Cornelia Becker

Second unrelated bone marrow transplantation without additional conditioning therapy after engraftment failure.

A 37-year-old female highly alloimmunized by multiple transfusions received a sex matched HLA-identical unrelated bone marrow transplant for hypoplastic MDS-RA with moderate myelofibrosis. Conditioning consisted of total body irradiation, cyclophosphamide and ATG, GVHD prophylaxis consisted of CsA, MTX and prednisolone. The CD34+ stem cell content of the first graft was relatively low due to an inadequate harvest. The patient appeared not to have engrafted by day 23 post-BMT. She therefore received a second sex mismatched HLA-identical unrelated bone marrow graft on day 25 after two days of 3.5 mg/kg methylprednisolone from a different donor. Over the ensuing days, the first marrow showed slow engraftment followed by engraftment of the second graft. The first graft was then rejected, as monitored by peripheral blood studies of chimerism. No signs of acute GVHD were observed. Despite successful trilineage engraftment and complete second donor chimerism, the patient died from disseminated toxoplasmosis encephalitis and pneumonia on day +104.

Low tumor burden is associated with early B-cell reconstitution and is a predictor of favorable outcome after non-myeloablative stem cell transplant for chronic lymphocytic leukemia

Abstract Reconstitution, engraftment kinetics and tumor cell clearance were analyzed after reduced intensity conditioning hematopoietic cell transplant (RIC-HCT) in patients with chronic lymphocytic leukemia (CLL). Patients were transplanted from unrelated (n = 40) or related (n = 10) donors after fludarabine and 2 Gy total body irradiation followed by cyclosporine and mycophenolate mofetil. The vast majority of patients (96%) engrafted with absolute neutrophil count (ANC) > 0.5 × 109/L at day + 22. CLL cells decreased (median 2%, range 0–69%) within 28 days, but disappeared by day + 180 after HCT. Donor T-cell chimerism increased to > 95% at day 56 and donor B-cell chimerism to 94% at day + 360. Overall survival was 51 ± 8%, incidence of progression 37 ± 7% and non-relapse related mortality (NRM) 30 ± 7% at 4 years. The most common causes of NRM were graft-versus-host disease (GvHD) (14%) and sepsis (6%). Disease status at HCT was significantly associated with early B-cell reconstitution (p = 0.04) and with increased risk of relapse/progression in univariate and multivariate analysis (p = 0.022). Tumor cells were undetectable by day + 180, although B-cell reconstitution did not occur until 1.5 years after RIC-HCT. The best predictors for progression-free survival (PFS) and overall survival (OS) were complete response (CR) or first partial response (PR1) and the absence of bulky disease at transplant, respectively.