Unrelated cord blood transplantation for adult patients with myelodysplastic syndrome-related secondary acute myeloid leukaemia

[Allogeneic cord blood transplantation for adults: current results and future development]

Hematopoietic stem cell transplantation is the choice treatment of many hematopoietic disorders. However, there is still no related or HLA-matched unrelated donor for one-third of the patients. Cord blood, which contains a lot of hematopoietic progenitors immunologically naive, represents not only an interesting alternative as hematopoietic stem cell source but also allows more HLA incompatibilities than the other sources. Promising results in children lead to develop cord blood transplantation in adults first of all in hematopoietic malignancies (acute leukemias and lymphoid diseases) and in a second time, in non-malignant diseases such as aplastic anaemia. The main problems for the development of this new strategy in adults are the poor number of cells per unit, the delay for hematopoietic recovery in comparison with other hematopoietic stem cell sources and, consequently higher transplant related mortality. In order to improve the results in adults, new strategies emerged. Double cord blood transplantation, expansion methods and intra-bone injection of the graft will be reviewed here, as well as alternative transplantation strategies such as non-myeloablative conditioning.

Umbilical cord blood transplantation for myeloid malignancies

PURPOSE OF REVIEW

To review the available data on the outcomes of pediatric and adult patients with acute myeloid leukemia, myelodysplastic syndrome and chronic myelogenous leukemia after umbilical cord blood transplantation.

RECENT FINDINGS

The literature shows that after umbilical cord blood transplantation the relapse rate, disease-free survival and overall survival of patients with myeloid malignancies is similar to other hematopoietic stem cells sources. Disease status at the time of transplantation is found in several studies to be a very important determinant of long-term outcome. Newer strategies such as double umbilical cord blood transplant and utilization of nonmyeloblative conditioning regimens show promising results.

SUMMARY

Umbilical cord blood is a valuable alternative source of hematopoietic stem cells for transplantation of patients with myeloid malignancies who need an allogeneic transplant, but lack a suitable sibling donor.

Induction of remission of relapsed acute myeloid leukemia after unrelated donor cord blood transplantation by concomitant low-dose cytarabine and calcitriol in adults

Low-dose cytarabine and calcitriol (LDCA + VD3) combination therapy was performed in two adult patients with acute myeloid leukemia (AML) that relapsed within 1 yr after unrelated donor cord blood transplantation (URD CBT) performed in a relapse or non-remission stage. Concomitant aclarubicin was also administered in one patient. Remission because of recovery of donor cord blood hematopoiesis was obtained in both patients. The treatment was low intensive, and neither adverse effects in terms of digestive symptoms nor hypercalcemia was observed. Activity of daily life was maintained. The patients were followed as outpatients after remission, and the remission duration was approximately 6 months in both patients. Although LDCA + VD3 therapy is minimally intensive chemotherapy, it may prolong the survival time of patients with relapsed AML after URD CBT.

Adult umbilical cord blood transplantation: a comprehensive review

Recent registry studies have established umbilical cord blood (UCB) transplantation as a safe and feasible alternative to bone marrow transplantation in adults when no sibling donor is available. There is, however, no gold standard to guide optimal treatment choices. We review here factors leading to the choice of the 'best available donor' and 'best available unit' in the case of UCB. For instance, it is clear that higher cell dose may partially overcome the negative impact of certain histocompatibility leukocyte antigen (HLA) disparities in UCB transplantation, leading us to choose the more closely HLA-matched unit with a cell dose >2.5 x 10(7)/kg. New approaches in adult UCB transplantation are systematically covered, with a quantitative appreciation of the evidence available to date. Reduced intensity conditioning, for example, broadens the range of potential recipients by reducing transplant-related mortality, but suffers from unproven risks and benefits long term. Potential advantages of multiple units over single unit transplants are discussed, with a particular emphasis on confounding factors that impact interpretation. The limited clinical results of ex vivo UCB expansion, the possible benefits of co-infusion of haploidentical cells and controversial issues (e.g. killer immunoglobulin-like receptor matching and alternative graft sources) are also addressed with a debate on the future of UCB transplantation.

Human umbilical cord blood progenitors: the potential of these hematopoietic cells to become neural

The mononuclear fraction from human umbilical cord blood (HUCB) contains a significant number of stem/progenitor cells that in theory could be come any cell in the body, including neurons. Taking into consideration that transdifferentiation would be a very rare event and also knowing that overlapping genetic programs for hematopoiesis and neuropoiesis exist, we undertook a characterization of the HUCB mononuclear fraction, including analysis of cellular subpopulations and their morphology, cell viability, proliferation, and expression of neural and hematopoietic antigens. Two cell populations were apparent-adherent and floating fractions. The adherent fraction was mainly lymphocytes (~53%) expressing hematopoietic antigens. Upon replate, the floating population had many cells that expressed stem cell antigens. More of the cells in this subfraction expressed neural proteins. Neurotrophin receptors trkB and trkC were present in both cell fractions, although expression was higher in the floating fraction. Our initial characterization suggests that a subpopulation of cells exists within the HUCB mononuclear fraction that seems to have the potential to become neural cells, which could then be used in the development of cell-based therapies for brain injuries and diseases.

Early Immune Reaction after Reduced-Intensity Cord-Blood Transplantation for Adult Patients

BACKGROUND

To investigate immune reactions after reduced-intensity cord-blood transplantation (RI-CBT).

MATERIALS AND METHODS

We reviewed medical records of 57 adult RI-CBT recipients. Preparative regimen comprised fludarabine, total-body irradiation, and either melphalan (n=51) or busulfan (n=6). Graft-versus-host disease (GvHD) prophylaxis was cyclosporine. PostRI-CBT immune reactions were classified according to time course: pre-engraftment immune reactions (PIR), engraftment syndrome (ES), and GvHD.

RESULTS

Forty-five patients achieved engraftment at a median of day 19. PIR was characterized by high-grade fever and weight gain and developed on a median of day 9 in 35 of the 45 evaluable patients, including 3 who did not achieve engraftment. PIR subsided spontaneously in 12 patients, whereas corticosteroids were required in the other 23. ES and grade I to IV acute GvHD developed in 36 and 29 patients, respectively. GvHD could not be distinguished from preceding PIR or ES in 10 patients. Causes of the 32 nonrelapse mortalities included GvHD (n=5) and PIR (n=1). There were no significant differences in relapse and nonrelapse deaths between patients with PIR and those without it (18% vs. 5%, and 60% vs. 65%, respectively).

CONCLUSIONS

Immune reactions after RI-CBT can be categorized into three distinct subtypes.

Cord blood transplantation in adult patients

Early clinical reports outlining outcomes for primarily pediatric patients undergoing UCB transplantation point to delayed time to hematopoietic recovery and favorable incidence and severity of GvHD. Recently, clinical reports in adult patients identified the feasibility of UCB transplantation for those patients lacking an available histocompatible-related or unrelated adult donor Intensive clinical and laboratory research is ongoing focused on strategies to foster UCB allogeneic donor engraftment thereby allowing wider application of this stem cell source for patients requiring allogeneic transplantation.

Transplants of umbilical-cord blood or bone marrow from unrelated donors in adults with acute leukemia

BACKGROUND

Promising results of cord-blood transplants from unrelated donors have been reported in adults.

METHODS

We compared outcomes in 682 adults with acute leukemia who received a hematopoietic stem-cell transplant from an unrelated donor: 98 received cord blood and 584 received bone marrow. The transplantations were performed from 1998 through 2002 and reported to Eurocord and the European Blood and Marrow Transplant Group.

RESULTS

Recipients of cord blood were younger than recipients of bone marrow (median, 24.5 vs. 32 years of age; P<0.001), weighed less (median, 58 vs. 68 kg; P<0.001), and had more advanced disease at the time of transplantation (52 percent vs. 33 percent, P<0.001). All marrow transplants were HLA matched, whereas 94 percent of cord-blood grafts were HLA mismatched (P<0.001). The median number of nucleated cells that were infused was 0.23x10(8) per kilogram of the recipient's body weight for cord blood and 2.9x10(8) per kilogram for bone marrow (P<0.001). Multivariate analysis showed lower risks of grade II, III, or IV acute graft-versus-host disease (GVHD) after cord-blood transplantation (relative risk, 0.57; 95 percent confidence interval, 0.37 to 0.87; P=0.01), but neutrophil recovery was significantly delayed (relative risk, 0.49; 95 percent confidence interval, 0.41 to 0.58; P<0.001). The incidence of chronic GVHD, transplantation-related mortality, relapse rate, and leukemia-free survival were not significantly different in the two groups.

CONCLUSIONS

Cord blood from an unrelated donor is an alternative source of hematopoietic stem cells for adults with acute leukemia who lack an HLA-matched bone marrow donor.

Wash-out of DMSO does not improve the speed of engraftment of cord blood transplantation: follow-up of 46 adult patients with units shipped from a single cord blood bank

BACKGROUND

Prolonged periods of marrow hypoplasia have been a problem in cord blood transplantation. DMSO is thought to produce osmotic shock to the progenitors when the thawed cells are infused into the patients. To solve this problem, a 2x dilution method originally developed in the New York Blood Center showed earlier myeloid engraftment,1 although follow-up clinical studies have not performed.

STUDY DESIGN AND METHODS

To clarify the influence of the removal of DMSO by this method on the speed of engraftment in unrelated cord blood transplantation, 46 adult patients with cord blood units processed by the Tokyo Cord Blood Bank from September 1998 to March 31, 2002 were studied. Twenty-four patients received 2.6 +/- 0.71 x 10(7) nucleated cells per kg without washing (nonwashed group), while 22 patients were received 2.7 +/- 0.52 x 10(7) nucleated cells per kg after 2x dilution washing (washed group).

RESULTS

The cumulative incidence of engraftment was not significantly different between the two groups. Median neutrophil recovery (>/=5 x 10(9)/L) in the nonwashed and washed groups was 26 and 25 days, respectively, and the median platelet recovery (>/=20 x 10(9)/L) in patients with myeloid engraftment was 44 and 40 days, respectively (NS). On the other hand, the doses of CFCs and CD34+ cells showed the influence on myeloid and platelet recovery.

CONCLUSION

A 2x dilution after thawing cord blood did not result in the improvement of myeloid engraftment speed.

Varicella-zoster virus infection in adult patients after unrelated cord blood transplantation: a single institute experience in Japan

Varicella-zoster virus (VZV) infection was studied in 40 adult patients who underwent cord blood transplantation (CBT) from unrelated donors. Twenty-five patients developed VZV reactivation at a median of 5 months after CBT (range 1.7-26 months). The cumulative incidence of VZV reactivation after CBT was 80% at 30 months. Twenty-two patients developed localized herpes zoster. The remaining three patients developed atypical non-localized herpes zoster, which was associated with visceral dissemination in one patient. All the patients responded well to antiviral therapy. Unexpectedly, the absence of grade II-IV acute graft-versus-host disease (GVHD) was associated with a higher rate of VZV reactivation after CBT (100% versus 55%, P=0.01). These results suggest that recovery of VZV-specific immune responses after CBT is delayed even in patients without severe acute GVHD.

Unrelated cord blood transplantation for adult patients with advanced myelodysplastic syndrome

We report the results of unrelated cord blood transplantation (CBT) for 13 adult patients with advanced myelodysplastic syndrome (MDS). The median age was 40 years, the median weight was 51 kg, and the median number of infused nucleated cells was 2.43 x 107/kg. Twelve patients had myeloid reconstitution, and the median time to more than 0.5 x 109/L (5 x 108/L) absolute neutrophil count was 22.5 days. A self-sustained platelet count more than 50 x 109/L was achieved in 11 patients at a median time of 49 days. Acute graft versus host disease (GVHD) occurred in 9 of 12 evaluable patients and chronic GVHD in 8 of 11 evaluable patients. Ten patients are alive and free of disease at between 171 and 1558 days after transplantation. The probability of disease-free survival at 2 years was 76.2%. These results suggest that adult advanced MDS patients without suitable related or unrelated bone marrow donors should be considered as candidates for CBT.

Cytomegalovirus infection following unrelated cord blood transplantation for adult patients: a single institute experience in Japan

Cytomegalovirus (CMV) infection in 28 adult patients after cord blood transplantation (CBT) from unrelated donors was compared with that after bone marrow transplantation from HLA (human leucocyte antigen)-matched related (R-BMT) and unrelated (U-BMT) donors. Positive CMV antigenaemia was seen in 19 (79%) of 24 CMV-seropositive patients at a median of 42 d (range 29-85 d) after CBT, but in zero of four CMV-seronegative patients. This did not differ significantly from values observed after R-BMT and U-BMT (66%, P = 0.22, and 60%, P = 0.15 respectively). Based on the antigenaemia results, 16 patients (67%) received pre-emptive ganciclovir therapy from a median of 47 d (range 36-67 d) after CBT. This proportion was higher than that observed after R-BMT (28%, P = 0.0048), but did not differ from that after U-BMT (50%, P = 0.21). In addition, the probability of requiring more than two courses of ganciclovir therapy after CBT (21%) was higher than after R-BMT and U-BMT (0%, P = 0.015 and 0.039 respectively). One patient (5%) developed CMV disease after U-BMT, whereas no patients developed CMV disease after CBT or R-BMT. The CMV serostatus, use of a steroid and HLA disparity affected the probability of requiring ganciclovir therapy after CBT (P = 0.024, 0.032 and 0.017 respectively). These results suggest that recovery of CMV-specific immunity after CBT is delayed when compared with BMT.

Using related donors other than genotypically HLA-matched siblings in allogeneic hematopoietic stem cell transplantation for hematologic disease: a single institution experience in Japan

Thirty patients with hematologic diseases received allogeneic hematopoietic stem cell transplants (HSCT) from related donors other than genotypically HLA-matched siblings. Their outcomes were compared with those of 102 patients who had received HSCT from genotypically HLA-matched siblings. All donors in the study group were HLA-haploidentical relatives, The degree of HLA mismatches in unshared haplotype was 0-locus (n = 6), 1-locus (n = 20), and 2-locus (n = 4). All patients in the study group achieved successful engraftment at a median of 17 days (range, 10-35 days). Grade II-IV and ITI-IV acute graft-versus-host disease (GVHD) occurred in 16 (53%) and 9 (30%) patients, respectively, in the study group, rates that were significantly higher than those of the control group, which were 33 (33%) and 12 (12%) patients, respectively (P = .034 and .022, respectively). The frequency of chronic GVHD was 85% (22 out of 26 evaluable patients) in the study group, a rate that was also significantly higher than that of the control group with 57% (52 of 91 patients) (P = .0078). The estimated probability of disease-free survival (DFS) for the study group was 56% at 5 years. When the 2 groups were compared according to the risk of disease, the probabilities of DFS at 5 years for patients with low risk in the study and for control groups were 100% and 84%, respectively, and those for patients with high risk were 43% and 42%, respectively. These results showed that the DFS for patients with both low and high risks in the study group was comparable to that of the control group. In conclusion, despite higher probabilities of acute and chronic GVHD, unmanipulated allogeneic HSCT from related donors other than genotypically HLA-matched siblings was considered to be a reasonable alternative for patients without genotypically HLA-matched sibling donors.

Unrelated donor umbilical cord blood transplantation in adults

Umbilical cord blood (UCB) has emerged as an appealing alternative source of hematopoietic stem cells for unrelated donor transplantation. Shorter time to transplant and an improved chance of finding a suitable graft are evident advantages over bone marrow transplantation from unrelated donors. The majority of UCB transplants from unrelated donors have been performed in children, but the number in adults has been growing steadily in recent years. We review herein the reported experience with that source of hematopoietic stem cells in adults with hematological malignancies. The available data support the use of UCB transplantation from unrelated donors for young adults with hematological malignancies and no appropriate bone marrow donor, especially for those requiring urgent transplantation.

A clinical comparison of unrelated cord blood transplantation and unrelated bone marrow transplantation for adult patients with acute leukaemia in complete remission

We performed a clinical comparison of unrelated cord blood transplantation (UCBT) and unrelated bone marrow transplantation in adult acute leukaemia patients in complete remission (CR) who received the same conditioning regimen, graft-versus-host disease (GvHD) prophylaxis and supportive treatment. The incidence of acute GvHD was almost the same between the two groups, but the haematopoietic recovery was delayed and the incidence of chronic GvHD was higher in the UCBT group. The probability of 2 year disease-free survival was similar between the two groups. These results suggest that adult acute leukaemia patients in CR without a suitable donor should be considered as candidates for UCBT.

Successful treatment of relapsed blastic natural killer cell lymphoma with unrelated cord blood transplantation

The prognosis for blastic natural killer (NK) cell lymphoma is generally dismal. We report a patient who was successfully treated with unrelated cord blood transplantation (UCBT). A 15-year-old boy was diagnosed as having blastic NK cell lymphoma in the cervical lymph nodes. Autologous peripheral blood stem cell transplantation was performed on achieving a complete remission. However, the disease recurred in the bone marrow 6 months later. Chemotherapy induced a second remission and the patient received UCBT with a conditioning regimen consisting of total body irradiation, thiotepa and cyclophosphamide. Chronic GVHD of the lung occurred, but it was well controlled with steroids. At the time of writing, he remains in remission 18 months after UCBT with an excellent performance status. UCBT may be an option for patients with blastic NK cell lymphoma.

Stem cell transplantation for leukemias following myelodysplastic syndromes or secondary to cytotoxic therapy

Two main forms of therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) have been recognized. The most frequent type, occurring after treatment with alkylating agents, is characterized by abnormalities of chromosomes 5 and/or 7 and t-MDS/AML following treatment with topoisomerase II inhibitors and is associated with molecular aberrations of MLL (11q23) and AML-1 (21q22). Individuals with certain polymorphisms associated with impaired detoxification of cytotoxic agents have an increased risk of developing MDS or AML after treatment of unrelated cancers. Multidrug chemotherapy is less effective for patients with MDS, or AML following MDS, or t-MDS/AML when compared with primary AML, and results in lower complete remission (CR) rates and lower long-term survival. Patients with good risk cytogenetic features, such as t(15; 17), t(8; 21) and inversion 16 are an exception as their treatment outcome is comparable with primary AML patients. Patients who attain a polyclonal and/or a cytogenetic CR may be candidates for autologous stem cell transplantation. For the remaining patients, the only curative option is allogeneic stem cell transplantation with stem cells from a histocompatible sibling or an alternative donor. Reduced intensity conditioning regimens may be considered for patients older than 50 years or patients with comorbidities. The advice is to treat patients early after diagnosis and preferably before progression as these patients have the highest chance of a favorable outcome.