Congenital amegakaryocytic thrombocytopenia: a case report of pediatric twins undergoing matched unrelated bone marrow transplantation.

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare inherited disorder that presents with thrombocytopenia in infancy and evolves into bone marrow failure over time. Allogeneic hematopoietic stem cell transplant remains the only curative treatment option. We report our experience with identical twin sisters diagnosed with CAMT and treated successfully with matched unrelated donor bone marrow transplants. Before the transplant, 1 twin developed pancytopenia, whereas the other had a relatively benign clinical course. Choice of conditioning regimens was based on their pretransplant bone marrow cellularity and presence or absence of panyhypoplasia. Both twins tolerated the procedure well with no significant complications.

Pretransplant conditioning with Campath-1H (alemtuzumab) in pediatric matched unrelated hematopoietic stem cell transplants: an institutional experience.

Graft versus host disease (GVHD) remains a major cause of mortality and morbidity after matched unrelated hematopoietic stem cell transplantation (HSCT). Campath-1 H (alemtuzumab), a humanized monoclonal antibody to CD52 antigen, is thought to reduce GVHD incidence through in vivo T-cell depletion. Through the same mechanism it can potentially increase the risk of relapse by reducing the graft versus leukemia effect and possibly increase the risk of infection due to delayed immune recovery. A retrospective case analysis of 17 pediatric matched unrelated HSCTs done in our institution between January 2003 and June 2009 with Campath-1H as part of the pretransplant conditioning regimen was conducted. Grade I-II acute GVHD was noted in 29.4% of the HSCTs. No patient developed chronic GVHD. All but one patient with severe aplastic anemia engrafted. A relapse of primary disease was noted in 35.3% of the transplants. Three patient deaths were due to relapse and 1 due to disseminated varicella infection. Overall survival was 100% and 94% at 100 days and 1 year, respectively. Our experience suggests Campath-1H used as part of pretransplant conditioning regimen in pediatric unrelated HSCTs effectively reduces the risk of serious GVHD with no apparent increase in life-threatening infections or relapse compared with that reported with conventional regimens. Larger studies, with longer duration of follow-up, are required to further assess its role with regards to graft versus leukemia effect and to establish if the decreased incidence of GVHD and infectious complications is sustained in larger cohorts.

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.