Purpose of review
In patients with type 1 diabetes with extreme glycemic variability, the restoration of pancreas endocrine function is potentially and completely achieved with islets of Langerhans ...(tissue derived from whole organ) or pancreas (whole organ) transplantation. The aim of our review is to report on the latest studies and to highlight the benefits and risks of the two procedures, providing clearer, more selective, evidence-based clinical indications that also consider the impact on the degenerative complications of diabetes as a potential benefit.
Recent findings
Clinical experience in this field has been dynamic over the last three decades, and has been characterized by the development of more standardized protocols and a clearer definition of clinical outcome. On the contrary, the recommendations thus far are not well delineated and tend to overlap, and the past ADA position statement for pancreas transplant alone has also been applied to islet transplant alone, without differentiation.
Summary
Both outcome-driven and non-outcome-driven criteria are considered in the conclusions, in an attempt to streamline indications for islet-alone or pancreas-alone transplantation.
Summary
Plasticity is a hallmark of macrophages, and in response to environmental signals these cells undergo different forms of polarized activation, the extremes of which are called classic (M1) ...and alternative (M2). Rapamycin (RAPA) is crucial for survival and functions of myeloid phagocytes, but its effects on macrophage polarization are not yet studied. To address this issue, human macrophages obtained from six normal blood donors were polarized to M1 or M2 in vitro by lipopolysaccharide plus interferon‐γ or interleukin‐4 (IL‐4), respectively. The presence of RAPA (10 ng/ml) induced macrophage apoptosis in M2 but not in M1. Beyond the impact on survival in M2, RAPA reduced CXCR4, CD206 and CD209 expression and stem cell growth factor‐β, CCL18 and CCL13 release. In contrast, in M1 RAPA increased CD86 and CCR7 expression and IL‐6, tumour necrosis factor‐α and IL‐1β release but reduced CD206 and CD209 expression and IL‐10, vascular endothelial growth factor and CCL18 release. In view of the in vitro data, we examined the in vivo effect of RAPA monotherapy (0·1 mg/kg/day) in 12 patients who were treated for at least 1 month before islet transplant. Cytokine release by Toll‐like receptor 4‐stimulated peripheral blood mononuclear cells showed a clear shift to an M1‐like profile. Moreover, macrophage polarization 21 days after treatment showed a significant quantitative shift to M1. These results suggest a role of mammalian target of rapamycin (mTOR) into the molecular mechanisms of macrophage polarization and propose new therapeutic strategies for human M2‐related diseases through mTOR inhibitor treatment.
To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from ...1999 to 2010.
A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999-2002), mid (2003-2006), or recent (2007-2010) transplant era based on annual follow-up to 5 years.
Insulin independence at 3 years after transplant improved from 27% in the early era (1999-2002, n = 214) to 37% in the mid (2003-2006, n = 255) and to 44% in the most recent era (2007-2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA(1c) and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007-2010 vs. 60-65% in 1999-2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001).
The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007-2010 compared with those in 1999-2006, with fewer islet infusions and adverse events per recipient.
Tissue-specific transcriptional regulation is central to human disease. To identify regulatory DNA active in human pancreatic islets, we profiled chromatin by formaldehyde-assisted isolation of ...regulatory elements coupled with high-throughput sequencing (FAIRE-seq). We identified ∼80,000 open chromatin sites. Comparison of FAIRE-seq data from islets to that from five non-islet cell lines revealed ∼3,300 physically linked clusters of islet-selective open chromatin sites, which typically encompassed single genes that have islet-specific expression. We mapped sequence variants to open chromatin sites and found that rs7903146, a TCF7L2 intronic variant strongly associated with type 2 diabetes, is located in islet-selective open chromatin. We found that human islet samples heterozygous for rs7903146 showed allelic imbalance in islet FAIRE signals and that the variant alters enhancer activity, indicating that genetic variation at this locus acts in cis with local chromatin and regulatory changes. These findings illuminate the tissue-specific organization of cis-regulatory elements and show that FAIRE-seq can guide the identification of regulatory variants underlying disease susceptibility.
Islet transplantation is an evolving therapy that may be considered for patients with type 1 diabetes mellitus complicated by severe hypoglycemia or labile diabetes, provided all other attempts to ...stabilize glycemic control have been exhausted. This multicenter trial confirms that islet transplantation using the Edmonton protocol can successfully restore long-term endogenous production of insulin and glycemic stability in such patients, but insulin independence is usually not sustainable.
Islet transplantation using the Edmonton protocol can successfully restore long-term endogenous production of insulin and glycemic stability in such patients, but insulin independence is usually not sustainable.
Despite substantial improvements in insulin therapy and the care of patients with type 1 diabetes mellitus, a subgroup of patients is disabled by refractory hypoglycemia. Cell-based therapy with islet transplantation offers the possibility of improved glycemic control. The past three decades have witnessed substantial progress in islet transplantation.
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Before the year 2000, few centers performing islet transplantation achieved high rates of sustainable insulin independence after this procedure among patients with type 1 diabetes mellitus.
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In 2000, Shapiro et al.
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reported their initial findings with up to a year of follow-up in seven consecutive subjects treated with glucocorticoid-free immunosuppressive . . .
Although long considered a promising treatment option for type 1 diabetes, pancreatic islet cell transformation has been hindered by immune system rejection of engrafted tissue. The identification of ...pathways that regulate post-transplant detrimental inflammatory events would improve management and outcome of transplanted patients. Here, we found that CXCR1/2 chemokine receptors and their ligands are crucial negative determinants for islet survival after transplantation. Pancreatic islets released abundant CXCR1/2 ligands (CXCL1 and CXCL8). Accordingly, intrahepatic CXCL1 and circulating CXCL1 and CXCL8 were strongly induced shortly after islet infusion. Genetic and pharmacological blockade of the CXCL1-CXCR1/2 axis in mice improved intrahepatic islet engraftment and reduced intrahepatic recruitment of polymorphonuclear leukocytes and NKT cells after islet infusion. In humans, the CXCR1/2 allosteric inhibitor reparixin improved outcome in a phase 2 randomized, open-label pilot study with a single infusion of allogeneic islets. These findings indicate that the CXCR1/2-mediated pathway is a regulator of islet damage and should be a target for intervention to improve the efficacy of transplantation.
Predicting clinical deterioration in COVID-19 patients remains a challenging task in the Emergency Department (ED). To address this aim, we developed an artificial neural network using textual (e.g. ...patient history) and tabular (e.g. laboratory values) data from ED electronic medical reports. The predicted outcomes were 30-day mortality and ICU admission. We included consecutive patients from Humanitas Research Hospital and San Raffaele Hospital in the Milan area between February 20 and May 5, 2020. We included 1296 COVID-19 patients. Textual predictors consisted of patient history, physical exam, and radiological reports. Tabular predictors included age, creatinine, C-reactive protein, hemoglobin, and platelet count. TensorFlow tabular-textual model performance indices were compared to those of models implementing only tabular data. For 30-day mortality, the combined model yielded slightly better performances than the tabular fastai and XGBoost models, with AUC 0.87 ± 0.02, F1 score 0.62 ± 0.10 and an MCC 0.52 ± 0.04 (p < 0.32). As for ICU admission, the combined model MCC was superior (p < 0.024) to the tabular models. Our results suggest that a combined textual and tabular model can effectively predict COVID-19 prognosis which may assist ED physicians in their decision-making process.
Background: Obesity may negatively impact clinical outcomes in kidney transplant (KT) recipients. Limited information is available on the prevalence of obesity in this population, and on the ...lifestyle habits associated with obesity. Methods: we conducted an online, anonymous survey to assess of the proportion of KT recipients with obesity, adherence to the Mediterranean diet (i.e., a dietary regimen with proven renal and cardiovascular outcomes) using the MEDI-Lite questionnaire, and level of physical activity using the International Physical Activity Questionnaire (IPAQ) short form among KT recipients. Results: 255 KT recipients participated. Median (25th−75th quartile) age was 56.0 (48.0; 62.0) years, 43.9% female, median BMI 23.9 (21.6; 26.5) kg/m2. The proportion of KT recipients with obesity was 9.8% (95% confidence interval, 6.4 to 14.1%). Adequate adherence to the Mediterranean diet (Medi-Lite score >9) was overall low (44.7%; 40.0 vs. 45.2% in those with or without obesity, respectively; p = 0.618). In participants with obesity the Medi-Lite score inversely correlated with BMI (R = −0.45; p < 0.025). Overall, 30.6% of participants had a low level of physical activity (44.0 vs. 29.1% of those with or without obesity, respectively; p = 0.125). The amount of energy expended walking was significantly lower among participants with obesity (462 (0.0; 1436) vs. 1056 (433; 2005) METs/week, p = 0.017). Conclusions: the burden of obesity among KT recipients is similar to that of the general population. Adherence to the Mediterranean diet was generally low, and nearly one-third of participants had a low level of physical activity. Building specialized multidisciplinary teams to manage obesity in KT recipients is urgently needed.
Acute respiratory failure (ARF) is a common cause of presentation to the Emergency Department (ED). High flow nasal cannula (HFNC) has been introduced as an alternative way to administer oxygen.
We ...performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing HFNC with conventional oxygen therapy (COT) and noninvasive ventilation (NIV) exclusively in the ED setting.
Inclusion criteria were: RCTs on adults with ARF admitted to the ED, investigating HFNC vs. COT or other modes of ventilation. Trials that compared HFNC support outside the ED, were published as an abstract, or nonrandomized were excluded.
Four RCTs comparing HFNC with COT and one HFNC to NIV met the criteria. Overall, 775 patients were included. The meta-analysis of the studies comparing HFNC and COT showed no differences in intubation requirement, treatment failure, hospitalization, or mortality. Intolerance was significantly higher with HFNC (risk ratio 6.81 95% confidence interval 1.18–39.19; p = 0.03). In the only available RCT comparing HFNC with NIV, no difference was found for intubation rate, treatment failure, tolerance, and dyspnea.
We did not find any benefit of HFNC compared with COT and NIV in terms of intubation requirement, treatment failure, hospitalization, and mortality; COT was better tolerated.
The liver is the current site of choice for pancreatic islet transplantation, even though it is far from being ideal. We recently have shown in mice that the bone marrow (BM) may be a valid ...alternative to the liver, and here we report a pilot study to test feasibility and safety of BM as a site for islet transplantation in humans. Four patients who developed diabetes after total pancreatectomy were candidates for the autologous transplantation of pancreatic islet. Because the patients had contraindications for intraportal infusion, islets were infused in the BM. In all recipients, islets engrafted successfully as shown by measurable posttransplantation C-peptide levels and histopathological evidence of insulin-producing cells or molecular markers of endocrine tissue in BM biopsy samples analyzed during follow-up. Thus far, we have recorded no adverse events related to the infusion procedure or the presence of islets in the BM. Islet function was sustained for the maximum follow-up of 944 days. The encouraging results of this pilot study provide new perspectives in identifying alternative sites for islet infusion in patients with type 1 diabetes. Moreover, this is the first unequivocal example of successful engraftment of endocrine tissue in the BM in humans.
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