Non-parametric estimation of survival probabilities with a time-dependent exposure switch: application to (simulated) heart transplant data

Background: To summarize the survival experience of patients waiting for heart transplant and to compare it with the post-transplant survival it is not possible to use the Kaplan-Meier estimator considering the intervention status as fixed in time because of the well known "immortaltime bias" issue.Methods: We reviewed and applied to a simulated dataset the available methods to perform a non-parametric analysis accounting for the time-varying nature of the transplant status. Specifically we considered the Simon-Makuch estimator and the recently proposed "clock-back" estimator.Results: We showed that the Simon-Makuch estimator for the survival of patients on list is unbiased but the corresponding estimator of the post-transplant survival is not reliable for non-markov contexts like the one considered. Instead, if the semi-Markov assumption could be postulated (the post-transplant mortality depends mainly on the time since transplant and not on the waiting time to the intervention), the "clock-back" estimator produces valid results.Conclusion: We enlightened the importance of testing the process memory assumptions (e.g. Markov properties) in order to choose the approach more reliable. Moreover, we recommend the use of the Simon-Makuch method to study the survival of patients before the interventionand the use of the "clock back" estimator for the post-intervention survival in semi-markovian contexts

axillary lymphadenectomy for breast cancer a randomized controlled trial comparing a bipolar vessel sealing system to the conventional technique

Abstract Aim To compare safety and efficacy of a bipolar vessel sealing system (BVSS) to the conventional technique in axillary node dissection. Methods 116 women with breast cancer were randomized to conventional node dissection surgical technique (control; n = 58) by scalpel and monopolar cautery or using an electrothermal BVSS (study group; n = 58). Results The median (range) total volume of fluid collected by drain and aspirations was 305 (30–1420) mL in the study group and 335 (80–1070) mL in the control group ( p = 0.325). The median (range) total volume of lymph collected by percutaneous aspirations was 207.5 (40–1050) mL in the study group and 505 (270–705) mL in the control group ( p = 0.010). The incidence of seroma was similar in both groups ( p = 0.845). The axillary drain was removed earlier in the study group than in controls ( p = 0.046). Conclusion The use of a BVSS offers marginal advantages when compared to the conventional technique

Pacemaker-detected severe sleep apnea predicts new-onset atrial fibrillation

Sleep apnea (SA) diagnosed on overnight polysomnography is a risk factor for atrial fibrillation (AF). Advanced pacemakers are now able to monitor intrathoracic impedance for automatic detection of SA events

468 glp compliant non clinical safety and biodistribution of a recombinant aav2 8 vector administered intravenously for treatment of mucopolysaccharidosis type vi

Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disorder caused by deficiency of the enzyme arylsulfatase B (ARSB), which results in widespread accumulation and excretion of toxic glycosaminoglycans. We recently developed a successful gene therapy approach based on a single systemic administration of AAV2/8 that targets liver of MPS VI animal models. In view of a gene therapy clinical trial for MPS VI, we performed GLP-compliant non-clinical studies to assess the safety and biodistribution of AAV2/8. TBG. hARSB, a recombinant AAV2/8 vector encoding human ARSB (hARSB) under the control of the thyroxine-binding globulin promoter (TBG). We used transgenic C57/BL6-TgARSBC91S mice that overexpress an inactive hARSB C91S mutant and are thus immune tolerant to hARSB. Mice were treated with either AAV2/8.TBG. hARSB or the vehicle alone, as control. Toxicity was evaluated on day 15 (D15) and 180 (D180) after systemic injection of 2×1013 gc/kg, which is 10X the highest dose proposed for the clinical study [20males(M)+20females(F)/treatment/timepoint]. No mortality, abnormal clinical signs and alteration in body weight, body temperature and food intake were observed through the study. Similarly, no clinically relevant changes in blood chemistry and hematology were found in treated mice compared to controls. Histopathology revealed thyroid epithelial hypertrophy in AAV-treated mice. AAV2/8.TBG. hARSB biodistribution and expression was evaluated on D15 and D180 at the dose of 2×1012 gc/kg, which is 1X the highest dose proposed for the clinical study (5M+5F/treatment/timepoint). Although vector DNA was present in all organs on D15, it was sequestered mainly in liver at levels at least 3 logs higher than those found in other organs. Vector DNA declined on D180, but remained high in liver. Accordingly, hARSB was mainly expressed stably in liver, supporting TBG tissue specificity. Vector DNA was found in gonads of both sexes at 3 logs lower than in liver. A robust reduction of vector DNA was observed on D180. A supportive study conducted in male rabbits showed that vector shedding in semen was only transient, which suggests that the risk of inadvertent germline transmission of AAV2/8. TBG.hARSB is minimal at least in male animals. An in situ hybridization study is ongoing in ovaries to elucidate AAV localization. Finally, AAV DNA was only transiently present in plasma, urine and stools of mice (up to D37, D2 and D14, respectively), which minimizes the potential risk associated with transmission to third parties and/or the environment. In conclusion, these studies show a safe profile of intravenous administrations of AAV2/8. TBG.hARSB and pave the way for the phase I/II clinical trial

Altered sphingolipid metabolism in N-(4-hydroxyphenyl) retinamide resistant A2780 human ovarian carcinoma cells

In the present work, we studied the effects of fenretinide (N-(4-hydroxyphenyl)retinamide (HPR)), a hydroxyphenyl derivative of all-trans-retinoic acid, on sphingolipid metabolism and expression in human ovarian carcinoma A2780 cells. A2780 cells, which are sensitive to a pharmacologically achievable HPR concentration, become 10-fold more resistant after exposure to increasing HPR concentrations. Our results showed that HPR was able to induce a dose- and time-dependent increase in cellular ceramide levels in sensitive but not in resistant cells. This form of resistance in A2780 cells was not accompanied by the overexpression of multidrug resistance-specific proteins MDR1 P-glycoprotein and multidrug resistance-associated protein, whose mRNA levels did not differ in sensitive and resistant A2780 cells. HPR-resistant cells were characterized by an overall altered sphingolipid metabolism. The overall content in glycosphingolipids was similar in both cell types, but the expression of specific glycosphingolipids was different. Specifically, our findings indicated that glucosylceramide levels were similar in sensitive and resistant cells, but resistant cells were characterized by a 6-fold lower expression of lactosylceramide levels and by a 6-fold higher expression of ganglioside levels than sensitive cells. The main gangliosides from resistant A2780 cells were identified as GM3 and GM2. The possible metabolic mechanisms leading to this difference were investigated. Interestingly, the mRNA levels of glucosylceramide and lactosylceramide synthases were similar in sensitive and resistant cells, whereas GM3 synthase mRNA level and GM3 synthase activity were remarkably higher in resistant cells

Eligibility for allogeneic transplantation in very high risk childhood acute lymphoblastic leukemia: the impact of the waiting time.

The advantage of allogeneic transplant from compatible related donors versus chemotherapy in children with very-high-risk acute lymphoblastic leukemia in first complete remission was previously demonstrated in an international prospective trial. This study quantified the impact of time elapsed in first remission in the same cohort. Of 357 pediatric patients with very-high-risk acute lymphoblastic leukemia, 259 received chemotherapy, 55 transplantation from compatible related and 43 from unrelated donors. The 5-year disease-free survival was 44.2% overall and 42.5% for chemotherapy only patients. The chemotherapy conditional 5-year disease-free survival increased to 44.4%, 47.6%, 51.7%, and 60.4% in patients who maintained their first remission for at least 3, 6, 9, and 12 months respectively. The overall outcome was superior to that obtained with chemotherapy-only at any time-point. The relative advantage of transplant from compatible related donors in very-high-risk childhood acute lymphoblastic leukemia was consistent for any time elapsed in first remission

Delirium symptoms duration and mortality in SARS-COV2 elderly: results of a multicenter retrospective cohort study

BACKGROUND: Since the occurrence of the SARS-COV2 pandemic, there has been an increasing interest in investigating the epidemiology of delirium. Delirium is frequent in SARS-COV2 patients and it is associated with increased mortality; however, no information is available on the association between delirium duration in SARS-COV2 patients and related outcomes. AIMS: The aim of this study is to investigate the association between the duration of delirium symptoms and in-hospital mortality in older patients with SARS-COV2 infection. METHODS: Retrospective cohort study of patients 65 years of age and older with SARS-CoV 2 infection admitted to two acute geriatric wards and one rehabilitation ward. Delirium symptoms duration was assessed retrospectively with a chart-based validated method. In-hospital mortality was ascertained via medical records. RESULTS: A total of 241 patients were included. The prevalence of delirium on admission was 16%. The median number of days with delirium symptoms was 4 (IQR 2–6.5) vs. 0 (IQR 0–2) in patients with and without delirium on admission. In the multivariable Cox regression model, each day with a delirium symptom in a patient with the same length of stay was associated with a 10% increase in in-hospital mortality (Hazard ratio 1.1, 95% Confidence interval 1.01–1.2; p = 0.03). Other variables associated with increased risk of in-hospital death were age, comorbidity, CPAP, CRP levels and total number of drugs on admission. CONCLUSIONS: The study supports the necessity to establish protocols for the monitoring and management of delirium during emergency conditions to allow an appropriate care for older patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40520-021-01899-8

Glutathione S-transferase homozygous deletions and relapse in childhood acute lymphoblastic leukemia: a novel study design in a large Italian AIEOP cohort

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Deciphering KRAS and NRAS mutated clone dynamics in MLL-AF4 paediatric leukaemia by ultra deep sequencing analysis

To induce and sustain the leukaemogenic process, MLL-AF4+ leukaemia seems to require very few genetic alterations in addition to the fusion gene itself. Studies of infant and paediatric patients with MLL-AF4+ B cell precursor acute lymphoblastic leukaemia (BCP-ALL) have reported mutations in KRAS and NRAS with incidences ranging from 25 to 50%. Whereas previous studies employed Sanger sequencing, here we used next generation amplicon deep sequencing for in depth evaluation of RAS mutations in 36 paediatric patients at diagnosis of MLL-AF4+ leukaemia. RAS mutations including those in small sub-clones were detected in 63.9% of patients. Furthermore, the mutational analysis of 17 paired samples at diagnosis and relapse revealed complex RAS clone dynamics and showed that the mutated clones present at relapse were almost all originated from clones that were already detectable at diagnosis and survived to the initial therapy. Finally, we showed that mutated patients were indeed characterized by a RAS related signature at both transcriptional and protein levels and that the targeting of the RAS pathway could be of beneficial for treatment of MLL-AF4+ BCP-ALL clones carrying somatic RAS mutations

The chemerin/CMKLR1 axis regulates intestinal graft-versus-host disease

: Gastrointestinal graft-versus-host disease (GvHD) is a major cause of mortality and morbidity following allogeneic bone marrow transplantation (allo-BMT). Chemerin is a chemotactic protein that recruits leukocytes to inflamed tissues by interacting with ChemR23/CMKLR1, a chemotactic receptor expressed by leukocytes, including macrophages. During acute GvHD, chemerin plasma levels were strongly increased in allo-BM-transplanted mice. The role of the chemerin/CMKLR1 axis in GvHD was investigated using Cmklr1-KO mice. WT mice transplanted with an allogeneic graft from Cmklr1-KO donors (t-KO) had worse survival and more severe GvHD. Histological analysis demonstrated that the gastrointestinal tract was the organ mostly affected by GvHD in t-KO mice. The severe colitis of t-KO mice was characterized by massive neutrophil infiltration and tissue damage associated with bacterial translocation and exacerbated inflammation. Similarly, Cmklr1-KO recipient mice showed increased intestinal pathology in both allogeneic transplant and dextran sulfate sodium-induced colitis. Notably, the adoptive transfer of WT monocytes into t-KO mice mitigated GvHD manifestations by decreasing gut inflammation and T cell activation. In patients, higher chemerin serum levels were predictive of GvHD development. Overall, these results suggest that CMKLR1/chemerin may be a protective pathway for the control of intestinal inflammation and tissue damage in GvHD