Long-term follow-up of peripheral blood stem cell transplantation from mismatched related and unrelated donors.

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) (''alternative donors'') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.

Reduced intensity preparative regimens for allogeneic hematopoietic stem cell transplantation: a single center experience.

According to recent reports, fast engraftment with minimal transplant-related toxicity and mortality (TRT, TRM) can be achieved by using reduced-intensity preparative regimens in allogeneic hematopoietic stem cell transplantation (HSCT). We report our experience with related (39%) and unrelated (61%) HSCT in 44 high risk patients (AML, ALL, CML, CLL) receiving either busulfan/fludarabine or busulfane/fludarabine/ATG or TBI/fludarabine as reduced-intensity preparative regimens. Organ toxicity was minimal with mild mucositis and no major bleeding. Acute GVHD was recorded in 64% of the patients. Twenty-three patients achieved complete remission after transplantation, and complete chimerism was obtained in all patients with stable engraftment (35 patients). Twenty-nine patients died: 15 due to relapse/progression, 14 due to TRM. Survival with median follow-up of 18.5 months was significantly better in patients with matched related transplants compared to patients with other transplants. However, there was no difference between related and unrelated transplants with regard to engraftment, TRM and GVHD. In conclusion, our results in high-risk patients transplanted in CR or with smoldering leukemia from a related donor are encouraging, although a longer follow-up and a larger group of patients is needed in order to evaluate the role of different reduced-intensity preparative regimens in unrelated and related HSCT.

Feasibility and safety of peripheral blood stem cell transplantation from unrelated donors: results of a single-center study.

We compared the outcomes in patients receiving unrelated peripheral blood stem cell transplants (PBSCT) with those receiving bone marrow transplants (BMT) in a matched pair analysis. Seventy-four patients with hematological malignancies with HLA-matched (77%) and mismatched (23%) donors were analyzed in this study. Thirty-four patients (45%) were considered as high risk patients. Sixty-eight patients received standard conditioning regimens with Bu/Cy or TBI/Cy. Six patients received an intensified conditioning regimen with the addition of etoposide, thiotepa or melphalan. GVHD prophylaxis consisted of prednisolone, cyclosporine and methotrexate. Groups were matched for patient, donor, transplant characteristics and HLA compatibility. Peripheral blood stem cell collection led to the collection of a higher number of CD34+ and CD3+ cells in comparison to bone marrow collection. Leukocyte engraftment in the PBSCT group occurred in 14 days (median; range 6-26 days) and in the BMT group in 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly. The incidence of grades II-lV acute GVHD in the group of HLA-identical patients was 35% in the PBSCT group and 25% in the BMT group (P < 0.33, log-rank). However, there was a significant difference (P < 0.05, log-rank) in incidence and time to onset of acute GVHD II-IV comparing all patients, including the 17 mismatched transplants. Disease-free survival was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days for PBSC and BMT transplants, respectively. In conclusion, our results indicate that allogeneic PBSCT led to significantly faster leukocyte engraftment but is associated with a higher incidence and more rapid onset of severe acute GVHD comparing all patients, including the 17 mismatched transplants. However, the incidence of severe acute GVHD in HLA-identical patients was not different between the PBSCT and BMT groups.

Mycophenolate mofetil for the prophylaxis of acute GVHD in HLA-mismatched bone marrow transplant patients.

Mycophenolate mofetil (MMF), a new immunosuppressive drug successfully used in renal and heart transplant recipients, was used in combination with cyclosporin A (CsA), methotrexate (MTX) and prednisolone for the prophylaxis of acute graft-versus-host disease (aGVHD) after bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT) from human leukocyte antigen (HLA)-mismatched, unrelated (n = 9) and related donors (n = 4) in an open single-centre phase II study. Thirteen patients, transplanted from HLA-mismatched donors of 18-57 yr of age, received 1 g MMF daily, starting at day 10, in addition to CsA and prednisolone for aGVHD prophylaxis. All patients were engrafted between days 13 and 15. Four of the 13 patients experienced aGVHD grade I/II (n = 2) and grade III (n = 2). All patients except 3 were alive on day 100 post-transplantation. No severe adverse effects of MMF were recorded. In our pilot study, we demonstrated that MMF can be used safely for the prophylaxis of aGVHD.

Lenograstim-mobilized peripheral blood progenitor cells in volunteer donors: an open label randomized split dose escalating study.

Mobilization of peripheral blood cell progenitor cells was investigated in 36 healthy sibling donors using three different split doses of glycosylated rhG-CSF (lenograstim). The donors were randomized into three groups: group 1 was given lenograstim at 8, group 2 at 11 and group 3 at 15 micrograms/kg/day in two split doses, subcutaneously for 4 and 5 days, respectively. Leukapheresis was performed on day 4 or 5 depending on the WBC and CD34+ cell count. We were able to demonstrate that there was a significant correlation between circulating CD34+ cells on the day of harvest and CD34+ cells in the apheresis products in all three groups. The number of CD34+ cells pre-apheresis was inversely correlated with age in group 1 and group 2. However, in group 3, the number of CD34+ cells pre-apheresis did not correlate with age. There was also a difference between the number of progenitor cells mobilized in the three dose groups regarding the time of harvest. Apheresis was performed in groups 1 and 2 on day 5 of mobilization in order to obtain a sufficient number of stem cells for allogeneic transplantation. In contrast, with the split dose of 15 micrograms/kg/day, harvest could be routinely performed on day 4 of stimulation. We conclude that lenograstim given twice a day at doses of 8, 11 and 15 micrograms/kg/day provided different CD34+ cell yields in normal donors, in particular, with regard to the time of harvest. The number of CD34+ cells pre-apheresis was not correlated with age in the group of donors mobilized with a split dose of 15 micrograms/kg/day, indicating that this dosage might also be suitable for older donors.

Second allogeneic hematopoietic stem cell transplantation as treatment for leukemia relapsing following a first transplant.

We report 27 patients with relapsed acute or chronic leukemia who underwent a second hematopoietic stem cell transplant (HSCT) from a related or unrelated donor. Seventeen patients were diagnosed with acute myelogenous leukemia (AML), six with acute lymphocytic leukemia (ALL) and four with chronic myeloid leukemia (CML). Ages ranged from 22 to 49 years (median 37); 13 patients were female and 14 male. Relapse was diagnosed between 1 and 45 months after the first HSCT. Sixteen patients who relapsed had received an autologous transplant initially and 11 an allogeneic transplant. Ten patients relapsed within 6 months and 17 patients later than 6 months. Chemotherapy was used as reinduction for relapse after HSCT in 16 patients who had received an autologous transplant and in three who had received an allogeneic transplant, since the latter did not respond to reduction of immunosuppression to induce a graft-versus-leukemia (GVL) reaction. Five of these 19 patients (26%) achieved complete remission (CR), seven patients did not respond to chemotherapy and seven achieved a partial remission (PR). The stem cell source for the second HSCT included bone marrow (n = 12) and PBSC (n = 4) from genotypically identical unrelated donors, PBSC (n = 7) and bone marrow (n = 3) from related donors. Currently eight of the 27 patients are alive and disease-free after the second HSCT. One patient is alive and disease-free after two allogeneic transplants (day +1538), eight patients, who relapsed after an autologous transplant followed by an allogeneic transplant (days +248 to +1140), acute myeloid leukaemia (n = 6) and chronic myeloid leukemia (n = 2) are alive and disease-free. The overall disease-free survival is 30% (8/27). The overall disease-free survival of autologous transplant patients subsequently undergoing an allogeneic transplant is 43% (P = 0.049). It is suggested that a second HSCT is possible for patients with leukemia relapse following the first autologous transplant. A second transplant might also be offered to patients relapsing after the first allogeneic HSCT. Bone Marrow Transplantation (2000) 25, 41-45.

Chronic eosinophilic leukemia: successful treatment with an unrelated bone marrow transplantation.

The optimal treatment of eosinophilic leukemia is still uncertain. We report the successful treatment of a 21-year-old patient with eosinophilic leukemia, without cytogenetic abnormalities, by bone marrow transplantation from an unrelated donor. The conditioning regimen for the transplantation consisted of fractionated total body irradiation and cyclophosphamide. Acute GVHD, grade I, post-transplantation was successfully treated. No other severe complications occured. The patient is alive in complete remission 21 months after unrelated bone marrow transplantation.

Genotoxic effects of 2-trans-hexenal in human buccal mucosa cells in vivo.

In 7 non-smoking healthy volunteers, the number of micronuclei (MN) was determined in exfoliated buccal mucosa cells before and after rinsing the mouth with an aqueous 10 ppm solution of 2-trans-hexenal during 3 consecutive days. All individuals showed at least a doubling of the MN frequency during one of the next 4 days. An increase of the mean group MN frequency was observed on the fourth day, becoming significant between the sixth and the seventh day. During the next 2 days, the MN frequency dropped down to nearly the control level. In a second study, 7 other volunteers were examined before and after eating 3-6 bananas per day over a period of 3 days. The bananas contained about 35 ppm of hexenal. Six of the 7 individuals showed at least a doubling of the MN frequency during one of the next 6 days. An increase in the mean MN counts was also observed, but the difference to the control value become non-significant during the test period. The results show for the first time that the flavoring constituent 2-trans-hexenal, which is present in many human foods exerts genotoxic effects on human buccal mucosa cells in vivo.