Unrelated donor hematopoietic transplantation

Peripheral blood stem cell transplantation from human leukocyte antigen-matched sibling donors and unrelated donors in acute myeloid leukemia patients

There have been rare comparative studies of hematopoietic stem cell transplantation from matched sibling donors (MSDs) and unrelated donors (URDs) with regard to peripheral blood stem cell transplantation (PBSCT). We performed a retrospective study of 104 consecutive acute myeloid leukemia (AML) patients who had received an allogeneic PBSCT from an MSD or a URD in order to compare transplant outcomes and posttransplant complications between the 2 groups of patients. The cumulative incidence of grade 2-4 acute graft-versus-host disease (aGVHD) at 100 days (22.6% with MSD vs. 35.3% with URD; p = 0.107) and that of chronic GVHD (cGVHD) at 2 years (72.9% with MSD vs. 56.1% with URD; p = 0.153) was not significantly different between the 2 groups. Multivariate analysis also indicated that a URD was not an independent predictor of grade 2-4 aGVHD or cGVHD. No statistically significant differences were observed in terms of relapse incidence (p = 0.371), nonrelapse mortality (p = 0.473), disease-free survival (p = 0.925) or overall survival (p = 0.534) at 2 years. URDs are comparable with MSDs as a donor type for PBSCT in AML patients if risk-stratified GVHD prophylaxis is adopted.

Immunotherapeutic approaches to improve graft-versus-tumor effect and reduce graft-versus-host disease

The therapeutic efficacy of allogeneic stem cell transplantation is mainly based on the alloreactive immune response of the graft against the host. However, the graft-versus-host process can be viewed as a double-edged sword since it is responsible for both the beneficial graft-versus-tumor effect and the deleterious graft-versus-host disease. During the last two decades, intensive research has been focused on the development of novel immunotherapeutic methods aimed to dissociate graft-versus-host disease from graft-versus-tumor effect. A brief description of these efforts is discussed in this review.

[Graft-versus-Host Disease (GvHD) - an update : Part 1: Pathophysiology, clinical features and classification of GvHD]

GvHD remains associated with significant morbidity and mortality despite new techniques for allogeneic stem cell transplantation (SCT), such as optimized conditioning regimens. Within the past ten years, the incidence of acute GvHD has remained unchanged and the incidence of chronic GvHD has even increased. The traditional classification of GvHD according to the time of clinical manifestation is now out-dated. Acute GvHD symptoms may even occur after 100 days; vice versa, primary chronic GvHD may already be observed one month after stem cell transplantation. The current classification introduced by the National Institutes of Health includes classic acute GvHD (up to 100 days), late-onset acute GvHD (after 100 days), as well as an overlap syndrome showing features of acute and chronic GvHD and classic chronic GvHD without any time limit. Diagnosis of GvHD of the skin remains difficult because of histological similarities to drug eruptions and viral exanthems. In this first part of the article the pathophysiology, classification, skin manifestations of acute and chronic GvHD and the histopathology will be presented. In a second part the prognosis, prophylaxis and therapy of GvHD will be discussed.

Myeloablative reduced-toxicity i.v. busulfan-fludarabine and allogeneic hematopoietic stem cell transplant for patients with acute myeloid leukemia or myelodysplastic syndrome in the sixth through eighth decades of life

The optimal pretransplant regimen for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) in patients ≥ 55 years of age remains to be determined. The myeloablative reduced-toxicity 4-day regimen i.v. busulfan (Bu) (130 mg/m(2)) and i.v. fludarabine (Flu) (40 mg/m(2)) is associated with low morbidity and mortality. We analyzed 79 patients ≥ 55 years of age (median, 58 years) with AML (n = 63) or MDS (n = 16) treated with i.v. Bu-Flu conditioning regimens between 2001 and 2009 (median follow-up, 24 months). The patients who received this regimen had a good performance status. The 2-year overall survival (OS) rates for patients in first complete remission (CR1), second CR (CR2), or refractory disease and for all patients at time of transplantation were 71%, 44%, 32%, and 46%, respectively; 2-year event-free survival (EFS) rates for patients in CR1, CR2, or refractory disease at time of transplantation and for all patients were 68%, 42%, 30%, and 44%, respectively. One-year transplant-related mortality (TRM) rates for patients who were in CR or who had active disease at the time of transplantation were 19% and 20%, respectively. Grade II-IV acute graft-versus-host (aGVHD) disease was diagnosed in 40% of the patients. Our results suggest that age alone should not be the primary reason for exclusion from receiving myeloablative reduced-toxicity conditioning with i.v. Bu-Flu preceding transplantation in patients with AML/MDS.

Reduced-intensity conditioning allogeneic transplantation from unrelated donors: evaluation of mycophenolate mofetil plus cyclosporin A as graft-versus-host disease prophylaxis

In the current study, we have analyzed the efficacy of cyclosporine A (CSA) plus mycophenolate mofetil (MMF) as graft-versus-host disease (GVHD) prophylaxis in the fludarabine plus melphalan or busulfan reduced intensity regimen (RIC) setting in a series of 44 patients receiving allogeneic transplantation from an unrelated donor. Only 23% were in the first complete remission at the time of transplant. Cumulative incidence of grades II-IV and III-IV acute GVHD (aGVHD) was 53% and 23%, respectively. Fifty-six percent had equal to or greater than grade 2 gut involvement. Cumulative incidence of overall and extensive chronic GVHD (cGVHD) was 93% and 63%, respectively. Ninety-two percent of patients who were evaluable +100 days after transplant were in complete remission. Relapse rate was 25% at 2 years. Event free (EFS) and overall survival (OS) at 2 years were 52%. Pharmacokinetic assays of mycophenolic acid (MPA) showed a therapeutic area under the curve (AUC) at the dosage of 3 g daily, although a large inter- and intraindividual variations of MPA plasma levels were found. In conclusion, the combination of CSA plus MMF in the fludarabine plus melphalan or busulfan RIC setting is feasible. Regarding GVHD, this combination allowed to control aGVHD but lead to a high incidence of cGVHD, so that newer strategies are required, especially in trying to decrease gastrointestinal involvement.

Change in plasma tumor necrosis factor receptor 1 levels in the first week after myeloablative allogeneic transplantation correlates with severity and incidence of GVHD and survival

Acute graft-versus-host disease (GVHD) remains a significant cause of mortality after hematopoietic cell transplantation (HCT). Tumor necrosis factor-alpha (TNF-alpha) mediates GVHD by amplifying donor immune responses to host tissues and by direct toxicity to target organs. We measured TNF receptor 1 (TNFR1) as a surrogate marker for TNF-alpha in 438 recipients of myeloablative HCT before transplantation and at day 7 after transplantation. Increases in TNFR1 levels more than or equal to 2.5 baseline correlated with eventual development of GVHD grade 2 to 4 (58% vs 32%, P < .001) and with treatment-related mortality (39% vs 17%, P < .001). In a multivariate analysis including age, degree of HLA match, donor type, recipient and donor sex, disease, and status at HCT, the increase in TNFR1 level at day 7 remained a significant predictor for outcome. Measurement of TNFR1 levels early after transplantation provides independent information in advance of important clinical outcomes, such as GVHD and death.

Allogeneic hematopoietic stem cell transplantation in the elderly

The development of reduced intensity or non-myeloablative conditioning (NST) in preparation for allogeneic stem cell transplantation (SCT) revolutionized the field and led to reconsideration of the dogma of upper age limit that was set up by the transplant centers as an eligibility parameter. Analysis of the literature data showed that NST regimens are associated with decreased transplant related mortality, and graft-versus-host disease, in comparison with standard myeloablative conditioning, in patients above the age of 50-55 years, or in younger patients with significant comorbidities. However we have to mention, that our considerations are based on the retrospective analysis of the literature data, and that well controlled prospective randomized studies are needed in order to definitely assess the role of NST. Comorbidity indices might be proved as the most important parameters for the choice of the most proper regimen for each patient in need and should be included in future trials.

Secondary malignancies after hematopoietic stem cell transplantation

Advances in the field of hematopoietic stem cell transplantation have led to an increasing number of cures of malignant and non-malignant diseases with this therapeutic approach. Long-term survivorship may, however, be associated with secondary malignancies, the result of a complex interaction of treatment-, recipient- and immunosuppression-related factors. Furthermore, the increasing use of donors other than human leukocyte antigen-identical siblings is associated with more intense immunosuppression, delayed immune recovery and higher incidence of B-cell post-transplantation lymphoproliferative disorders. Here, we review the incidence and the risk factors associated with these complications of hematopoietic stem cell transplants.

Effect of graft-versus-host disease prophylaxis on 3-year disease-free survival in recipients of unrelated donor bone marrow (T-cell Depletion Trial): a multi-centre, randomised phase II-III trial

BACKGROUND

Graft-versus-host disease (GVHD) reduces the efficacy of unrelated donor bone marrow transplantation in patients with lymphohaemopoietic malignancy. A multi-centre, randomised trial was undertaken to determine the effects of ex-vivo T-cell depletion versus methotrexate and cyclosporine immunosuppression on 3-year disease-free survival.

METHODS

Between Mar 1, 1995, and Oct 31, 2000, 405 patients with lymphohaemopoietic malignancy, from 15 participating centres, were randomly assigned to undergo transplantation with either T-cell depleted marrow and cyclosporine A (TCD arm; n=201) or methotrexate and cyclosporine A after transplantation of T-replete marrow (M/C arm; n=204). The primary outcome was 3-year disease-free survival and was analysed by intention to treat.

FINDINGS

Five patients died before transplantation. Seven in the TCD arm received T-replete grafts. Disease-free survival at 3 years was 27% (95% CI 21-33) and 34% (27-40) in recipients of TCD and M/C, respectively (p=0.16). TCD was associated with significantly more rapid neutrophil recovery (15 days vs 20 days, p<0.0001), less grade III-IV acute GVHD (18%vs 37%, p<0.0001), reduced grade III-IV toxicities (19%vs 29%, p=0.017), reduced duration of initial hospitalisation, but higher risk of chronic myelogenous leukaemia relapse (20%vs 7%, p=0.009) and cytomegalovirus infection (28%vs 17%, p=0.023) than was M/C.

INTERPRETATION

Disease-free survival at 3 years did not differ between TCD and M/C groups. Relapse and opportunistic infection are important obstacles to successful unrelated donor bone marrow transplantation, irrespective of the method of GVHD prophylaxis used.

Once-daily intravenous busulfan and fludarabine: clinical and pharmacokinetic results of a myeloablative, reduced-toxicity conditioning regimen for allogeneic stem cell transplantation in AML and MDS

Postulating favorable antileukemic effect with improved safety, we used intravenous busulfan and fludarabine as conditioning therapy for allogeneic hematopoietic stem cell transplantation (HSCT) for acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). Fludarabine 40 mg/m2 and intravenous busulfan 130 mg/m2 were given once daily for 4 days, with tacrolimus-methotrexate as graft-versus-host disease (GVHD) prophylaxis. We treated 74 patients with AML and 22 patients with MDS; patients had a median age of 45 years (range, 19-66 years). Only 20% of the patients were in first complete remission (CR) at transplantation. Donors were HLA-compatible related (n = 60) or matched unrelated (n = 36). The CR rate for 54 patients with active disease was 85%. At a median follow-up of 12 months, 1-year regimen-related and treatment-related mortalities were 1% and 3%, respectively. Two patients had reversible hepatic veno-occlusive disease. Actuarial 1-year overall survival (OS) and event-free survival (EFS) were 65% and 52% for all patients, and 81% and 75% for patients receiving transplants in CR. Recipient age and donor type did not influence OS or EFS. Median busulfan clearance was 109 mL/min/m2 and median daily area-under-the-plasma-concentration-versus-time-curve was 4871 micromol-min, with negligible interdose variability in pharmacokinetic parameters. The results suggest that intravenous busulfan-fludarabine is an efficacious, reduced-toxicity, myeloablative-conditioning regimen for patients with AML or MDS undergoing HSCT.

Reduced-intensity conditioning for unrelated donor hematopoietic stem cell transplantation as treatment for myeloid malignancies in patients older than 55 years

Hematopoietic stem cell transplantation from unrelated donors is an effective treatment for myeloid malignancies, but its use is usually restricted to young patients without comorbidities. The development of reduced-intensity preparative regimens has allowed the extension of this form of treatment to older and medically infirm patients. We assessed the outcomes of patients older than 54 years who received unrelated donor transplants for the treatment of myeloid malignancies in our institution. There were 29 patients (median age, 59 years) with advanced acute myeloid leukemia (n = 13), myelodysplastic syndrome (n = 7), and chronic myeloid leukemia (n = 9) included. With a median follow-up of 27 months, the probability of overall and event-free survival, and nonrelapse mortality at one year were 44%, 37%, and 55%, respectively. Grades II to IV acute graft-versus-host disease (GVHD) occurred in 41% of patients and chronic GVHD developed in 63% of patients surviving more than 100 days. Of the 11 survivors, 9 were interviewed and reported good quality of life after transplantation using the Functional Assessment of Cancer Therapy-Bone Marrow Transplant Scale (FACT-BMT) questionnaire, with high scores in all dimensions. Unrelated donor transplantation is a treatment option for older patients with myeloid malignancies. The results in this cohort of patients are comparable with those reported in younger patients with similarly advanced disease.

[Cutaneous graft-versus-host disease]

Although stem cell transplantation is a life-saving measure and the treatment of choice for many patients with various hematologic malignancies, a high incidence of complications and a transplantation associated mortality of about 30% are to be expected.Graft-versus-Host Disease (GvHD) is the major cause of morbidity and mortality after stem cell transplantation. GvHD can arise at various time points. Acute GvHD occurs during the first 100 days after transplantation in up to 50% of graft recipients, while chronic GvHD develops in about 30-50% usually within 100-500 days following allogeneic stem cell transplantation. It can involve the skin, liver, gastrointestinal tract, and less frequently the lungs, eyes and neuromuscular system. Early diagnosis of GvHD can be difficult, as drug reactions, viral infections and cutaneous reactions to radiation therapy may have clinical and histological similarities. In this review, the various cutaneous manifestations of GvHD, the histopathologic features, prophylaxis and therapy of acute and chronic GvHD are discussed in light of the recent literature.