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.     

Acute graft-versus-host disease after unrelated donor umbilical cord blood transplantation: analysis of risk factors

Acute graft-versus-host disease (GVHD) occurs less frequently after umbilical cord blood transplantation (UCBT). More recent investigations include the use of 2 partially human leukocyte antigen (HLA)-matched UCB units, or double UCB graft, to meet the minimum cell-dose requirement. The purpose of this analysis was to assess the relative risk of acute GVHD in 265 consecutive patients receiving transplants with UCB graft composed of 1 (n = 80) or 2 (n = 185) units. The incidence of grade III-IV acute GVHD was similar between cohorts. However, the incidence of grade II-IV acute GVHD was higher among double UCBT recipients (58 vs 39%, P < .01). Three risk factors for grade II-IV acute GVHD were identified in multiple regression analysis: use of 2 UCB units, use of nonmyeloablative conditioning, and absence of antithymocyte globulin in the conditioning regimen. Transplantation-related mortality (TRM) at 1 year, however, was significantly lower after double UCBT (24 vs 39%, P = .02) even if recipients had grade II-IV acute GVHD (20 vs 39%, P = .05). These data suggest that, despite a higher incidence of grade II acute GVHD in recipients of 2 partially HLA-matched UCB units, there is no adverse effect on TRM. This study is registered at (http://www.clinicaltrials.gov) under the identifiers NCT00305682 and NCT00309842.     

Reduced intensity allogeneic umbilical cord blood transplantation in children and adolescent recipients with malignant and non-malignant diseases

There is a significant amount of morbidity and mortality following myeloablative umbilical cord blood transplantation (UCBT). Reduced intensity (RI) conditioning offers an alternative to myeloablative conditioning before UCBT. We investigated RI-UCBT in 21 children and adolescents with malignant (n=14), and non-malignant diseases (n=7). RI conditioning consisted of fludarabine (150-180 mg/m2) with either busulfan (< or = 8 mg/kg)+rabbit antithymocyte globulin (R-ATG; n=16) or cyclophosphamide+R-ATG+/-etoposide (n=5). Human leukocyte antigen match: 4/6 (n=13), 5/6 (n=5) and 6/6 (n=3). The median total nucleated cell and CD34+ cell dose per kilogram were 3.58 x 10(7) and 2.54 x 10(5), respectively. The median time for neutrophil and platelet engraftment was 17.5 and 52 days, respectively. There were six primary graft failures (chronic myelogenous leukemia (CML), beta-thalassemia, hemophagocytic lymphohistiocytosis (HLH) and myelodysplastic syndrome (MDS)). The probability of developing grade II to grade IV acute graft-versus-host disease (GVHD) and chronic GVHD was 28.6 and 16.7%, respectively. Incidence of transplant-related mortality (TRM) was 14%. The 5 years overall survival (OS) in all patients was 59.8%. The 5 years OS for patients with average versus poor-risk malignancy was 77.8 versus 22.2% (P=0.03). RI-UCBT may result in graft failure in specific high-risk chemo-na?ve patients (CML, beta-thalassemia, HLH and MDS), but in more heavily pretreated pediatric and adolescent recipients results in rapid engraftment and may be associated with decreased severe GVHD and TRM.     

Outcomes of unrelated cord blood transplantation in pediatric recipients

We report results of unrelated cord blood transplants (UCBT) in 29 pediatric recipients in one center and the risk factors associated with survival. Median age: 9 years (0.5-20); diagnosis: ALL (9), AML (4), CML (1), HD (3), HLH (1), NHL (3), NBL (2); B-thal (1), FA (1), FEL (1), Krabbe (1), WAS (1), SAA (1); median follow-up: 11 months; conditioning: total body irradiation (TBI)-ablative (14), chemotherapy-ablative (6) and reduced intensity chemotherapy (9); GVHD prophylaxis: MMF/FK506 (18), cyclosporin A (CsA)+steroids+/-MMF (7) or CsA+methotrexate (MTX) (4); median total nucleated cells (TNC): 3.8 x 10(7)/kg (1.1-11); median CD34+: 2.3 x 10(5)/kg (0.2-9.9); and HLA match: 2 (6/6), 5 (5/6), 22 (4/6). Neutrophil engraftment by cumulative incidence curves 63% (median 28 (95% confidence interval (CI) 18-32)). Probability of >/=grade II acute graft-versus-host disease (aGVHD) by day +60 27%, >/=grade III aGVHD 20% and chronic graft-versus-host disease 3%. Estimated 1-year overall survival (OS) 46% (95% CI 30-71) and standard risk 60% (95% CI 29-100%). Variables associated with improved survival by multivariate analysis include non-TBI-ablative conditioning (P=0.024), CD34+/kg (P=0.038) and gender (P=0.048). These results suggest that CD34/kg cell dose and non-TBI-ablative conditioning may be important variables influencing OS following UCBT in pediatric recipients. Given the small number of patients, these results should be viewed cautiously.     

Unrelated cord blood transplantation for thalassaemia: a single-institution experience of 35 patients

Our study was designed to prospectively determine whether or not unrelated cord blood transplantation (CBT) can produce outcomes comparable to related donor transplantation for children with β-thalassaemia. In 35 patients, 40 transplants were performed between October 2003 and September 2009. HLA matching at enrolment was 6/6 (n=8), 5/6 (n=16), 4/6 (n=27), or 3/6 (n=1) by low-resolution HLA-A, -B, and high-resolution DRB1. These patients received non-manipulated grafts without ex vivo expansion or T-cell depletion. The median number of nucleated and CD34+ cells infused was 7.8 × 10(7)/kg (range, 2.8-14.7 × 10(7)/kg) and 4.0 × 10(5)/kg (range, 1.7-19.9 × 10(5)/kg), respectively. The 5-year OS and thalassaemia-free survival after the first transplant were 88.3 and 73.9%, respectively. The cumulative incidence of TRM at 2 years was 11.7%. Fourteen patients developed chronic skin GVHD. Thirty patients were alive and transfusion-independent with a Lansky performance score ≥80% achieved between 6 and 76 months post transplant (median, 36 months). These data compare acceptably with the survival rates of related-donor BMT for thalassaemia and suggest that patients without an available HLA-compatible sibling but who have well-matched unrelated donors should also be considered for CBT.     

Reduced-intensity conditioning reduces the risk of severe infections after allogeneic peripheral blood stem cell transplantation

We compared the occurrence of severe infections following 71 reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell transplants (PBSCT) and 123 standard myeloablative PBSCT (MINI and STAND groups, respectively) from HLA-identical siblings. The probability of 1-year infection-related mortality (IRM) was 19% in the STAND group and 10% in the MINI group (log-rank, P = 0.3). On multivariate analysis the only significant variable associated with a higher risk of IRM was the development of moderate-to-severe GVHD (P = 0.005). The probability of developing CMV infection was 39% in the STAND group and 21% in the MINI group (P = 0.03) (43% and 21%, respectively, in seropositive donor/recipient pairs, P = 0.01), and the probability of developing CMV disease was 9.5% and 1%, respectively (P = 0.05) (11% and 1%, respectively, in seropositive donor/recipient pairs, P = 0.03). Multivariate analysis of CMV infection identified four variables associated with a higher risk: CMV positive serostatus (P = 0.05), STAND transplant group (P = 0.02), the development of moderate-to-severe GVHD (P < 0.001) and a dose of CD34(+) cells infused below 6 x 10(6)/kg (P = 0.01). Invasive fungal infections and pneumonias of unknown origin did not differ between groups, and neither did other severe non-CMV viral infections and bacterial infections. Our results suggest that RIC allogeneic PBSCT may decrease the risk of dying from an opportunistic infection and reduces the occurrence of CMV infection and disease. Overall, the development of GVHD (acute or chronic) is an important risk factor for these complications. Other infections continue to pose a significant threat to recipients of RIC allografts, stressing that prophylactic and supportive measures are an important aspect in their care.     

Faster engraftment of neutrophils and platelets with peripheral blood stem cells from unrelated donors: a comparison with marrow transplantation

Engraftment was achieved in 43/45 (95%) recipients of peripheral blood stem cells (PBSC) from HLA-compatible unrelated donors (n = 45), compared to all 45 patients in matched controls receiving bone marrow and 14/18 (78%) recipients of CD34-selected PBSC (P < 0.01). The time to reach ANC >0.5 x 10(9)/l was a median of 16 days in the PBSC and CD34 groups, compared to 20 days in the bone marrow controls (P < 0.001 vs PBSC). The time to reach platelets >50 x 10(9)/l was a median of 23 days in the PBSC group and 24 days in the CD34 group, which was significantly faster than 29 days in the bone marrow controls (P < 0.01). Acute GVHD grades II-IV developed in 30% in the PBSC group, 20% in the recipients of bone marrow and 18% in the CD34 group. The corresponding figures for chronic GVHD were 59%, 85% and 0% (P < 0.01) in the three groups, respectively. The probability of non-relapse death was 27% in the recipients of PBSC, 21% in the bone marrow controls and 60% in the CD34 group (NS). The 2-year leukaemia-free survival was 46% in the PBSC group, 41% in the bone marrow group and 25% in the CD34 group (NS).     

Transplantation in patients with SCID: mismatched related stem cells or unrelated cord blood?

Pediatric patients with SCID constitute medical emergencies. In the absence of an HLA-identical hematopoietic stem cell (HSC) donor, mismatched related-donor transplantation (MMRDT) or unrelated-donor umbilical cord blood transplantation (UCBT) are valuable treatment options. To help transplantation centers choose the best treatment option, we retrospectively compared outcomes after 175 MMRDTs and 74 UCBTs in patients with SCID or Omenn syndrome. Median follow-up time was 83 months and 58 months for UCBT and MMRDT, respectively. Most UCB recipients received a myeloablative conditioning regimen; most MMRDT recipients did not. UCB recipients presented a higher frequency of complete donor chimerism (P = .04) and faster total lymphocyte count recovery (P = .04) without any statistically significance with the preparative regimen they received. The MMRDT and UCBT groups did not differ in terms of T-cell engraftment, CD4(+) and CD3(+) cell recoveries, while Ig replacement therapy was discontinued sooner after UCBT (adjusted P = .02). There was a trend toward a greater incidence of grades II-IV acute GVHD (P = .06) and more chronic GVHD (P = .03) after UCBT. The estimated 5-year overall survival rates were 62% ± 4% after MMRDT and 57% ± 6% after UCBT. For children with SCID and no HLA-identical sibling donor, both UCBT and MMRDT represent available HSC sources for transplantation with quite similar outcomes.     

Factors influencing haematological recovery after allogeneic haemopoietic stem cell transplants: graft-versus-host disease, donor type, cytomegalovirus infections and cell dose

Platelet recovery after allogeneic haemopoietic stem cell transplant (HSCT) and predictive factors were analysed in 342 patients with haematological malignancies. All patients were prepared with cyclophosphamide plus total body irradiation, and received an unmanipulated HSCT from an HLA-identical sibling (n = 270), a matched unrelated donor (n = 67) or an identical twin (n = 5). The source of stem cells was peripheral blood (n = 15) or bone marrow (n = 327). Graft-vs.-host disease (GvHD) prophylaxis consisted of cyclosporin A with or without methotrexate. The proportion of patients with < 50 x 10(9)/l platelets on d +50, d +100, d +200 and d +365 after HSCT was 26%, 27%, 14% and 11% respectively. Thrombocytopenia was independent of the degree of complete donor chimaerism. Four variables were predictive of platelet recovery: donor type, acute GvHD, cytomegalovirus (CMV) infection and number of cells infused at transplant. Recipients of an unrelated graft had lower platelet counts (49 x 10(9)/l) on d +50 than identical sibling grafts (10(8) x 10(9)/l) (P < 0.001) and twin grafts (149 x 10(9)/l) (P < 0.001). Patients with GvHD grades 0, I, II, III and IV had significantly different platelet counts on d +50 (153 x 10(9)/l, 102 x 10(9)/l, 85 x 10(9)/l, 32 x 10(9)/l and 22 x 10(9)/l; P < 0.001) and thereafter. Thrombocytopenia was more frequent in patients with high-level CMV antigenaemia (> four positive cells/2 x 105) (P < 0.0001) and in patients who received a low cell dose at transplant (< or = 4.1 x 10(8)/kg) (P = 0.009). Platelet counts predicted transplant-related mortality (TRM) and were higher at all time intervals in patients surviving the transplant. Patients with grade II GvHD and > 50 x 10(9)/l platelets had a lower TRM than patients with grade II GvHD and < or = 50 x 10(9)/l platelets (14% vs. 40%, P < 0.0001). In conclusion, (i) a significant proportion of allogeneic HSCT recipients are thrombocytopenic long-term, irrespective of complete donor chimaerism, (ii) thrombocytopenia identifies patients at greater risk of lethal complications, and (iii) platelet recovery is influenced by GvHD, donor type, CMV infections and cell dose, not by stem cell source or other patient-disease-related variables.     

Late infections after allogeneic bone marrow transplantations: comparison of incidence in related and unrelated donor transplant recipients

Infectious complications are a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). We have evaluated the incidence of late infections (beyond day +50) in recipients of related (RD) and unrelated donor (URD) allogeneic BMT, factors associated with increased risks of infection, and the impact of the late infections on survival. Between 1989 and 1991, 249 patients received an RD (n = 151) or URD (n = 98) allogeneic BMT at the University of Minnesota and all late infections were investigated. Three hundred sixty-seven late infectious events developed in 162 patients between 50 days and 2 years after BMT. The incidence of any late infection was greater in URD versus RD recipients (84.7% v 68.2%, respectively; P = .009). In multivariate analysis, advanced graft- versus-host disease (GVHD) was significantly associated with late infections. The effect of GVHD was apparent only in RD recipients (relative risk [RR], 2.29; P = .003), whereas URD recipients, with or without GVHD, had more late infections compared with RD recipients without GVHD. Multivariate analysis showed that late posttransplantation infections were the dominant independent factor associated with increased nonrelapse mortality (RR, 5.5; P = .0001), resulting in improved 3-year survival for RD versus URD recipients (49.9% +/- 8% v 34.4% +/- 10%; P = .004). In this study, we observed that late infections are more frequent in URD recipients, resulting in substantially higher nonrelapse mortality. This prolonged period of increased infectious risk in URD recipients suggests the need for aggressive surveillance and therapy of late infections and perhaps prolonged antibiotic prophylaxis for all URD BMT recipients.     

A comparison of immune reconstitution and graft-versus-host disease following myeloablative conditioning versus reduced toxicity conditioning and umbilical cord blood transplantation in paediatric recipients

Immune reconstitution appears to be delayed following myeloablative conditioning (MAC) and umbilical cord blood transplantation (UCBT) in paediatric recipients. Although reduced toxicity conditioning (RTC) versus MAC prior to allogeneic stem cell transplantation is associated with decreased transplant-related mortality, the effects of RTC versus MAC prior to UCBT on immune reconstitution and risk of graft-versus-host disease (GVHD) are unknown. In 88 consecutive paediatric recipients of UCBT, we assessed immune cell recovery and immunoglobulin reconstitution at days +100, 180 and 365 and analysed risk factors associated with acute and chronic GVHD. Immune cell subset recovery, immunoglobulin reconstitution, and the incidence of opportunistic infections did not differ significantly between MAC versus RTC groups. In a Cox model, MAC versus RTC recipients had significantly higher risk of grade II-IV acute GVHD [Hazard Ratio (HR) 6·1, P = 0·002] as did recipients of 4/6 vs. 5-6/6 HLA-matched UCBT (HR 3·1, P = 0·03), who also had significantly increased risk of chronic GVHD (HR 18·5, P = 0·04). In multivariate analyses, MAC versus RTC was furthermore associated with significantly increased transplant-related (Odds Ratio 26·8, P = 0·008) and overall mortality (HR = 4·1, P = 0·0001). The use of adoptive cellular immunotherapy to accelerate immune reconstitution and prevent and treat opportunistic infections and malignant relapse following UCBT warrants further investigation.     

A novel reduced-intensity stem cell transplant regimen for nonmalignant disorders

Bone marrow transplantation (BMT) benefits nonmalignant diseases but is limited by regimen-related toxicity, graft-versus-host disease (GVHD), donor availability, and graft rejection (GR). To overcome some of these barriers, we developed a new conditioning strategy for these patients. In total, 16 patients received Campath-1H (33/48 mg; days -21 to -19), fludarabine (150 mg/m(2); days -8 to -4), melphalan (140/70 mg/m(2); day -3), and transplant using related/unrelated stem cells. GVHD prophylaxis included cyclosporine/methylprednisolone for cord cells. Other recipients also received methotrexate. Risk factors for GR included multiple transfusions (6), low stem cell numbers (1), and immunologic/metabolic disorders (3). Donor engraftment was present in 14/16 recipients. Neutrophils (ANC>0.5 x 10(9)/l) and platelets (>50 x 10(9)/l) engrafted at a median of 13 and 24 days. Two patients died of Pseudomonas sepsis prior to engraftment, one of CMV disease, and another of intracranial hemorrhage. With median follow-up of 281 days (78-907), 12/16 are stable/improved, or cured. Acute GVHD was absent (n=10) or mild and transient (grade1-2 skin) (n=4). There was no chronic GVHD. Toxicities were predominantly early infections within 100 days, and correlated with lymphopenia (CD4+ T and B cells). Stable engraftment and low incidence of significant GVHD, irrespective of age or stem cell source, make this reduced-intensity regimen attractive for nonmalignant disorders.     

Intensive strategy to prevent CMV disease in seropositive umbilical cord blood transplant recipients

Seropositive umbilical cord blood transplant (UCBT) recipients are at increased risk for CMV complications. To reduce CMV complications, we adopted an intensive strategy that consisted of ganciclovir administered before transplantation (5 mg/kg intravenously daily from day -8 to day -2), high-dose acyclovir (2 g, 3 times daily) after transplantation, and biweekly monitoring with a serum CMV PCR for preemptive therapy. Hazard rates and cumulative incidence of CMV complications along with days treated were compared in high-risk CMV-seropositive UCBT recipients who received the intensive strategy and a historical cohort who received a standard strategy. Of 72 seropositive patients, 29 (40%) received standard prophylaxis and 43 (60%) the new intensive approach. The hazard rate (HR) for CMV reactivation was lower for patients receiving the intensive strategy (HR 0.27, 95% confidence interval 0.15-0.48; P < .001) and led to fewer cases of CMV disease by 1 year (HR 0.11, 95% confidence interval 0.02-0.53; P = .006). In patients who reactivated, the intensive strategy also led to fewer days on CMV-specific antiviral therapy (median 42% [interquartile range 21-63] vs 70% [interquartile range 54-83], P < .001). Use of an intensive CMV prevention strategy in high-risk CMVseropositive UCBT recipients results in a significant decrease in CMV reactivation and disease.     

Unrelated cord blood transplantation in children with idiopathic severe aplastic anemia

Early results of unrelated cord blood transplantation (UCBT) for severe aplastic anemia (SAA) were poor with a high rate of engraftment failure. This was attributed to the combination of lower graft cell dose and intact host immune system. We performed UCBT in nine children (median age 9 years) with refractory SAA using increasingly immunosuppressive preparative regimens. The time from diagnosis to UCBT was 3.4-20 months (median age 7.2 years), with all children having failed at least one course of immunosuppression. Donor/recipient HLA matching was six of six (n=1), five of six (n=2) and four of six (n=6). The median nucleated cell dose infused was 5.7 x 10(7) cells/kg (range 3.5-20 x 10(7) cells/kg). Six patients were engrafted after the first UCBT. Two of the three patients without hematopoietic reconstitution were engrafted after a second UCBT. All children receiving >or=120 mg/kg of CY in the preparative regimen were engrafted. The median time to myeloid engraftment was 25 (17-59 days) days. Acute GVHD developed in two, and chronic GVHD in five patients. Five patients developed EBV viremia post transplant (lymphoproliferative disorder in three patients). At a median follow-up of 34 months, seven patients are alive and transfusion-independent. UCBT is a feasible treatment strategy for children with refractory SAA lacking a well-matched adult donor.     

Unrelated donor bone marrow transplantation for the treatment of Fanconi anemia.

Bone marrow transplantation (BMT) is the only known cure for the hematologic manifestations of Fanconi anemia (FA). Potential benefits of unrelated donor BMT for FA, however, have been severely limited by graft rejection and treatment-related mortality with resultant poor survival. Therefore, we evaluated the impact of potential prognostic factors on hematopoietic recovery, graft-versus-host disease (GVHD), and mortality in 98 recipients of unrelated donor BMT who received transplants between 1990 and 2003. Probabilities of neutrophil (89% vs 69%; P = .02) and platelet (74% vs 23%; P < .001) recovery were higher after fludarabine-containing regimens than nonfludarabine-containing regimens. Risks of acute GVHD (relative risk [RR], 4.29; P < .001) were higher with non-T-cell-depleted grafts. The day-100 mortality rate was significantly higher after nonfludarabine-containing regimens than fludarabine-containing regimens (65% vs 24%, respectively; P < .001). Corresponding 3-year adjusted overall survival rates were 13% versus 52% (P < .001). In addition, mortality was higher in recipients who were older (> 10 years), who were cytomegalovirus (CMV) seropositive, and who received more than 20 blood product transfusions before BMT. Based on these results, significant practice changes are suggested: use of a fludarabine-containing conditioning regimen in the context of T-cell-depleted marrow allografts, and earlier referral for transplantation prior to excessive transfusions in patients with marrow failure.     

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.     

Virological, clinical, and ophthalmologic features of cytomegalovirus retinitis after hematopoietic stem cell transplantation.

We identified 10 patients who developed cytomegalovirus (CMV) retinitis after HSCT during a 14-year period. The median day of diagnosis of CMV retinitis after transplantation was day 251 (range, days 106--365). CMV retinitis was associated with CMV serostatus of donor or recipient (P=0.01), CMV reactivation before day 100 (P=0.007), delayed lymphocyte engraftment (P<0.05), and chronic graft versus host disease (GVHD; P<0.001). In allogeneic recipients of HSCT who were alive at day 100 after transplantation and had chronic clinical extensive GVHD, the incidence of GVHD was 1.4% (8 of 577). Five of 10 patients had other manifestation of CMV disease before retinitis occurred (4 with gastrointestinal disease and 1 with interstitial pneumonia; median time, 70 days before onset of CMV retinitis; range, 58--279 days), and 4 others had CMV excretion. CMV retinitis was bilateral in 4 patients; 9 of 10 patients had ocular symptoms (i.e., decreased vision and floaters). Six of 7 patients responded well to ganciclovir or foscarnet systemic treatment, 1 improved only after switching to cidofovir, and 1 patient who received a transplant in 1983 did not respond to acyclovir treatment. In conclusion, CMV retinitis is an uncommon late complication after HSCT that occurs mainly in seropositive allograft recipients with previous CMV reactivation and chronic GVHD, and with delayed engraftment of lymphocytes.     

Increased risk of complicated CMV infection with the use of mycophenolate mofetil in allogeneic stem cell transplantation

Mycophenolate mofetil (MMF) is increasingly used for prophylaxis and therapy of GVHD in allogeneic stem cell transplantation. In some recent reports of use of MMF in solid organ transplantation a high incidence of CMV disease has been described. We evaluated the frequency and course of active CMV infection in patients who received MMF compared to those who did not receive MMF after allogeneic stem cell transplantation. We retrospectively analyzed 48 adult patients who consecutively underwent unmanipulated allogeneic bone marrow (n = 15) or peripheral stem cell transplantation (n = 33) from HLA-compatible family donors (n = 30) or unrelated donors (n = 18) from February 1997 to September 2000 at our institution. Only patients who were evaluable for the first 100 days were included in this analysis. Sixteen patients received MMF post transplant (MMF+). CMV-antigenemia was monitored by CMV-pp65 antigen. CMV-antigenemia occurred in 14 patients and was virtually only observed in CMV-IgG+ recipients (13/23, 56%). CMV-IgG+/MMF+ patients developed a higher incidence of CMV-antigenemia (8/9, 89%) compared to the CMV-IgG+/MMF- patients (5/14, 35%; P < 0.05). Moreover, five of six patients with persistent or recurrent CMV-antigenemia received MMF. No patient in either group developed CMV disease or died of CMV-related complications. In multivariate analysis including MMF treatment, unrelated vs related donor, GVHD, CMV-serostatus of the donor and stem cell graft type, only MMF treatment was found to be a significant risk factor for both overall and complicated CMV infection.     

Randomized clinical trial of ganciclovir vs acyclovir for prevention of cytomegalovirus antigenemia after allogeneic transplantation

Cytomegalovirus (CMV) disease remains a major cause of morbidity following allogeneic stem cell transplantation (SCT). In a prospective randomized trial, we tested prophylactic therapy with ganciclovir or acyclovir for patients at high risk of disease. Ninety-one CMV seropositive recipients of related (n = 53) and unrelated (n = 38) donor transplants were enrolled. All patients received intravenous (i.v.) ganciclovir 5 mg/kg every 12 h days -7 to -2, followed by acyclovir 10 mg/kg i.v. every 8 h from day -1 until neutrophil engraftment. Patients were then randomly assigned to either ganciclovir (n = 45) or acyclovir (n = 46) until day 100 post transplant. Any degree of antigenemia was treated with ganciclovir 5 mg/kg i.v. twice a day for 2 weeks, followed by 5 mg/kg i.v. each weekday for 6 weeks. At day 100, the cumulative incidence of antigenemia was 31% (95% CI 17-45%) for ganciclovir and 41% (95% CI 26-56%) (P = 0.22) for acyclovir prophylaxis, respectively. The assigned prophylaxis cohort did not predict for CMV antigenemia. The cumulative incidence of CMV disease at 12 months was 13% (95% CI 3-23%) and 17% (95% CI 6-28%) (P = 0.59) for the ganciclovir- and acyclovir-treated groups, respectively. An absolute neutrophil count (ANC) 相似文献   

Direct visualization of cytomegalovirus-specific T-cell reconstitution after allogeneic stem cell transplantation

Cytomegalovirus (CMV) remains an important cause of morbidity and mortality after allogeneic stem cell transplantation (SCT), but cytotoxic T lymphocytes (CTL) may play a critical role in controlling CMV reactivation. Fluorescent HLA-peptide tetramers containing immunodominant peptides from CMV were used to prospectively monitor the recovery of CMV CTL in recipients of allogeneic transplants from siblings (n = 13) or unrelated donors (n = 11). In patients given allografts from a sibling when both the patient and donor were seropositive for CMV before SCT, recovery of CMV-specific CTL was rapid and reached up to 21% of all CD8(+) T cells. Early reconstitution of CMV-specific immunity was not observed if either the donor or recipient was seronegative for CMV. In recipients of transplants from volunteer unrelated donors, recovery of CMV-specific CTL was delayed in comparison to that in recipients of transplants from siblings and no CTL were observed within the first 100 days after SCT. CTL numbers were increased after episodes of CMV reactivation but were suppressed by prednisolone therapy. Recovery of CMV-specific CTL to levels greater than 10 x 10(6)/L was associated with protection from CMV disease. It was concluded that use of HLA-peptide tetramers to quantify CMV CTL is valuable for studying T-cell responses after allogeneic SCT. It should allow prediction of CMV reactivation in individual patients and assist in the development of adoptive T-cell immunotherapy.