Mesenchymal stem cells (MSC) have immunomodulatory effects. The aim was to study the effect of MSC infusion on graft-versus-host disease (GVHD). We gave MSC to eight patients with steroid-refractory grades III-IV GVHD and one who had extensive chronic GVHD. The MSC dose was median 1.0 (range 0.7 to 9)×106/kg. No acute side-effects occurred after the MSC infusions. Six patients were treated once and three patients twice. Two patients received MSC from HLA-identical siblings, six from haplo-identical family donors and four from unrelated mismatched donors. Acute GVHD disappeared completely in six of eight patients. One of these developed cytomegalovirus gastroenteritis. Complete resolution was seen in gut (6), liver (1) and skin (1). Two died soon after MSC treatment with no obvious response. One of them had MSC donor DNA in the colon and a lymph node. Five patients are still alive between 2 months and 3 years after the transplantation. Their survival rate was significantly better than that of 16 patients with steroid-resistant biopsy-proven gastrointestinal GVHD, not treated with MSC during the same period (P=0.03). One patient treated for extensive chronic GVHD showed a transient response in the liver, but not in the skin and he died of Epstein-Barr virus lymphoma. MSC is a very promising treatment for severe steroid-resistant acute GVHD.

Purpose: Reduced intensity conditioning regimen (RIC) is increasingly used in hematopoietic stem cell transplantation (HSCT). Unrelated donor (UD) transplants have more complications. We wanted to examine if RIC is a valid treatment option using UD in acute myeloblastic leukemia (AML). Patients and Methods: Between 1999 and 2005, 401 patients with AML were treated with RIC and 1,154 received myeloablative conditioning (MAC), using UD and reported to the European Group for Blood and Marrow Transplantation Registry. Patients < and ≥ 50 years of age were analyzed separately. Results: Patients receiving RIC were older, received transplants more recently, received peripheral blood stem cells more frequently, and were treated with total-body irradiation less often. In multivariable analysis, in patients younger than 50 years of age, nonrelapse mortality (NRM) was similar using RIC (hazard ratio [HR], 0.85; P = .41), relapse was increased (HR, 1.46; P = .02) and leukemia-free survival (LFS) was the same (HR, 0.88; P = .28), as compared with MAC. In patients ≥ 50 years of age, NRM was decreased in the RIC group (HR, 0.64; P = .04), relapse probability was not significantly different (HR, 1.34; P = .16) and LFS was similar (HR, 1.04; P = .79) compared with MAC. Conclusion: RIC-UD transplants are associated with higher relapse in AML patients younger than 50 years of age and decreased NRM in those ≥ 50 years compared with MAC-UD. LFS was similar after both conditioning regimens, regardless of age. Therefore, RIC-UD extend the use of allotransplants for elderly patients and strategies that decrease relapse should be considered mainly in younger patients with AML.

Graft failure is a significant complication following allogeneic hematopoietic cell transplantation (alloHCT). It may result from rejection caused by recipient T cells, natural killer (NK) cells, or antibodies. It is increased in HLA-mismatched grafts, unrelated grafts, T cell-replete transplants, sensitized patients, and in patients treated with reduced-intensity conditioning (RIC). In recipients of unrelated grafts, graft failure is increased in patients receiving major AB0 blood group mismatched transplants (P = .008). Recent data also suggest that donor-specific antibodies to CD34(+)/VEGFR-2(+) cells may be involved in graft failure after alloHCT. Graft failure may be overcome by more intensified conditioning, increased cell dose, or more effective immunosuppression. With more frequent use of RIC, cord blood grafts and other HLA-mismatched transplants, graft failure is an increasing problem after alloHCT.

Mesenchymal stem cells (MSC) possess anti-inflammatory properties and participate in tissue repair. We used MSC to heal therapy-induced tissue toxicity. Ten consecutive patients, treated with MSC due to tissue toxicity following allogeneic hematopoietic stem cell transplantation, (ASCT) were included. Their median age was 48 (13–64) years. Seven had hemorrhagic cystitis grades 2–5, two had pneumomediastinum and one had perforated colon and peritonitis. MSC donors were mainly third-party, HLA-mismatched (n=11), HLA-haploidentical (n=3) and, in two cases, the HLA-identical ASCT sibling donors. MSC were given intravenously, the median cell dose was 1.0 (range 0.7–2) × 10⁶/kg. In five patients, the severe hemorrhagic cystitis cleared after MSC infusion. Gross hematuria disappeared after median 3 (1–14) days. Two patients had reduced transfusion requirements after MSC infusion, but died of multiorgan failure. In one of them, MSC donor DNA was demonstrated in the urinary bladder. In two patients, pneumomediastinum disappeared after MSC infusions. A patient with steroid-resistant graft-versus-host disease of the gut experienced perforated diverticulitis and peritonitis that was reversed twice by MSC. MSC is a novel treatment for therapy-induced tissue toxicity.

Purpose: Granulocyte colony-stimulating factor (G-CSF) is given after bone marrow transplantation (BMT) to shorten the neutropenic phase. Its effects have not been evaluated in a large patient population. Patients and Methods: We studied 1,789 patients with acute leukemia receiving BMT and 434 patients receiving peripheral-blood stem cells (PBSCs) from HLA-identical siblings from 1992 to 2002 and reported the findings to the European Group for Blood and Marrow Transplantation. Among the BMT and PBSC patients, 501 (28%) and 175 (40%), respectively, were treated with G-CSF during the first 14 days after the transplantation. The outcome variables were entered into a Cox proportional hazards model. Results: BMT and PBSC patients treated with G-CSF had a faster engraftment of absolute neutrophils greater than 0.5 × 10⁹/L (P < .01), but platelet engraftment ( > 50 × 10⁹/L) was slower (P < .001). In the BMT patients, acute graft-versus-host disease (GVHD) grades II to IV was 50% ± 5% (± 95% CI) in the G-CSF group versus 39% ± 3% in the controls (relative risk [RR], 1.33; P = .007, in the multivariate analysis). The incidence of chronic GVHD was also increased (RR, 1.29; P = .03). G-CSF was associated with an increase in transplantation-related mortality (TRM; RR, 1.73; P = .00016) and had no effect on relapse but reduced survival (RR, 0.59; P < .0001) and leukemia-free survival rates (LFS; RR, 0.64; P = .0003). No such effects of G-CSF were seen in patients receiving PBSC. Conclusion: After BMT, platelet engraftment was delayed, and GVHD and TRM were increased. Survival and LFS were reduced. This suggests that G-CSF should not be given shortly after BMT.