Impact of annual TB screening on stone quarry workers in high-incidence Portuguese municipalities

SETTING

The Portuguese municipalities of Penafiel and Marco de Canaveses are high TB incidence areas, where stone quarry workers represent a vulnerable population.

OBJECTIVE

To assess the annual rate of TB infection (ARI) in stone quarry workers and to compare it with the TB notification rate in the general community.

DESIGN

An annual TB infection screening strategy using interferon-gamma release assay (IGRA) was implemented in 2018 for workers from high-risk stone quarries. A prospective cohort was enrolled and workers screened in periods of 2 years were included. IGRA-positive workers were referred for preventive treatment. ARI was calculated as the proportion of workers with IGRA conversion.

RESULTS

Of the 232 IGRA-negative workers in 2018, 20 tested positive in 2019 (8.6% ARI). Of 171 IGRA-negative workers in 2019, eight tested positive in 2021 (4.7% in 2 years). Two of the 150 IGRA-negative workers in 2021 tested positive in 2022 (1.3% ARI). ARI decreased by 84.9% between 2019 and 2022. In the two municipalities, the TB notification rate declined 23.9% between 2018 and 2021.

CONCLUSION

A more pronounced reduction in ARI was observed among stone quarry workers regularly screened for TB infection compared to the notification rate among the general population in high-incidence municipalities. A screening strategy for high-risk populations, together with enforced community measures, could foster risk reduction in the community..

Decline of tuberculosis notification rate in different populations and regions in Portugal, 2010-2017

BACKGROUND

Tuberculosis (TB) incidence declined in Portugal in recent decades, but trends differ between regions and population subgroups. We investigated these differences to inform prevention and control programmes.

METHODS

We extracted TB notifications from the Portuguese National TB Surveillance System (SVIG-TB) in 2010-2017, disaggregated by region, age group, nationality and HIV status. We calculated notification rates using denominators from the Portuguese National Institute of Statistics and the Joint United Nations Programme on HIV/AIDS and performed stratified time series analysis. We estimated interannual decline percentages and 95% confidence intervals (CI) using Poisson and binomial negative regression models.

RESULTS

The overall TB notification rate decreased from 25.7 to 17.5/100,000 population from 2010 to 2017 (5.2%/year) in Portugal. Interannual decline did not differ significantly between regions, but it was smaller amongst non-Portuguese nationals (-1.57% [CI: -4.79%, 1.75%] vs -5.85% [CI: -6.98%, -4.70%] in Portuguese nationals); children under five years of age (+1.77% [CI: -4.61%, 8.58%] vs -5.38% [CI: -6.33%, -4.42%] in other age groups); and HIV-negative people (-6.47% [CI: -9.10%, -3.77%] vs -11.29% [CI; -17.51%, -4.60%] in HIV-positive).

CONCLUSIONS

The decline in TB notification rates in Portugal during the study period has been steady. However, the decline amongst non-Portuguese nationals, children under five years of age and non-infected-HIV patients was lower. No significant differences were observed between regions. Changes in TB epidemiology in specific risk groups and geographical areas should be closely monitored to achieve the objectives of the End TB Strategy. We recommend intensifying screening of TB in the subpopulations identified.

Children with extended oligoarticular and polyarticular juvenile idiopathic arthritis have alterations in B and T follicular cell subsets in peripheral blood and a cytokine profile sustaining B cell activation

OBJECTIVES

The main goal of this study was to characterise the frequency and phenotype of B, T follicular helper (Tfh) and T follicular regulatory (Tfr) cells in peripheral blood and the cytokine environment present in circulation in children with extended oligoarticular juvenile idiopathic arthritis (extended oligo JIA) and polyarticular JIA (poly JIA) when compared with healthy controls, children with persistent oligoarticular JIA (persistent oligo JIA) and adult JIA patients.

METHODS

Blood samples were collected from 105 JIA patients (children and adults) and 50 age-matched healthy individuals. The frequency and phenotype of B, Tfh and Tfr cells were evaluated by flow cytometry. Serum levels of APRIL, BAFF, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-17A, IL-21, IL-22, IFN-γ, PD-1, PD-L1, sCD40L, CXCL13 and TNF were measured by multiplex bead-based immunoassay and/or ELISA in all groups included.

RESULTS

The frequency of B, Tfh and Tfr cells was similar between JIA patients and controls. Children with extended oligo JIA and poly JIA, but not persistent oligo JIA, had significantly lower frequencies of plasmablasts, regulatory T cells and higher levels of Th17-like Tfh cells in circulation when compared with controls. Furthermore, APRIL, BAFF, IL-6 and IL-17A serum levels were significantly higher in paediatric extended oligo JIA and poly JIA patients when compared with controls. These immunological alterations were not found in adult JIA patients in comparison to controls.

CONCLUSIONS

Our results suggest a potential role and/or activation profile of B and Th17-like Tfh cells in the pathogenesis of extended oligo JIA and poly JIA, but not persistent oligo JIA.

Src-Dependent NM2A Tyrosine Phosphorylation Regulates Actomyosin Remodeling

Non-muscle myosin 2A (NM2A) is a key cytoskeletal enzyme that, along with actin, assembles into actomyosin filaments inside cells. NM2A is fundamental for cell adhesion and motility, playing important functions in different stages of development and during the progression of viral and bacterial infections. Phosphorylation events regulate the activity and the cellular localization of NM2A. We previously identified the tyrosine phosphorylation of residue 158 (pTyr¹⁵⁸) in the motor domain of the NM2A heavy chain. This phosphorylation can be promoted by Listeria monocytogenes infection of epithelial cells and is dependent on Src kinase; however, its molecular role is unknown. Here, we show that the status of pTyr¹⁵⁸ defines cytoskeletal organization, affects the assembly/disassembly of focal adhesions, and interferes with cell migration. Cells overexpressing a non-phosphorylatable NM2A variant or expressing reduced levels of Src kinase display increased stress fibers and larger focal adhesions, suggesting an altered contraction status consistent with the increased NM2A activity that we also observed. We propose NM2A pTyr¹⁵⁸ as a novel layer of regulation of actomyosin cytoskeleton organization.

Diagnostic and therapeutic approach of central sleep apnea in heart failure - the role of adaptive servo-ventilation. A statement of the Portuguese society of pulmonology and the Portuguese sleep association

It is known that patients with heart failure (HF) have an increased risk of developing central sleep apnoea (CSA), with Cheyne-Stokes respiration. The development of servo-ventilation aimed to treat CSA and improve the quality of life (QoL) of these patients. A large randomized clinical study, SERVE-HF, was conducted in order to test this theory in patients with HF and reduced ejection fraction (HFrEF). The results from this trial seemed to indicate that, in these patients, there was no beneficial effect of the assisted ventilation in CSA treatment. More surprisingly, an increased rate of all-cause or cardiovascular mortality was observed. This has led to dramatic changes in clinical practice, with decreased frequency of servo-ventilation prescription across Europe, including Portugal, due to changes in the guidelines. However, SERVE-HF was conducted only in severe systolic HF patients with CSA, and caution must be taken when extrapolating these results to HF patients with preserved ejection fraction or CSA patients without HF. The study also showed poor adherence, methodological and statistical gaps, including study design, patient selection, data collection and analysis, treatment adherence, and group crossovers, which have not been discussed in the trial as potential confounding factors and raise several concerns. Moreover, the adaptive servo-ventilation (ASV) device used in SERVE-HF was unable to lower the minimum support pressure below 3 mm H₂0, and this has been suggested as one of the probable contributing reasons to the excess mortality observed in this study. This limitation has since been solved, and this ASV device is no longer used. This paper describes the results of a Portuguese Task Force on the treatment of central sleep apnoea in patients with chronic HF.

Cells Responding to Closely Related Cholesterol-Dependent Cytolysins Release Extracellular Vesicles with a Common Proteomic Content Including Membrane Repair Proteins

The plasma membrane (PM) protects cells from extracellular threats and supports cellular homeostasis. Some pathogens produce pore-forming toxins (PFTs) that disrupt PM integrity by forming transmembrane pores. High PFT concentrations cause massive damage leading to cell death and facilitating infection. Sub-lytic PFT doses activate repair mechanisms to restore PM integrity, support cell survival and limit disease. Shedding of extracellular vesicles (EVs) has been proposed as a key mechanism to eliminate PFT pores and restore PM integrity. We show here that cholesterol-dependent cytolysins (CDCs), a specific family of PFTs, are at least partially eliminated through EVs release, and we hypothesize that proteins important for PM repair might be included in EVs shed by cells during repair. To identify new PM repair proteins, we collected EVs released by cells challenged with sub-lytic doses of two different bacterial CDCs, listeriolysin O and pneumolysin, and determined the EV proteomic repertoire by LC-MS/MS. Intoxicated cells release similar EVs irrespectively of the CDC used. Also, they release more and larger EVs than non-intoxicated cells. A cluster of 70 proteins including calcium-binding proteins, molecular chaperones, cytoskeletal, scaffold and membrane trafficking proteins, was detected enriched in EVs collected from intoxicated cells. While some of these proteins have well-characterized roles in repair, the involvement of others requires further study. As proof of concept, we show here that Copine-1 and Copine-3, proteins abundantly detected in EVs released by intoxicated cells, are required for efficient repair of CDC-induced PM damage. Additionally, we reveal here new proteins potentially involved in PM repair and give new insights into common mechanisms and machinery engaged by cells in response to PM damage.

Assessment of the outcomes of SARS-CoV-2 infection in children and young people followed at Portuguese pediatric rheumatology clinics

INTRODUCTION

Coronavirus Disease 2019 (COVID-19) generally appears to have milder clinical symptoms and fewer laboratory abnormalities in children. It remains unknown whether children and young people with inflammatory chronic diseases who acquire SARS-CoV-2 infection have a more severe course, due to either underlying disease or immunosuppressive treatments.

OBJECTIVES

To assess the epidemiological features and clinical outcomes of children and young people with inflammatory chronic diseases followed at Pediatric Rheumatology Clinics who were infected with SARS-CoV-2.

METHODS

A multicentric prospective observational study was performed. Data on demographic variables, clinical features and treatment were collected between March 2020 and September 2021, using the Rheumatic Diseases Portuguese Register (Reuma.pt) and complemented with data from the hospital clinical records.

RESULTS

Thirty-four patients were included, 62% were female, with a median age of 13 [8-16] years and a median time of inflammatory chronic disease of 6 [3-10] years. The most common diagnoses were juvenile idiopathic arthritis (n=22, 64.7%), juvenile dermatomyositis (n=3, 8.8%) and idiopathic uveitis (n=3, 8.8%). Twenty patients were on conventional synthetic disease modifying drugs (csDMARDs) and 10 on biologic DMARDs (bDMARDs). Five patients had an active inflammatory disease at the time of infection (low activity). Seven patients had an asymptomatic infection while 27 patients (79%) had symptoms: cough (n=12), fever (n=11), rhinorrhea (n=10), headache (n=8), malaise (n=8), fatigue (n=7), anosmia (n=5), myalgia (n=5),dysgeusia (n=4), odynophagia (n=4), chest pain (n=2), diarrhea (n=2), arthralgia (n=1), vomiting (n=1) and conjunctivitis (n=1). No patient required hospitalization or directed treatment, and all recovered without sequelae. In 8 patients there was a change in the baseline medication during the infection: suspension of bDMARDs (n=4), reduction of bDMARDs (n=1), suspension of csDMARDs (n=4) and reduction of csDMARDs (n=2). Only in one patient with juvenile dermatomyositis (who discontinued bDMARDs and csDMARDs), the underlying disease worsened.

CONCLUSIONS

This is the first study involving children with inflammatory chronic diseases followed at Rheumatology Clinics and SARS-CoV-2 infection in Portugal. In our cohort, mild illness was predominant, which is consistent with the literature. There was no need for hospitalization or specific treatment, and, in most cases, no worsening of the underlying disease was identified.

Effectiveness of a hybrid digital substance abuse prevention approach combining e-Learning and in-person class sessions

Background

Effective school-based programs for preventing substance abuse offer considerable public health potential. Yet limited class time and uneven implementation fidelity can be barriers to widespread adoption and high-quality implementation. A hybrid digital approach may be effective and help address these barriers.

Objective

To evaluate the effectiveness of a hybrid substance abuse prevention program for middle school students consisting of e-learning modules and in-person class sessions.

Design

Twenty-three United States (U.S.) middle schools were randomly assigned either to an intervention condition (13 schools) or a treatment-as-usual control condition (10 schools) where standard health education material was delivered. There were 1,447 participants who completed the pre-test and post-test assessments, of which 48.3% were male and 51.7% female.

Intervention

The hybrid digital intervention consisted of 14 brief e-learning modules and six classroom sessions adapted from an evidence-based program designed for classroom implementation to increase knowledge of adverse consequences of substance use and improve social skills, personal coping skills, and skills for resisting social influences to smoke, drink, or use drugs.

Measures

Participating students completed online pre-test and post-test surveys to assess substance use, knowledge, and life skills.

Results

There were significant reductions in substance use for the hybrid digital condition compared to the control condition as well as significant increases in health knowledge, skills knowledge, and life skills.

Conclusions

A hybrid digital approach to substance abuse prevention is effective and offers potential for overcoming common barriers to widespread adoption and high-quality implementation.

POS0496 CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS HAVE ALTERATIONS IN B AND T FOLLICULAR CELL SUBSETS IN PERIPHERAL BLOOD

Background

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children1. Our group has recently demonstrated that extended oligoarticular (eoJIA) and polyarticular JIA (pJIA) mostly evolve to a rheumatoid arthritis (RA) like phenotype in adulthood2. Disturbances in B cells, T follicular helper (Tfh) and T follicular regulatory (Tfr) cell immune responses are associated with the pathogenesis of RA3,4, but their exact role in JIA development is not entirely known.

Objectives

The main goal of this study was to characterize the frequency and phenotype of B, Tfh and Tfr cells in peripheral blood of children with eoJIA and pJIA when compared to healthy controls and children with persistent oligoarticular JIA (poJIA).

Methods

Blood samples were collected from children with eoJIA (n=5), pJIA (n=11) and poJIA (n=19) treated with disease modifying anti-rheumatic drugs. A group of age-matched healthy individuals (n=8) was used as control. Peripheral blood mononuclear cells were isolated and the frequency and phenotype of B, Tfh and Tfr cells were evaluated by flow cytometry.

Results

The frequency of B, Tfh and Tfr cells was similar between JIA patients and controls. Children with eoJIA and pJIA, but not poJIA, had higher levels of naïve B cells and lower frequencies of post-switch memory B cells and plasmablasts when compared to controls. Th17-like Tfh cells were significantly increased in all JIA patients when compared to controls. B cell phenotype was similar between JIA patients and controls, but a reduced activated phenotype of Tfh cells was observed in JIA patients in comparison to controls.

Conclusion

Changes in B and Tfh cell subpopulations, but not in Tfr cells, were found in peripheral blood of children with JIA when compared to controls. The increased frequencies of Th17-like Tfh cells detected in JIA when compared to controls suggests a potential role of these cells in JIA pathogenesis. A treatment effect on the activation state of B, Tfh and Tfr cells cannot be excluded.

References

[1]Ravelli, A. & Martini, A. Juvenile Idiopathic Arthritis. Lancet 369, 767–778 (2007).

[2]Oliveira-ramos, F. et al. Juvenile idiopathic arthritis in adulthood: fulfillment of classification criteria for adult rheumatic diseases, long-term outcomes and predictors of inactive disease, functional status and damage. 1–10 (2016)

[3]Moura, R. A., Graca, L. & Fonseca, J. E. To B or not to B the conductor of rheumatoid arthritis orchestra. Clin. Rev. Allergy Immunol. 43, 281–291 (2012).

[4]Deng, J., Wei, Y., Fonseca, V. R., Graca, L. & Yu, D. T follicular helper cells and T follicular regulatory cells in rheumatic diseases. Nat. Rev. Rheumatol. 15, 475–490 (2019).

Acknowledgements

C. Tomé was supported by a fellowship from Fundação para a Ciência e a Tecnologia (FCT) (PD/BD/135520/2018), Portugal. This work was supported by a grant from Sociedade Portuguesa de Reumatologia.

Disclosure of Interests

None declared.

The Yin and Yang of Pneumolysin During Pneumococcal Infection

Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont Streptococcus pneumoniae, the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form transmembrane pores in host cells, disrupting plasma membrane integrity and deregulating cellular homeostasis. At lytic concentrations, PLY causes cell death. At sub-lytic concentrations, PLY triggers host cell survival pathways that cooperate to reseal the damaged plasma membrane and restore cell homeostasis. While PLY is generally considered a pivotal factor promoting S. pneumoniae colonization and survival, it is also a powerful trigger of the innate and adaptive host immune response against bacterial infection. The dichotomy of PLY as both a key bacterial virulence factor and a trigger for host immune modulation allows the toxin to display both "Yin" and "Yang" properties during infection, promoting disease by membrane perforation and activating inflammatory pathways, while also mitigating damage by triggering host cell repair and initiating anti-inflammatory responses. Due to its cytolytic activity and diverse immunomodulatory properties, PLY is integral to every stage of S. pneumoniae pathogenesis and may tip the balance towards either the pathogen or the host depending on the context of infection.

Neonatal lupus: a clinical challenge

Neonatal lupus is an uncommon entity. The main manifestations are cutaneous and cardiac. It is caused by transplacental passage of maternal antibodies (anti-Ro/SSA or anti-La/SSB), and the diagnosis is made by its detection in the mother or child. The authors present a case of a 4-month-old female infant, with a cutaneous eruption since she was 2 months old. She had no relevant personal or family history. Analytically she had an increase in liver enzymes. The histological aspect of the skin biopsy led to an autoimmunity study on the mother and infant, both of which had positive anti-Ro/SSA antibodies, confirming the diagnosis of neonatal lupus. Cardiological study was normal. The skin lesions resolved during the first year of life. Skin lesions are the most frequent non-cardiac clinical manifestation of neonatal lupus, and they are self-limited. When there is no family history, nor cardiac involvement, the diagnosis can be challenging.

Behçet's disease: a case report about a rare cause of intra-cardiac mass

BACKGROUND

Intra-cardiac masses are always a challenging diagnosis, especially when it involves the right side of the heart. There are multiples aetiologies that can be responsible for these masses, namely thrombosis, neoplasm, or vegetations. Occasionally, these may be related to an autoimmune process not yet diagnosed. We present a case of a 17-year-old patient with an exuberant right ventricular mass due to a not yet diagnosed Behçet's disease. The best approach and treatment for these patients remains uncertain.

CASE SUMMARY

The authors present a case of a 17-year-old patient with a right ventricular mass who presented as an initial manifestation of Behçet's disease. It was firstly assumed as a thrombotic mass and medicated with anticoagulation, with no resolution. After performing a cardiac magnetic resonance, the case was discussed in a multidisciplinary team, including cardiology, paediatrics, and rheumatology, and the diagnosis of Behçet's disease with cardiac complication was established. The patient started immunosuppressive therapy with clinical and echocardiographic response.

DISCUSSION

Behçet's disease is a multi-systemic autoimmune vasculitis that usually manifests by recurrent oral and genital ulcers as well as ocular symptoms. Cardiac manifestations are rare but important aspects of the course of the disease, especially in what concerns morbidity burden. The treatment of these cardiovascular complications is generally empirical and involves the treatment of the underlying disease.

Stabilin-1 plays a protective role against Listeria monocytogenes infection through the regulation of cytokine and chemokine production and immune cell recruitment

Scavenger receptors are part of a complex surveillance system expressed by host cells to efficiently orchestrate innate immune response against bacterial infections. Stabilin-1 (STAB-1) is a scavenger receptor involved in cell trafficking, inflammation, and cancer; however, its role in infection remains to be elucidated. Listeria monocytogenes (Lm) is a major intracellular human food-borne pathogen causing severe infections in susceptible hosts. Using a mouse model of infection, we demonstrate here that STAB-1 controls Lm-induced cytokine and chemokine production and immune cell accumulation in Lm-infected organs. We show that STAB-1 also regulates the recruitment of myeloid cells in response to Lm infection and contributes to clear circulating bacteria. In addition, whereas STAB-1 appears to promote bacterial uptake by macrophages, infection by pathogenic Listeria induces the down regulation of STAB-1 expression and its delocalization from the host cell membrane.

We propose STAB-1 as a new SR involved in the control of Lm infection through the regulation of host defense mechanisms, a process that would be targeted by bacterial virulence factors to promote infection.

Depression after stroke

Stroke treatment has dramatically improved in recent decades. However, although new treatments have reduced its mortality and the severity of its physical and cognitive sequelae, many people still have incapacitating disabilities following a stroke. Depression is the most common psychiatric disorder following stroke; it is important to recognise and treat as it limits motor and cognitive rehabilitation. Antidepressant medication is an effective treatment and can improve adherence to clinically recommended physical and cognitive tasks, thereby enhancing functional remodelling of neuronal pathways and improving rehabilitation outcomes.

The effect of denudation and injection timing in the reproductive outcomes of ICSI cycles: new insights into the risk of in vitro oocyte ageing

STUDY QUESTION

Does the time elapsed between oocyte pick-up (OPU) and denudation or injection affect the probability of achieving a live birth (LB) in ICSI cycles?

SUMMARY ANSWER

Prolonged oocyte culture before denudation (>4 h) was associated with an increase in clinical pregnancy (CP), LB and cumulative LB (CLB) rates when compared with earlier denudation timings.

WHAT IS KNOWN ALREADY

Oocyte maturation is a complex and dynamic process involving structural and biochemical modifications in the cell necessary to support fertilization and early embryo development. While meiotic competence is easily identifiable by the presence of an extruded first polar body, cytoplasmic maturation cannot be assessed microscopically. Culturing oocytes with their surrounding cumulus cells (CCs) prior to ICSI can enhance the completion of in vitro cytoplasmic maturation; conversely, prolonged culture may induce cell degeneration. The optimal culture intervals prior to oocyte denudation and/or injection have not yet been established and may prove relevant for the improvement of ICSI reproductive outcomes.

STUDY DESIGN, SIZE, DURATION

This is a single-centre retrospective cohort analysis of 1378 ICSI cycles performed between January 2005 and October 2018. Data were categorized according to: (i) the time interval between OPU and denudation (<3 h, 3-4 h and ≥4 h), (ii) the time interval between denudation and ICSI (<1.5 h, 1.5-2 h, ≥2 h) and (iii) the time interval between OPU and ICSI (<5 h, 5-6 h and ≥6 h). The effect of these timings on fertilization, CP, LB and CLB rates were compared. The culture intervals between different procedures were dependent exclusively on laboratory workload.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ICSI cycles performed in women younger than 40 years old using autologous gametes with at least one metaphase II injected oocyte were included. The effect of oocyte culture duration prior to denudation and injection of the oocytes was compared using multivariable regression accounting for potential confounding variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Fertilization and oocyte damage rate after ICSI was found to be independent of the time interval to denudation (<3 h, 3-4 h and ≥4 h) and/or injection (<5 h, 5-6 h and ≥6 h). Extending oocyte culture before denudation significantly improved CP (29.5%, 42.7% and 50.6%, respectively), LB (25.1%, 34.4% and 40.7%, respectively) and CLB rates (26.0%, 36.1% and 42.2%, respectively), particularly if the time interval was at least 4 h. Additionally, LB (31.7%, 35.8% and 27.4%, respectively) and CLB rates (34.2%, 36.6% and 27.7%, respectively) were also dependent on the time from OPU to injection.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by its retrospective nature and potential unmeasured confounding cannot be excluded. Furthermore, the effect of even shorter or longer periods of culture before denudation and/or injection were not evaluated and should not be extrapolated from these results.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings propose new evidence of a previously unrecognized protective effect of the CCs-oocyte interactions in human ART, raising the question of a possible downstream effect in embryogenesis which significantly affects LB rates. Additionally, this is the first study to suggest a negative effect of further extending culture before ICSI on LB and CLB rates, thus potentially allowing for the narrowing of an optimal ICSI time interval. Simple strategies such as the establishment of more effective time frames to perform these procedures and adjusting laboratory practice may prove beneficial, ultimately improving ICSI reproductive outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Management of Patients with Multiple Sclerosis During the COVID-19 Pandemics: A Portuguese Single-Centre Experience

N/a.

Optimizing screening for depression, anxiety disorders, and post-traumatic stress disorder in inpatient addiction treatment: A preliminary investigation

OBJECTIVE

Substance use disorders (SUD) are frequently comorbid with other psychiatric conditions, but a comprehensive diagnostic assessment is often not feasible clinically. Efficient psychometrically-validated screening tools exist for commonly comorbid conditions, but cutoff accuracies have typically not been evaluated in addiction treatment settings. This study examined the performance of several widely-used screening measures in relation to diagnostic status from a clinical interview to identify and validate cutoff scores in an inpatient SUD treatment setting.

METHOD

Participants were 99 patients in a large residential SUD treatment program in Ontario, Canada. Participants completed a screening battery, including the Patient Health Questionnaire - 9 (PHQ-9), Generalized Anxiety Disorder - 7 (GAD-7), and Post-Traumatic Stress Disorder Checklist-5 (PCL-5), and underwent a semi-structured diagnostic clinical interview. Receiver operating characteristic curves were used to determine optimal cutoff scores on the screening tool against the interview-based diagnosis.

RESULTS

Area under the curve (AUC) was statistically significant for all screens and were as follows: PHQ-9 = 0.70 (95% CI = 0.59-0.80), GAD-7 = 0.74 (95% CI = 0.63-0.84), and PCL-5 = 0.79 (95% CI = 0.66-0.91). The optimal accuracy cutoff scores based on sensitivity and specificity were: PHQ-9 ≥ 16, GAD-7 ≥ 9, the PCL-5 ≥ 42.

CONCLUSIONS

In general, the candidate screeners performed acceptably in this population. However, the optimal cutoff scores were notably higher than existing guidelines for depression and PTSD, potentially due to the general elevations in negative affectivity among individuals initiating SUD treatment. Further validation of these cutoff values is warranted.

PUBLIC HEALTH SIGNIFICANCE

This study provides modified screening cutoff scores for major depression, anxiety disorders, and post-traumatic stress disorder in addiction treatment settings.

Respiratory support in COPD patients after acute exacerbation with monitoring the quality of support (Rescue2-monitor): an open-label, prospective randomized, controlled, superiority clinical trial comparing hospital- versus home-based acute non-invasive ventilation for patients with hypercapnic chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is expected to be the 3rd leading cause of death worldwide by 2020. Despite improvements in survival by using acute non-invasive ventilation (NIV) to treat patients with exacerbations of COPD complicated by acute hypercapnic respiratory failure (AHRF), these patients are at high risk of readmission and further life-threatening events, including death. Recent studies suggested that NIV at home can reduce readmissions, but in a small proportion of patients, and with a high level of expertise. Other studies, however, do not show any benefit of home NIV. This could be related to the fact that respiratory failure in patients with stable COPD and their response to mechanical ventilation are influenced by several pathophysiological factors which frequently coexist in the same patient to varying degrees. These pathophysiological factors might influence the success of home NIV in stable COPD, thus long-term NIV specifically adapted to a patient's "phenotype" is likely to improve prognosis, reduce readmission to hospital, and prevent death. In view of this conundrum, Rescue2-monitor (R2M), an open-label, prospective randomized, controlled study performed in patients with hypercapnic COPD post-AHRF, will investigate the impact of the quality of nocturnal NIV on the readmission-free survival. The primary objective is to show that any of 3 home NIV strategies ("rescue," "non-targeted," and "targeted") will improve readmission-free survival in comparison to no-home NIV. The "targeted" group of patients will receive a treatment with personalized (targeted) ventilation settings and extensive monitoring. Furthermore, the influence of comorbidities typical for COPD patients, such as cardiac insufficiency, OSA, or associated asthma, on ventilation outcomes will be taken into consideration and reasons for non-inclusion of patients will be recorded in order to evaluate the percentage of ventilated COPD patients that are screening failures. ClinicalTrials.gov NCT03890224 . Registered on March 26, 2019.

Severe skeletal lesions, osteopenia and growth deficit in a child with pulmonary tuberculosis (mid-20th century, Portugal)

OBJECTIVE

This case-study provides a summary of skeletal lesions seen in a case of diagnosed juvenile pulmonary tuberculosis with extensive multifocal bony lesions.

MATERIALS

Skeleton of a 9-year-old girl who died in the 1940s in Lisbon, Portugal. The remains of this individual are part of the Lisbon skeletal reference collection curated at the National Museum of Natural History and Science.

METHODS

Lesions and paleopathological conditions were identified and documented through macroscopic, radiographic, computed tomographic, and mammographic analysis.

RESULTS

The skeleton shows a variety of lytic lesions on the ribs and thoracic vertebrae including complete destruction of the bodies and fusion of the vertebral arches of four vertebrae, kyphosis, and scoliosis. Further pathological conditions were identified, including bone erosion, premature fusion of the left femoral head and greater trochanter, and abnormal size and shape changes to the lower limbs including loss of bone mass and stunting of the long bones.

CONCLUSIONS

Skeletal lesions are indicative of spondylitis, Pott's disease, and prolonged bedrest.

SIGNIFICANCE

This case is one of the few examples of confirmed juvenile pulmonary tuberculosis with skeletal lesions prior to the antibiotic era. As such, it provides a reference for the skeletal abnormalities which may be observed in archaeological tuberculosis cases.

LIMITATIONS

Pulmonary tuberculosis was recorded as cause of death, however there is no documentation to know the length of illness period or the existence of any comorbidities.

SUGGESTIONS FOR FURTHER RESEARCH

Consideration of multi-focal lesions is recommended when analyzing individuals with suspected tuberculosis.

Virulence gene repression promotes Listeria monocytogenes systemic infection

The capacity of bacterial pathogens to infect their hosts depends on the tight spatiotemporal regulation of virulence genes. The Listeria monocytogenes (Lm) metal efflux pump repressor CadC is highly expressed during late infection stages, modulating lipoprotein processing and host immune response. Here we investigate the potential of CadC as broad repressor of virulence genes. We show that CadC represses the expression of the bile salt hydrolase impairing Lm resistance to bile. During late infection, in absence of CadC-dependent repression, the constitutive bile salt hydrolase expression induces the overexpression of the cholic acid efflux pump MdrT that is unfavorable to Lm virulence. We establish the CadC regulon and show that CadC represses additional virulence factors activated by σ^B during colonization of the intestinal lumen. CadC is thus a general repressor that promotes Lm virulence by down-regulating, at late infection stages, genes required for survival in the gastrointestinal tract. This demonstrates for the first time how bacterial pathogens can repurpose regulators to spatiotemporally repress virulence genes and optimize their infectious capacity.

Reuma.pt/vasculitis - the Portuguese vasculitis registry

Background

The vasculitides are a group of rare diseases with different manifestations and outcomes. New therapeutic options have led to the need for long-term registries. The Rheumatic Diseases Portuguese Register, Reuma.pt, is a web-based electronic clinical record, created in 2008, which currently includes specific modules for 12 diseases and > 20,000 patients registered from 79 rheumatology centres. On October 2014, a dedicated module for vasculitis was created as part of the European Vasculitis Society collaborative network, enabling prospective collection and central storage of encrypted data from patients with this condition. All Portuguese rheumatology centres were invited to participate. Data regarding demographics, diagnosis, classification criteria, assessment tools, and treatment were collected. We aim to describe the structure of Reuma.pt/vasculitis and characterize the patients registered since its development.

Results

A total of 687 patients, with 1945 visits, from 13 centres were registered; mean age was 53.4 ± 19.3 years at last visit and 68.7% were females. The most common diagnoses were Behçet’s disease (BD) (42.5%) and giant cell arteritis (GCA) (17.8%). Patients with BD met the International Study Group criteria and the International Criteria for BD in 85.3 and 97.2% of cases, respectively. Within the most common small- and medium-vessel vasculitides registered, median [interquartile range] Birmingham Vasculitis Activity Score (BVAS) at first visit was highest in patients with ANCA-associated vasculitis (AAV) (17.0 [12.0]); there were no differences in the proportion of patients with AAV or polyarteritis nodosa who relapsed (BVAS≥1) or had a major relapse (≥1 major BVAS item) during prospective assessment (p = 1.00, p = 0.479). Biologic treatment was prescribed in 0.8% of patients with GCA, 26.7% of patients with AAV, and 7.6% of patients with BD. There were 34 (4.9%) deaths reported.

Conclusions

Reuma.pt/vasculitis is a bespoke web-based registry adapted for routine care of patients with this form of rare and complex diseases, allowing an efficient data-repository at a national level with the potential to link with other international databases. It facilitates research, trials recruitment, service planning and benchmarking.

A B-Learning course to reduced self-stigma in schizophrenia: preparing individuals to active life

Introduction

Psychosocial Education is defined as give to the patient structured, systematic and didactic information about mental illness and his treatment. Actually is one the most frequent rehabilitation approaches, being used in several mental health departments. The good results obtained by this approach are congruent with the principles and guidelines defined for best practices in rehabilitation process (Rummel-Kluge et al, 2006).

Aims

Describe a psycho educative b-learning program develop to reduce self-stigma in schizophrenic individuals.

Methods

A psycho educative B-Learning program was developed using the results of other studies. This program was after applied during 4 months with 21 schizophrenic individuals followed in a psychiatric department, evaluated in a pre and pos-test model.

Results

The program includes 10 sessions intentionally prepared for those individuals, given information to reduced self-stigma using topics such us myths, stereotypes, self-esteem, self-confidence, relapse prevention, social interaction, feel include in the community, being able to ask for help and to recover. All those topics where discuss using Moodle platform from Porto University within a group in the presence of the therapist and individually at home. A sociodrama group was also developed.

Conclusions

This approach seems to empower the individuals, allowing them to achieve the program by their own rhythm and to participate within a group but also to be in contact using the Moodle platform, decreasing feeling of loneliness. Primary results seem to be good, with low relapse, low absenteeism in class and some success in finding a job.

Listeria monocytogenes Wall Teichoic Acid Glycosylation Promotes Surface Anchoring of Virulence Factors, Resistance to Antimicrobial Peptides, and Decreased Susceptibility to Antibiotics

The cell wall of Listeria monocytogenes (Lm), a major intracellular foodborne bacterial pathogen, comprises a thick peptidoglycan layer that serves as a scaffold for glycopolymers such as wall teichoic acids (WTAs). WTAs contain non-essential sugar substituents whose absence prevents bacteriophage binding and impacts antigenicity, sensitivity to antimicrobials, and virulence. Here, we demonstrated, for the first time, the triple function of Lm WTA glycosylations in the following: (1) supporting the correct anchoring of major Lm virulence factors at the bacterial surface, namely Ami and InlB; (2) promoting Lm resistance to antimicrobial peptides (AMPs); and (3) decreasing Lm sensitivity to some antibiotics. We showed that while the decoration of WTAs by rhamnose in Lm serovar 1/2a and by galactose in serovar 4b are important for the surface anchoring of Ami and InlB, N-acetylglucosamine in serovar 1/2a and glucose in serovar 4b are dispensable for the surface association of InlB or InlB/Ami. We found that the absence of a single glycosylation only had a slight impact on the sensibility of Lm to AMPs and antibiotics, however the concomitant deficiency of both glycosylations (rhamnose and N-acetylglucosamine in serovar 1/2a, and galactose and glucose in serovar 4b) significantly impaired the Lm capacity to overcome the action of antimicrobials. We propose WTA glycosylation as a broad mechanism used by Lm, not only to properly anchor surface virulence factors, but also to resist AMPs and antibiotics. WTA glycosyltransferases thus emerge as promising drug targets to attenuate the virulence of bacterial pathogens, while increasing their susceptibility to host immune defenses and potentiating the action of antibiotics.

475 A rare cause of right ventricular mass

Introduction

Intracardiac masses are always a challenging diagnosis, especially when it involves the right side of the heart. There are multiples etiologies that can be responsible for these masses, namely thrombosis, neoplasm or vegetations. Occasionally, these may be related to an autoimmune process not yet discovered.

Case Report

17-year-old male, with a previous history of genital ulcers, medicated with penicillin with complete resolution of symptoms.

In January 2019, he started an history of recurrent fever, associated with right anterior thoracalgia, weight loss and oral afthosis. He went to the emergency department several times, where he was medicated with antibiotic, with partial symptom relief.

Three months later, he returned to medical attention due to an episode of abundant hemoptysis, followed by hematemesis and cough. At hospital admission, he was hemodynamically stable, tachycardic (100/min) and with occasional episodes of cough. Cardiac and pulmonary auscultation were unremarkable. Thoracic CT revealed the presence of pulmonary thromboembolism (PTE) and a large mass in the right ventricle (RV). It was performed an echocardiogram (echo) that confirmed the presence of a large mass in the RV (50x53mm) from which a projecting hypermobile mass appeared to prolapse into the right atrium.

Taking into account the diagnosis of PTE and the presence of a right ventricular mass, the patient was hospitalized and started anticoagulation. The case was immediately discussed with cardiac surgery, that confirmed that there was no surgical indication. During hospitalization, there were no more episodes of hemoptysis or hematemesis.Consecutive echos were performed, that did not reveal a significant decrease in mass dimensions despite anticoagulation. Viral serologies and autoimmunity panel were all negative. Cardiac RMI was performed raising the suspicion of a possible mass covered with thrombus.

After discussion with rheumatology, and according to clinical signs, the hypothesis of vasculitis was placed, and the patient started treatment with steroids. This treatment had to be suspended after a few days due to an infectious intercurrence. After a course of antibiotic therapy, the patient started therapy with cyclophosphamide with good clinical and echocardiographic response (reduced mass dimensions).

It was admitted Behçet’s disease with cardiac complications, and the patient was referred to the rheumatology consultation.

Conclusion

Behçet’s disease is a multi-system, chronic disorder that behaves like vasculitis.There are some typical clinical manifestations associated with this disease, such as oral and genital afthosis, uveitis, arthritis, skin lesions and nervous system involvement.Presentations with cardiac symptoms are one of the extremely rare manifestations of this disease, posing a challenge for the treating physician.

Abstract 475 Figure. Right ventricular mass

The European Portuguese version of the ASAS Health Index for Patients with Spondyloarthritis: Measurement properties

OBJECTIVE

The Assessments of SpondyloArthritis international Society Health Index (ASAS HI), estimates the impact of Spondyloarthritis (SpA) on global functioning and health. This article assesses the construct validity, reliability and responsiveness of the Portuguese version of the ASAS HI.

PATIENTS AND METHODS

Patients fulfilling ASAS classification criteria for axial (axSpA) or peripheral SpA (pSpA) were included. Construct validity was assessed through Spearman's correlation analysis with other health outcomes. Discriminant validity was tested comparing the ASAS HI across disease activity and functional states using the Kruskal-Wallis test. Internal consistency was assessed by Cronbach's α, and test-retest reliability by intraclass correlation coefficients (ICC). Responsiveness was evaluated by the standardized response mean (SRM) in patients with active disease who required therapy escalation.

RESULTS

Among the 91 patients included, 67% were male, mean (SD) age 47.2 (12.9) years, 63 patients with axSpA and 28 patients with pSpA. The hypothesis defined a priori to test construct validity were confirmed. The ASAS HI showed ability to discriminate between patients with different disease activity and functional states (p<0.001). Internal consistency (Cronbach's α: 0.88) and test-retest reliability [ICC=0.76 (95%CI 0.09-0.91)] were good. Responsiveness was moderate (SRM=-0.53). The smallest detectable change was 3.0.

CONCLUSIONS

The Portuguese version of the ASAS HI is a comprehensible questionnaire that is valid, reliable and responsive. It can be used to assess the impact of SpA and its treatment on functioning and health, in clinical practice and for research purposes.

Juvenile bullous systemic lupus erythematosus - case report

Bullous systemic lupus erythematosus (BSLE) is a rare autoimmune subepidermal blistering disease, with few cases described in childhood. We report a case of bullous systemic lupus erythematosus refractory to corticosteroid therapy in a 16-year-old female who was successfully treated with low dose dapsone. We highlight the rarity and the relevance of skin biopsy for a correct diagnosis of BSLE.

A multicentre study of street foods purchased in urban areas of Central Asia: the FEEDCities Project

Background

Street food (SF) is a strong tradition in Central Asia, where urbanization and westernization of food habits is occurring. Research on SF consumption is scarce, and crucial to understand its implications for public health. This study aims to describe the SF purchases in urban areas of Tajikistan, Kyrgyzstan, Turkmenistan and Kazakhstan.

Methods

A cross-sectional study was conducted in Dushanbe, Bishkek, Ashgabat and Almaty in 2016/2017. SF markets (n = 34) and vending sites (n = 270) were selected by random and systematic sampling. Data on customers’ characteristics and food items purchased was collected by direct observation. Nutritional composition of the food items (n = 852) was obtained by laboratorial analysis (n = 582) or food composition tables and labels (n = 270).

Results

A total of 714 customers were identified. The most commonly purchased foods and beverages were savoury pastries/snacks (23.2%), main dishes (19.0%), sweet pastries/confectionery (17.9%), tea/coffee (11.3%) and soft drinks/juices (9.8%). Fruit was the least frequently purchased food (1.1%). Nearly one-third of customers purchased industrial food items; this proportion was significantly higher in Kazakhstan (43.2%) and Turkmenistan (32.3%). The median energy content of a SF purchase ranged between 352kcal (Tajikistan) and 568kcal (Turkmenistan). The median saturated (SFA) and trans fat contents were 4.74g and 0.36g, respectively; the highest values were 9.01g for SFA (Turkmenistan) and 0.60g for trans fat (Kazakhstan), accounting for 40.6% and 27.3% of the maximum daily recommendations, respectively. Sodium-potassium ratio was far above recommended, reaching the highest values of 6.57 and 5.17 in Tajikistan and Kyrgyzstan.

Conclusions

Frequent purchase of industrial food reflects a shift to a westernized dietary pattern. Public health policies in these settings should aim to increase fruit availability and to improve SF nutritional composition, namely its lipid profile and sodium content.

Key messages

A relevant proportion of customers bought industrial foods, while fruit was rarely purchased, reflecting the nutrition transition process that is occurring in developing countries. Street food meals showed concerning levels of saturated fat, trans-fat and sodium, which must be considered when designing strategies targeted to improve the urban food environment in these settings.

How challenging can neuropsychiatric systemic lupus erythematous be? experience from a tertiary care centre

Neuropsychiatric Systemic Lupus Erythematous comprises several neurologic and psychiatric manifestations attributable to Lupus Erythematous Systemic. Diagnosis implies exclusion of non- Systemic Lupus Erythematous -related diseases that might mimic the same symptoms and should be prompt in order to avoid delaying the treatment. Treatment is dictated by the underlying pathogenesis and includes immunosuppression and/or anti-platelet agents/anticoagulation. We report four cases of Neuropsychiatric Systemic Lupus Erythematous, illustrating how challenging it can be to diagnose and treat these patients.

P3563The influence of circadian patterand obstructive sleep apnean of blood pressure in nocturnal arrhythmias in hypertensive patients

Introduction

There is growing evidence suggesting hypertension is related to the occurrence of arrhythmias. When occurring predominantly during the night, two potential entities commonly present in hypertensive patients could be related with increased arrhythmogenesis: (1) the lack of normal nocturnal dipping of blood pressure (BP) (non-dipping pattern of hypertension) or (2) obstructive sleep apnea (OSA). Thus, nocturnal arrhythmias (NAs) can identify hypertensive patients with OSA and/or non-dipping pattern, both related with adverse outcomes.

Aims

To determine if NAs are related with non-dipping hypertension, OSA or both.

Methods

We studied hypertensive patients who performed ambulatory blood pressure monitoring (ABPM) and also polysomnography and 24-hour Holter monitoring. Non-dipping pattern was considered when nocturnal BP reduction was inferior to 10%. Based on Holter monitoring, NAs were present when atrial fibrillation, frequent premature atrial contractions (PACs) (>30 PACs/hour), runs of >4 consecutive PACs, frequent premature ventricular contractions (PVCs) (>30PVCs/hour) or runs of >4 consecutive PVCs were present predominantly during sleeping hours. During polyssonography, apnoea/hypopnoea index (AHI) and oxygen saturation (SaO2) were analysed. Moderate to severe OSA was considered when AHI >15.

Results

We studied 104 patients [median age 62 (54–70) years, 65% male): 42 (40%) had moderate to severe OSA (median AHI=11 (6–26), mean SaO2=94% (92–95)] and 64 (61%) were non-dippers. NAs occurred in 18 patients (17%) and they were independently associated with AHI (Odds Ratio (OR) for a one unit increase 1.04, 95% confidence interval (CI) 1.01–1.07, p=0.03) but not with SaO2 (OR 0.96, CI 0.78–1.19, p=0.73) nor non-dipping pattern (OR 1.23, CI 0.38–3.98, p=0.72). No interaction was found between OSA and non-dipping hypertension (p=0.35). In patients with dipping pattern (n=40), AHI was higher in NAs patients comparing with no NAs patients (median AHI 29 versus 10, p=0.04), while in those with non-dipping pattern (n=64), AHI was not statistically different between patients with and without NAs (21 versus 11, p=0.12) (figure).

Figure 1

Conclusion

In this population of hypertensive patients, the presence of NAs was associated with OSA severity (i.e AHI), but not with the non-dipping pattern of hypertension. The importance of obstructive events in arrhythmogenesis seemed to be more pronounced in dipping patients, suggesting the abnormal high blood pressure during the night may also have some impact on NAs in non-dipping patients. Overall, our results suggest that OSA screening should be considered when nocturnal arrhythmias are detected in hypertensive patients, but ABPM should not be forgotten since multiple mechanisms can be involved in nocturnal arrhythmogenesis.

P3795Should we also screen for obstructive sleep apnea in patients presenting with excessive supraventricular ectopic activity?

Background

It is recommended to consider obstructive sleep apnoea (OSA) screening in atrial fibrillation (AF) patients with risk factors, due to the strong evidence of an association between these two entities. Excessive supraventricular ectopic activity (ESVEA) has been proposed to be a risk factor for AF. However, strong evidence between ESVEA and OSA has not been established.

Objective

We aimed to determine if ESVEA is associated with moderate to severe OSA since its treatment may prevent AF.

Methods

We studied patients who performed polysomnography and 24-hour Holter monitoring. Patients with atrial fibrillation were excluded. ESVEA was defined as more than 30 PACs per hour (frequent PACs) or runs of >4 consecutive PACs. The circadian pattern of PACs was also evaluated. Sleeping hours were used to define “nocturnal”. Moderate to severe OSA was defined when polyssonography demonstrated a apnoea/hypopnoea index (AHI) >15. We examined the association between ESVEA and moderate to severe OSA during wakefulness and sleep.

Results

We studied 290 patients [median age 65 (55–72) years, 62% males, body mass index (BMI) 30 (27–34)]. 112 (38%) had moderate to severe OSA. Median AHI was 11 (5–24) and mean oxygen saturation was 94% (92–95). Median PACs was 35 (9–117) and 29 patients (10%) had frequent PACs. Runs of >4PACs occurred in 114 patients (39%). Forty-three patients (15%) had predominant nocturnal PACs and 42 (14%) had nocturnal runs of PACs. Multivariate logistic regression analysis demonstrated only nocturnal PACs were associated with moderate to severe OSA (p=0.027) (table 1).

Multivariate logistic regression Odds Ratio 95% Confidence Interval p-value Male gender 4.49 2.48–8.17 <0.001 Body mass index (kg/m2) 1.09 1.03–1.15 0.002 Nocturnal PACs 4.12 1.17–14.46 0.027 Variables not included in the model: age, number of PACs/h, frequent PACs (>30 PAcs/hour), runs of PACs (>4 consecutive PACs), nocturnal frequent PACs and nocturnal runs of PACs.

Conclusion

OSA screening in patients presenting with nocturnal PACs should be routinely considered, especially in male and obese. Treating moderate to severe OSA patients with CPAP has a potential benefit in preventing ESVEA and consequently AF.

Perfringolysin O-Induced Plasma Membrane Pores Trigger Actomyosin Remodeling and Endoplasmic Reticulum Redistribution

Clostridium perfringens produces an arsenal of toxins that act together to cause severe infections in humans and livestock animals. Perfringolysin O (PFO) is a cholesterol-dependent pore-forming toxin encoded in the chromosome of virtually all C. perfringens strains and acts in synergy with other toxins to determine the outcome of the infection. However, its individual contribution to the disease is poorly understood. Here, we intoxicated human epithelial and endothelial cells with purified PFO to evaluate the host cytoskeletal responses to PFO-induced damage. We found that, at sub-lytic concentrations, PFO induces a profound reorganization of the actomyosin cytoskeleton culminating into the assembly of well-defined cortical actomyosin structures at sites of plasma membrane (PM) remodeling. The assembly of such structures occurs concomitantly with the loss of the PM integrity and requires pore-formation, calcium influx, and myosin II activity. The recovery from the PM damage occurs simultaneously with the disassembly of cortical structures. PFO also targets the endoplasmic reticulum (ER) by inducing its disruption and vacuolation. ER-enriched vacuoles were detected at the cell cortex within the PFO-induced actomyosin structures. These cellular events suggest the targeting of the endothelium integrity at early stages of C. perfringens infection, in which secreted PFO is at sub-lytic concentrations.

Mechanisms protecting host cells against bacterial pore-forming toxins

Pore-forming toxins (PFTs) are key virulence determinants produced and secreted by a variety of human bacterial pathogens. They disrupt the plasma membrane (PM) by generating stable protein pores, which allow uncontrolled exchanges between the extracellular and intracellular milieus, dramatically disturbing cellular homeostasis. In recent years, many advances were made regarding the characterization of conserved repair mechanisms that allow eukaryotic cells to recover from mechanical disruption of the PM membrane. However, the specificities of the cell recovery pathways that protect host cells against PFT-induced damage remain remarkably elusive. During bacterial infections, the coordinated action of such cell recovery processes defines the outcome of infected cells and is, thus, critical for our understanding of bacterial pathogenesis. Here, we review the cellular pathways reported to be involved in the response to bacterial PFTs and discuss their impact in single-cell recovery and infection.