Bone marrow transplantation in children using unrelated donors at Huddinge Hospital

Cytomegalovirus reactivation triggers the late onset of hyperthyroidism after autologous peripheral blood transplantation

Thyroid dysfunction is an important issue in patients receiving autologous and allogenic hematopoietic stem cell transplantation (HSCT). However, the exact mechanisms underlying thyrotoxicosis secondary to HSCT remain unclear. The present case exhibited a reversed imbalance in helper/suppressor T-cell populations and B-cell dysregulation for a long time after transplantation, and the reactivation of cytomegalovirus may have been associated with the development of clinical hyperthyroidism. The long-term monitoring of thyroid function, T-cell populations, and cytomegalovirus after HSCT is important.

Evans syndrome after unrelated bone marrow transplantation for refractory cytopenia of childhood

Post-transplant ES, which is often resistant to therapies, has seldom been described. This report describes a case of ES after UBMT for RCC. A five-yr-old boy developed RCC with no evidence of monosomy 7. Because no matching family donors were available for SCT and immunosuppressive therapy was ineffective, UBMT was performed when he was six yr old. The conditioning regimen included TAI (3 Gy) and administration of FLU, CY, and rabbit antithymocyte globulin. The recovery of blood cells was good. He displayed grade II acute GVHD involving only the skin. ES developed on day 66, with positive results for Epstein-Barr virus DNA and HHV 6. Cytopenia was resolved with treatment with RTX, GCV, an escalated dose of steroids, high-dose gammaglobulin, and romiplostim. No relapse has occurred since discontinuing steroids on day 177 and romiplostim on day 268. Post-SCT ES after UBMT is rare, and the risk factors and therapies are unclear. Prospective analysis and collection of cases from multiple centers are required for clarification.

Stem cell transplantation for patients with Evans syndrome

Evans syndrome (ES) is a chronic hematological disorder characterized by autoimmune hemolytic anemia and immune-mediated thrombocytopenia that often requires profound and long-term immunosuppression. Only a few small case series or single case studies of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) in patients with ES have been reported in the literature, with long-term remissions being observed after both autologous and allogeneic HSCT. Patients with ES suffering from refractory disease, multiple relapses and serious disease-related complications should be offered allogeneic HSCT, which is the only treatment with curative potential. Autologous HSCT might be preferable in patients with serious pre-existing comorbidities lacking an HLA-identical donor. Owing to the rarity of this disease and the small number of patients receiving HSCT for ES, prospective controlled studies on this approach are not available. A prospective registration of patients transplanted for ES would allow the development of optimal transplant strategies.

Tacrolimus with mini-methotrexate as prophylaxis for graft-versus-host disease in pediatric patients after allogeneic peripheral blood stem cell transplant or bone marrow transplant

Experience with tacrolimus in combination with mini-methotrexate to prevent graft-versus-host disease (GVHD) is limited in pediatric patients undergoing allogeneic blood or bone marrow transplants. We reviewed our use of this regimen in 24 pediatric patients who had 26 blood or marrow transplants. Acute GVHD occurred in 7 patients (4 unrelated donor transplants, 3 matched sibling transplants; 5 grade I to II, 1 grade III, and 1 not classifiable). One patient had extensive chronic GVHD (matched sibling transplant). In our experience, tacrolimus with mini-methotrexate has been well tolerated with minimal toxicity.

[A case of autoimmune hemolytic anemia complicating hematopoietic cell transplantation]

A 32-yr-old male diagnosed with myelodysplastic syndrome underwent an unmanipulated, unrelated, HLA matched, peripheral blood stem cell transplantation. The patient and donor were both blood type O, CcDEe. Twelve weeks post-transplantation, he developed acute autoimmune hemolytic anemia (AIHA). He was transfused multiple times with washed O red cells. High-dose steroid therapy was initiated and he underwent splenectomy; however, AIHA was refractory to therapy. The patient was further treated with combined treatment modalities including immunosuppressive therapy with mycophenolate mofetil and cyclosporine and three cycles of plasma exchange, and AIHA responded to treatment. This is the third case of AIHA complicating hematopoietic stem cell transplantation reported in Korea. Since AIHA is relatively common after hematopoietic stem cell transplantation, accurate and timely diagnosis of the disease and treatment strategies with multiple modalities are necessary.

Risk factors in pediatric stem cell transplantation for leukemia

To investigate which factors impact on survival, relapse, relapse free survival, transplant-related mortality (TRM) and graft-versus-host disease (GVHD) in children who undergo allogeneic stem cell transplantation, we included all 181 children transplanted due to leukemia at our unit. At the end of follow up 54% of the patients were alive, 27% had died due to relapse while 19% had died of other causes. Survival was similar in recipients of related (55%) and unrelated grafts (48%). Risk factors identified in univariate analysis were brought into a multivariable analysis. However, an unrelated donor was not identified as a risk factor for any of the five end-points analysed. A donor positive for three to four herpes viruses increased the risk of acute GVHD, TRM and death. A female to male transplant increased the risk of TRM, particularly if combined with a mismatch. Early stage of disease as well as human leukocyte antigen (HLA)-matching independently predicted survival. The risk of relapse increased after 1992. Chronic GVHD independently decreased the risk of relapse (relative risk RR, 0.39) and death (RR 0.42). We conclude that in children with leukemia other specific donor characteristics such as HLA-matching, gender, parity, and exposure to herpes viruses were more important for outcome than relationship.

Fatal Evans' syndrome after matched unrelated donor transplantation for hyper-IgM syndrome

A 3 and 1/2-yr-old boy underwent matched unrelated stem cell transplantation (SCT) for hyper-IgM syndrome. He developed acute and chronic skin graft-vs.-host disease (GVHD). Ten months following SCT he presented with severe hemolytic anemia and thrombocytopenia (Evans' syndrome). Treatment included high-dose steroids, intravenous immunoglobulins, cyclosporine, mycophenolate mofetil, chemotherapeutic agents (cyclophosphamide, vincristine, VP-16), immunoadsorption, and anti-CD20 and anti-CD52 monoclonal antibodies without response. The patient died 16 months after SCT.

Graft-versus-leukaemia effect in children: chronic GVHD has a significant impact on relapse and survival

To examine whether graft-versus-host-disease (GVHD) is associated with a graft-versus-leukaemia (GVL) effect that also influences the outcome of allogeneic stem cell transplantation (SCT) in childhood acute leukaemia, we evaluated all consecutive (n=169) children who had undergone SCT for ALL and AML at our centre. Median follow-up was 7 years. The 5-year probability of chronic GVHD was 34%. Median time to relapse was 24 months in children with chronic GVHD and 6 months in those without. The corresponding 5-year probabilities of relapse were 30 and 45% (P=0.01). The 5-year probability of survival was 54%. Patients with chronic GVHD had a significantly better survival, 77 vs 51% (P=0.01). In a Cox regression model, chronic GVHD independently decreased the risk of relapse (RR 0.44) and further predicted an increased chance of relapse-free survival (RR 1.7) and survival (RR 2.6). The impact of chronic GVHD on survival was most apparent in late-stage disease and in ALL. Acute GVHD was not an independent predictor for relapse or death in this study. This study is in support of a GVL effect in childhood leukaemia related to chronic GVHD, reducing the risk of relapse and improving survival.

Posttransplant immune-mediated hemolysis

BACKGROUND

Immune-mediated hemolysis is a well-recognized complication of transplantation, but few reports have drawn together the different mechanisms that could be involved.

STUDY DESIGN AND METHODS

The clinical and laboratory records of three patients are used to illustrate different types and complexities of posttransplant immune-mediated RBC destruction.

RESULTS

Patient 1 received bone marrow from an HLA-matched, unrelated donor. At 7 months after transplant, his Hb level fell to 50 g per L. The serum contained warm autoantibodies, and the DAT was strongly positive for IgG, IgM, and C3d; an eluate yielded IgG and IgM autoantibodies. Autoimmune hemolytic anemia was diagnosed. Patient 2, blood group A, experienced severe hemolysis 14 days after receiving a lung from a group O donor. The DAT was positive for IgG. Serum and RBC eluate contained anti-A produced by immunocompetent B cells in the transplanted lung-this was the passenger lymphocyte syndrome. Patient 3 experienced posttransplant hemolysis caused by two different immune mechanisms. Originally group A, D- with anti-C, -D, -E, she received a peripheral blood progenitor cell (PBPC) transplant from her HLA-identical group A, D+ son. Six months later, chimerism was evident; the remaining recipient marrow was still producing antibodies that destroyed D+ RBCs made by the transplant. Later, autoimmune hemolytic anemia also developed; the DAT became positive for IgG, and warm autoantibodies were eluted from D- RBCs.

CONCLUSION

An understanding of the causes and circumstances under which posttransplant immune hemolysis arises is required for proper management. As more patients become long-term survivors of unrelated bone marrow and/or PBPC transplants, chimerism and complex serologic problems will become more common.

Fludarabine-based protocol for haploidentical peripheral blood stem cell transplantation in Hurler syndrome

To assess the feasibility of performing a haploidentical peripheral blood stem cell transplantation (PBSCT) in a child with Hurler syndrome after a novel conditioning regimen consisting of fludarabine monophosphate, anti-T-lymphocyte globulin, low-dose busulfan, and single-dose total body irradiation of 750 cGy. A 16-month old boy with Hurler syndrome underwent haploidentical PBSCT from his 3/6 HLA-matched sister. Pretransplant conditioning consisted of fludarabine (30 mg/m2 per day) from day -10 to day -5, busulfan (4 mg/kg per day) on days -7 and -6, rabbit anti-T-lymphocyte globulin (10 mg/kg per day) from day -4 to day -1, and total body irradiation of 750 cGy on day -1. In vitro T-cell depletion was carried out with rat antihuman CDw52 monoclonal antibody (Campath-1G). The fludarabine-based protocol was well-tolerated, with mild toxicity and no major transplant-related complications or graft-versus-host disease. Engraftment was complete and stable. Chimerism was 100% donor origin, as determined by restriction fragment length polymorphism. Cytogenetic and polymerase chain reaction-various number of tandem repeats (PCR-VNTR) analyses of peripheral blood and bone marrow showed 100% reconstitution with female donor cells. The patient underwent the transplant 30 months ago and is in good clinical condition, with normal counts, no signs of graft-versus-host disease, and no infectious episodes; neurologic signs have stabilized. Haploidentical PBSCT, T-cell-depleted by means of Campath-1G, may serve as a therapeutic alternative for patients with Hurler syndrome when a fully matched sibling is not available.

Unrelated bone marrow transplantation in children: outcome and a comparison with sibling donor grafting

The clinical course of 59 children, who underwent BMT during 1988-1998 with a matched unrelated donor (MUD), was compared with 59 case controls receiving a sibling donor marrow. Thirty-eight patients had haematological malignancies while 21 had a nonmalignant disorder. The cumulative incidence of acute GVHD grade II-IV was 28% for MUD recipients vs 11% (P = 0.014) for sibling recipients. Extensive chronic GVHD was rare in both groups. The 5-year probability of survival was 52% for MUD vs 77% for sibling recipients (P= 0.014). For children with malignancies the 4-year probability of survival was 52% for MUD vs 67% for sibling recipients with a RFS of 49% vs 62%. In the ALL patients the survival of the MUD recipients was 77% and equalled that of the sibling group. For SAA survival was 43% vs 86% (P = 0.09) and for metabolic disorders 63% vs 89% (P = 0.025). The transplant-related mortality was higher in the MUD group, while death due to relapse was equally distributed. These results of MUD BMT in children compare favourably with most previous reports, and support the use of alternative donors in cases who lack an HLA-identical siblings. Bone Marrow Transplantation (2000).

Follow-up of chimerism, including T- and B-lymphocytes and granulocytes in children more than one year after allogeneic bone marrow transplantation

In bone-marrow-transplanted children, early detection of graft failure, relapse, and other potentially treatable problems is facilitated by the use of polymerase chain reaction (PCR) assays that monitor whether blood and marrow cells are of recipient or donor origin. Presence of mixed donor-recipient chimerism (MC) within the first year after BMT frequently correlates with clinical problems. To study if MC detected one year or more post-BMT was also often associated with clinical problems, the chimeric status in 33 children surviving 1-11 yr (median: 2 yr) after BMT was investigated. A PCR with a sensitivity of 1-2%, using fluorescent primers analyzing DNA fragment length polymorphisms, was applied. T- and B-cells and granulocytes were immunomagnetically isolated and tested separately for all patients. Of the 33 patients, of whom 21 had received pretreatment including total body irradiation (TBI), 27 (82%) exhibited full donor chimerism. Six children (18%), four of whom had received pretreatment without TBI, had MC. In three of these children, all with aplastic anemia, isolated T-cell MC had not posed apparent clinical problems. In two patients, both with MC including B-cells, immune hemolytic anemia was observed. A sixth patient with AML presented with MC and relapse. In two of the six children MC was detected only by cell subset analysis. In conclusion, analysis of MC in leukocyte subsets is more informative than analysis of whole blood only and may reveal clinically important variations in the origin of different cell populations. The prevalence of MC is lower after the first year post-BMT, and when present is less often associated with clinical problems.

Epstein-Barr virus (EBV) load in bone marrow transplant recipients at risk to develop posttransplant lymphoproliferative disease: prophylactic infusion of EBV-specific cytotoxic T cells

A semiquantitative polymerase chain reaction assay was used to monitor the blood levels of Epstein-Barr virus (EBV)-DNA in 9 patients receiving allogeneic bone marrow transplants (BMT). Four of 5 recipients of HLA-mismatched T-cell–depleted grafts showed a 4- to 5-log increase of EBV-DNA within 1 to 3 months after BMT. Administration of 2 to 4 infusions of 107 EBV-specific cytotoxic T-lymphocytes (CTLs)/m2 starting from the time of maximal virus load resulted in a 2- to 3-log decrease of virus titers in 3 patients. One patient, who received a T-cell culture lacking a major EBV-specific component, progressed to fatal EBV-positive lymphoma. Administration of EBV-CTLs before the onset of the EBV-DNA peak resulted in stabilization of the virus titers within 2 to 3 logs above the normal levels in the fifth patient. A moderate increase of virus titers was also detected in 3 of 4 patients receiving unmanipulated HLA-matched grafts, whereas 1 patient with Wiskott-Aldrich syndrome reached a 5-log increase of EBV-DNA load within 70 days after BMT. Our results suggest that a rapid increase of circulating EBV-DNA occurs in the absence of EBV-specific T-cell precursors or in the presence of congenital immune defects that prevent the reestablishment of virus-specific immunity. Prophylactic administration of EBV-CTLs early after BMT appears to provide the most effective protection against the development of EBV-associated lymphoproliferative disease.

Pediatric marrow transplantation for acute leukemia using unrelated donors and T-replete or -depleted grafts: a case-matched analysis

A retrospective, case-matched analysis of the short-term toxicity, risk of GVHD and relapse as well as outcome in pediatric unrelated marrow transplantation was conducted by comparing recipients of T-replete and -depleted grafts in a two-center setting. Both groups contained 30 patients with acute leukemia matched by age at transplant, gender, primary diagnosis and disease status. Acute (90% vs 53%) and chronic (48% vs 0%) GVHD were more common among recipients of T-replete grafts. No significant differences in graft rejection/failure or viral infections were encountered between the two groups. Relapses were more prevalent (37% vs 15%) among recipients of T-depleted grafts. Outcome (EFS) was similar in the two groups. Consequently, in the analysis of transplant outcome, the higher risk of procedure-related, toxic complications among pediatric recipients of T-replete marrow grafts appears to be balanced by an increased risk of relapse among the recipients of T-depleted grafts.

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.

Controversies and new approaches to treatment of Langerhans cell histiocytosis

There continues to be genuine ambivalence as to whether Langerhans cell histiocytosis (LCH) is a primary neoplastic or immuno-dysregulatory disorder. Treatment strategies have moved from one camp to the other depending upon the most current alleged successes or failures. This has been particularly true for patients who fall outside of the sphere where treatment is minimal or where known treatment approaches are clearly beneficial. However, there is growing evidence that LCH is both the result of clonal proliferation of Langerhans cells and the immunologic consequence of increased cellular activation. This new knowledge should be the basis for the development of new therapeutic approaches for patients with LCH and its complications.