Charles Peters

The potential benefits of unrelated donor marrow transplantation are offset by the immunologic complications of graft-versus-host disease (GVHD) and infection. Therefore, we used cryopreserved umbilical cord blood (UCB) as a strategy to reduce the risks of GVHD and treatment-related mortality (TRM) and improve survival. Data on 102 patients (median age 7.4 years) who received transplants between 1994 and 2001 for the treatment of malignant (n = 65; 68% were high-risk patients) and nonmalignant (n = 37) diseases were evaluated. Log-rank tests and Cox regression analyses were used to determine the effects of various demographic, graft-related, and treatment factors on engraftment, GVHD, TRM, relapse, and survival. As of October 15, 2001, the median follow-up was 2.7 years (range, 0.3-7.2). Incidences of neutrophil and platelet engraftment were 0.88 (CI, 0.81-0.95) and 0.65 (CI, 0.53-0.77), respectively. Notably, incidences of severe acute and chronic GVHD were 0.11 (CI, 0.05-0.17) and 0.10 (CI, 0.04-0.16), respectively. At 1 year after transplantation, proportions of TRM and survival were 0.30 (CI, 0.21-0.39) and 0.58 (CI, 0.48-0.68), respectively. In Cox regression analyses, CD34 cell dose was the one factor consistently identified as significantly associated with rate of engraftment, TRM, and survival. Despite the low incidence of GVHD, the proportion of patients with leukemia relapse at 2 years was 0.17 (CI, 0.00-0.38) and 0.45 (CI, 0.28-0.61) for patients with standard and high-risk disease, respectively. There is a high probability of survival in recipients of UCB grafts that are disparate in no more than 2 human leukocyte antigens (HLAs) when the grafts contain at least 1.7 x 10(5) CD34(+) cells per kilogram of recipient's body weight. Therefore, graft selection should be based principally on CD34 cell dose when multiple UCB units exist with an HLA disparity of 2 or less.

Cerebral X-linked adrenoleukodystrophy (X-ALD) is a disorder of very-long-chain fatty acid metabolism, adrenal insufficiency, and cerebral demyelination. Death occurs within 2 to 5 years of clinical onset without hematopoietic cell transplantation (HCT). One hundred twenty-six boys with X-ALD received HCT from 1982 to 1999. Survival, engraftment, and acute graft-versus-host disease were studied. Degree of disability associated with neurologic and neuropsychological function and cerebral demyelination were evaluated before and after HCT. Complete data were available and analyzed for 94 boys with cerebral X-ALD. The estimated 5- and 8-year survival was 56%. The leading cause of death was disease progression. Donor-derived engraftment occurred in 86% of patients. Demyelination involved parietal-occipital lobes in 90%, leading to visual and auditory processing deficits in many boys. Overall 5-year survival of 92% in patients with 0 or 1 neurologic deficits and magnetic resonance imaging (MRI) severity score less than 9 before HCT was superior to survival for all others (45%; P <.01). Baseline neurologic and neuropsychological function, degree of disability, and neuroradiologic status predicted outcomes following HCT. In this first comprehensive report of the international HCT experience for X-ALD, we conclude that boys with early-stage disease benefit from HCT, whereas boys with advanced disease may be candidates for experimental therapies.

Untreated patients with Hurler syndrome (MPSIH) experience progressive neurologic deterioration and early death. Allogeneic bone marrow transplantation (BMT) ameliorates or halts this course. The Storage Disease Collaborative Study Group was formed to evaluate the effectiveness and toxicity of BMT. Effectiveness was defined as engrafted survival with continuing cognitive development. Fifty-four patients deficient in leukocyte alpha-L-iduronidase enzyme activity (median age, 1.8 years; range, 0.4 to 7.9) received high-dose chemotherapy with or without irradiation and BMT from HLA-genotypically identical sibling (GIS) or HLA-haploidentical related (HIR) donors between September 16, 1983 and July 14, 1995; all children were included in this report. Thirty-nine of 54 patients (72%) engrafted following the first BMT. The probability of grade II to IV acute graft-versus-host disease (GVHD) at 100 days was 32% for GIS and 55% for HIR patients. The probability of extensive chronic GVHD was 0% for GIS and 24% for HIR patients. The actuarial probability of survival at 5 years was 64% for all patients, 75% for GIS patients, 53% for HIR patients, and 53% for patients with donor marrow engraftment. The baseline Mental Developmental Index (MDI) was examined both for children less than and greater than 24 months of age at BMT. Children transplanted before 24 months had a mean baseline MDI of 78, while those transplanted after 24 months had a mean baseline MDI of 63 (P = . 0002). Both baseline and post-BMT neuropsychologic data were available for 26 of 30 engrafted survivors. Of 14 patients transplanted before 24 months of age, nine demonstrated developmental trajectories that were normal or somewhat slower than normal. In contrast, of 12 patients transplanted after 24 months of age, only three showed developmental trajectories that were normal or somewhat slower than normal (P = .01). For children with a baseline MDI greater than 70, there was a significant correlation between the MDI at follow-up study and leukocyte alpha-L-iduronidase enzyme activity (P = .02). Children were more likely to maintain normal cognitive development if they were fully engrafted following BMT from a donor with homozygous normal leukocyte alpha-L-iduronidase enzyme activity. Children who developed acute GVHD of grade II or worse had significantly poorer cognitive outcomes (P < .009). No difference in the post-BMT MDI was observed between patients whose preparative therapies did (n = 10; radiation dose, 300 to 1,400 cGy) or did not (n = 16) include radiation. We conclude that MPSIH patients, particularly those less than 24 months of age with a baseline MDI greater than 70, can achieve a favorable long-term outcome with continuing cognitive development and prolonged survival after successful BMT from a related donor with homozygous normal enzyme activity.

Long-term survival and improved neuropsychological function have occurred in selected children with Hurler syndrome (MPS I H) after successful engraftment with genotypically matched sibling bone marrow transplantation (BMT). However, because few children have HLA-identical siblings, the feasibility of unrelated donor (URD) BMT as a vehicle for adoptive enzyme therapy was evaluated in this retrospective study. Forty consecutive children (median, 1.7 years; range, 0.9 to 3.2 years) with MPS I H received high-dose chemotherapy with or without radiation followed by BMT between January 27, 1989 and May 13, 1994. Twenty-five of the 40 patients initially engrafted. An estimated 49% of patients are alive at 2 years, 63% alloengrafted and 37% autoengrafted. The probability of grade II to IV acute graft-versus-host disease (GVHD) was 30%, and the probability of extensive chronic GVHD was 18%. Eleven patients received a second URD BMT because of graft rejection or failure. Of the 20 survivors, 13 children have complete donor engraftment, two children have mixed chimeric grafts, and five children have autologous marrow recovery. The BM cell dose was correlated with both donor engraftment and survival. Thirteen of 27 evaluable patients were engrafted at 1 year following URD BMT. Neither T-lymphocyte depletion (TLD) of the bone marrow nor irradiation appeared to influence the likelihood of engraftment. Ten of 16 patients alive at 1 year who received a BM cell dose greater than or equal to 3.5 x 10(8) cells/kg engrafted, and 62% are estimated to be alive at 3 years. In contrast, only 3 of 11 patients receiving less than 3.5 x 10(8) cells/kg engrafted, and 24% are estimated to be alive at 3 years (P = .05). The mental developmental index (MDI) was assessed before BMT. Both baseline and post-BMT neuropsychological data were available for 11 engrafted survivors. Eight children with a baseline MDI greater than 70 have undergone URD BMT (median age, 1.5 years; range, 1.0 to 2.4 years). Of these, two children have had BMT too recently for developmental follow-up. Of the remaining six, none has shown any decline in age equivalent scores. Four children are acquiring skills at a pace equal to or slightly below their same age peers; two children have shown a plateau in learning or extreme slowing in their learning process. For children with a baseline MDI less than 70 (median age, 2.5 years; range, 0.9 to 2.9 years), post-BMT follow-up indicated that two children have shown deterioration in their developmental skills. The remaining three children are maintaining their skills and are adding to them at a highly variable rate. We conclude that MPS I H patients with a baseline MDI greater than 70 who are engrafted survivors following URD BMT can achieve a favorable long-term outcome and improved cognitive function. Future protocols must address the high risk of graft rejection or failure and the impact of GVHD in this patient population.

Over 400 patients with lysosomal and peroxisomal storage diseases have received hematopoietic stem cell transplantation from normal donors. Without treatment, all of these diseases have an inexorable fate leading to central nervous system deterioration and early death. On the other hand, all of the engrafted hosts have had a remarkable positive clinical improvement in response to normalization of previously deficient enzymatic activity. Survival data for those engrafted indicates continued life-span as long as two decades beyond transplantation. The particular diseases treated in this way are included in this article. The specific indications and methods for transplantation are also included in this article.