Maria Screnci

Pre-transplant prognostic factors for patients with high-risk leukemia undergoing an unrelated cord blood transplantation

Summary:From July 1995 to December 2001, 42 patients with leukemia aged 1–42 years underwent cord blood transplant (CBT) from unrelated, ⩽2 antigen HLA mismatched donors. In all, 26 patients were in ⩽2nd complete remission and 16 in more advanced phase. Conditioning regimens, graft-versus-host disease (GVHD) prophylaxis and supportive policy were uniform for all patients. The cumulative incidence of engraftment was 90% (95% CI: 0.78–0.91). The cumulative incidence of III–IV grade acute- and chronic-GVHD was 9% (95% CI: 0.04–0.24) and 35% (95% CI: 0.21–0.60), respectively. The 4-year cumulative incidence of transplant-related mortality (TRM) and relapse was 28% (95% CI: 0.17–0.47) and 25% (95% CI: 0.14–0.45), respectively. The 4-year overall survival (OS), leukemia-free survival (LFS) and event-free survival (EFS) were 45% (95% CI: 0.27–0.63), 47% (95% CI: 0.30–0 .64) and 46% (95% CI: 0.30–0.62), respectively. In multivariate analysis, the most important factor affecting outcomes was the CFU-GM dose, associated with CMV serology (P=0.003 and 0.04, respectively) in influencing OS and with patient sex (P=0.008 and 0.03, respectively) in influencing LFS. Finally, CFU-GM dose was the only factor that affected EFS significantly (P=0.02). In conclusion, the infused cell dose expressed as in vitro progenitor cell growth is highly predictive of outcomes after an unrelated CBT and should be considered the main parameter in selecting cord blood units for transplant.

Flt3L induces the ex‐vivo amplification of umbilical cord blood committed progenitors and early stem cells in short‐term cultures

Umbilical cord blood (UCB) has been successfully used for haemopoietic stem cell transplantation, although its use has been cautiously limited to paediatric patients because of the reduced volume produced. The clinical results have confirmed that either engraftment or survival significantly correlate with cell dose infused. We have standardized a culture method providing in a short time a significant amplification of both committed progenitors and primitive stem cells for clinical use.

Umbilical cord blood transplant from unrelated HLA-mismatched donors in children with high risk leukemia

In the last 3 years, 14 children with high-risk leukemia (11 ALL, 2 AML and 1 CML) underwent cord blood transplantation from unrelated HLA-mismatched donors at a median of 99 days from the start of search. Eight patients were transplanted in second CR, one in accelerated phase, three at relapse and two patients in first CR. Conditioning regimen (fractionated TBI, etoposide, CY and anti-lymphocyte serum) and prophylaxis of GVHD (CsA and 6-methylprednisolone) were identical for all patients. Neutrophils > 0.5 × 109/l were reached at a median of 33 days from transplant, but in four cases we observed an autologous hematopoietic reconstitution (three spontaneous, one after autologous BM rescue). Acute and chronic GVHD were observed in 10/14 and 3/8 evaluable cases, respectively. Three patients died of transplant-related toxicity and three patients relapsed. The probabilities of event-free, disease-free and overall survival were 50, 53 and 64%, respectively. Cord blood transplant from HLA-mismatched unrelated donor is a valid option for the treatment of children with high-risk leukemia. With our eligibility criteria, conditioning regimen and prophylaxis of graft-versus-host disease, the main obstacles to successful transplant were represented by graft failure and fatal acute GVHD.

A prospective molecular study of chimaerism in patients with haematological malignancies receiving unrelated cord blood or bone marrow transplants: detection of mixed chimaerism predicts graft failure with or without early autologous reconstitution in cord blood recipients

We prospectively studied the chimaerism status in the bone marrow (BM) and peripheral blood (PB) of 23 patients receiving umbilical cord (UCB, 14 cases) or BM (nine cases) transplants from unrelated donors by PCR amplification of four individual‐specific VNTR genetic loci. Haematological engraftment, with persistent full donor pattern, was observed in 10/14 (72%) patients receiving UCB and in 9/9 (100%) patients transplanted with marrow from an unrelated donor (MUD). In contrast, the remaining four patients converted to an autologous pattern. Three out of these four patients had an early autologous haematological reconstitution reaching a neutrophil level >0.5 × 109/l at days 27, 33 and 37 after transplant, respectively. In all three of these patients, chimaerism analysis demonstrated an early appearance of donor cells (i.e. within 35 d after UCB transplant) showing a transient full donor (one case) or mixed chimaerism condition (two cases). Despite the early autologous haemopoietic reconstitution, one of the three patients died of GVHD at day 60, which was explained by the demonstration of low levels of donor lymphoid cells. In the MUD group all nine patients converted to a persistent full donor pattern with haematological reconstitution, accompanied in two of them by transient mixed chimaerism lasting to days 60 and 270 after transplant. Our data show that monitoring of chimaerism may predict graft failure with or without early autologous haemopoietic reconstitution in patients receiving unrelated UCB transplants. Furthermore, chimaerism analysis may identify, in patients with autologous reconstitution, those at risk of severe GVHD in whom immunosuppressive therapy should not be discontinued.

Alpha‐2b‐interferon as single therapy for patients with chronic myeloid leukemia relapsing after T‐cell depleted allogeneic bone marrow transplantation

Abstract: 20 CML patients with hematological (5 pts) or only cytogenetic (15 pts) relapse occurring after allogeneic BMT have been treated with alpha‐2b‐interferon (IFN) at a starting dose of 5 times 106 IU/m2, subcutaneously, three times a week. All 5 patients with hematological relapse achieved hematological remission without reduction of bone marrow Ph1‐positive cells. With a median follow‐up of 43 months (range 6–48) from the hematological relapse, 3 patients are alive and 2 patients died from non‐lymphoid blast crisis. 7 out of 15 patients with only cytogenetic relapse remain in hematological remission at a median of 37 months (range 3–45) from cytogenetic relapse, with 2 patients achieving complete cytogenetic remission confirmed at the molecular level by disappearance of the bcr rearranged band. With a median follow‐up of 21 months (range 6–46), 8 patients progressed from cytogenetic to hematological relapse: 4 patients died from blast crisis and the other 4 patients are currently alive in chronic phase. For the 15 patients, the actuarial survival from BMT is 71% at 5 years.