Second Allogeneic Hematopoietic Cell Transplantation for Patients with Fanconi Anemia and Bone Marrow Failure

Graft rejection markers in children undergoing hematopoietic cell transplant for bone marrow failure

CXCL9, BAFF, and sC5b-9 are potential biomarkers and therapeutic targets for graft rejection after transplant.

Fever monitoring is a widely available and informative predictor of graft rejection after transplant.

Graft rejection (GR) is a poorly understood complication of hematopoietic cell transplant (HCT). GR risk factors are well published, but there are no reliable biomarkers or therapies known. Fever is the most common symptom of GR, but no study has evaluated fever kinetics as a diagnostic marker of GR. The objectives of this study were to identify mechanisms, biomarkers, and potential therapies for GR after HCT. Chemokine ligand 9 (CXCL9), B-cell activating factor (BAFF), and complement markers (sC5b-9, C3a, and C5a) were measured in 7 patients with GR and compared with 15 HCT controls. All patients had a diagnosis of aplastic anemia, Fanconi anemia, or genetically undefined chromosomal fragility syndrome. All patients with GR were febrile during GR; therefore, control patients who underwent HCT were matched for diagnosis and early fevers after HCT. Patients withh GR had significantly higher CXCL9, BAFF, and sC5b-9 at the time of fever and GR compared with control patients who underwent HCT at the time of fever. The maximum fever was significantly higher and occurred significantly later in the transplant course in patients with GR compared with febrile HCT controls. These data support the use of CXCL9, BAFF, sC5b-9, and fever kinetics as GR markers. Two patients with GR underwent a second HCT that was complicated by high fevers. Both patients received interferon and complement blockers during their second HCT, and both preserved their graft. These laboratory and clinical findings support larger studies to evaluate the safety and efficacy of interferon, complement, and BAFF inhibitors for the prevention and treatment of GR after HCT.

Non-myeloablative conditioning for second hematopoietic cell transplantation for graft failure in patients with non-malignant disorders: a prospective study and review of the literature

Allogeneic hematopoietic cell transplantation (HCT) effectively treats several non-malignant disorders such as selected lysosomal disorders, cerebral adrenoleukodystrophy and hemoglobinopathies. However, rates of graft failure (GF) in non-malignant populations exceed those of patients with malignant indications for HCT. Salvage conditioning regimens and outcomes for second HCT for GF vary immensely in the literature. We report 17 consecutive pediatric patients with non-malignant disorders who underwent a second allogenic HCT for GF using a non-myeloablative, low-dose busulfan-based regimen. Graft sources for the second transplant included umbilical cord blood, unrelated bone marrow and unrelated PBSCs. Median age at time of second HCT was 6.6 years (1.1-14.6 years). Fourteen of seventeen patients (82%) achieved engraftment, with a 3-year overall survival of 82% (95% CI, 54-94%). Day 100 transplant-related mortality was 12% (95% CI, 0-27%). CMV and adenovirus reactivation occurred in 30% and fungal infections in 18%. The incidence of grade II-IV acute GvHD disease was 35% (95% CI, 13-58%) with only 6% grade III-IV (95% CI, 0-17%). In summary, we illustrate excellent overall survival and acceptable toxicity using a non-myeloablative conditioning regimen for second HCT as salvage therapy for first GF in patients with non-malignant conditions.

Successful treatment of secondary graft failure following unrelated cord blood transplant with hematopoietic growth factors in a pediatric patient with Fanconi anemia

Graft failure following allogeneic HCT in Fanconi anemia is associated with significant mortality. Retransplantation may be considered; however, the limited toxicity profile of HGFs also makes them an option for the treatment of graft failure. We describe a five-yr-old female diagnosed with Fanconi anemia and marrow failure treated with HCT. The course was complicated by secondary graft failure treated successfully with HGFs including G-CSF, EPO, and romiplostim. The outcome could be related to the intervention, but could also be the natural course of recovery, including recovering from a recent CMV infection treated with ganciclovir. We found the use of HGFs to be an effective and safe alternative to the potential complications as well as morbidity and mortality associated with the use of retransplantation.