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In this Correspondence, P. Pelegrin and colleagues found that the deposition of amyloid in tissues in Cryopyrin-Associated Periodic Syndrome were promoted by the extracellular presence of the inflammasome adaptor protein ASC, opening exciting new directions in clinical practice to obtain a novel therapy towards secondary amyloidosis in inflammasomopathies. [ABSTRACT FROM AUTHOR]

Background & Aims: Successful immunosuppression withdrawal (ISW) is possible for a subfraction of liver transplant (LT) recipients but the factors that define the risk of ISW failure are largely unknown. One candidate prognostic factor for ISW success or operational tolerance (OT) is longer time between LT and ISW which we term "pre‐withdrawal time". To clarify the impact of pre‐withdrawal time span on subsequent ISW success or failure, we conducted a systematic review with meta‐analysis. Methods: We systematically interrogated the literature for LT recipient ISW studies reporting pre‐withdrawal time. Eligible articles from Embase, Medline, and the Cochrane Central Register of Controlled Trials were used for backward and forward citation searching. Pre‐withdrawal time individual patient data (IPD) was requested from authors. Pooled mean differences and time‐response curves were calculated using random‐effects meta‐analyses. Results: We included 17 studies with 691 patients, 15 of which (620 patients) with IPD. Study‐level risk of bias was heterogeneous. Mean pre‐withdrawal time was greater by 427 days [95% confidence interval (CI) 67–788] in OT compared to non‐OT patients. This increase was potentiated to 799 days (95% CI 369–1229) or 1074 days (95% CI 685–1463) when restricting analysis to adult or European study participants. In time‐response meta‐analysis for adult or European ISW candidates, likelihood of OT increased by 7% (95% CI 4–10%) per year after LT (GRADE low‐ and moderate‐certainty of evidence, respectively). Conclusions: Our data support the impact of pre‐withdrawal time in ISW decision‐making for adult and European LT recipients. PROSPERO REGISTRATION: CRD42021272995. [ABSTRACT FROM AUTHOR]

Background and purpose: A high number of intratumoural infiltrating natural killer (NK) cells is associated with better survival in several types of cancer, constituting an important first line of defence against tumours. Hypoxia in the core of solid tumours induces cellular stress and ATP release into the extracellular space where it triggers purinergic receptor activation on tumour‐associated immune cells. The aim of this study was to assess whether activation of the purinergic receptor P2X7 by extracellular ATP plays a role in the NK cells antitumour activity. Experimental approach: We carried out in vitro experiments using purified human NK cells triggered through P2X7 by extracellular ATP. NK cell killing activity against the tumour target cells K562 was studied by means of NK cytotoxicity assays. Likewise, we designed a subcutaneous solid tumour in vivo mouse model. Key results: In this study we found that human NK cells, expressing a functional plasma membrane P2X7, acquired an anergic state after ATP treatment, which impaired their antitumour activity and decreased IFN‐γ secretion. This effect was reversed by specific P2X7 antagonists and pretreatment with either IL‐2 or IL‐15. Furthermore, genetic P2rx7 knockdown resulted in improved control of tumour size by NK cells. In addition, IL‐2 therapy restored the ability of NK cells to diminish the size of tumours. Conclusions and implications: Our results show that P2X7 activation represents a new mechanism whereby NK cells may lose antitumour effectiveness, opening the possibility of generating modified NK cells lacking P2X7 but with improved antitumour capacity. [ABSTRACT FROM AUTHOR]

Background: Since the declaration of the pandemic, humanitarian medicine has been discontinued. Until now, there have been no general recommendations on how humanitarian surgical missions should be organized. Methods: Based on our experience in the field of humanitarian surgical missions to Sub-Saharan Africa, a panel of recommendations in times of COVID-19 was developed. The fields under study were as follows: (1) Planning of a multidisciplinary project; (2) Organization of the infrastructure; (3) Screening, management and treatment of SARS-COV-2; (4) Diagnostic tests for SARS-COV-2; (5) Surgical priorization and (6) Context of patients during health-care assistance. We applied a risk bias measurement to obtain a consensus among humanitarian health-care providers with experience in this field. Results: A total of 94.36% of agreement were reached for the approval of the recommendations. Emergency surgery must be a priority, and elective surgery adapted. For emergency surgery, we established a priority level 1a (< 24 h) and 1b (< 72 h). For an elective procedure, according our American College of Surgeon adaptation score, process with more than 60 points should be reconsidered. Due to the low life expectancy in many African countries, we consider 45–50 years as age of risk. In case of SARS-COV-2 active infection or high clinical suspicion, the screening, management and treatment should be following the international guidelines adapted to duration of the stay, available infrastructure, size of the cooperation team and medical resources. Conclusions: Humanitarian surgical mission in times of COVID-19 is a challenge that must extrapolate the established recommendations to the local cooperation environment. [ABSTRACT FROM AUTHOR]

Objective Gain-of-function NLRP3 mutations cause cryopyrin-associated periodic syndrome (CAPS), with gene mosaicism playing a relevant role in the pathogenesis. This study was undertaken to characterize the genetic cause underlying late-onset but otherwise typical CAPS. Methods We studied a 64-year-old patient who presented with recurrent episodes of urticaria-like rash, fever, conjunctivitis, and oligoarthritis at age 56 years. DNA was extracted from both unfractionated blood and isolated leukocyte and CD34+ subpopulations. Genetic studies were performed using both the Sanger method of DNA sequencing and next-generation sequencing (NGS) methods. In vitro and ex vivo analyses were performed to determine the consequences that the presence of the variant have in the normal structure or function of the protein of the detected variant. Results NGS analyses revealed the novel p.Gln636Glu NLRP3 variant in unfractionated blood, with an allele frequency (18.4%) compatible with gene mosaicism. Sanger sequence chromatograms revealed a small peak corresponding to the variant allele. Amplicon-based deep sequencing revealed somatic NLRP3 mosaicism restricted to myeloid cells (31.8% in monocytes, 24.6% in neutrophils, and 11.2% in circulating CD34+ common myeloid progenitor cells) and its complete absence in lymphoid cells. Functional analyses confirmed the gain-of-function behavior of the gene variant and hyperactivity of the NLRP3 inflammasome in the patient. Treatment with anakinra resulted in good control of the disease. Conclusion We identified the novel gain-of-function p.Gln636Glu NLRP3 mutation, which was detected as a somatic mutation restricted to myeloid cells, as the cause of late-onset but otherwise typical CAPS. Our results expand the diversity of CAPS toward milder phenotypes than previously reported, including those starting during adulthood. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE The negative affective states of withdrawal involve the recruitment of brain and peripheral stress circuitry [noradrenergic activity, induction of the hypothalamic-pituitary-adrenocortical (HPA) axis and activation of heat shock proteins (Hsps)]. Corticotropin-releasing factor (CRF) pathways are important mediators in the negative symptoms of opioid withdrawal. We performed a series of experiments to characterize the role of the CRF1 receptor in the response of stress systems to morphine withdrawal and its effect in the heart using genetically engineered mice lacking functional CRF1 receptors. EXPERIMENTAL APPROACH Wild-type and CRF1 receptor-knockout mice were treated with increasing doses of morphine. Precipitated withdrawal was induced by naloxone. Plasma adrenocorticotropic hormone (ACTH) and corticosterone levels, the expression of myocardial Hsp27, Hsp27 phosphorylated at Ser82, membrane (MB)- COMT, soluble (S)-COMT protein and NA turnover were evaluated by RIA, immunoblotting and HPLC. KEY RESULTS During morphine withdrawal we observed an enhancement of NA turnover in parallel with an increase in mean arterial blood pressure (MAP) and heart rate (HR) in wild-type mice. In addition, naloxone-precipitated morphine withdrawal induced an activation of HPA axis and Hsp27. The principal finding of the present study was that plasma ACTH and corticosterone levels, MB-COMT, S-COMT, NA turnover, and Hsp27 expression and activation observed during morphine withdrawal were significantly inhibited in the CRF1 receptor-knockout mice. CONCLUSION AND IMPLICATIONS Our results demonstrate that CRF/CRF1 receptor activation may contribute to stress-induced cardiovascular dysfunction after naloxone-precipitated morphine withdrawal and suggest that CRF/CRF1 receptor pathways could contribute to cardiovascular disease associated with opioid addiction. [ABSTRACT FROM AUTHOR]

Prostaglandins (PGs) are important lipid mediators involved in the development of inflammatory associated pain and fever. PGE2 is a well-established endogenous pyrogen activated by proinflammatory cytokine interleukin (IL)-1β. P2X7 receptors (P2X7Rs) expressed by inflammatory cells are stimulated by the danger signal extracellular ATP to activate the inflammasome and release IL-1β. Here we show that P2X7R activation is required for the release of PGE2 and other autacoids independent of inflammasome activation, with an ATP EC50 for PGE2 and IL-1β release of 1.58 and 1.23 mM, respectively. Furthermore, lack of P2X7R or specific antagonism of P2X7R decreased the febrile response in mice triggered after intraperitoneal LPS or IL-1β inoculation. Accordingly, LPS inoculation caused intraperitoneal ATP accumulation. Therefore, P2X7R antagonists emerge as novel therapeutics for the treatment for acute inflammation, pain and fever, with wider anti-inflammatory activity than currently used cyclooxygenase inhibitors. [ABSTRACT FROM AUTHOR]

P2X7 receptor-mediated purinergic signaling is a well-known mechanism involved in bone remodeling. The P2X7 receptor has been implicated in the pathophysiology of various bone and cartilage diseases, including rheumatoid arthritis (RA), a widespread and complex chronic inflammatory disorder. The P2X7 receptor induces the release into the synovial fluid of the proinflammatory factors (e.g., interleukin-1β, prostaglandins, and proteases) responsible for the clinical symptoms of RA. Thus, the P2X7 receptor is emerging as a novel anti-inflammatory therapeutic target, and various selective P2X7 receptor antagonists are under clinical trials. Extracellular ATP signaling acting through the P2X7 receptor is a complex and dynamic scenario, which varies over the course of inflammation. This signaling is partially modulated by the activity of ectonucleotidases, which degrade extracellular ATP to generate other active molecules such as adenosine or pyrophosphates. Recent evidence suggests differential extracellular metabolism of ATP during the resolution of inflammation to generate pyrophosphates. Extracellular pyrophosphate dampens proinflammatory signaling by promoting alternative macrophage activation. Our paper shows that bisphosphonates are metabolically stable pyrophosphate analogues that are able to mimic the anti-inflammatory function of pyrophosphates. Bisphosphonates are arising per se as promising anti-inflammatory drugs to treat RA, and this therapy could be improved when administrated in combination with P2X7 receptor antagonists. [ABSTRACT FROM AUTHOR]

After liver transplantation, long-term immunosuppression (IS) administration is commonly complicated by renal dysfunction and cardiovascular complications. Twenty liver transplant patients on cyclosporine (CyA)-based IS were followed up prospectively after IS withdrawal. They consisted of 10 electively weaned patients and 10 either forcibly or incidentally weaned patients. Liver biochemical tests, blood pressure, serum creatinine, serum urea, serum uric acid, triglycerides, cholesterol and glucose were monitored after the start of weaning. Eight of the 20 patients (40%) were IS therapy free for a mean period of 61 ± 39 months (range: 10–132 months). Of the remaining 12 patients, mild or moderate acute rejection occurred in six patients (30%), and mixed inflammatory portal tract infiltrate was seen in another six patients (30%). At the end of the study, mean (SD) serum creatinine had fallen by 0.28 (0.10) mg/dL (p < 0.001) in operationally tolerant (T) patients whereas the serum creatinine level increased in IS-dependent patients [+0.35 (0.35) mg/dL] (p = 0.005). In T patients, serum cholesterol, serum uric acid, fasting glucose and diastolic arterial pressure values significantly decreased. IS withdrawal can be achieved in selected liver transplant patients, and can improve not only kidney function, but also other CyA-associated side effects, such as hypercholesterolemia, hyperuricemia, hypertension and diabetes. [ABSTRACT FROM AUTHOR]