Abnormalities of Thymic Stroma may Contribute to Immune Dysregulation in Murine Models of Leaky Severe Combined Immunodeficiency

Lymphostromal cross-talk in the thymus is essential to allow generation of a diversified repertoire of T lymphocytes and to prevent autoimmunity by self-reactive T cells. Hypomorphic mutations in genes that control T cell development have been associated with immunodeficiency and immune dysregulation both in humans and in mice. We have studied T cell development and thymic stroma architecture and maturation in two mouse models of leaky severe combined immune deficiency, carrying hypomorphic mutations in rag1 and lig4 genes. Defective T cell development was associated with abnormalities of thymic architecture that predominantly affect the thymic medulla, with reduction of the pool of mature medullary thymic epithelial cells (mTECs). While the ability of mTECs to express autoimmune regulator (Aire) is preserved in mutant mice, the frequency of mature mTECs expressing Aire and tissue-specific antigens is severely reduced. Similarly, the ability of CD4+ T cells to differentiate into Foxp3+ natural regulatory T cells is preserved in rag1 and lig4 mutant mice, but their number is greatly reduced. These data indicate that hypomorphic defects in T cell development may cause defective lymphostromal cross-talk and impinge on thymic stromal cells maturation, and thus favor immune dysregulation

HCV cirrhotic patients treated with direct acting antivirals: detection of tubular dysfunction and resolution after viral clearance

Background/aims: Hepatitis C virus (HCV) has been identified in tubular epithelial cells of infected patients, however the presence of tubular dysfunction, which is a risk factor for chronic kidney disease, has never been examined in vivo. The present prospective longitudinal study aimed to estimate the prevalence of tubular dysfunction alone or with glomerular damage and its evolution after HCV clearance in cirrhotic patients. Methods: One-hundred-thirty-five consecutive Child-Pugh-A cirrhotic patients were evaluated before antiviral treatment and six months after the end of therapy. Tubular dysfunction was evaluated by urinary-alpha1-microglobulin-to-creatinine-ratio (α1-MCR), glomerular damage was assessed by urinary-albumin-to-creatinine-ratio (ACR). Results: Almost all the patients (93.3%) showed a normal or mildly decreased e-GFR (KDIGO-G1/G2-categories). Tubular dysfunction was found in 23.7% (32/135) of patients, co-occurring with glomerular damage in 37.5% (12/32) of cases, while glomerular damage was found in 16.3% (22/135) of patients. In multiple logistic regression, glomerular damage and the concomitant presence of diabetes and hypertension were the only predictors significantly associated with tubular dysfunction. After HCV-clearance, patients experienced a significant reduction of α1-MCR levels (21.0 vs 10.5 μg/mg, p=0.009) and tubular dysfunction resolved in 57.1% of subjects. Conclusions: Tubular dysfunction is an unrecognized feature of HCV-related kidney disease in cirrhotic patients and its presence should be primarily investigated in subjects with glomerular damage, diabetes and hypertension, despite normal e-GFR. Tubular dysfunction resolves in the majority of cases after HCV clearance, however, it may persist after antiviral treatment and further studies should evaluate its long term impact on kidney function

Body mass index rather than the phenotype impacts precocious ultrasound cardiovascular risk markers in polycystic ovary syndrome

Objective Research into cardiovascular disease (CV) prevention has demonstrated a variety of ultrasound (US) markers predicting risk in the general population but which have been scarcely used for polycystic ovary syndrome (PCOS). Obesity is a major factor contributing to CV disease in the general population, and it is highly prevalent in PCOS. However, it is still unclear how much risk is attributable to hyperandrogenism. This study evaluates the most promising US CV risk markers in PCOS and compares them between different PCOS phenotypes and BMI values. Design Women fulfilling the Rotterdam criteria for PCOS were recruited from our outpatient clinic for this cross-sectional study. Methods Participants (n\u2009=\u2009102) aged 38.9 \ub1 7.4 years were stratified into the four PCOS phenotypes and the three BMI classes (normal-weight, overweight, obese). They were assessed for clinical and biochemical parameters together with the following US markers: coronary intima-media thickness (cIMT), flow-mediated vascular dilation (FMD), nitroglycerine-induced dilation (NTG), and epicardial fat thickness (EFT). Results There was no statistical difference among the four phenotypes in terms of cIMT, FMD, NTG or EFT, however all the US parameters except NTG showed significant differences among the three BMI classes. Adjusting for confounding factors in multiple regression analyses, EFT retained the greatest direct correlation with BMI and cIMT remained directly correlated but to a lesser degree. Conclusions This study showed that obesity rather than the hyperandrogenic phenotype negatively impacts precocious US CV risk markers in PCOS. In addition, EFT showed the strongest association with BMI, highlighting its potential for estimating CV risk in PCOS

Blocking Jak/STAT signalling using tofacitinib inhibits angiogenesis in experimental arthritis

Objective: During rheumatoid arthritis (RA), the angiogenic processes, occurring with pannus-formation, may be a therapeutic target. JAK/STAT-pathway may play a role and the aim of this work was to investigate the inhibiting role of a JAK-inhibitor, tofacitinib, on the angiogenic mechanisms occurring during RA. Methods: After ethical approval, JAK-1, JAK-3, STAT-1, STAT-3 and VEGF expression was evaluated on RA-synovialtissues. In vitro, endothelial cells (ECs), stimulated with 20 ng/ml of VEGF and/or 1 μM of tofacitinib, were assessed for tube formation, migration and proliferation, by Matrigel, Boyden chamber assay and ki67 gene-expression. In vivo, 32 mice received collagen (collagen-induced arthritis (CIA)) and 32 mice PBS (control). At day 19, CIA and controls mice were divided: 16 mice receiving vehicle and 16 mice receiving tofacitinib. At day 35, the arthritis score, the thickness of paw joints and the serum levels of VEGF and Ang-2 were evaluated. Results: The expression of JAK-1, JAK-3, STAT-1, STAT-3 and VEGF in synovial tissue of RA-patients were significantly higher than healthy controls. In vitro, tofacitinib inhibited the ECs ability to form vessels, to proliferate and to migrate. In vivo, administration of tofacitinib prevented the increase of the arthritis score, the paw thickness, the synovial vessels and VEGF and Ang-2 serum-accumulation, when compared to CIA without tofacitinib. Conclusions: We explored the anti-angiogenic role of tofacitinib, reporting its ability to inhibit in vitro the angiogenic mechanisms of ECs and in vivo the formation of new synovial vessels, occurring in CIA model. These findings suggest that the therapeutic effect of tofacitinib during RA may be also related to its anti-angiogenic activity

Cardiac Magnetic Resonance to Predict Cardiac Mass Malignancy: The CMR Mass Score

Background: Multimodality imaging is currently suggested for the noninvasive diagnosis of cardiac masses. The identification of cardiac masses' malignant nature is essential to guide proper treatment. We aimed to develop a cardiac magnetic resonance (CMR)-derived model including mass localization, morphology, and tissue characterization to predict malignancy (with histology as gold standard), to compare its accuracy versus the diagnostic echocardiographic mass score, and to evaluate its prognostic ability. Methods: Observational cohort study of 167 consecutive patients undergoing comprehensive echocardiogram and CMR within 1-month time interval for suspected cardiac mass. A definitive diagnosis was achieved by histological examination or, in the case of cardiac thrombi, by histology or radiological resolution after adequate anticoagulation treatment. Logistic regression was performed to assess CMR-derived independent predictors of malignancy, which were included in a predictive model to derive the CMR mass score. Kaplan-Meier curves and Cox regression were used to investigate the prognostic ability of predictors. Results: In CMR, mass morphological features (non-left localization, sessile, polylobate, inhomogeneity, infiltration, and pericardial effusion) and mass tissue characterization features (first-pass perfusion and heterogeneity enhancement) were independent predictors of malignancy. The CMR mass score (range, 0-8 and cutoff, ≥5), including sessile appearance, polylobate shape, infiltration, pericardial effusion, first-pass contrast perfusion, and heterogeneity enhancement, showed excellent accuracy in predicting malignancy (areas under the curve, 0.976 [95% CI, 0.96-0.99]), significantly higher than diagnostic echocardiographic mass score (areas under the curve, 0.932; P=0.040). The agreement between the diagnostic echocardiographic mass and CMR mass scores was good (κ=0.66). A CMR mass score of ≥5 predicted a higher risk of all-cause death (P<0.001; hazard ratio, 5.70) at follow-up. Conclusions: A CMR-derived model, including mass morphology and tissue characterization, showed excellent accuracy, superior to echocardiography, in predicting cardiac masses malignancy, with prognostic implications

Prognostic Relevance of Type 4a Myocardial Infarction and Periprocedural Myocardial Injury in Patients With Non–ST-Segment–Elevation Myocardial Infarction

Background: Periprocedural myocardial injury (PMI) with or without type 4a myocardial infarction (MI) might occur in patients with non-ST-segment-elevation MI (NSTEMI) after percutaneous coronary intervention (PCI). This study investigated the incidence and prognostic relevance of these events, according to current definitions, in patients with NSTEMI undergoing PCI. The best cardiac troponin I (cTnI) threshold of PMI for prognostic stratification is also suggested. Methods: Consecutive patients with NSTEMI from January 2017 to April 2022 undergoing PCI with stable or falling pre-PCI cTnI levels were enrolled. According to the Fourth Universal Definition of Myocardial Infarction, the study population was stratified into those experiencing (1) PMI with type 4a MI, (2) PMI without type 4a MI, or (3) no PMI. Post-PCI cTnI increase >20% with an absolute postprocedural value of ≥5 times the 99th percentile upper reference limit within 48 hours after PCI was used to define PMI. The primary end point was 1-year all-cause mortality, and the secondary end point consisted of major adverse cardiovascular events at 1 year, including all-cause mortality, nonfatal reinfarction, urgent revascularization, nonfatal ischemic stroke, and hospitalization for heart failure. Internal validation was performed in patients enrolled between May 2022 and April 2023. Results: Among 1412 patients with NSTEMI undergoing PCI with stable or falling cTnI levels at baseline, 240 (17%) experienced PMI with type 4a MI, 288 (20.4%) experienced PMI without type 4a MI, and 884 (62.6%) experienced no PMI. PMI was associated with an increased risk of adverse clinical outcomes, with patients with type 4a MI demonstrating the highest rates of 1-year all-cause mortality and major adverse cardiovascular events. A post-PCI ΔcTnI >20% but ≤40% showed similar outcomes to patients without PMI, whereas >40% was identified as the optimal threshold for prognostically relevant PMI, confirmed in an internal validation cohort of 305 patients. Conclusions: Periprocedural ischemic events were frequent in patients with NSTEMI undergoing PCI with prognostic implications. A post-PCI ΔcTnI >40%, combined with an absolute postprocedural value of ≥5 times the 99th percentile upper reference limit, was identified as the optimal threshold for diagnosing prognostically relevant PMI. Recognizing these events may improve risk stratification and management of patients with NSTEMI

Managing a Mass CO Poisoning: Critical Issues and Solutions From the Field to the Hyperbaric Chamber

Carbon monoxide acute intoxication is a common cause of accidental poisoning in industrialized countries and sometimes it produces a real mass casualty incident. The incident described here occurred in a church in the province of Verona, when a group of people was exposed to carbon monoxide due to a heating system malfunction. Fifty-seven people went to the Emergency Department. The mean carboxyhemoglobin (COHb) level was 10.1\ub15.7% (range: 3-25%). The clinicians, after medical examination, decided to move 37 patients to hyperbaric chambers for hyperbaric oxygen (HBO) therapy. This is the first case report that highlights and analyses the logistic difficulties of managing a mass carbon monoxide poisoning in different health care settings, with a high influx of patients in an Emergency Department and a complex liaison between emergency services. This article shows how it is possible to manage a complex situation with good outcome. (Disaster Med Public Health Preparedness. 2016;page 1 of 5)

The glycosaminoglycan-binding domain of PRELP acts as a cell type–specific NF-κB inhibitor that impairs osteoclastogenesis

The PRELP heparin sulfate–binding protein translocates to the nucleus, where it impairs NF-κB transcriptional activity, which in turn regulates bone homeostasis

Expansion of immunoglobulin-secreting cells and defects in B cell tolerance in Rag-dependent immunodeficiency

The contribution of B cells to the pathology of Omenn syndrome and leaky severe combined immunodeficiency (SCID) has not been previously investigated. We have studied a mut/mut mouse model of leaky SCID with a homozygous Rag1 S723C mutation that impairs, but does not abrogate, V(D)J recombination activity. In spite of a severe block at the pro–B cell stage and profound B cell lymphopenia, significant serum levels of immunoglobulin (Ig) G, IgM, IgA, and IgE and a high proportion of Ig-secreting cells were detected in mut/mut mice. Antibody responses to trinitrophenyl (TNP)-Ficoll and production of high-affinity antibodies to TNP–keyhole limpet hemocyanin were severely impaired, even after adoptive transfer of wild-type CD4+ T cells. Mut/mut mice produced high amounts of low-affinity self-reactive antibodies and showed significant lymphocytic infiltrates in peripheral tissues. Autoantibody production was associated with impaired receptor editing and increased serum B cell–activating factor (BAFF) concentrations. Autoantibodies and elevated BAFF levels were also identified in patients with Omenn syndrome and leaky SCID as a result of hypomorphic RAG mutations. These data indicate that the stochastic generation of an autoreactive B cell repertoire, which is associated with defects in central and peripheral checkpoints of B cell tolerance, is an important, previously unrecognized, aspect of immunodeficiencies associated with hypomorphic RAG mutations