In vitro cytotoxicity evaluation of resveratrol-loaded nanoparticles: Focus on the challenges of in vitro methodologies

Assessment of toxic effects is mandatory before market placement of pharmaceutical and cosmetic products. Nanotoxicology is an emerging regulatory concern and still a challenging field. Topical application of resveratrol (RSV) has been extensively studied owing to its multi-mechanistic skin anti-aging effects. Nanoencapsulation has been suggested as a promising solution to overcome RSV stability issues. In this work RSV-loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were prepared using a homogenization/sonication technique. Cytotoxicity assays were conducted with an immortalized cell line of human keratinocytes (HaCaT). For a comprehensive cytotoxicity characterization MTT and Alamar Blue^® reduction assays (assessment of metabolic activity), Neutral red uptake (evaluation of lysosomal integrity), and Trypan blue (assessment of membrane integrity) were used. The results obtained with the different assays were not always concordant, as put in evidence by an adequate statistical analysis. Experimental parameters such as washing steps were found to be critical. The study is of interest because it draws attention to the importance of careful selected experimental conditions of in vitro nanotoxicological tests. Experimental protocols should be adapted taking into account nano-related features such as interference with the dyes and light dispersion/absorption properties.

Impact of HLA in cord blood transplantation outcomes

Umbilical cord blood (UCB) emerged in the last 20 years as a valid alternative source of hematopoietic stem cell (HSC) in allogeneic transplantation setting, mainly in the absence of a fully human leucocyte antigen (HLA)-matched sibling. The probability of finding a matched unrelated donor through the registries varies from 20 to 70%, depending on the ethnicity of the patients. Therefore, patients in need may benefit of an HLA-mismatched hematopoietic stem cell transplantation from haploidentical donors or from UCB. One of the advantages of using UCB is the lower incidence of acute graft-versus-host-disease and allowance of greater HLA mismatch. Conversely, the low number of HSCs and lymphocytes and specific immunological features of T cells are associated with delayed engraftment and immune reconstitution and consequently, increased opportunistic infections. Nevertheless, retrospective studies showed similar results comparing UCB with other stem cell sources, both in pediatric and adult setting. The ability to use partially HLA-matched UCB units allows expanding the donor pool. Many UCB banks have strategies to increase their inventory including UCB grafts that have rare haplotypes. HLA and cell dose are very important factors associated with outcomes after umbilical cord blood transplantation (UCBT) that interact with each other. Increasing cell dose counterbalances the number of HLA disparities. Understanding those interactions, the role of HLA mismatches and other immunogenic factors, are important to allow clinicians to choose the best cord blood graft for patients. This review will describe the role of HLA in UCBT setting.

Prevalence of secondhand smoke exposure in asthmatic children at home and in the car: A cross-sectional study

OBJECTIVE

To compare secondhand smoke exposure (SHSe) prevalence at home and inside the car between asthmatic and non-asthmatic Portuguese children.

MATERIALS AND METHODS

This is a cross-sectional study that assessed children's SHSe in a representative sample of nine Portuguese cities. A validated self-reported questionnaire was administered to a random sample of 4th grade students during the school year of 2010/2011. The asthma prevalence was defined by the answers to three questions regarding asthma symptoms, medication and inhaler use. We performed chi-square tests and analysed frequencies, contingency tables, confidence intervals, and odd-ratios.

RESULTS

The self-reported questionnaire was administered to 3187 students. Asthma prevalence was 14.8% (472 students). Results showed that 32.3% of non-asthmatic children and 32.4% of asthmatic children were exposed to secondhand smoke as at least one of their household members smoked at home. The prevalence of parental smoking, smoking among fathers and smoking among mothers at home was also similar in both groups (asthmatic and non-asthmatic children). SHSe inside the car was 18.6% among non-asthmatic children and 17.9% among asthmatic children.

CONCLUSIONS

Asthmatic and non-asthmatic children were equally exposed to secondhand smoke, because no significant differences were found between the two groups concerning the prevalence of SHSe at home and inside the car. These findings highlight the need to include SHSe brief advice in paediatric asthma management.

High proportions of regulatory T cells in PBSC grafts predict improved survival after allogeneic haematopoietic SCT

Regulatory T cells (Tregs) modulate immune responses and improve survival in murine transplant models. However, whether the Treg content of allogeneic cell grafts influences the outcome in human haematopoietic stem cell (HSC) transplantation is not well established. In a prospective study of 94 adult allogeneic PBSC transplants (60% unrelated; 85% reduced intensity conditioning), the median Treg (CD3(+)CD4(+)CD25(+)FOXP3(+)CD127(dim/-)) dose transplanted was 4.7 × 10(6)/kg, with Tregs accounting for a median of 2.96% of CD4(+) T cells. Patients transplanted with grafts containing a Treg/CD4(+) T-cell ratio above the median had a 3-year overall survival of 75%, compared with 49% in those receiving grafts with a Treg/CD4(+) T-cell ratio below the median (P=0.02), with a 3-year non-relapse mortality of 13% and 35%, respectively (P=0.02). In multivariate analysis, a high graft Treg/CD4(+) T-cell ratio was an independent predictor of lower non-relapse mortality (hazard ratio (HR), 0.30; P=0.02), improved overall survival (HR, 0.45; P=0.03) and improved sustained neutrophil (HR, 0.52; P=0.002), platelet (HR, 0.51; P<0.001) and lymphocyte (HR, 0.54; P=0.009) recovery. These data support the hypothesis that the proportion of Tregs in allogeneic HSC grafts influences clinical outcome and suggest that Treg therapies could improve allogeneic HSC transplantation.

Predicting survival using clinical risk scores and non-HLA immunogenetics

Previous studies of non-histocompatibility leukocyte antigen (HLA) gene single-nucleotide polymorphisms (SNPs) on subgroups of patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) revealed an association with transplant outcome. This study further evaluated the association of non-HLA polymorphisms with overall survival in a cohort of 762 HSCT patients using data on 26 polymorphisms in 16 non-HLA genes. When viewed in addition to an already established clinical risk score (EBMT-score), three polymorphisms: rs8177374 in the gene for MyD88-adapter-like (MAL; P=0.026), rs9340799 in the oestrogen receptor gene (ESR; P=0.003) and rs1800795 in interleukin-6 (IL-6; P=0.007) were found to be associated with reduced overall survival, whereas the haplo-genotype (ACC/ACC) in IL-10 was protective (P=0.02). The addition of these non-HLA polymorphisms in a Cox regression model alongside the EBMT-score improved discrimination between risk groups and increased the level of prediction compared with the EBMT-score alone (gain in prediction capability for EBMT-genetic-score 10.8%). Results also demonstrated how changes in clinical practice through time have altered the effects of non-HLA analysis. The study illustrates the significance of non-HLA genotyping prior to HSCT and the importance of further investigation into non-HLA gene polymorphisms in risk prediction.

Transfusion in CMV seronegative T-depleted allogeneic stem cell transplant recipients with CMV-unselected blood components results in zero CMV transmissions in the era of universal leukocyte reduction: a U.K. dual centre experience

OBJECTIVES

To establish rates of cytomegalovirus (CMV) transmission with use of CMV-unselected (CMV-U), leukocyte-reduced blood components transfused to CMV-seronegative patient/CMV-seronegative donor (CMV neg/neg) allogeneic stem cell transplantation (SCT) recipients including those receiving T-depleted grafts.

BACKGROUND

CMV infection remains a major cause of morbidity following SCT. CMV-seronegative SCT recipients are particularly at risk of transfusion transmitted CMV (TT-CMV) and until recently they have received blood components from CMV-seronegative donors with significant resource implications. Although leukocyte reduction of blood components is reported to minimise risk of TT-CMV, its efficacy in high-risk situations, such as in T-depleted transplant recipients, is unknown.

METHODS

We retrospectively analysed the incidence of TT-CMV in CMV neg/neg allogeneic SCT recipients transfused with CMV-U, leukocyte-reduced blood components in two transplantation centres in the UK. Patients were monitored for CMV infection by weekly CMV polymerase chain reaction testing. Leukocyte reduction of blood components was in accordance with current UK standards.

RESULTS

Among 76 patients, including 59 receiving in vivo T-depletion, no episodes of CMV infection were detected. Patients were transfused with 1442 CMV-unselected, leukocyte-reduced components, equating to 1862 donor exposures.

CONCLUSIONS

Our findings confirm the safety of leukocyte reduction as a strategy in preventing TT-CMV in high-risk allogeneic SCT recipients.

Comparison of outcomes after unrelated cord blood and unmanipulated haploidentical stem cell transplantation in adults with acute leukemia

Outcomes after unmanipulated haploidentical stem cell transplantation (Haplo) and after unrelated cord blood transplantation (UCBT) are encouraging and have become alternative options to treat patients with high-risk acute leukemia without human leukocyte antigen (HLA) matched donor. We compared outcomes after UCBT and Haplo in adults with de novo acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Median follow-up was 24 months. Analysis was performed separately for patients with AML, n=918 (Haplo=360, UCBT=558) and ALL, n=528 (Haplo=158 and UCBT=370). UCBT was associated with delayed engraftment and higher graft failure in both AML and ALL recipients. In multivariate analysis, UCBT was associated with lower incidence of chronic graft-vs-host disease both in the AML group (hazard ratio (HR)=0.63, P=0.008) and in the ALL group (HR=0.58, P=0.01). Not statistically significant differences were observed between Haplo and UCBT for relapse incidence (HR=0.95, P=0.76 for AML and HR=0.82, P=0.31 for ALL), non-relapse mortality (HR=1.16, P=0.47 for AML and HR=1.23, P=0.23 for ALL) and leukemia-free survival (HR 0.78, P=0.78 for AML and HR=1.00, P=0.84 for ALL). There were no statistically differences on main outcomes after unmanipulated Haplo and UCBT, and both approaches are valid for acute leukemia patients lacking a HLA matched donor. Both strategies expand the donor pool for patients in need.

Prediction of non-relapse mortality in recipients of reduced intensity conditioning allogeneic stem cell transplantation with AML in first complete remission

Non-relapse mortality (NRM) after allogeneic hematopoietic stem cell transplantation (alloHSCT) can be predicted by the hematopoietic cell transplantation comorbidity index (HCT-CI) and the European Group for Blood and Marrow Transplantation (EBMT) score, which are composed of different parameters. We set out to integrate the parameters of both scores in patients with acute myeloid leukemia (AML) in first complete remission (CR1) receiving reduced intensity conditioning (RIC) alloHSCT. All parameters from the HCT-CI and the EBMT-score with the addition of patient and donor cytomegalovirus serology were evaluated in 812 patients by multivariable analysis with end-point NRM at 2 years. Subsequently, 16 parameters were selected based on hazard ratio >1.2, and were incorporated into a novel score, which was further internally validated by bootstrapping. Both the HCT-CI and the EBMT-score showed relatively weak predictive value, whereas the integrated score allowed to identify three clearly distinct risk groups with 2-year NRM estimates of 8±2% (low-risk), 17±2% (intermediate-risk) and 38±4% (high-risk), which also translated in prediction of overall survival. Collectively, integration of the most dominant parameters from the HCT-CI and the EBMT-score allowed to develop a simple and robust, integrated score with improved prediction of NRM for AML patients proceeding to RIC alloHSCT in CR1.

Allogeneic hematopoietic SCT for adults AML using i.v. BU in the conditioning regimen: outcomes and risk factors for the occurrence of hepatic sinusoidal obstructive syndrome

I.v. BU is frequently used in the conditioning regimen prior to allogeneic hematopoietic SCT (allo-HSCT); however, overall outcomes, incidence of hepatic sinusoidal obstructive syndrome (SOS) and its risk factors are not well known. With this aim, we performed a study on 257 AML adult recipients. Seattle Criteria were used for diagnosis and classification of SOS. The median age was 44 years. Donors were HLA-identical siblings in 60%, HLA-matched unrelated in 29% and HLA mismatched in 11%. Conditioning regimen was myeloablative in 84% (i.v. BU with CY was the most frequently used regimen) and it was reduced intensity in 16% (i.v. BU associated with fludarabine). Acute and chronic GVHD was observed in 28% and 44%, respectively. Two-year incidence of non-relapse mortality was 16±2% and 2-year leukemia-free survival for patients in CR1, CR2 and non remission at HSCT were 55±4%, 58±7%, and 20±5%, respectively. At 6 months, incidence of SOS was 7.8±2%; and it was severe in eight patients (3%). Factors associated with the occurrence of SOS were: HLA-mismatched donor HSCT (P=0.002) and patients transplanted in non-remission (P=0.002). In conclusion, outcomes of HSCT using i.v. BU are encouraging in this setting, SOS incidence is low and it is influenced by the type of donor and disease status at the time of transplant.

Comparison of outcomes after single or double cord blood transplantation in adults with acute leukemia using different types of myeloablative conditioning regimen, a retrospective study on behalf of Eurocord and the Acute Leukemia Working Party of EBMT

We report outcomes after single (s) and double (d) umbilical cord blood transplantation (UCBT) after myeloablative conditioning (MAC) regimen for 239 patients transplanted for acute leukemia in first complete remission (CR1). All sUCBT patients received a total nucleated cell dose >2.5 × 10(7)/kg. Conditioning regimen for sUCBT was total body irradiation (TBI)12 Gy- or busulfan (BU)-based ± fludarabine (Flu) (n=68, group 1), thiotepa+BU+Flu (TBF) (n=88, group 2), and for dUCBT it was TBI12 Gy+cyclophosphamide ± Flu (n=83, group 3). dUCBT recipients were younger, received higher cell dose and less frequently antithymocyte globulin. In multivariate analysis, we found similar neutrophil recovery among the three groups; however, acute graft-versus-host disease II-IV was higher in dUCBT compared with others. Non-relapse mortality and relapse incidence were not statistically different among the three groups. Leukemia-free survival was 30% for sUCBT using TBI- or BU-based MAC compared with 48% for sUCBT TBF and 48% for dUCBT (P=0.02 and P=0.03, respectively), and it was not statistically different between sUCBT with TBF and dUCBT. In conclusion, use of sUCBT with adequate cell dose (>2.5 × 10(7)/kg) and a specific conditioning regimen in the MAC setting results in similar outcomes as dUCBT. The choice of TBF conditioning regimen for sUCBT may improve results, and whether this regimen may be effective in dUCBT should be further analyzed.

Comparison of conditioning regimens of various intensities for allogeneic hematopoietic SCT using HLA-identical sibling donors in AML and MDS with <10% BM blasts: a report from EBMT

In this multicenter retrospective study, the long-term outcomes of 878 adults with AML and refractory anemia with excess blasts (RAEB) with BM blasts <10% who underwent transplantation with an HLA-identical sibling donor between 1998 and 2004 were analyzed according to four regimens of conditioning intensity: reduced-intensity conditioning (RIC) (either intermediate RIC (IntermRIC) or non-myeloablative (NMA) RIC), and myeloablative conditioning (MC) in 718 patients (either conventional MC or hyperintense MC. In multivariate cox analysis, patients undergoing NMA transplantation had lower non-relapse mortality risk in the first 100 days after transplantation (P<0.01), but a higher risk beyond day +100 (P=0.02), as well as higher relapse incidence in the first 12 months (P<0.01), but the risk was similar in all groups beyond 12 months. The probabilities of PFS and OS up to 7 years were significantly lower only in the NMA subgroup (P0.01 for both). The 7-year OS was 53%, 29%, 56% and 51%, respectively. Our data suggest that prospective studies comparing RIC regimens (especially IntermRIC) with MC are appropriate in patients with AML and RAEB who are in a non-advanced disease status.

Bone marrow or peripheral blood stem cell transplantation from unrelated donors in adult patients with acute myeloid leukaemia, an Acute Leukaemia Working Party analysis in 2262 patients

BACKGROUND

No survival benefit of using blood stem cells instead of bone marrow (BM) has been shown in matched unrelated donor (MUD) transplantation.

DESIGN AND METHODS

In a retrospective registry analysis, we compared the use of blood stem cells (n = 1502) and BM (n = 760) from unrelated donors in patients aged 18-60 years with acute myeloid leukaemia (AML) undergoing myeloablative conditioning between 1997 and 2008. The blood stem cell recipients were older (P < 0.01), had more advanced disease (P < 0.0001) and received less total body irradiation (P < 0.0001) and more antithymocyte globulin (P = 0.01).

RESULTS

Recovery of neutrophils and platelets was faster with blood stem cells (P < 0.0001). The incidence of acute graft-versus-host disease (GVHD) was similar, but there was more chronic GVHD in the blood stem cell group [hazard ratio (HR) = 1.29, P = 0.02]. There were no significant differences in nonrelapse mortality (NRM), relapse incidence and leukaemia-free survival (LFS) between the two groups amongst patients with AML in remission. In patients with advanced leukaemia, NRM was lower (HR = 0.61, P = 0.02) and LFS was prolonged (HR = 0.67, P = 0.002) when blood stem cells were used. At 3 years, LFS for all patients, regardless of remission status, was 41% for both treatment groups. The outcome was not affected after multivariable analysis adjusted for confounders.

CONCLUSION

Blood stem cells compared with BM in MUD transplantation for patients with AML in remission resulted in the same rates of LFS. In patients with advanced leukaemia, the blood stem cell group had reduced NRM and improved LFS.

The impact of center experience on results of reduced intensity: allogeneic hematopoietic SCT for AML. An analysis from the Acute Leukemia Working Party of the EBMT

Allogeneic hematopoietic SCT with reduced-intensity conditioning (RIC-HSCT) is increasingly adopted for the treatment of older adults with AML. Our goal was to verify for the first time, if center experience influences outcome of RIC-HSCT. Results of 1413 transplantations from HLA-matched related or unrelated donors for adult patients with AML in first CR were analyzed according to the level of center activity. Transplants were performed in 203 European centers between 2001 and 2007. The 2-year probability of leukemia-free survival (LFS) after RIC-HSCT performed in centers with the lowest activity (< or =15 procedures/7 years) was 43±3% compared with 55±2% in the remainder (P<0.001). The incidence of non-relapse mortality (NRM) was 24±3% and 15±1% (P=0.004), whilst relapse rate was 33±3% and 31±1% (P=0.33), respectively. In a multivariate model, adjusted for other prognostic factors, low RIC-HSCT activity was associated with decreased chance of LFS (hazard ratio (HR)=0.64; P<0.001) and increased risk of NRM (HR=1.47, P=0.04) and relapse (HR=1.41, P=0.01). Center experience is a very important predictor of outcome and should be considered in future analyses evaluating the results of RIC-HSCT. The reasons why centers with low RIC-HSCT activity have worse outcomes should be further investigated.

Impact of graft-versus-host disease after reduced-intensity conditioning allogeneic stem cell transplantation for acute myeloid leukemia: a report from the Acute Leukemia Working Party of the European group for blood and marrow transplantation

This report investigated the impact of graft-versus-host disease (GVHD) on transplantation outcomes in 1859 acute myeloid leukemia patients given allogeneic peripheral blood stem cells after reduced-intensity conditioning (RIC allo-SCT). Grade I acute GVHD was associated with a lower risk of relapse (hazards ratio (HR)=0.7, P=0.02) translating into a trend for better overall survival (OS; HR=1.3; P=0.07). Grade II acute GVHD had no net impact on OS, while grade III-IV acute GVHD was associated with a worse OS (HR=0.4, P<0.0.001) owing to high risk of nonrelapse mortality (NRM; HR=5.2, P<0.0001). In time-dependent multivariate Cox analyses, limited chronic GVHD tended to be associated with a lower risk of relapse (HR=0.72; P=0.07) translating into a better OS (HR=1.8; P<0.001), while extensive chronic GVHD was associated with a lower risk of relapse (HR=0.65; P=0.02) but also with higher NRM (HR=3.5; P<0.001) and thus had no net impact on OS. In-vivo T-cell depletion with antithymocyte globulin (ATG) or alemtuzumab was successful at preventing extensive chronic GVHD (P<0.001), but without improving OS for ATG and even with worsening OS for alemtuzumab (HR=0.65; P=0.001). These results highlight the role of the immune-mediated graft-versus-leukemia effect in the RIC allo-SCT setting, but also the need for improving the prevention and treatment of severe GVHD.

Outcomes and prognostic factors of adults with acute lymphoblastic leukemia who relapse after allogeneic hematopoietic cell transplantation. An analysis on behalf of the Acute Leukemia Working Party of EBMT

To describe outcomes, treatment and prognostic factors that influence survival of adult patients with acute lymphoblastic leukemia (ALL), who relapsed after allogeneic hematopoietic cell transplantation (HCT), we retrospectively analyzed 465 ALL adult patients from European Group for Blood and Marrow Transplantation (EBMT) centers who relapsed after a first HCT performed in complete remission (CR1 65%, CR2/3 35%). Salvage treatments were: supportive care (13%), cytoreductive therapy (43%), donor lymphocyte infusion without or with prior chemotherapy (23%) and second HCT (20%). Median time from HCT to relapse was 6.9 months, median follow-up was 46 months and median survival after relapse was 5.5 months. Estimated 1-, 2- and 5-year post-relapse survival was 30 ± 2%, 16 ± 2% and 8 ± 1%, respectively. In a multivariate analysis, adverse factors for survival were: late CR (CR2/3) at transplant (P<0.012), early relapse after transplant (<6.9 months, P <0.0001) and peripheral blast percent at relapse (P <0.0001). On the basis of multivariate model for survival, three groups of patients were identified with estimated 2 year survival of 6 ± 2, 17 ± 3 and 30 ± 7%. Outcome of ALL patients relapsing after HCT is dismal and there is a need for new therapies. Our study provides the standard expectations in ALL relapse and may help in the decision of post-relapse therapy.