003), and even 4-fold for aGVHD (III-IV) (HR=4.24, 95% CI: 1.70-10.56, P=.002), but not for other transplant endpoints. No significant association of the Rh matching status with any of the HSCT endpoints was seen. These results suggest that ABO minor mismatches may play a role in aGvHD pathophysiology, possibly by providing the setting for T cell activation and antibody mediated damage. To decrease the risk of aGVHD, ABO matching should be considered in HSCT.

Outcome of patients less than 55 years of age with high-risk acute leukemia who did not have an human leukocyte antigen-identical related donor: a long-term study of 97 consecutive patients

Between January 1993 and December 2000, an unrelated donor search (UDS) was initiated for 97 consecutive patients [46 acute lymphoblastic leukemia (ALL) and 51 acute myeloid leukemia (AML)]. Leukemia was considered to be of poor prognosis in cases of refractory disease (n=70), unfavourable karyotype (n=22) or miscellaneous (n=5). All patients had previously received various chemotherapies and 9 had undergone an autologous stem cell transplantation (SCT). The median age at UDS initiation was 25 (range 2.7-55) years. The median time to identify a suitable living donor or cord blood (CB) was 60 days. Eventually, 33 patients received unrelated allo-SCT (including 9 CB), 12 auto-SCT, 39 chemotherapy and 13 palliative treatment. At a median of 54 months, 18 patients were alive, including 15 in remission. The 4-year overall survival rates were 32%, 37%, 15% and 0% for allo-SCT, auto-SCT, chemotherapy or palliative treatment, respectively. Patients who received either allo- or auto-SCT had better survival than those who did not (P<0.0001). For ALL, only allo-SCT significantly improved survival (P<0.007). Finally, patients who received allo-SCT died less often of relapse than patients who did not (P<0.0001). Unrelated allo-SCT gives a substantial long-term survival and cure in patients with high-risk acute leukemia. For patients who achieve remission and for whom UDS fails, auto-SCT may prove to be a good approach. For patients who fail to enter into remission, intensive salvage chemotherapy has a very limited effect.