BackgroundInterplays between Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB) in human and host professional phagocytes, namely macrophages (Mφs) and dendritic cells (DCs), are central to immune protection against TB and to TB pathogenesis. We and others have recently shown that the C-type lectin dendritic cell–specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN; CD209) mediates important interactions between mycobacteria and human monocyte-derived DCs (MoDCs) in vitro.Methods and FindingsIn order to explore the possible role of DC-SIGN in M. tuberculosis infection in vivo, we have analysed DC-SIGN expression in broncho-alveolar lavage (BAL) cells from patients with TB (n = 40) or with other non-mycobacterial lung pathologies, namely asthma (n = 14) and sarcoidosis (n = 11), as well as from control individuals (n = 9). We show that in patients with TB, up to 70% of alveolar Mφs express DC-SIGN. By contrast, the lectin is barely detected in alveolar Mφs from all other individuals. Flow cytometry, RT-PCR, and enzyme-linked immunosorbent assay analyses of BAL-derived fluids and cells indicated that M. tuberculosis infection induces DC-SIGN expression in alveolar Mφs by a mechanism that is independent of Toll-like receptor-4, interleukin (IL)-4, and IL-13. This mechanism most likely relies on the secretion of soluble host and/or mycobacterial factors that have yet to be identified, as both infected and uninfected bystander Mφs were found to express DC-SIGN in the presence of M. tuberculosis. Immunohistochemical examination of lung biopsy samples from patients with TB showed that the bacilli concentrate in pulmonary regions enriched in DC-SIGN-expressing alveolar Mφs in vivo. Ex vivo binding and inhibition of binding experiments further revealed that DC-SIGN–expressing alveolar Mφs constitute preferential target cells for M. tuberculosis, as compared to their DC-SIGN− counterparts. In contrast with what has been reported previously in MoDCs in vitro, ex vivo DC-SIGN ligation by mycobacterial products failed to induce IL-10 secretion by alveolar Mφs, and IL-10 was not detected in BALs from patients with TB.ConclusionAltogether, our results provide further evidence for an important role of DC-SIGN during TB in humans. DC-SIGN induction in alveolar Mφs may have important consequences on lung colonization by the tubercle bacillus, and on pulmonary inflammatory and immune responses in the infected host.
The COPD Patient Management European Trial (COMET) investigated the efficacy and safety of a home-based COPD disease management intervention for severe COPD patients.The study was an international open-design clinical trial in COPD patients (forced expiratory volume in 1 s <50% of predicted value) randomised 1:1 to the disease management intervention or to the usual management practices at the study centre. The disease management intervention included a self-management programme, home telemonitoring, care coordination and medical management. The primary end-point was the number of unplanned all-cause hospitalisation days in the intention-to-treat (ITT) population. Secondary end-points included acute care hospitalisation days, BODE (body mass index, airflow obstruction, dyspnoea and exercise) index and exacerbations. Safety end-points included adverse events and deaths.For the 157 (disease management) and 162 (usual management) patients eligible for ITT analyses, all-cause hospitalisation days per year (mean±sd) were 17.4±35.4 and 22.6±41.8, respectively (mean difference -5.3, 95% CI -13.7 to -3.1; p=0.16). The disease management group had fewer per-protocol acute care hospitalisation days per year (p=0.047), a lower BODE index (p=0.01) and a lower mortality rate (1.9% 14.2%; p<0.001), with no difference in exacerbation frequency. Patient profiles and hospitalisation practices varied substantially across countries.The COMET disease management intervention did not significantly reduce unplanned all-cause hospitalisation days, but reduced acute care hospitalisation days and mortality in severe COPD patients.
Background Rarely, Legionnaires’ disease (LD) can progress into a slowly or nonresolving form. Methods A nationwide retrospective study was conducted by the French National Reference Center for Legionella (2013–2017) including cases of slowly or nonresolving LD defined as persistent clinical symptoms, computed tomography (CT) scan abnormalities, and Legionella detection in lower respiratory tract specimens by culture and/or real-time (RT) polymerase chain reaction (PCR) >30 days after symptom onset. Results Twelve cases of community-acquired slowly or nonresolving LD were identified among 1686 cases of culture-positive LD. Median (interquartile range [IQR]) age was 63 (29–82) years. Ten (83.3%) patients had ≥1 immunosuppressive factor. Clinically, 9 patients transiently recovered before further deterioration (median [IQR] symptom-free interval, 30 [18–55] days), 3 patients had uniformly persistent symptoms (median [IQR] time, 48 [41.5–54] days). Two patients had >2 recurrences. CT scan imagery found lung abscess in 5 (41.6%) cases. Slowly or nonresolving LD was diagnosed on positive Legionella cultures (n = 10, 83.3%) at 49.5 (IQR, 33.7–79) days. Two cases were documented through positive Legionella RT PCR at 52 and 53 days (cycle threshold detection of 21.5 and 33.7, respectively). No genomic microevolution and no Legionella resistance to antibiotics were detected. The median (IQR) duration of treatment was 46.5 (21–92.5) days. Two empyema cases required thoracic surgery. At a median (IQR) follow-up of 26 (14–41.5) months, LD-attributable mortality was 16.6% (n = 2). Conclusions Slowly or nonresolving LD may occur in immunocompromised patients, possibly leading to lung abscess and empyema.
Introduction The Coronavirus disease-2019 outbreak (COVID-19) has been declared a pandemic by the World Health Organization. Studies report both a severe inflammatory syndrome and a procoagulant state in severe COVID-19 cases, with an increase of venous thromboembolism, including pulmonary embolism (PE) and deep vein thrombosis (DVT). In this context, we discuss the use of doppler ultrasonography (DUS) in the screening and diagnosis of DVT in ambulatory and hospitalized patients with, or suspected of having, COVID-19, outside the intensive care unit (ICU). Material and methods Non-systematic review of the literature. Results In patients hospitalized for or suspected of COVID-19 infection with the presence of either (a) DVT clinical symptoms, (b) a strong DVT clinical probability (Wells score > 2) or (c) elevated D-dimer levels without DVT clinical symptoms and without PE on lung CT angio-scan, DVT should be investigated with DUS. In the presence of PE diagnosed clinically and/or radiologically, additional systematic DVT screening using DUS is not recommended during the COVID-19 pandemic. The use of 4-points compression DUS for DVT screen and diagnosis is the most appropriate method in this context. Discussion Systematic DUS for DVT screening in asymptomatic COVID patients is not recommended unless the patient is in the ICU. This would increase the risk of unnecessarily exposing medical staff to SARS-CoV-2 and monopolizing limited resources during this period.
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