Searching for alternative hematopoietic stem cell donors for pediatric patients

The use of alternative hematopoietic stem cell (HSC) donors has been witnessing important progress, mainly due to: (i) better HLA matching at the allelic level between donor and recipient in unrelated HSC transplantation (HSCT) translating into better patient outcome; (ii) better donor choice and patient selection in unrelated, often HLA-mismatched, cord blood transplantation and (iii) new strategies of adoptive cell therapy aimed at improving the results of T-cell-depleted haploidentical HSCT from a relative. Currently, it is possible to find an HSC donor for virtually almost all children with an indication to receive allogeneic HSCT and lacking an HLA-identical sibling. Each of the three options of HSCT from alternative donors has advantages and limitations. Therefore, any physician has to carefully evaluate, for each single pediatric patient in need of an allograft, all the possible alternatives to choose the best HSC donor, taking into account type of disease to be treated, urgency of transplantation, donor characteristics and center's experience. This review will analyze in detail the advantages and limitations of each of the three options of alternative donor HSCT and the main criteria to be used for choosing the most suitable donor for pediatric patients lacking an HLA-identical sibling.

Long-term outcomes after allogeneic stem cell transplantation for children with hematological malignancies

We analyzed long-term outcomes and psycho-social aspects in 112 children with malignancies surviving 1 year after hematopoietic stem cell transplantation. At 10 years, overall survival was 75+/-5%, TRM 18+/-4% and relapse 14+/-3%; 10-year cumulative incidence of infections was 31+/-4%, cataract 44+/-4%, pulmonary dysfunction 20+/-4%, bone and joint complications 29+/-5%, hypothyroidism 36+/-4%, cardiac complications 11+/-3% and secondary malignancies 7+/-3%. Total body irradiation (TBI) was the most significant risk factor associated with cataract, pulmonary impairment, osteoarticular complications and hypothyroidism. Chronic graft-versus-host disease was associated with higher incidence of pulmonary dysfunction. The number of complications per patient increased with time. Half of the patients had psychological disturbance, 13 signs of depression and 16 a history of eating behavior disorders; 54% of patients with one or more long-term complications had psychological problems. Sixty-nine patients had learning difficulties and 36 achieved normal scholarship. With increased follow-up, development of late effects and of psycho-social disturbance are of major concern. While the use of single-dose TBI has now been abandoned, other risk factors are still of concern in the early 2000s.

Hematopoietic stem cell transplantation for adults with acute promyelocytic leukemia in the ATRA era: a survey of the European Cooperative Group for Blood and Marrow Transplantation

We performed a survey of the European Cooperative Group for Blood and Marrow Transplantation to analyze the outcome of 625 acute promyelocytic leukemia (APL) patients transplanted with auto- or allogeneic-hematopoietic stem cell transplantation (autoHSCT, alloHSCT) after 1993, in first (CR1) or in second complete remission (CR2). Leukemia-free survival (LFS) at 5 years in CR1 was 69% for 149 patients autografted and 68% for 144 patients allografted, whereas in CR2, LFS was 51% in 195 autoHSCT and 59% in 137 alloHSCT recipients, respectively. In the group of autoHSCT for CR1 (n=149), higher relapse incidence (RI) was associated with shorter time from diagnosis to transplant (<7.6 months); transplant-related mortality (TRM) was increased in older patients (>47 years), whereas for CR2, longer time from diagnosis to transplant (>18 months) was associated with increased LFS and decreased RI. In the alloHSCT group for CR1 (n=144), age (<33 years) was associated with increased LFS and decreased TRM and for CR2 (n=137), the use of mobilized peripheral blood stem cells was associated with decreased TRM. Female recipient, a female donor to male recipient and transplants performed before 1997 were associated with decreased RI. In conclusion, HSCT still appears to have a role in APL, especially for patients in CR2.

Haematopoietic stem cell transplantation trends in children over the last three decades: a survey by the paediatric diseases working party of the European Group for Blood and Marrow Transplantation

This paper describes the trends in haematopoietic stem cell transplantation (HSCT) activity for children in Europe over the last three decades. We analysed 31,713 consecutive paediatric HSCTs reported by the European Group for Blood and Marrow Transplantation (EBMT) centres between 1970 and 2002. Data were taken from the EBMT registry and were compared according to period and centre category (paediatric or combined). Since 1996, there has been a significant increase in the number of HSCTs performed exclusively by paediatric centres, as well as in the number of alternative donor HSCTs, and in the use of peripheral blood stem cells (P<0.0001). The number of allogeneic HSCTs (allo-HSCTs) for acute lymphoblastic leukaemia, acute myeloblastic leukaemia and chronic myeloid leukaemia remained stable, whereas it increased for myelodysplastic syndromes and lymphomas, and decreased significantly for non-malignant diseases (P<0.0001). Multivariate analysis showed that younger age, human leukocyte antigen genoidentical donors, HSCT performed after 1996 and transplant centres performing more than 10 allo-HSCT/year were all associated with decreased transplant-related mortality (TRM) (P<0.0001). The number of autologus HSCTs (auto-HSCTs) for acute leukaemia decreased significantly, whereas it increased for solid tumours (P<0.0001). Multivariate analysis showed that both auto-HSCT performed before 1996 and paediatric solid tumours (P<0.0001) had higher TRM. Indications for paediatric HSCT have changed considerably during the last seven years. These changes provide tools for decision making in health-care planning and counselling.

HLA-identical sibling allogeneic peripheral blood stem cell transplantation with reduced intensity conditioning compared to autologous peripheral blood stem cell transplantation for elderly patients with de novo acute myeloid leukemia

We conducted a retrospective registry-based analysis to compare the outcome of 361 allogeneic human leukocyte antigen (HLA)-identical peripheral blood stem cell transplants (PBSCT) with reduced intensity conditioning (RIC) to that of 1369 autologous (auto) PBSCT in patients aged 50 years or older with de novo acute myeloid leukemia (AML), performed from 1997 until 2003 and reported to the European Group for Blood and Marrow Transplantation. Median age was 58 and 57 years in the RIC and auto groups, respectively. RIC patients had more advanced disease at the time of transplant. At a median follow-up of 24 months for RIC and 16 months for auto, multivariate analysis showed a lower risk for relapse (RR 0.77, P=0.013) without increased non-relapse mortality (NRM) in RIC patients (RR 1.26, P=0.28). Moreover, leukemia-free survival (RR 1.22, P=0.02) and overall survival (OS) (RR 1.32, P=0.005) were superior in the RIC group. In patients in 1st (CR), fewer relapses were counterbalanced by significantly increased NRM. Therefore, there was no survival advantage in this subgroup. In patients in 2nd or subsequent CR, LFS and OS were superior in the RIC group. RIC transplants show encouraging results in this older patient population with de novo AML.

Activating KIR genes are associated with CMV reactivation and survival after non-T-cell depleted HLA-identical sibling bone marrow transplantation for malignant disorders

Combinations of HLA and killer immunoglobulin-like receptors (KIR) may affect outcome in T-cell depleted haematopoietic stem cell transplantation (HSCT). The KIR gene family includes inhibitory (KIR2DL and 3DL) and activating receptors (KIR2DS). Ligands are HLA-C (KIR2D) and HLA-Bw4 (KIR3DL1) for inhibitory KIR and are still unknown for activating KIR. The impact of activating KIR genotypes from donor and recipient is poorly documented in HSCT outcome. Here, HLA and KIR genotypes were determined in 131 pairs from non-T-cell depleted HLA-identical sibling HSCT. No effect of 'missing KIR ligand' was detected on acute graft-versus-host disease (GVHD), relapse, survival or infections even in myeloid malignancies. However, additional activating KIR genes in the donor compared to the recipient's genotype or an identity between donor and recipient activating KIR genotypes was associated with a lower transplant-related mortality (TRM) (P=0.005) and in a multivariate analysis with a better survival (P=0.02, HR=0.28; P=0.013, HR=0.29) and a lower incidence of cytomegalovirus (CMV) reactivation (P=0.009, HR=0.36). These data highlight the impact of donor-activating KIR genes on TRM, overall survival and CMV reactivation in HLA-identical sibling HSCT.

Allogeneic and autologous transplantation for haematological diseases, solid tumours and immune disorders: definitions and current practice in Europe

The Accreditation Subcommittee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred since the first report was published in 1996. Haemopoietic stem cell transplantation today includes grafting with allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. The introduction of alternative therapies has challenged well-established indications such as imatinib for chronic myeloid leukaemia. An updated report with revised tables and operating definitions is presented here.

High-resolution HLA typing by sequencing for HLA-A, -B, -C, -DR, -DQ in 122 unrelated cord blood/patient pair transplants hardly improves long-term clinical outcome

To determine the impact of high-resolution (HR) HLA typing with outcomes after UCBT, DNAs of 122 pairs were analysed for HLA class I and class II mismatches (MM) based on HR typing. For HLA-A, -B on low-resolution typing and -DRB1 on HR typing, the following MM situation resulted: no MM (13%), one MM (40%), two MM (36%), three MM (8%), four MM (3%). For A, B, C, DR and DQ based on HR typing the following MM occurred: No MM (4%), one MM (10%), two MM (15%), three MM (22%), four MM (25%), five MM (12%), six MM (6%), seven MM (3%), eight MM (2%). There was no significant association between number of MM (HR) for both HLA-A, -B and -DRB1 and HLA-A, -B, -C, -DRB1 and DQB1 and aGvHD grade II-IV. There was a trend that MM in class I HR were associated with neutrophil recovery; HLA-A locus typing analysed in HvG direction was associated with reduced cumulative incidence of engraftment (P=0.04), the same for C-KIR in HvG direction (P=0.01). No significant correlation was found between numbers of HLA-MM on the HR level with 2-year survival. The analysis shows that the degree of mismatching in UCBT is even higher than expected.

Comparative outcome of reduced intensity and myeloablative conditioning regimen in HLA identical sibling allogeneic haematopoietic stem cell transplantation for patients older than 50 years of age with acute myeloblastic leukaemia: a retrospective survey from the Acute Leukemia Working Party (ALWP) of the European group for Blood and Marrow Transplantation (EBMT)

Results of reduced intensity conditioning regimen (RIC) in the HLA identical haematopoietic stem cell transplantation (HSCT) setting have not been compared to those after myeloablative (MA) regimen HSCT in patients with acute myeloblastic leukaemia (AML) over 50 years of age. With this aim, outcomes of 315 RIC were compared with 407 MA HSCT recipients. The majority of RIC was fludarabine-based regimen associated to busulphan (BU) (53%) or low-dose total body irradiation (24%). Multivariate analyses of outcomes were used adjusting for differences between both groups. The median follow-up was 13 months. Cytogenetics, FAB classification, WBC count at diagnosis and status of the disease at transplant were not statistically different between the two groups. However, RIC patients were older, transplanted more recently, and more frequently with peripheral blood allogeneic stem cells as compared to MA recipients. In multivariate analysis, acute GVHD (II-IV) and transplant-related mortality were significantly decreased (P=0.01 and P<10(-4), respectively) and relapse incidence was significantly higher (P=0.003) after RIC transplantation. Leukaemia-free survival was not statistically different between the two groups. These results may set the grounds for prospective trials comparing RIC with other strategies of treatment in elderly AML.

Cause of death after allogeneic haematopoietic stem cell transplantation (HSCT) in early leukaemias: an EBMT analysis of lethal infectious complications and changes over calendar time

We analysed a large homogeneous group of 14,403 patients transplanted for early leukaemia from an HLA-identical sibling and reported to the EBMT in four time cohorts: 1980-1989 (24%), 1990-1994 (26%), 1995-1998 (30%) and 1999-2001 (20%). We focused on death from infection. End points were survival, death from relapse and transplant-related mortality (TRM), which was subdivided into death from graft-versus-host disease (GvHD) (1315 patients; 25% of deaths), infection (597 patients; 11% of deaths) or 'other' causes (1875 patients; 34% of deaths). Survival increased from 52% at 5 years in the first to 62% in the third cohort (P<0.05) and TRM decreased from 36 to 26% (P<0.05) due to a reduction in death from infection (P<0.001). GvHD, 'other' causes and relapse did not improve. The relative proportions of bacteria (217 patients; 36%), viruses (183 patients; 31%), fungi (166 patients; 28%) or parasites (32 patients; 5%) as cause of infectious death (cumulative incidence of death at 5 years 1.8, 1.6, 1.4 and > or = 0.3%, respectively) and median time to death from infections (3 months (range 0-158 months)) did not change. Death from infections has been reduced significantly, but it still represents an ongoing risk after HSCT and draws attention to the time beyond the initial period of neutropenia.

A 10-year median follow-up study after allogeneic stem cell transplantation for chronic myeloid leukemia in chronic phase from HLA-identical sibling donors

We report long-term outcome in 102 patients with cCML transplanted from an HLA-identical sibling donor from 1982 to 1998. The conditioning regimen was based on cyclophosphamide associated with either total body irradiation (TBI) (37 patients) or with busulfan (63 patients). Graft-versus-host disease (GvHD) prophylaxis consisted of cyclosporin and methotrexate in the majority of the patients. Fifteen year overall survival was estimated at 53% (95% confidence interval (CI), 44-65) with a plateau after 2.5 years. Long-term survival was adversely affected by: longer time from chronic myeloid leukemia (CML) diagnosis to transplantation, older age at time of transplantation and GvHD (acute grade III-IV or chronic extensive). The main cause of death was infection, related to GvHD in 69% of patients. Splenectomy also significantly increased the risk of bacterial infection. 15-year relapse was estimated at 8% (95% CI, 0.1-14). Late malignancies occurred in seven patients, four of whom had an invasive cancer. Other frequent late complications included cataracts, psychological depression, osteonecrosis and hypothyroidism. These complications were more frequent following splenectomy, TBI and in patients with chronic extensive GvHD. We conclude that allogeneic transplantation with a related donor can cure more than half of CML patients in chronic phase, although physicians should be alert to long-term complications.

Granulocyte colony-stimulating factor for poor graft function after allogeneic stem cell transplantation: 3 days of G-CSF identifies long-term responders

Poor graft function (PGF) is a frequent cause of morbidity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). To study the value of granulocyte colony-stimulating factor (G-CSF) in PGF, we retrospectively analyzed 81 episodes of PGF in 66 patients transplanted from 01/94 to 01/99 from an HLA-identical sibling (n = 45) or an unrelated (n = 21) donor. Median age was 29 years, 55 patients had malignancies. A total of 11 patients received a CD34+ selected graft. Viral infections (25%), myelotoxic drug (33%), fungal/bacterial infections (14%), and GVHD (31%) were present before PGF diagnosis. Median time from allo-HSCT to PGF was 75 (25-474) days. All patients were treated with G-CSF. In 77/81 episodes, there was a response that was sustained in 57. A total of 27 patients presented an increase of white cell count (WBC) >0.1 x 10(9)/l after 3 days of G-CSF. The 5-year survival was 37% and was significantly better in patients with increased WBC > 0.1 x 10(9)/l after 3 days of G-CSF (65 vs 18%, P < 0.0001). In multivariate analysis, increased WBC > 0.1 x 10(9)/l after 3 days of G-CSF (P = 0.002) was associated with better survival, while BuCy-based conditioning (P = 0.02) and GVHD (P = 0.005) were associated with higher risk of death. In conclusion, hematological response after 3 days with G-CSF predicted a better survival for patients with PGF after allo-SCT.

History of the clinical use of umbilical cord blood hematopoietic cells

The first cord blood (CB) transplant was performed in 1988 in a patient with Fanconi anemia. The donor was his HLA-identical sister who was known by pre-natal diagnosis to be HLA identical and not affected by the Fanconi mutation. The CB was collected and cryopreserved at birth. The transplant was successful without GvHD and the patient is currently alive and free of disease more than 15 years after transplant, with full hematologic and immunologic donor reconstitution. At the time of the first transplant, little was known about the biologic properties of CB cells and it was thanks to the pioneering work of H. E. Broxmeyer and E. A. Boyse, who studied the progenitor cell content of CB, and of A. D. Auerbach, who realized the pre-natal diagnosis of Fanconi anemia, that this transplant was possible. Since this first transplant, many questions have been answered but others are still open for further research. For example: would a single CB unit contain enough stem cells to permanently engraft children and adults? Would maternal cell contamination in fetal blood engraft and give severe GvHD? What are the immunologic properties of CB cells? How does it interfere with GvHD, GvL and immune reconstitution? Is the immune immaturity of CB lymphocytes able to overcome the HLA barrier and authorize HLA-mismatched transplants? Is it possible to establish CB banks for unrelated and related transplants? What would be the criteria for collection, quality control and cryopreservation?

Use of intrathecal prophylaxis in allogeneic haematopoietic stem cell transplantation for malignant blood diseases: a survey of the European Group for Blood and Marrow Transplantation (EBMT)

SUMMARY

A survey was carried out among EBMT centres to describe the current practice concerning intrathecal (i.t.) prophylaxis in allogeneic stem cell transplantation for malignant diseases in patients with no central nervous system (CNS) manifestations of the disease at any time. A total of 90 centres reported their practice: 42 centres (47%) never used pre-transplant i.t. prophylaxis as part of the conditioning, whereas 48 centres (53%) gave i.t. prophylaxis to selected groups. The main indications were acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), and lymphoma (53, 33, and 23% of all centres, respectively). Prophylaxis was usually given to all patients with ALL, but often restricted to high-risk patients in AML and lymphoma. Of the 90 centres, 29 (32%) gave prophylactic i.t. treatment after the transplantation, mainly for the same indications as pre-transplant. This survey illustrates the heterogeneity in the current practice of i.t. prophylaxis in allogeneic transplantation for malignant blood disorders in Europe. The documentation in the literature to support the use of i.t. prophylaxis as part of transplantation for malignant diseases in patients without preceding CNS involvement is sparse. Based on the rarity of isolated CNS relapse after allogeneic stem cell transplantation, EBMT does not recommend routine i.t. prophylaxis to patients without prior CNS involvement.

Transplantation of peripheral blood stem cells as compared with bone marrow from HLA-identical siblings in adult patients with acute myeloid leukemia and acute lymphoblastic leukemia

PURPOSE

Several studies show that allogeneic peripheral blood stem cells (PBSCs) engraft more rapidly than bone marrow (BM). However, the data are inconsistent with regard to acute and chronic graft-versus-host disease (GVHD), relapse, transplant-related mortality (TRM), and leukemia-free survival (LFS).

PATIENTS AND METHODS

Between January 1994 and December 2000, 3,465 adult patients (older than 15 years of age) were reported to the European Group for Blood and Marrow Transplantation Registry from 224 centers. Among acute myeloid leukemia (AML) patients, 1,537 patients received BM and 757 patients received PBSC. In acute lymphoblastic leukemia (ALL) patients, the corresponding figures were 826 versus 345 patients who were analyzed for engraftment, GVHD, TRM, relapse, LFS, and survival.

RESULTS

In multivariate analysis, the recovery of neutrophils and platelets was faster with PBSC than with BM (P <.0001). Chronic GVHD was associated with PBSC in patients with AML (relative risk [RR], 2.11; 95% confidence interval, 1.66 to 2.7; P <.0001) and ALL (RR, 1.56; 95% confidence interval, 1.09 to 2.27; P =.02). PBSC versus BM in patients with AML or ALL was not significantly associated with acute GVHD, TRM, relapse, survival, or LFS. In multivariate analysis of patients with AML, factors significantly associated with improved LFS included first remission at transplant (P <.0001), promyelocytic leukemia (M3) versus other French-American-British types (P <.0001), and donor age below median 37 years (P =.02). In patients with ALL, first remission (P <.0001) and methotrexate included in the immunosuppressive regimen (P =.001) were associated with improved LFS.

CONCLUSION

Allogeneic PBSC results in faster neutrophil and platelet engraftment and a higher incidence of chronic GVHD than BM. However, acute GVHD, TRM, relapse, survival, and LFS were similar in patients receiving PBSCs versus BM.

Influence of bone marrow graft lymphocyte subsets on outcome after HLA-identical sibling transplants

OBJECTIVE

The aim of this study was to analyze bone marrow lymphocyte subsets and CD34 cell dose and their influence on the outcomes of bone marrow transplantation.

MATERIALS AND METHODS

Forty-eight patients (median age 30 years, range 5-54) receiving HLA-identical sibling bone marrow transplantation for hematologic malignancies were analyzed.

RESULTS

Median number (range) of nucleated cells and CD34+ cells infused were 2.4 (0.4-6.0) x 10(8)/kg and 3.5 (0.5-13.0) x 10(6)/kg, respectively. Probability of neutrophil recovery was 97%. In a multivariate analysis, time to neutrophil recovery was shortened when a higher number of CD3/CD8 cells was infused (> or =1.0 x 10(7)/kg) (hazard ratio [HR] = 2.13, p = 0.018); when the patient was female or had negative cytomegalovirus serology (HR = 2.03, p = 0.03; HR = 0.41, p = 0.009; respectively). The incidence of grade II to IV acute graft-vs-host disease (GVHD) was 47%. Infusion of >1 x 10(7) CD4 infused/kg increased the risk of acute GVHD (HR = 2.86, p = 0.03). Nineteen of 40 patients at risk experienced chronic GVHD, the risk of which was increased by diagnosis of chronic leukemia (p = 0.03), <2.0 x 10(8) nucleated cells infused/kg (p = 0.05), and a low number of all lymphocyte subsets, except CD19. Estimated 3-year survival rate was 54%. Risk of death was increased in patients receiving <3.5 x 10(6)CD34 infused/kg (HR = 0.37, p = 0.02). Only six patients relapsed.

CONCLUSIONS

A high cell dose of CD3/CD8 is associated with faster neutrophil recovery, whereas a high cell dose of CD4+ cells increases the incidence of acute GVHD. A high number of nucleated cells and CD34+ cells infused was associated with decreased risk of chronic GVHD and improved survival, respectively.

Factors affecting lymphocyte subset reconstitution after either related or unrelated cord blood transplantation in children -- a Eurocord analysis

Immune recovery after cord blood transplantation (CBT) is of concern owing to the low number of lymphocytes transferred with the graft and their immaturity. Risk factors influencing lymphocyte subset reconstitution related to disease, patient, donor and transplant were studied in 63 children (< 16 years), given either related (n = 14) or unrelated (n = 49) CBT for malignant (n = 33) or non-malignant diseases (n = 30). Only children with sustained myeloid engraftment were analysed. Absolute numbers of T (CD3(+), CD4(+), CD8(+)), B and natural killer (NK) cells were reported 2--3, 6, 9, 12 and 12--24 months after CBT. Median patient age was 4.0 years (0--15) and median follow-up was 23 months (1.7--61.0). Twenty-six patients received human leucocyte antigen (HLA)-matched CBT and 37 received HLA-mismatched CBT. The median number of nucleated cells (NCs) collected/recipient weight was 6.1 x 10(7)/kg. In this selected population, the estimate 2 year survival was 85%. Lymphocyte reconstitution (defined as the median time to reach the normal value of age-matched healthy children) was 3, 6 and 8 months for NK, B and CD8(+) cells, while it was 11.7 months for both CD3(+) and CD4(+) lymphocytes. In the multivariate analysis, factors favouring T-cell recovery were: related donor (P = 0.002); higher NCs/kg (P = 0.005) and recipient cytomegalovirus (CMV)-positive serology (P = 0.04). Presence of acute graft-versus-host disease (GVHD) delayed T-cell recovery (P = 0.04). To summarize, in children with sustained myeloid engraftment the concern that lymphocyte recovery after CBT could be delayed does not appear to be substantiated by our results.

Results of unrelated umbilical cord blood hematopoietic stem cell transplantation

The number of umbilical cord blood transplants is increasing worldwide. The purpose of Eurocord is to evaluate the results and to compare the outcome of umbilical cord blood transplants with allogeneic bone marrow transplants. Data have been reported to Eurocord by multiple transplant centers. Close links have been established with the cord blood banks through Netcord. Bone marrow transplant data have been provided by transplant centers and also through the European Group for Blood and Marrow Transplantation (EBMT) and International Bone Marrow Transplant Registries (IBMTR). Eurocord has analyzed the outcome of unrelated umbilical cord blood transplants from 121 transplant centers and 29 countries. The results showed that survival with unrelated mismatched umbilical cord blood transplants was comparable to that with unrelated bone marrow transplants. Engraftment with cord blood was delayed, resulting in an increased incidence of early transplant complications. The incidence of acute and chronic graft-vs.-host disease was reduced with cord blood grafts even in human leukocyte antigen (HLA)-mismatched transplants and in adults. In patients with leukemia, the rate of relapse was similar to the rate of relapse after bone marrow transplant. The overall event-free survival with umbilical cord blood transplantation was not statistically different when compared to bone marrow transplants. This large registry study confirms the potential benefit of using umbilical cord blood hematopoietic stem cells for allogeneic transplants.

Results of unrelated umbilical cord blood hematopoietic stem cell transplant

The number of umbilical cord blood transplants (UCBT) is increasing worldwide, and the purpose of Eurocord is to evaluate the results and compare the outcome of UCBT with allogeneic bone marrow transplants (BMT). Data have been reported to Eurocord by many transplant centers. Close links have been established with cord blood banks through Netcord. BMT data have been provided by transplant centers and also by the European Blood and Marrow Transplant (EBMT) and International Bone Marrow Transplant Registries (IBMTR). Eurocord has analyzed the outcome of unrelated UCBT from 121 transplant centers and 29 countries. The results have shown that survival with unrelated mismatched UCBT was comparable to that with unrelated BMT. Engraftment with cord blood was delayed, resulting in an increased incidence of early transplant complications. The incidence of acute and chronic graft-versus-host-disease (GVHD) was reduced with cord blood grafts even in HLA mismatched transplants and in adults. In patients with leukemia, the rate of relapse was similar to that after BMT. The overall event-free survival with UCBT was not statistically different when compared to BMT. In conclusion, this large registry study confirms the potential benefit of using umbilical cord blood hematopoietic stem cells for allogeneic transplants.

Comparison of outcomes of unrelated bone marrow and umbilical cord blood transplants in children with acute leukemia

In order to compare the outcomes of unrelated umbilical cord blood transplants (UCBTs) or bone marrow transplants, 541 children with acute leukemia (AL) transplanted with umbilical cord blood (n = 99), T-cell-depleted unrelated bone marrow transplants (T-UBMT) (n = 180), or nonmanipulated (UBMT) (n = 262), were analyzed in a retrospective multicenter study. Comparisons were performed after adjustment for patient, disease, and transplant variables. The major difference between the 3 groups was the higher number in the UCBT group of HLA mismatches (defined by serology for class I and molecular typing for DRB1). The donor was HLA mismatched in 92% of UCBTs, in 18% of UBMTs, and in 43% of T-UBMTs (P <.001). Other significant differences were observed in pretransplant disease characteristics, preparative regimens, graft-versus-host disease (GVHD) prophylaxis, and number of cells infused. Nonadjusted estimates of 2-year survival and event-free survival rates were 49% and 43%, respectively, in the UBMT group, 41% and 37% in the T-UBMT group, and 35% and 31% in the UCBT group. After adjustment, differences in outcomes appeared in the first 100 days after the transplantation. Compared with UBMT recipients, UCBT recipients had delayed hematopoietic recovery (Hazard ratio [HR] = 0.37; 95% confidence interval [95CI]: 0.27-0.52; P <.001), increased 100 day transplant-related mortality (HR = 2.13; 95CI: 1.20-3.76; P <.01) and decreased acute graft-versus-host disease (aGVHD) (HR = 0.50; 95CI: 0.34-0.73; P <.001). T-UBMT recipients had decreased aGVHD (HR = 0.25; 95CI: 0.17-0.36; P <.0001) and increased risk of relapse (HR = 1.96; 95CI: 1.11-3.45; P =.02). After day 100 posttransplant, the 3 groups achieved similar results in terms of relapse. Chronic GVHD was decreased after T-UBMT (HR = 0.21; 95CI: 0.11-0.37; P <.0001) and UCBT (HR = 0.24; 95CI: 0.01-0.66; P =.002), and overall mortality was higher in T-UBMT recipients (HR = 1.39; 95CI: 0.97-1.99; P <.07). In conclusion, the use of UCBT, as a source of hematopoietic stem cells, is a reasonable option for children with AL lacking an acceptably matched unrelated marrow donor.

Influence of CD34(+) marrow cell dose on outcome of HLA-identical sibling allogeneic bone marrow transplants in patients with chronic myeloid leukaemia

In order to study the influence of bone marrow CD34(+) cell dose on the outcome of allogeneic bone marrow transplantation (BMT), we analysed the results of BMT from HLA-identical siblings donors in 50 patients with chronic myeloid leukaemia (CML). The median numbers of nucleated cells (NC) and CD34(+) cells infused were 2.18 x 10(8)/kg (0.05-4.14 x 10(8)/kg) and 3.12 x 10(6)/kg (0.35-8.52 x 10(6)/kg), respectively. All patients engrafted. In univariate analysis, there was no correlation between the number of CD34(+) cells infused and the time to neutrophil recovery (P = 0.17). The Kaplan-Meier estimate of grade II-IV acute graft-versus-host disease (GVHD) at day 100 was 53 +/- 14% and 2-year survival was 46 +/- 15%. A number of CD34(+) cells infused greater than the median was the main factor increasing survival (P = 0.0006) and decreasing 100 day transplant-related mortality (P = 0.009). Patient-, disease- and transplant-related characteristics were not statistically different among patients receiving more or less than the median number of CD34(+) cells. The rate of infectious deaths was significantly higher in patients receiving less than 3.12 x 10(6) CD34/kg (48% vs 16%, P = 0.01). In a multivariable analysis, two factors associated with increased risk of death were advanced disease status at transplant (HR: 2.5 (95% CI: 1.09-5.75), P = 0.03) and a lower number of marrow CD34(+) cells infused/kg (HR: 4.55 (95% CI: 1.87-10.90), P = 0.0008).

Resistant herpes simplex virus type 1 infection: an emerging concern after allogeneic stem cell transplantation

Fourteen cases of severe acyclovir-resistant herpes simplex virus type 1 (HSV-1) infection, 7 of which showed resistance to foscarnet, were diagnosed among 196 allogeneic stem cell transplant recipients within a 29-month period. Recipients of unrelated stem cell transplants were at higher risk. All patients received foscarnet; 8 subsequently received cidofovir. Strains were initially foscarnet-resistant in 3 patients and secondarily so in 4 patients. In vitro resistance to acyclovir or foscarnet was associated with clinical failure of these drugs; however, in vitro susceptibility to foscarnet was associated with complete response in only 5 of 7 patients. No strain from any of the 7 patients was resistant in vitro to cidofovir; however, only 3 of 7 patients achieved complete response. Therefore, acyclovir- and/or foscarnet-resistant HSV-1 infections after allogeneic stem cell transplantation have become a concern; current strategies need to be reassessed and new strategies must be evaluated in this setting.

Graft-versus-host disease in children who have received a cord-blood or bone marrow transplant from an HLA-identical sibling. Eurocord and International Bone Marrow Transplant Registry Working Committee on Alternative Donor and Stem Cell Sources

BACKGROUND

Umbilical-cord blood as an alternative to bone marrow for hematopoietic stem-cell transplantation may lower the risk of graft-versus-host disease (GVHD).

METHODS

We studied the records of 113 recipients of cord blood from HLA-identical siblings from the period from 1990 through 1997 and compared them with the records of 2052 recipients of bone marrow from HLA-identical siblings during the same period. The study population consisted of children 15 years of age or younger. We compared the rates of GVHD, hematopoietic recovery, and survival using Cox proportional-hazards regression to adjust for potentially confounding factors.

RESULTS

Recipients of cord blood were younger than recipients of bone marrow (median age, 5 years vs. 8 years; P<0.001), weighed less (median weight, 17 kg vs. 26 kg; P<0.001), and were less likely to have received methotrexate for prophylaxis against GVHD (28 percent vs. 65 percent, P<0.001). Multivariate analysis demonstrated a lower risk of acute GVHD (relative risk, 0.41; P=0.001) and chronic GVHD (relative risk, 0.35; P=0.02) among recipients of cord-blood transplants. As compared with recovery after bone marrow transplantation, the likelihood of recovery of the neutrophil count and the platelet count was significantly lower in the first month after cord-blood transplantation (relative risk, 0.40 [P<0.001], and relative risk, 0.20 [P<0.001]), respectively. Mortality was similar in the two groups (relative risk of death in the recipients of cord blood, 1.15; P=0.43).

CONCLUSIONS

Recipients of cord-blood transplants from HLA-identical siblings have a lower incidence of acute and chronic GVHD than recipients of bone marrow transplants from HLA-identical siblings.

Bone marrow transplantation in severe Glanzmann's thrombasthenia with antiplatelet alloimmunization

Glanzmann's thrombasthenia is an autosomal recessive disorder characterized by a lack of platelet aggregation due to the absence of platelet glycoprotein IIb and IIIa. Usually, the disease leads to mild hemorrhage but sometimes bleeding is severe enough to be life-threatening. We report the case of a 16-year-old girl, presenting with very severe type 1 Glanzmann's thrombasthenia, successfully treated with an HLA-identical sibling bone marrow transplant (BMT). We also update the clinical and laboratory data of her brother, who had received a BMT 16 years ago for the same disease. In the light of these two cases and two others published in the literature, we discuss the indications for BMT from HLA-identical sibling donors in Glanzmann's thrombasthenia. Alloimmunization against the missing platelet GPIIb/IIIa complex and severity of bleeding episodes may constitute sufficient criteria for allogeneic BMT after careful assessment of the risk-benefit of such a procedure, although this remains exceptional in this disease. Bone Marrow Transplantation (2000) 25, 327-330.

[Severe and recent hyponatremia and hypokalemia associated to the use of hydrochlorothiazide, enalapril and citalopram. Clinical case]

We report a 72 years old hypertensive female, treated with enalapril 10 mg/day and hydrochlorothiazide 25 mg/day during three years. She presented a depressive disorder and cytalopram was prescribed in a dose of 10 mg/day. Two weeks before admission, a serum electrolyte analysis disclosed normal results and the cytalopram dose was increased to 20 mg/day. The patient was admitted with a hyponatremic encephalopathy with a plasma sodium of 100 mEq/L and a plasma potassium of 2.0 mEq/L. Cytalopram, enalapril and hydrochlorothiazide were discontinued, hypertonic NaCl and KCl were administered. The patient had a favorable evolution with a remarkable improvement of her symptoms.

Haematopoietic transplant potential of unrelated and related cord blood: the first six years of the EUROCORD/NETCORD Bank Germany

To date, human umbilical cord blood (CB) has been employed successfully in well over 1000 allogeneic (unrelated and sibling) stem cell transplantations. Because of primary limitations in volume and cell numbers, over 90% of these transplantations were performed in children. Therefore requests for well standardised cord blood units of high quality are now increasing constantly. Examination and standardisation of unrelated and related cord blood stem cell preparations and banking as well as their biological characterisation was already initiated in Düsseldorf in 1992. Hitherto a total of 3236 CB samples with a mean volume of 89 +/- 25 ml, a mean total number of nucleated cells (NC) of 10 +/- 5 x 10(8) and a mean number of CFU-GM of 6 +/- 5 x 10(5) have also been validated by haematological, immunological and microbiological criteria. In addition to that, 97 directed CB donations of siblings with a clinical indication have been characterised and banked along the same lines. All CB units were collected from the umbilical cord vein immediately after vaginal full term delivery or caesarean section, then frozen and stored in liquid nitrogen. 1940 CB units were stored unseparated, the other 1296 were volume reduced using Hetastarch (HES) with a mean recovery of 85 +/- 13% of the nucleated cells, 86 +/- 12% and 84 +/- 13% for CFC and CD34+ cells, respectively. Only 5.0 ml of a CB sample is required for routine laboratory testing as there are HLA-class I typing, HLA-class II typing by sequence specific oligonucleotide probes (PCR-SOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony forming assays, and CD34+ status as well as certain viral infections such as CMV, Hepatitis B, C, HIV, Parvo B19 by PCR technology before releasing the CB unit for transplantation. For apparent viral infections, maternal sera obtained at birth were tested for HBsAg, anti-HBc, anti-HCV, -HAV-(IgG, IgM), -HIV-1-2, -EBV- (IgG, IgM), -HTLVI-II, -CMV (IgM, IgG), toxoplasmosis and syphilis. Within the last three years a total of 4860 preliminary searches and 680 extended unit reports were submitted to the CB bank Düsseldorf by fax or World Wide Web. So far 68 unrelated and 3 related CB units were delivered. From these 70 have been transplanted in 30 different transplant centres world-wide. Until now the evaluation of the first 53 unrelated CB-transplantations was performed together with the EUROCORD transplant registry. Three patients were excluded from the analysis, since they received an unrelated CB-transplant for non-engraftment after previous allotransplants. The median patient age of these 50 patients was 5.0 years (range 0.3-44), the median weight 18 kg (range 4-70 kg). The majority of the patients transplanted for malignancies (66%) suffered from ALL (n = 19), AML (n = 7), CML (n = 4) and lymphoma (n = 2) with two third (75%) in an intermediate (2nd CR) or advanced stage of disease (> 2nd CR); 13 patients had metabolic diseases and immunodeficiencies and three had aplastic anaemia. All CB samples as well as the patients' blood samples were typed in Düsseldorf for HLA-class I by serology confirmed by PCR-SSP and by high resolution DNA typing for HLA-DRB1 and HLA-DQB1 alleles. 96% of the 50 patients receiving unrelated CB were mismatched at one or more HLA-antigens. 41 of the 50 patients transplanted with unrelated CB from Düsseldorf were evaluable for engraftment with an overall engraftment rate of 83%. According to the defined criteria of EUROCORD, 9 of the 50 patients were not evaluable for engraftment, since they died before day 60. The present median follow-up time is 14 months (1.4-38). The Kaplan-Meier estimate of survival at one year is 42 percent. The three paediatric patients after sibling CB transplantations (ALL, amegakaryocytic thrombocytopenia and CML) are alive with a follow-up time of 350, 379 days and 531 days. (ABSTRACT TRUNCATED)

Factors associated with outcome after cord blood transplantation in children with acute leukemia. Eurocord-Cord Blood Transplant Group

We have analyzed factors influencing the outcome of 102 children with acute leukemia given a cord blood transplantation (CBT) and reported to the Eurocord Registry. Seventy patients with acute lymphoblastic and 32 with acute myeloid leukemia were given either a related (n = 42) or an unrelated (n = 60) CBT. Children given CBT during first or second complete remission were considered as belonging to the good-risk group (n = 66), whereas those who received a transplant in a more advanced stage of disease were assigned to the poor-risk group (n = 36). In the related group (RCBT), 12 of 42 patients received transplantation from an HLA-disparate donor, whereas in the unrelated group (UCBT) 54 of 60 received an HLA mismatched CBT. Kaplan-Meier estimates for neutrophil recovery at day 60 were 84% +/- 7% in RCBT and 79 +/- 6% in UCBT (P =.16). In multivariate analysis, the most important factor influencing neutrophil engraftment in UCBT was a nucleated cell dose infused greater than 3.7 x 10(7)/kg (P =.05, relative risk [RR] of 1.85, 95% confidence interval [CI]: 0.98-3.4). The incidence of grade II through IV acute graft-versus-host disease was 41% +/- 8% in the RCBT group and 37% +/- 6% in the UCBT group (P =.59). Kaplan-Meier estimates of 2-year event-free survival (EFS) after RCBT or UCBT were 39% +/- 8% and 30% +/- 7%, respectively (P =.19). In multivariate analysis, the most important factor influencing EFS was disease status at time of transplantation: good-risk patients had a 2-year EFS of 49% +/- 7% as compared to 8% +/- 5% in patients with more advanced disease (P =.0003, RR: 0.40, 95% CI: 0.24 to 0. 65). This was a consequence of both an increased 1-year transplant related mortality and a higher 2-year relapse rate in the poor-risk group (65% +/- 9% and 77% +/- 14%, respectively), as compared with good risk patients (34% +/- 6% and 31% +/- 9%, respectively). These data confirm that allogeneic CBT from either a related or an unrelated donor is a feasible procedure able to cure a significant proportion of children with acute leukemia, especially if transplanted in a favorable phase of disease.

Peripheral stem cells in bone marrow transplantation. Cord blood stem cell transplantation

Since it was shown that the number of haematopoietic stem cells contained in one sample of cord blood was sufficient for engrafting children and adults, cord blood banking has developed world wide. Cord blood banking has several advantages, including availability of this source of stem cells, low viral infection rate at birth, speed of the search and the possibility of collecting cord blood in ethnic groups under-represented in bone marrow donor registries. Other possible advantages which require further study, include a low risk of acute graft-versus-host disease, even with some degree of HLA mismatch. More than 700 cord blood transplants have been reported worldwide. The Eurocord Registry has analysed 250 cases. Briefly, analysis of the clinical results has shown that related cord blood transplants give better results than unrelated cord blood transplants. Factors associated with better survival in related and unrelated transplants were younger age, diagnosis with better results in inborn errors and children with acute leukaemia in first or second remission. High number of nucleated cells in the transplant and recipient negative cytomegalovirus serology were also favourable risk factors for survival.

Survival and prognostic factors of invasive aspergillosis after allogeneic bone marrow transplantation

To determine prognostic factors for survival in bone marrow transplant recipients with invasive aspergillosis (IA), we retrospectively reviewed 27 IA cases observed in our bone marrow transplantation unit between January 1994 and October 1994. On 30 September 1997, six patients were alive and disease-free. The median survival after IA diagnosis was 36 days. Of eight variables found to be related to survival according to the univariate analysis, graft-versus-host disease (GVHD) status at IA diagnosis (P = .0008) and the cumulative prednisolone dose taken during the week preceding IA diagnosis (CPDlw) (P < .0001) were selected by a backward stepwise Cox regression model. A three-stage classification was established: CPD1w of < or =7 mg/kg (3 of 8 patients died; 60-day survival rate, 88%), CPD1w of >7 mg/kg and no GVHD (9 of 10 patients died; 60-day survival rate, 20%), and CPD1w of >7 mg/kg and active acute grade 2 or more or extensive chronic GVHD (9 of 9 patients died; 30-day survival rate, 0) (P < .0001).

[Thyrotoxicosis induced by amiodarone]

The Authors report a case of toxic multinodular goiter induced by longstanding administration of Amiodarone, in which the option was near total thyroidectomy for control of toxic symptoms without withdrawal of the antiarhuthmic drug. In this case, the post-operative period was complicated by compressive cervical hematoma, which was managed by performing an emergent tracheostomy.

[Thyrotoxicosis induced by amiodarone]

The Authors report a case of toxic multinodular goiter induced by longstanding administration of Amiodarone, in which the option was near total thyroidectomy for control of toxic symptoms without withdrawal of the antiarhuthmic drug. In this case, the post-operative period was complicated by compressive cervical hematoma, which was managed by performing an emergent tracheostomy.

Unusual complications after bone marrow transplantation for dyskeratosis congenita

Dyskeratosis congenita (DC) is a rare inherited disorder often associated with aplastic anaemia. We report the cases of five boys transplanted with an HLA-identical related donor for severe aplastic anaemia (SAA) associated to DC; in all cases successful engraftment was observed. Three patients died 2-8 years after bone marrow transplantation (BMT) with signs of endothelial cell damage syndrome (kidney microangiopathy and liver veno-occlusive disease). Another boy died 1 year after BMT from Evans syndrome and invasive aspergillosis. One boy currently presents anaemia, polyarthritis of unknown origin, pulmonary fibrosis and gut malabsorption 7.5 years after BMT. SAA associated with DC can be successfully treated by allogeneic BMT. However, these early and late complications observed are very unusual after BMT and probably reflect the association of transplanted-related factors, evolution of the underlying disease, and increased sensitivity of endothelial cells. Modified conditioning approaches, advances in supportive care and surveillance of these unusual complications offer the possibility of improved outcome for these patients.

Cord blood banking and transplant in Europe. Eurocord

The number of cord blood transplants has been increasing very quickly with more than 250 cases reported to Eurocord Registry and more than 500 patients transplanted via the New York Cord Blood Bank. Cord blood transplants have been performed either with related or unrelated cord blood. Several cord blood banks established a group called Netcord whose goal is the standardization of the procedures, the organization of internal audits for accreditation and qualification, and the communication and exchange by internet of donor search on an international basis. More than 15,000 units of frozen cord blood are currently available and this number is increasing rapidly worldwide. Analysis of the clinical results has shown that related cord blood transplants give better results than unrelated cord blood transplants. Factors associated with better survival in related and unrelated cord blood transplants were lower age, diagnosis, with better results in inborn errors and in good risk children with acute leukemia. A larger number of nucleated cells in the transplant and the recipient being negative for CMV serology were also favourable risk factors for survival. Engraftment was improved with higher numbers of cells and HLA identity. Graft versus Host disease was reduced when compared to transplants of adult allogeneic bone marrow or peripheral blood progenitor cells. HLA disparities did not influence GVH; the only factor associated with increased GVH was positive CMV serology in the recipient. This study shows that cord blood is an alternative source of hematopoietic stem cells for allogeneic transplantation in children and in some adults. HLA disparity is not a limiting factor but the number of cells infused is important; currently the use of a number of nucleated cells inferior to 1 x 10(7)/kg is not recommended. Several questions remain including the criteria of choice of the donor, the indications in children and in adults, the comparison of cord blood transplants to other sources of hematopoietic stem cells and the role of growth factors and expansion for improving the speed of engraftment.

Cord blood banking and transplant in Europe. Eurocord

Cord blood banks have increased the use of cord blood transplants (CBT) for patients with hematological disorders. EUROCORD has established a registry for providing information on the outcome of CBT. Questionnaires were sent to all EUROCORD members to collect information on patients transplanted from 1988 to 1996. One hundred and forty-three CBT, performed in 45 centers, were analyzed for survival, engraftment and graft-versus-host disease (GVHD). Results in recipients of related and unrelated transplants were analyzed separately. In 78 patients who received CB from a related donor, 1-year survival was 63 +/- 6%. Age, weight, HLA identity and negative cytomegalovirus (CMV) serology in the recipient were significant favorable prognostic factors. Among these 78 patients, the incidence of grade > or = II GVHD was 9% in HLA matched CBT and 50% in mismatched CBT. Neutrophil engraftment was associated with age < 6 years (P = 0.02), weight < 20 kg (P = 0.02). It was 73% in patients receiving < 3.7 x 10(7) nucleated cells (NC) infused/kg and 85% in patients receiving more (P = 0.06). Among 65 patients, who received CB from an unrelated donor, 1-year survival was 29 +/- 7%. Negative recipient CMV serology was associated with improved survival (P = 0.01). Acute GVHD > or = II was observed in 40% of these patients. Negative recipient CMV serology was the most important factor for predicting GVHD (P = 0.04). Neutrophil recovery was 76% in patients receiving < 3.7 x 10(7) NC/kg and 94% in patients receiving more (P = 0.008). Cord blood is a feasible alternative source of hematopoietic stem cells for treating patients with various hematological disorders.

Cord blood transplantation (CBT) in hemoglobinopathies. Eurocord

Patients with beta-thalassemia (Hbeta th) and sickle cell anemia (SCA) can be treated with bone marrow transplantation. Stem cells from cord blood have several theoretical advantages, however, the place of cord blood transplant for hemoglobinopathies has not yet been established. We report here the EUROCORD experience of 10 patients (Hbeta th = 7, SCA = 3) transplanted with related cord blood.

Related cord blood transplants: the Eurocord experience from 78 transplants. Eurocord Transplant group

Eurocord Transplant has established a registry for studying results of cord blood transplant. We have analyzed 78 patients who have received a related CBT between October 1988 and December 1996. The median follow-up time was 29 months (1-99). The median age was 5 years (0.2-20), median weight 19 kg (5-50). Forty-six patients had a malignant disease: 32 acute leukemia (AL), six chronic myeloid leukemia (CML), four myelodysplastic syndrome, two neuroblastoma and two non-Hodgkin lymphoma. Thirty-two patients were transplanted for non-malignant diseases including 17 bone marrow failure syndromes (BMFS), three sickle cell anemia, five thalassemia and seven inborn errors. The donor was an HLA-identical sibling in 60 cases and an HLA-mismatched donor in 18 cases. As conditioning, 36 patients received irradiation and 40 patients received associated busulfan-containing regimens. GVHD prophylaxis consisted of CsA alone in 36 cases, CsA associated with prednisone in eight cases, CsA, methotrexate (Mtx) with or without prednisone in 28 cases and CsA with monoclonal antibody or ATG in four cases. The median number of nucleated cells (NC) infused/kg was 3.9 x 10(7) (0.7-15). One-year survival was 63 +/- 6%. Age, weight, HLA identity and negative cytomegalovirus (CMV) serology in the recipient were significant favorable prognostic factors. Among these 78 patients, the incidence of grade > or = II GVHD was 9% in HLA-matched CBT and 50% in mismatched CBT (P < 0.001). Neutrophil engraftment was associated with age <6 years (P = 0.02) and weight <20 kg (P = 0.02). It was 73% in patients receiving <3.7 x 10(7) nucleated cells (NC) infused/kg and 85% in patients receiving more (P = 0.06). Favorable factors for platelets engraftment were age <6 years (P = 0.03), weight <20 kg (P = 0.002) and HLA identity (P < 0.0001). Related cord blood transplantation offers a good alternative to BMT. Theses results are in favor of freezing cord blood in families in whom a transplant might be indicated.

European results of unrelated cord blood transplants. Eurocord group

This report summarizes the results of unrelated cord blood transplants. Sixty-five patients were reported to Eurocord. One year survival was 29%. Factors associated with survival were diagnosis, inborn errors had a better survival than leukemia or aplastic anemia; higher number of cells infused and negative pre-transplant CMV serology were also favorable factors. Granulocyte and platelet engraftment were associated with a higher number of nucleated cells infused, GVH incidence was low especially in CMV negative patients, it was not associated with the degree of HLA disparity. These results were similar to other series reported in the USA and showed the benefit of using mismatched unrelated cord blood in clearly defined situations.

Cord blood transplantation for children with acute leukemia. Eurocord Transplant Group

Over the past decade, allogeneic cord blood transplantation (CBT) has been widely used for treating patients with malignant disorders. However, the reported low incidence of GVHD observed after allogeneic CBT might be a major drawback in leukemic recipients and at present it is not clear whether CBT really predisposes patients to an increased risk of leukemia relapse. In order to further elucidate the role of CBT in children with hematological malignancies, 54 patients with ALL or AML given either a related (31 cases) or an unrelated (23 cases) CBT in 25 centers participating in the Eurocord Registry were analyzed. Overall survival of related and unrelated CBT recipients was substantially similar, the most important factor influencing patients' outcome being disease state at time of transplantation. In fact, due to a markedly increased relapse rate, poor-risk children (ie patients transplanted in more advanced disease) experienced a significantly worse EFS than those given CBT in a more favorable disease phase (ie CR1 or CR2). These data confirm that allogeneic CBT from either a related or an unrelated donor is a feasible procedure able to cure a significant proportion of children with acute leukemia, especially if transplanted in a favorable phase of disease.

Outcome of cord-blood transplantation from related and unrelated donors. Eurocord Transplant Group and the European Blood and Marrow Transplantation Group

BACKGROUND

Cord-blood banks have increased the use of cord-blood transplantation in patients with hematologic disorders. We have established a registry containing information on the outcome of cord-blood transplantation.

METHODS

We sent questionnaires to 45 transplantation centers for information on patients receiving cord-blood transplants from 1988 to 1996. Reports on 143 transplantations, performed at 45 centers, were studied, and the responses were analyzed separately according to whether the donor was related or unrelated to the recipient.

RESULTS

Among 78 recipients of cord blood from related donors, the Kaplan-Meier estimate of survival at one year was 63 percent. Younger age, lower weight, transplants from HLA-identical donors, and cytomegalovirus-negative serologic results in the recipient were favorable prognostic factors. Graft-versus-host-disease of at least grade II occurred at estimated rates of 9 percent in 60 recipients of HLA-matched cord blood and 50 percent in 18 recipients of HLA-mismatched cord blood. Neutrophil engraftment was associated with an age of less than six years (P = 0.02) and a weight of less than 20 kg (P = 0.02), and it occurred in 85 percent of patients receiving 37 million or more nucleated cells per kilogram of body weight. Among 65 patients who received cord blood from unrelated donors, the Kaplan-Meier estimate of survival at one year was 29 percent. Cytomegalovirus-negative serologic status in these recipients was associated with improved survival (P = 0.03) and was the most important predictor of graft-versus-host disease (P = 0.04). Neutrophil recovery occurred in 94 percent of the patients who received 37 million or more nucleated cells per kilogram from unrelated donors.

CONCLUSIONS

Cord blood is a feasible alternative source of hematopoietic stem cells for pediatric and some adult patients with major hematologic disorders, particularly if the donor and the recipient are related.