Brigitta Omazic

The allogeneic graft-versus-cancer effect.

Allogeneic haematological stem cell transplantation (HSCT) has developed into immunotherapy. Donor CD4+, CD8+ and natural killer (NK) cells have been reported to mediate graft‐versus‐leukaemia (GVL) effects, using Fas‐dependent killing and perforin degranulation to eradicate malignant cells. Cytokines, such as interleukin‐2, interferon‐γ and tumour necrosis factor‐α potentiate the GVL effect. Post‐transplant adoptive therapy of cytotoxic T‐cells (CTL) against leukaemia‐specific antigens, minor histocompatibility antigens, or T‐cell receptor genes may constitute successful approaches to induce anti‐tumour effects. Clinically, a significant GVL effect is induced by chronic rather than acute graft‐versus‐host disease (GVHD). An anti‐tumour effect has also been reported for myeloma, lymphoma and solid tumours. Reduced intensity conditioning enables HSCT in older and disabled patients and relies on the graft‐versus‐tumour effect. Donor lymphocyte infusions promote the GVL effect and can be given as escalating doses with response monitored by minimal residual disease. A high CD34+ cell dose of peripheral blood stem cells increases GVL. There is a balance between effective immunosuppression, low incidence of GVHD and relapse. For instance, T‐cell depletion of the graft increases the risk of relapse. This paper reviews the current knowledge in graft‐versus‐cancer effects. Future directions, such as immunotherapy using leukaemia‐specific CTLs, allo‐depleted T‐cells and suicide gene manipulated T‐cells, are presented.

Improved Survival after Allogeneic Hematopoietic Stem Cell Transplantation in Recent Years. A Single-Center Study

We analyzed the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) over the past 2 decades. Between 1992 and 2009, 953 patients were treated with HSCT, mainly for a hematologic malignancy. They were divided according to 4 different time periods of treatment: 1992 to 1995, 1996 to 2000, 2001 to 2005, and 2006 to 2009. Over the years, many factors have changed considerably regarding patient age, diagnosis, disease stage, type of donor, stem cell source, genomic HLA typing, cell dose, type of conditioning, treatment of infections, use of granulocyte-colony stimulating factor (G-CSF), use of mesenchymal stem cells, use of cytotoxic T cells, and home care. When we compared the last period (2006-2009) with earlier periods, we found slower neutrophil engraftment, a higher incidence of acute graft-versus-host disease (aGVHD) of grades II-IV, and less chronic GVHD (cGHVD). The incidence of relapse was unchanged over the 4 periods (22%-25%). Overall survival (OS) and transplant-related mortality (TRM) improved significantly in the more recent periods, with the best results during the last period (2006-2009) and a 100-day TRM of 5.5%. This improvement was also apparent in a multivariate analysis. When correcting for differences between the 4 groups, the hazard ratio for mortality in the last period was 0.59 (95% confidence interval [CI]: 0.44-0.79; P < .001) and for TRM it was 0.63 (CI: 0.43-0.92; P = .02). This study shows that the combined efforts to improve outcome after HSCT have been very effective. Even though we now treat older patients with more advanced disease and use more alternative HLA nonidentical donors, OS and TRM have improved. The problem of relapse still has to be remedied. Thus, several different developments together have resulted in significantly lower TRM and improved survival after HSCT over the last few years.

Unrelated versus related allogeneic stem cell transplantation after reduced intensity conditioning.

Background. The use of reduced intensity conditioning (RIC) regimens in allogeneic hematopoietic stem cell transplantation (HSCT) has increased over the past five years. Patients. In this study, involving 137 patients, we compared the outcome after RIC in patients receiving grafts from matched unrelated donors (MUD; n=74) and sibling donors (n=63). The MUD and sibling groups were comparable regarding diagnosis, including solid tumors and hematological malignancies, and conditioning regimens. Results. Engraftment was successful in most patients (88%), with no significant difference between MUD and sibling transplants. Cytomegalovirus (CMV) infection was more common in the MUD group (65%) than in the sibling group (46%) (P=0.04). No difference in severe acute graft-versus-host disease (GVHD) was found between the groups. However, the incidence of chronic GVHD was higher after sibling transplants. This was probably due to higher donor age in this group, since this was the only significant risk factor for chronic GVHD in multivariate analysis. The incidence of transplant related mortality (TRM) was significantly higher after MUD transplantation (40%) than after sibling transplantation (16%) (P<0.01). Because relapse/disease progression was more common after sibling transplantation, there was no significant difference in overall survival between the two groups. Conclusion. Using unrelated donors after RIC is feasible, but it resulted in more CMV infection and increased transplant-related mortality. Survival was comparable to that of sibling transplants.

Allogeneic hematopoietic stem cell transplantation for inherited disorders : Experience in a single center

Background. Allogeneic hematopoietic stem cell transplantation (ASCT) is a possible cure for many inherited disorders. Methods. We report 20 years of experience in 71 patients. The disorders include 7 immunodeficiencies, 21 hematological disorders, 13 histiocytic disorders, 9 mucopolysaccharoidoses, 7 metachromatic leukodystrophies (MLD), 3 adrenoleukodystrophies (ALD), 2 adrenomyeloneuropathy (AMN), 6 patients with Gaucher’s disease, 1 Sandhoff’s disease, and 2 patients with aspartylglucosaminuria. Their median age was 4 (0-39) years. The donors were 29 HLA-identical related, 27 matched unrelated (MUD) and 15 HLA mismatches. Results. In recipients of HLA-identical sibling grafts, none developed acute GVHD grades II-IV as against 22% in all others. The overall cumulative incidence of chronic GVHD was 17%. The 5-year survival rates were 93%, 84%, and 46% in recipients of grafts from HLA-identical siblings, MUD and HLA-mismatches, respectively. The overall 10-year survival rate was 69%. All of the surviving patients with immunodeficiencies and hemoglobinopathies are well. Four patients with Hurler’s disease are also well, apart from skeletal problems. Five patients with Gaucher’s disease are between 14 and 22 years after the transplant. Two infants with MLD deteriorated, a girl with the juvenile form has stable disease and one woman with the adult form has improved. Among four survivors with ALD/AMN, three are well and one has dementia. Two patients with aspartylglucosaminuria have stable disease. Conclusion. In patients with inborn errors of metabolism, ASCT gives a high survival rate using HLA-matched donors. Beneficial effects are seen in those who are transplanted early.

Hemorrhagic cystitis: a retrospective single-center survey.

Abstract:  Severe hemorrhagic cystitis (HC) may be a life‐threatening complication in allogeneic stem cell transplantation (SCT). In order to improve the strategies for prophylaxis and treatment, we retrospectively analyzed data on patients who underwent SCT at our center from 1990 through 2005. Patients with HC were identified through our database and their medical charts were reviewed. Grades 2–5 and 3–5 HC developed in 109/834 patients (13.1%) and 27/834 patients (3.2%), respectively. The frequency of HC decreased over the time from 18.0% in 1990–1992 to 9.5% in 2002–2005 (p = 0.005). HC started on a median of 35 (0–166) days post‐transplant and persisted for a median of 23 (2–270) days. Transplant‐related mortality was 21% in patients without HC, 15% in those with HC of grade 2, 55% in those with grade 3, and 71% in patients with HC of grades 4–5 (p < 0.001). In multivariate analysis, the risk factors for HC were myeloablative conditioning, busulphan, cytomegalovirus infection, hematological malignancy, and acute graft‐versus‐host disease (aGVHD). With four risk factors, the risk of HC development was 31%. Risk factors for severe HC of grades 3–5 were aGVHD and bacteremia.

Randomized PCR-based therapy and risk factors for invasive fungal infection following reduced-intensity conditioning and hematopoietic SCT

Invasive fungal infections (IFIs) are major complications after allogeneic hematopoietic SCT (HSCT). PCR-based assays able to detect fungal DNA have been reported to precede clinical diagnosis of IFI. We performed a prospective study to evaluate a PCR-based pre-emptive approach. Ninety-nine patients undergoing reduced-intensity conditioning (RIC) HSCT were followed with fungal PCR during the first 100 days post transplantation. Patients who tested positive were randomized to receive liposomal amphotericin B, or to no intervention. After day 100, PCR tests were performed only on clinical suspicion of IFI. A single positive PCR test was not associated with IFI, irrespective of treatment. After day 100, PCR tests for Aspergillus did not contribute to diagnosis of invasive aspergillosis (IA). The cumulative incidence rates of proven or probable IA during the first year after transplantation were 9%. GVHD grades II–IV (P=0.0014), CMV-seronegative recipient with CMV-seropositive donor (P⩽0.001), and conditioning with alemtuzumab (P=0.014) were significant risk factors for developing IA in a multivariate model. In this study, PCR on peripheral blood was a poor indicator of IFI early after RIC HSCT. Aspergillus PCR tests performed on clinical suspicion after day 100 were insufficiently sensitive to be diagnostically useful.

Risk factors for acute graft-versus-host disease grades II–IV after reduced intensity conditioning allogeneic stem cell transplantation with unrelated donors—a single centre study

We analysed factors associated with moderate to severe acute GVHD in 111 patients treated with fludarabin-based reduced intensity conditioning (RIC) and allogeneic haematopoietic stem cell transplantation (HSCT). Most patients had a haematological malignancy. Donors were 97 HLA-A, -B and -DRβ1 identical unrelated and 14 HLA-A, -B or -DRβ1 allele mismatched unrelated donors. In the univariate analysis, we found ten factors associated with acute GVHD. These were diagnosis (P=0.06), GVHD prophylaxis with combinations other than CsA+MTX (P=0.006), graft nucleated (P<0.001) and CD34 (P<0.001) cell-dose, bidirectional ABO mismatch (P=0.001), conditioning (P=0.002), hospital vs home-care (P=0.06), ATG dose (P<0.001), donor herpes virus serology (P=0.07) and an immunized female donor to male recipient (P=0.05). In the multivariate analysis, three factors remained significant: a high CD34 cell dose (P<0.001), low dose (4 mg/kg) ATG (P<0.001), and an immunized female donor to male recipient (P<0.01). Patients receiving a CD34 cell dose ⩾17.0 × 106 per kg had a higher incidence of GVHD, 53.7%, compared to 22.3% in patients receiving a lower dose (P=0.002). In patients without any of these risk factors (n=70), the incidence of acute GVHD was 14.1%, while it was 38.0 and 85.0% in patients with one (n=29) or two (n=10) risk factors (P<0.001). We concluded that risk factors for acute GVHD using RIC are similar as using myeloablative conditioning.

A prospective randomized study using N-acetyl-L-cysteine for early liver toxicity after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (ASCT) and its conditioning with chemoradiotherapy often results in liver toxicity, the most severe form being veno-occlusive liver disease (VOD). N-acetyl-L-cysteine (NAC), an antioxidant glutathione precursor, may provide protection from liver toxicity. Patients with elevated bilirubin (>26 mmol/l) and/or elevated (ALT) (>1.4 μkat/l) and/or aspartate aminotransferase (AST) (>1.4 μkat/l) levels were randomized to treatment with NAC or no treatment. Among 522 transplanted patients, 160 were included in the trial. NAC was given, 100 mg/kg per day, as a 6-h i.v. infusion until normalization of bilirubin, ALT and AST values. Maximum bilirubin level was the same in patients randomized to NAC (n=72) or controls (n=88). Increase and recovery of ALT and AST were the same in patients randomized to NAC or controls. There were two patients in the NAC group who developed VOD, as compared to three of the controls. To conclude, NAC does not improve liver toxicity after ASCT.

A prospective randomized toxicity study to compare reduced-intensity and myeloablative conditioning in patients with myeloid leukaemia undergoing allogeneic haematopoietic stem cell transplantation

To our knowledge, no randomized toxicity studies have been conducted to compare myeloablative conditioning (MAC) and reduced‐intensity conditioning (RIC) in allogeneic haematopoietic stem cell transplantation (HSCT).

Granulocyte colony-stimulating factor induced acute and chronic graft-versus-host disease.

Background. A recent experimental study in mice shed new light on the controversy as to whether granulocyte colony-stimulating factor (G-CSF) increases graft-versus-host disease (GVHD). Total body irradiation and bone marrow were found to be prerequisites for acute GVHD. This study encouraged us to perform a retrospective clinical study. Methods. We compared 260 patients given G-CSF prophylaxis after allogeneic hematopoietic stem-cell transplantation with 205 controls transplanted between 1993 and 2003. Results. G-CSF hastened the engraftment of neutrophils, but that of platelets was delayed (P<0.0001). The proportion of acute GVHD of grades II to IV was 29% in the G-CSF group and 19% in the controls (P<0.01) and that of chronic GVHD was 54% and 43%, respectively (P=0.019). G-CSF increased acute and chronic GVHD in patients preferentially conditioned with chemotherapy. Unexpectedly, it exacerbated acute GVHD in recipients of peripheral blood stem cells and enhanced chronic GVHD in bone marrow recipients. A multivariable analysis showed that acute GVHD (hazards ratio=1.52, P=0.03) and chronic GVHD (hazards ratio=1.51, P=0.004) were associated with G-CSF. There was no significant difference between study groups regarding nonrelapse mortality, relapse, or survival. Conclusion. G-CSF increased acute and chronic GVHD in patients treated with chemotherapy but did not affect relapse or survival.