Allogeneic stem cell transplantation after fludarabine, melphalan and thymoglobulin followed by early withdrawal of prophylactic immunosuppression in patients with acute lymphoblastic leukemia - update of single center study.

Presented are updated results of allogeneic hematopoietic stem cell transplantations (HSCTs) in 25 adult patients with acute lymphoblastic leukemia (ALL) in complete remission (CR) after a reduced intensity conditioning (RIC) combining fludarabine (150 mg/m2) and melphalan (140 mg/m2) with thymoglobulin (4.5 mg/kg or recently 4.0 mg/kg) followed by early initiation of reduction and withdrawal of prophylactic posttransplant immunosuppression. The median post-transplant follow-up was 32 (range, 4-87) months. Stable engraftment of donor's hematopoiesis was achieved in all patients. Acute graft versus host disease (GVHD) as well as the chronic one were equally observed in four cases (16%). Five patients (20%) relapsed with ALL in the median of 9 (range, 3-15) months after HSCT. During the above post-transplant follow-up, 4 recipients (16%) died. Disease progression and posttransplant complications were the cause of death in three (12%) and one (4%) of them, respectively. The probabilities of 2-year event-free (EFS) and overall survival (OS) were 70.3% (95% CI 51.9-88.7%) and 86.1% (95% CI 71.6-100%), respectively. Presented study confirmed our previously reported promising results and this approach may be considered as an alternative to traditional HSCTs performed in high-risk patients with ALL.

A novel HLA-B allele, HLA-B*35:279, identified by sequencing-based typing in a Czech patient.

The identification of a novel HLA-B*35:279 allele in a Czech patient is described. This allele is identical to the B*35:03:01 variant except the G/A nucleotide exchange at position 652 of the HLA-B gene that corresponds to the amino acid substitution from valine to isoleucine in alpha 3 domain of the HLA-B antigen.

Allogeneic stem cell transplantation after fludarabine, melphalan and thymoglobulin followed by early withdrawal of prophylactic immunosuppression could be an effective approach to patients with acute lymphoblastic leukemia.

Presented are results of allogeneic hematopoietic stem cell transplantations (HSCTs) in 13 patients with high-risk acute lymphoblastic leukemia (ALL) in the first complete remission after a reduced intensity conditioning combining fludarabine (150 mg/m2) and melphalan (140 mg/m2) with thymoglobulin (4.5 mg/kg). The immunosuppressive effect of T-cell depletion reducing the risk of graft-versus-host disease (GVHD) and non-relapse mortality was compensated by early initiation of reduction and withdrawal of prophylactic immunosuppression aimed at maintaining effective immunological antileukemic control. The median post-transplant follow-up was 23 (range, 10-65) months. Stable engraftment of donor's hematopoiesis was achieved in all patients. Acute GVHD was observed in two cases (15.4%); the chronic form was not noted. Two patients (15.4%) relapsed with ALL at 3 and 16 months after transplantation. During the above post-transplant follow-up, all 13 recipients were alive, with a probability of 2-year disease-free survival of 76.9% (95% CI 51-100%). Although the results were obtained with a small pilot study group it may be assumed that, given the prognostic risk of most patients and the nearly 2-year median post-transplant follow-up, the approach may be considered as an alternative to HSCTs after traditional myeloablative or reduced conditioning regimens with standard GVHD prophylaxis.

High-dose therapy and autologous stem cell transplantation in patients with diffuse large B-cell lymphoma in first complete or partial remission.

Improved survival has been observed in poor-risk diffuse large B-cell lymphoma (DLBCL) patients treated with high-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) in first complete remission. Retrospective studies have suggested that HDT with ASCT can improve survival also in partial responders but some doubts about the advantage of intensive therapy in such patients still remain. We evaluated retrospectively the results of HDT and ASCT in 55 patients with confirmed DLBCL treated between May 1999 and July 2006. Thirty-six patients (65%) showed partial remission (PR) and 19 patients (35%) reached complete remission (CR) after induction treatment with (44%) or without (56%) concomitant rituximab (R) immunotherapy. After HDT and ASCT, 69% of patients fulfilled the criteria of CR, 22% had unconfirmed CR (CRu), 7% remained in PR and 1 patient (2%) relapsed. Twenty patients in PR after the induction treatment reached CR after ASCT, 12 other PR patients achieved CRu. The 5-year event-free survival (EFS) of the 55 transplanted patients was 76% (95% confidence interval /CI/, 63% to 89%) and the 5-year overall survival (OS) was 85% (95% CI, 73% to 97%). The EFS and OS rates differed significantly only between patients younger than 40 years and older groups (p=0.022 and p=0.046, respectively). On univariate analysis of prognostic factors, EFS and OS were not affected by any of the following: age, sex, stage, subtype of DLBCL, initial lactate dehydrogenase, beta-2-microglobulin and serum thymidine kinase levels, International Prognostic Index (IPI) and age-adjusted IPI scores, induction treatment with or without rituximab and type of primary therapeutic response (CR vs PR). These results show that first-line HDT and ASCT for adults up to the age of 65 years with poor-risk DLBCL is a feasible and effective treatment option even in the era of R-chemotherapy in CR as well as for patients in PR.

Presence of cytochrome P450 enzymes in human CD34+ haematopoietic progenitor cells.

Human CD34+ cells (haematopoietic stem and progenitor cells separated from peripheral blood) were shown to express CYP2E1 protein by Western blotting. For the first time, the specific CYP2E1 activity (chlorzoxazone 6-hydroxylation) was also detected. No CYP3A4 protein neither the CYP3A-specific nifedipine oxidase activity were detectable. The results obtained indicate differences in content of active CYP proteins in populations of stem and progenitor cells from different species as the CYP3A2 (a rat form similar to human CYP3A4) was shown to be expressed in bone marrow derived cells by RT-PCR (Avital et al. 2001).