[Influence of the COVID-19 pandemia on the ophthalmologic emergency department in the Toulouse University Hospital during the first lockdown from March the 17th to May the 10th of 2020]

INTRODUCTION

We conducted this study to assess the impact of the COVID-19 pandemic and the lockdown in France from March 17, 2020 to May 10, 2020, on the ophthalmic emergency department at Toulouse University Hospital, compared to the period from March 2 to March 16, 2020.

MATERIALS AND METHODS

This was a retrospective observational study, conducted in the ophthalmic emergency department of Toulouse University Hospital. We included the patients presenting to the emergency department from March 2 to May 10, 2020. We recorded age, sex, day of visit, time until care was received, past ocular history, outpatient or inpatient status, final diagnosis and its severity, outpatient or inpatient disposition, and medical or surgical treatment after the emergency department visit.

RESULTS

We found a substantial decrease in the number of patients per day, mostly during the first month of the lockdown: 44 patients per day before the lockdown compared to 23 patients per day during the first month, followed by 38 patients per day for the second month of lockdown; more patients visiting promptly; and elderly patients represented a higher proportion of patients.

CONCLUSION

The first lockdown in France due to the COVID-19 pandemic had an impact on the Toulouse ophthalmic emergency department, especially concerning the number of patients per day; this study helps to assess individual behavior in this context of a public health crisis.

Doramectin efficacy against Psoroptes ovis in sheep: Evaluation of pharmacological strategies

The aims of this study were to evaluate the efficacy of two injectable formulations of doramectin (DRM) against Psoroptes ovis in sheep infested under controlled experimental conditions and to characterize the DRM plasma disposition kinetics in the infested animals. To this end, sheep were experimentally infested with a P. ovis strain from a farm with a history of treatment failure, and then treated either with DRM 1% (traditional preparation) on days 0 and 7 or with DRM 3.15% (long-acting formulation) on day 0. The efficacy of each treatment was calculated by counting live mites in skin scrapings. Plasma samples were obtained from each animal and DRM concentrations were measured by HPLC. After the two doses of DRM 1%, the maximum efficacy (98.8%) was reached on day 28, whereas after the single dose of DRM 3.15%, the maximum efficacy (100%) was reached on day 35 and ratified on day 42. The long-acting formulation allowed obtaining higher exposure and more sustained concentrations of DRM than the traditional preparation. Although both DRM formulations studied were effective according to international protocols, they did not reach 100% effectiveness in the time required for approved pharmaceutical products against sheep scab, according to Argentine regulations.

Vaccine confidence among parents: Large scale study in eighteen European countries

BACKGROUND

Despite the fact that vaccines save 2-3 million lives worldwide every year, a percentage of children are not getting appropriately vaccinated, thus leading to disease outbreaks. One of the major reasons of low vaccine uptake in Europe is vaccine hesitancy, contributing to the recent measles outbreaks. Monitoring of vaccine hesitancy is valuable in early identification of vaccine concerns.

METHODS

We performed an eighteen country European survey on parents' attitudes and behaviors regarding their children's immunization. Parents having at least one child 1-4 years old were mostly recruited by primary care paediatricians to reply to a web-based questionnaire. The questionnaire was developed by the European Academy of Paediatrics Research in Ambulatory Setting Network steering committee, based on similar surveys. An individual level hesitancy score was constructed using the answers to 21 questions, and correlations of the score with socio-demographic characteristics and types of providers were explored. To assess inter country differences, a country level self -reported confidence was defined.

RESULTS

Fifty six percent and 24% of 5736 respondents defined themselves as "not at all hesitant", and "somewhat hesitant", respectively. Parents who consulted general practitioners were more hesitant than parents who consulted pediatricians (p < 0.05). Consultation with homeopathists was associated with the highest reported hesitancy (p < 0.05). Vaccine confidence was highest in Portugal and Cyprus, and lowest in Bulgaria and Poland.

CONCLUSION

The majority of parents in Europe believe in the importance of childhood vaccination. However, significant lack of confidence was found in certain European countries, highlighting the need for continuous monitoring, awareness and response plans. The possible influence of different types of healthcare providers on parental decisions demonstrated for the first time in our survey, calls for further research. Monitoring and continuous medical education efforts aimed mostly at those professionals who might not be likely to recommend vaccination are suggested.

Survival beyond the perinatal period expands the phenotypes caused by mutations in GLE1

Mutations in GLE1 underlie Lethal Congenital Contracture syndrome (LCCS) and Lethal Arthrogryposis with Anterior Horn Cell Disease (LAAHD). Both LCCS and LAAHD are characterized by reduced fetal movements, congenital contractures, and a severe form of motor neuron disease that results in fetal death or death in the perinatal period, respectively. We identified bi-allelic mutations in GLE1 in two unrelated individuals with motor delays, feeding difficulties, and respiratory insufficiency who survived beyond the perinatal period. Each affected child had missense variants predicted to result in amino acid substitutions near the C-terminus of GLE1 that are predicted to disrupt protein-protein interaction or GLE1 protein targeting. We hypothesize that mutations that preserve function of the coiled-coil domain of GLE1 cause LAAHD whereas mutations that abolish the function of the coiled-coil domain cause LCCS. The phenotype of LAAHD is now expanded to include multiple individuals surviving into childhood suggesting that LAAHD is a misnomer and should be re-named Arthrogryposis with Anterior Horn Cell Disease (AAHD).

Human lung fibroblasts may modulate dendritic cell phenotype and function: results from a pilot in vitro study

In human lung fibrotic lesions, fibroblasts were shown to be closely associated with immature dendritic cell (DC) accumulation. The aim of the present pilot study was to characterize the role of pulmonary fibroblasts on DC phenotype and function, using co-culture of lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) and from control patients, with a DC cell line MUTZ-3. We observed that co-culture of lung control and IPF fibroblasts with DCs reduced the expression of specific DC markers and down-regulated their T-cell stimulatory activity. This suggests that pulmonary fibroblasts might sustain chronic inflammation in the fibrotic lung by maintaining in situ a pool of immature DCs.

Large number of imported chikungunya cases in mainland France, 2014: a challenge for surveillance and response

During the summer of 2014, all the pre-requisites for autochthonous transmission of chikungunya virus are present in southern France: a competent vector, Aedes albopictus, and a large number of travellers returning from the French Caribbean islands where an outbreak is occurring. We describe the system implemented for the surveillance of chikungunya and dengue in mainland France. From 2 May to 4 July 2014, there were 126 laboratory-confirmed imported chikungunya cases in mainland France.

Detection of alveolar fibrocytes in idiopathic pulmonary fibrosis and systemic sclerosis

Background

Fibrocytes are circulating precursors for fibroblasts. Blood fibrocytes are increased in patients with idiopathic pulmonary fibrosis (IPF). The aim of this study was to determine whether alveolar fibrocytes are detected in broncho-alveolar lavage (BAL), to identify their prognostic value, and their potential association with culture of fibroblasts from BAL.

Methods

We quantified fibrocytes in BAL from 26 patients with IPF, 9 patients with Systemic Sclerosis(SSc)-interstitial lung disease (ILD), and 11 controls. BAL cells were cultured to isolate alveolar fibroblasts.

Results

Fibrocytes were detected in BAL in 14/26 IPF (54%) and 5/9 SSc patients (55%), and never in controls. Fibrocytes were in median 2.5% [0.4–19.7] and 3.0% [2.7–3.7] of BAL cells in IPF and SSc-ILD patients respectively. In IPF patients, the number of alveolar fibrocytes was correlated with the number of alveolar macrophages and was associated with a less severe disease but not with a better outcome. Fibroblasts were cultured from BAL in 12/26 IPF (46%), 5/9 SSc-ILD (65%) and never in controls. The detection of BAL fibrocytes did not predict a positive culture of fibroblasts.

Conclusion

Fibrocytes were detected in BAL fluid in about half of the patients with IPF and SSc-ILD. Their number was associated with less severe disease in IPF patients and did not associate with the capacity to grow fibroblasts from BAL fluid.

Inhibition of HSP27 blocks fibrosis development and EMT features by promoting Snail degradation

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by myofibroblast proliferation. Transition of epithelial/mesothelial cells into myofibroblasts [epithelial-to-mesenchymal transition (EMT)] occurs under the influence of transforming growth factor (TGF)-β1, with Snail being a major transcription factor. We study here the role of the heat-shock protein HSP27 in fibrogenesis and EMT. In vitro, we have up- and down-modulated HSP27 expression in mesothelial and epithelial cell lines and studied the expression of different EMT markers induced by TGF-β1. In vivo, we inhibited HSP27 with the antisense oligonucleotide OGX-427 (in phase II clinical trials as anticancer agent) in our rat subpleural/pulmonary fibrosis models. We demonstrate that HSP27 is strongly expressed during the fibrotic process in patients with IPF and in different in vivo models. We showed that HSP27 binds to and stabilizes Snail and consequently induces EMT. Conversely, HSP27 knockdown leads to Snail proteasomal degradation, thus inhibiting TGF-β1-induced EMT. Inhibition of HSP27 with OGX-427 efficiently blocks EMT and fibrosis development. Controls in vivo were an empty adenovirus that did not induce fibrosis and a control antisense oligonucleotide. The present work opens the possibility of a new therapeutic use for HSP27 inhibitors against IPF, for which there is no conclusively effective treatment.

[Transurethral resection (TUR) in saline plasma vaporization of the prostate versus standard TUR of the prostate: an economic evaluation]

OBJECTIVE

To evaluate and compare the hospital costs of the transurethral resection in saline plasma vaporization of the prostate (TURis-PVP) and the standard TUR of the prostate (TURP).

BACKGROUND

their efficiency and short terms outcomes are similar.

PATIENTS AND METHODS

In an observational retrospective and monocentric study, 86 consecutive patients with benign prostatic enlargement (BPE) secondary to benign prostatic hyperplasia (BPH) were enrolled in two non randomized groups. TURP was performed in 44 cases and TURis-PVP in 42 cases. Patients with prostate cancer, urethral stenosis or bladder neck stenosis were not included. Hospital costs with a 3-month follow-up were measured using the database and hospital cost accounting system of the Medical Information Department.

RESULTS

Patients from both series had similar preoperative characteristics concerning the age, ASA score, urologic history, and antithrombosis treatments. Catheterization period, complications and rehospitalisation rates were similar. With TURis-PVP, prostatic volume was larger (60±24mL vs. 42±16mL; P<0.05), hospital stay was shorter (4.0±2.8days vs. 4.4±2.1days; P<0.05), single-used materials costs were higher (332±64€ vs. 40±18€; P<0.05). The costs of the first hospitalization were 3721±843€ with TURis-PVP and were 3712±880€ with TURP (P=0.14). Global costs with a 3-month follow-up were 3867±1104€ with TURis-PVP and were 4074±1624€ with TURP (P=0.53).

CONCLUSION

In this study, the costs for the hospital are lightly higher in TURis-PVP, due to single use systems, but there is no significant difference for global costs between TURP and TURis-PVP with a 3-month follow-up difference for the health care system.

[When the pupil becomes the teacher]

OBJECTIVE

To evaluate the theoretical teaching provided to ophthalmology residents in Toulouse during the 2006-2007 academic year using the PowerVote(®) system. PUPILS AND METHOD: This was a prospective study concerning all ophthalmology residents in Toulouse. Classes were given by the house doctors and senior registrars as PowerPoint presentations lasting about 45 min. Just before each lecture, the house doctors took a 5 min test comprising five multiple choice questions. There were two lectures per month on average. One month after the course of lectures ended, the course as a whole was evaluated using the PowerVote(®) tool, on objectives given to the house doctors in advance. The teaching concerned the macula.

RESULTS

Ten residents took part in the final evaluation in 2007. The residents who had given lectures obtained significantly better results, not only in the initial test but also in the final one.

DISCUSSION

Teaching can take many forms. We evaluated teaching by the students themselves. The more involved a house doctor was in teaching, the better he remembered the lesson.

CONCLUSION

Giving a theoretical lecture enables residents to reach a higher level, which is further improved if they are involved in the teaching. The use of PowerVote(®) is an interesting pedagogical tool.

[Results of 125-iodine seed implant with preplanning system in 250 patients with prostate cancer]

INTRODUCTION

We review the experience with prostate carcinoma patients treated with permanent implants of 125-I seeds and the outcome eight years after the beginning of this technique.

MATERIAL AND METHODS

From 2002 to 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand(®) and preplanning system. Mean age was 68 (49-78). Mean PSA was 7.32 (2.31 - 14.6). T1-T2a was the stage in 98%, and Gleason ≤ 6 in 96%. Low risk cases were 81% and intermediate risk 19% (ten of them received 46 Gy EBRT). Hormonal treatment was used in 42%.

RESULTS

With a mean follow-up of 48 months, 14 patients (5.7%) showed biochemical failure (BF). Eleven patients (4.5%) with theoretical BF were observed and PSA decreased without treatment. Actuarial PSA relapse-free survival at 5 years was 91%, (92% low risk, 86% intermediate cases), and 92% vs 81% with PSA <10 vs >10 (p<0.05). Rectum complications were G2 in 0.6%. A urinary catheter was necessary in 6.5%. Sexual function was conserved in 60%. Mean V100 was 89% and D90 143 Gy.

CONCLUSION

The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Cases with PSA bounces should be controlled before starting a salvage treatment.

Identification of periplakin as a new target for autoreactivity in idiopathic pulmonary fibrosis

RATIONALE

Injury to alveolar epithelial cells is central to the pathophysiology of idiopathic pulmonary fibrosis (IPF). An abnormal autoimmune response directed against antigens of the alveolar epithelium may contribute to the disease.

OBJECTIVES

To detect circulating autoantibodies (autoAbs) directed against epithelial structures.

METHODS

We performed immunoblot by separating human placental amnion extract or alveolar epithelial cell (A549 cell line) proteins on polyacrylamide gels, blotting on nitrocellulose membranes, and incubating with serum from patients with IPF (n = 40) or healthy subjects (n = 40). Proteomic analysis and mass spectrometry characterized the target protein. Inhibition experiments performed with the correspondent recombinant protein confirmed our results.

MEASUREMENTS AND MAIN RESULTS

We identified IgG autoAbs recognizing a 200-kD protein in the serum of patients with IPF. Proteomic analysis identified this protein as human periplakin (PPL), a component of desmosomes. Anti-PPL Abs were found by immunoblot in both serum and bronchoalveolar lavage in patients with IPF: 16/40 (40%) of them were positive versus none of the control subjects. Immunohistochemistry revealed that PPL was strongly expressed in bronchial and alveolar epithelium, but that PPL exhibited changes in intracellular localization among normal and fibrotic alveolar epithelium. In an alveolar epithelial wound repair assay, an anti-PPL IgG decreased cell migration. Recombinant PPL induced bronchoalveolar lavage T lymphocyte proliferation. Patients with IPF with anti-PPL Abs had a more severe respiratory disease, despite no difference in survival.

CONCLUSIONS

We found a new circulating autoAb directed against PPL in patients with IPF, associated with a more severe disease.

Nationwide outbreak of Salmonella serotype Kedougou associated with infant formula, Spain, 2008

On 5 August 2008, the National Centre of Microbiology in Madrid, Spain, notified an increase in Salmonella Kedougou isolations compared to 2007, with 21 cases including 19 children under one year of age. Active case finding and a matched case-control study were carried out to confirm this increase, identify source, transmission mode and risk factors in order to implement control measures. Cases were defined as any child under one year of age with S. Kedougou isolated since 1 January 2008, and were matched for age, sex, medical practitioner and diagnosis week with controls who were selected among patients of the cases' medical practitioners. An ad hoc questionnaire was completed for cases and controls and a univariate analysis was conducted to identify risk factors. We found 42 isolates from 11 of the 19 Spanish Regions. Completed questionnaires were available for 39 of 42 patients identified; 31 were children under one year of age and fulfilled the case definition. The median age of the 31 cases was 4.3 months and 13 were male. Main symptoms were diarrhoea (n=31) and fever (n=13). Ten cases required hospitalisation. All 31 cases had consumed infant formula milk of Brand A which was associated with illness in the univariate analysis (exact matched odds ratio: 74.92; 95% confidence interval: 12.89-∞). All patient isolates showed indistinguishable pulsed-field gel electrophoresis and antimicrobial susceptibility patterns. Five milk samples from three cases' households were negative for Salmonella. Our results suggest that Brand A was the transmission vehicle of S. Kedougou in the outbreak that occurred in Spain between January and August 2008. Food safety authorities recalled five batches of Brand A milk on 26 August 2008. No further cases have been detected as of 15 September 2009.

Nationwide outbreak of Salmonella serotype Kedougou associated with infant formula, Spain, 2008

On 5 August 2008, the National Centre of Microbiology in Madrid, Spain, notified an increase in Salmonella Kedougou isolations compared to 2007, with 21 cases including 19 children under one year of age. Active case finding and a matched case-control study were carried out to confirm this increase, identify source, transmission mode and risk factors in order to implement control measures. Cases were defined as any child under one year of age with S. Kedougou isolated since 1 January 2008, and were matched for age, sex, medical practitioner and diagnosis week with controls who were selected among patients of the cases' medical practitioners. An ad hoc questionnaire was completed for cases and controls and a univariate analysis was conducted to identify risk factors. We found 42 isolates from 11 of the 19 Spanish Regions. Completed questionnaires were available for 39 of 42 patients identified; 31 were children under one year of age and fulfilled the case definition. The median age of the 31 cases was 4.3 months and 13 were male. Main symptoms were diarrhoea (n=31) and fever (n=13). Ten cases required hospitalisation. All 31 cases had consumed infant formula milk of Brand A which was associated with illness in the univariate analysis (exact matched odds ratio: 74.92; 95% confidence interval: 12.89-infinity). All patient isolates showed indistinguishable pulsed-field gel electrophoresis and antimicrobial susceptibility patterns. Five milk samples from three cases' households were negative for Salmonella. Our results suggest that Brand A was the transmission vehicle of S. Kedougou in the outbreak that occurred in Spain between January and August 2008. Food safety authorities recalled five batches of Brand A milk on 26 August 2008. No further cases have been detected as of 15 September 2009.

Induction of heme oxygenase-1, biliverdin reductase and H-ferritin in lung macrophage in smokers with primary spontaneous pneumothorax: role of HIF-1alpha

Background

Few data concern the pathophysiology of primary spontaneous pneumothorax (PSP), which is associated with alveolar hypoxia/reoxygenation. This study tested the hypothesis that PSP is associated with oxidative stress in lung macrophages. We analysed expression of the oxidative stress marker 4-HNE; the antioxidant and anti-inflammatory proteins heme oxygenase-1 (HO-1), biliverdin reductase (BVR) and heavy chain of ferritin (H-ferritin); and the transcription factors controlling their expression Nrf2 and HIF-1α, in lung samples from smoker and nonsmoker patients with PSP (PSP-S and PSP-NS), cigarette smoke being a risk factor of recurrence of the disease.

Methodology/Principal Findings

mRNA was assessed by RT-PCR and proteins by western blot, immunohistochemistry and confocal laser analysis. 4-HNE, HO-1, BVR and H-ferritin were increased in macrophages from PSP-S as compared to PSP-NS and controls (C). HO-1 increase was associated with increased expression of HIF-1α mRNA and protein in alveolar macrophages in PSP-S patients, whereas Nrf2 was not modified. To understand the regulation of HO-1, BVR and H-ferritin, THP-1 macrophages were exposed to conditions mimicking conditions in C, PSP-S and PSP-NS patients: cigarette smoke condensate (CS) or air exposure followed or not by hypoxia/reoxygenation. Silencing RNA experiments confirmed that HIF-1α nuclear translocation was responsible for HO-1, BVR and H-ferritin induction mediated by CS and hypoxia/reoxygenation.

Conclusions/Significance

PSP in smokers is associated with lung macrophage oxidative stress. The response to this condition involves HIF-1α-mediated induction of HO-1, BVR and H-ferritin.

A role for dendritic cells in bleomycin-induced pulmonary fibrosis in mice?

RATIONALE

Lung dendritic cells (DCs) have been shown to accumulate in human fibrotic lung disease, but little is known concerning a role for DCs in the pathogenesis of fibrotic lung.

OBJECTIVES

To characterize lung DCs in an in vivo model of bleomycin-induced pulmonary fibrosis in mice.

METHODS

We characterized the kinetics and activation of pulmonary DCs during the course of bleomycin-induced lung injury by flow cytometry on lung single-cell suspensions. We also characterized the lymphocytes accumulating in bleomycin lung and the chemokines susceptible to favor the recruitment of immune cells.

MEASUREMENTS AND MAIN RESULTS

We show, for the first time, that increased numbers of CD11c(+)/major histocompatibility complex class II(+) DCs, including CD11b(hi) monocyte-derived inflammatory DCs, infiltrate the lung of treated animals during the fibrotic phase of the response to bleomycin. These DCs are mature DCs expressing CD40, CD86, and CD83. They are associated with increased numbers of recently activated memory T cells expressing CD44, CD40L, and CD28, suggesting that fully mature DCs and Ag-experienced T cells can drive an efficient effector immune response within bleomycin lung. Most importantly, when DCs are inactivated with VAG539, a recently described new immunomodulator, VAG539 treatment attenuates the hallmarks of bleomycin lung injury.

CONCLUSIONS

These findings identify lung DCs as key proinflammatory cells potentially able to sustain pulmonary inflammation and fibrosis in the bleomycin model.

ENaC-mediated alveolar fluid clearance and lung fluid balance depend on the channel-activating protease 1

Sodium transport via epithelial sodium channels (ENaC) expressed in alveolar epithelial cells (AEC) provides the driving force for removal of fluid from the alveolar space. The membrane-bound channel-activating protease 1 (CAP1/Prss8) activates ENaC in vitro in various expression systems. To study the role of CAP1/Prss8 in alveolar sodium transport and lung fluid balance in vivo, we generated mice lacking CAP1/Prss8 in the alveolar epithelium using conditional Cre-loxP-mediated recombination. Deficiency of CAP1/Prss8 in AEC induced in vitro a 40% decrease in ENaC-mediated sodium currents. Sodium-driven alveolar fluid clearance (AFC) was reduced in CAP1/Prss8-deficient mice, due to a 48% decrease in amiloride-sensitive clearance, and was less sensitive to β₂-agonist treatment. Intra-alveolar treatment with neutrophil elastase, a soluble serine protease activating ENaC at the cell surface, fully restored basal AFC and the stimulation by β₂-agonists. Finally, acute volume-overload increased alveolar lining fluid volume in CAP1/Prss8-deficient mice. This study reveals that CAP1 plays a crucial role in the regulation of ENaC-mediated alveolar sodium and water transport and in mouse lung fluid balance.

Alveolar fibroblasts in acute lung injury: biological behaviour and clinical relevance

Although fibroblasts are key cells in the lung repair/fibrosis process, their characteristics are poorly studied in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The aims of our study were to: 1) determine the biological behaviour of alveolar fibroblasts during ALI; and 2) to evaluate the clinical relevance of positive alveolar fibroblast culture from patients with ALI/ARDS. Cells were cultured from bronchoalveolar lavage (BAL) obtained from 68 critically ill, ventilated patients: ALI n = 17; ARDS n = 31; and ventilated controls n = 20. Patients were followed for 28 days and clinical data was recorded. We studied proliferation, migration and collagen-1 synthesis capacities of fibroblasts. Cells expressing fibroblast markers were cultured from BAL obtained in six (35%) ALI patients and six (19%) ARDS patients, but never from ventilated controls. Alveolar fibroblasts exhibited a persistent activated phenotype with enhanced migratory and collagen-1 production capacities, with hyporesponsiveness to prostaglandin E(2) compared to normal lung fibroblasts (p< or =0.04). Positive fibroblast culture was associated with both an increased collagen-1 concentration and monocyte/macrophage percentage in BAL fluid (p< or =0.01), and with a reduced duration of mechanical ventilation (p<0.001). We conclude that activated alveolar fibroblasts can be cultured either in ALI or ARDS and that their presence might reflect the initiation of the organising phase of ALI.

Imbalance in the pro-hepatocyte growth factor activation system in bleomycin-induced lung fibrosis in mice

Hepatocyte growth factor (HGF) is a growth factor for alveolar epithelial cells. Activation of pro-HGF to HGF is regulated by the HGF activator (HGFA), a serine protease, and a specific inhibitor (HGFA inhibitor-1, HAI-1). An imbalance in the HGFA/HAI-1 system might contribute to lung fibrosis. Pro-HGF activation capacity from bronchoalveolar lavage (BAL) fluid was evaluated 3, 7, and 14 days after the intratracheal bleomycin injection (Bleo) in mice with or without thrombin. BAL fluid from naïve mice was used as control. HGFA and HAI-1 mRNA were evaluated by QPCR in the whole lung or by Western blot in BAL fluid. BAL fluid from control mice and Bleo mice activated pro-HGF in vitro at a similar degree. Thrombin accelerated proHGF activation by Bleo BAL on Day 3 and Day 7, but not on Day 14, or in control BAL. Incubation of pro-HGF with BAL from Bleo Day 3 and Day 7 mice increased phosphorylation of HGFR on A549 cells. Thrombin-induced pro-HGF activation was inhibited by an anti-HGFA antibody and accelerated by an anti-HAI-1 antibody. Active HGFA was not detected in control BAL and was strongly induced in Bleo BAL. HGFA concentrations were higher on Day 3 and Day 7 than on Day 14. HAI-1 was detected at low levels in control BAL and increased strongly by Day 3 with stable concentrations until Day 14. By demonstrating an imbalance between HGFA and HAI-1 expression in BAL fluid, our results highlight a defective thrombin-dependent proHGF activation system at the fibrotic phase of bleomycin-induced pulmonary fibrosis.

Altered Nrf2/Keap1-Bach1 equilibrium in pulmonary emphysema

BACKGROUND

Oxidative stress, resulting from the increased oxidative burden and decreased level of antioxidant proteins, plays a role in the pathophysiology of smoking-related pulmonary emphysema. Expression of several antioxidant proteins, such as heme oxygenase-1 (HO-1), glutathione peroxidase 2 (GPX2) and NAD(P)H:quinone oxidoreductase 1 (NQO1), results from an equilibrium created by positive or negative regulation by the transcription factors Nrf2, Keap1 and Bach1, respectively. However, whether the expression of these transcription factors is altered in emphysema and could account for decreased expression of antioxidant proteins is not known. A study was undertaken to investigate the expression and subcellular localisation of Nrf2, Keap1 and Bach1 as potential regulators of HO-1, GPX2 and NQO1 in alveolar macrophages, a key cell in oxidative stress, in lung surgical specimens from non-smokers without emphysema and smokers with and without emphysema.

METHODS AND RESULTS

Western blot, immunohistochemical and laser scanning confocal analysis revealed that the Nrf2 protein level decreased significantly in whole lung tissue and alveolar macrophages (cytosol and nucleus) in patients with emphysema compared with those without emphysema. Conversely, Bach1 and Keap1 levels were increased in patients with emphysema. These modifications were associated with a parallel decrease in the expression of HO-1, GPX2 and NQO1 at the cellular level, which was inversely correlated with airway obstruction and distension indexes, and increased macrophage expression of the lipid peroxidation product 4-hydroxy-2-nonenal. Silencing RNA experiments in vitro in THP-1 cells were performed to confirm the cause-effect relation between the loss of Nrf2 and the decrease in HO-1, NQO1 and GPX2 expression. Nrf2/Keap1-Bach1 equilibrium was altered in alveolar macrophages in pulmonary emphysema, which points to a decreased stress response phenotype.

CONCLUSIONS

This finding opens a new view of the pathophysiology of emphysema and could provide the basis for new therapeutic approaches based on preservation and/or restoration of such equilibrium.

[Physiopathology of sarcoidosis]

Sarcoidosis results from an uncontrolled cell-mediated immune reaction involving activated T cells and monocytes-macrophages, characterized by the formation of typical granulomas at the sites of the lesions. The interactions between both cell types induce the release of several mediators that play a central role in the development of granulomas, allowing to design new therapies. The aetiology of sarcoidosis remains unknown, but the disease is currently viewed as the consequence of a chronic immunological response associating a genetic susceptibility and specific environmental factors.

Modulation of bleomycin-induced lung fibrosis by serotonin receptor antagonists in mice

Serotonin (5-hydroxytryptamine; 5-HT) is known to increase proliferation and collagen synthesis by fibroblasts. Two receptor subtypes, 5-HT2A and 5-HT2B, have been shown to play the most important roles in the lung. In the present study, the role of serotonin in lung fibrosis was investigated using the bleomycin mouse model. Serotonin concentrations in lung homogenates increased significantly over the time course of bleomycin-induced fibrosis, with a maximum at day seven. The expression of serotonin receptors 5-HT2A and 5-HT2B increased in the lung after bleomycin treatment, as assessed by PCR, specific binding and immunohistochemistry. Blockage of 5-HT2A receptors by ketanserin and 5-HT2B receptors by SB215505 reduced bleomycin-induced lung fibrosis, as demonstrated by reduced lung collagen content and reduced procollagen 1 and procollagen 3 mRNA expression. Serotonin antagonists promoted an antifibrotic environment by decreasing the lung mRNA levels of transforming growth factor-beta1, connective growth factor and plasminogen activator inhibitor-1 mRNA, but had minimal effects on lung inflammation as assessed by bronchoalveolar lavage cytology analysis. Interestingly, the 5-HT2B receptor was strongly expressed by fibroblasts in the fibroblastic foci in human idiopathic pulmonary fibrosis samples. In conclusion, the present study showed involvement of serotonin in the pathophysiology of bleomycin-induced lung fibrosis in mice and identified it as a potential therapeutic target in lung fibrotic disorders.

[Mechanisms in pulmonary fibrosis]

Despite the continuous and renewed interest in IPF, the precise biological mechanisms underlying the development of fibrosis and leading to the irreversible destruction of the lung are still unknown. Inflammation seems to play a minor role at the initiation of the disease. Identification of excessive apoptosis of alveolar epithelial cells led to the hypothesis that the disorder results from repeated alveolar epithelial cell injury and activation. In turn, alveolar epithelial cells induce the recruitment, proliferation, and activation of mesenchymal cells with the formation of fibroblastic foci and the abnormal accumulation of extracellular matrix. Fibroblastic foci are connected in a tridimensional reticulum. Circulating mesenchymal precursors called fibrocytes, and transdifferenciation of epithelial cells, endothelial cells and/or mesothelial cells, may all contribute to the accumulation of fibroblasts in the lung.

Sarcoidosis

Sarcoidosis is a multisystemic disorder of unknown cause characterized by the formation of immune granulomas in involved organs. It is an ubiquitous disease with incidence (varying according to age, sex, race and geographic origin) estimated at around 16.5/100,000 in men and 19/100,000 in women. The lung and the lymphatic system are predominantly affected but virtually every organ may be involved. Other severe manifestations result from cardiac, neurological, ocular, kidney or laryngeal localizations. In most cases, sarcoidosis is revealed by persistent dry cough, eye or skin manifestations, peripheral lymph nodes, fatigue, weight loss, fever or night sweats, and erythema nodosum. Abnormal metabolism of vitamin D3 within granulomatous lesions and hypercalcemia are possible. Chest radiography is abnormal in about 90% of cases and shows lymphadenopathy and/or pulmonary infiltrates (without or with fibrosis), defining sarcoidosis stages from I to IV. The etiology remains unknown but the prevailing hypothesis is that various unidentified, likely poorly degradable antigens of either infectious or environmental origin could trigger an exaggerated immune reaction in genetically susceptible hosts. Diagnosis relies on compatible clinical and radiographic manifestations, evidence of non-caseating granulomas obtained by biopsy through tracheobronchial endoscopy or at other sites, and exclusion of all other granulomatous diseases. The evolution and severity of sarcoidosis are highly variable. Mortality is estimated at between 0.5–5%. In most benign cases (spontaneous resolution within 24–36 months), no treatment is required but a regular follow-up until recovery is necessary. In more serious cases, a medical treatment has to be prescribed either initially or at some point during follow-up according to clinical manifestations and their evolution. Systemic corticosteroids are the mainstay of treatment of sarcoidosis. The minimal duration of treatment is 12 months. Some patients experience repeated relapses and may require long-term low-dose corticosteroid therapy during years. Other treatments (immunosuppressive drugs and aminoquinolins) may be useful in case of unsatisfactory response to corticosteroids, poor tolerance and as sparing agents when high doses of corticosteroids are needed for a long time. In some strictly selected cases refractory to standard therapy, specific antiTNF-α agents may offer precious improvement. Some patients benefit from topical corticosteroids.

Dendritic Cells Accumulate in Human Fibrotic Interstitial Lung Disease

RATIONALE

There is growing evidence that resident cells, such as fibroblasts and epithelial cells, can drive the persistent accumulation of dendritic cells (DCs) in chronically inflamed tissue, leading to the organization and the maintenance of ectopic lymphoid aggregates. This phenomenon, occurring through a chemokine-mediated retention mechanism, has been documented in various disorders, but not in fibrotic interstitial lung disorders in which the presence of organized lymphoid follicles has been documented.

OBJECTIVES

To characterize the distribution of DCs in fibrotic lung, and to analyze the expression of the main chemokines known to regulate DC recruitment.

METHODS

Lung resection tissue (lungs with idiopathic pulmonary fibrosis; n = 12; lungs with nonspecific interstitial pneumonia, n = 5; control lungs, n = 5) was snap-frozen for subsequent immunohistochemical techniques on serial sections and reverse transcriptase-polymerase chain reaction analysis.

MEASUREMENTS AND MAIN RESULTS

Results were similar in idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia lungs, which were heavily infiltrated by immature DCs in established fibrosis and in areas of epithelial hyperplasia. Altered epithelial cells and fibroblasts, particularly in fibroblastic foci, frankly expressed all chemokines (CCL19, CCL20, CCL22, and CXCL12) susceptible to favor the recruitment of immune cells. Lymphoid follicles were infiltrated by maturing DCs, which could originate from the pool of DCs accumulating in their vicinity.

CONCLUSIONS

These findings suggest that resident cells in pulmonary fibrosis can sustain chronic inflammation by driving the accumulation of DCs with the potential to mature locally within ectopic lymphoid follicles. Future strategies should consider DCs or chemokines as therapeutic targets in the treatment of pulmonary fibrosis.

Increased uptake of 111In-octreotide in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by an uncontrolled accumulation and activation of lung fibroblasts. A modulation of fibroblast activation has been observed in various systems with octreotide, a synthetic somatostatin analog with strong affinity for the somatostatin receptor subtype 2 (sst2). One aim of our study was to evaluate the expression of somatostatin receptors in the lungs of patients with IPF. A second aim was to evaluate the relationship between 111In-octreotide uptake and the effect of pulmonary fibrosis as assessed by lung function tests and parameters and by radiologic findings.

METHODS

We investigated 11 patients with IPF, 6 patients with pulmonary fibrosis associated with systemic sclerosis (SSc), and 19 patients with disease not of the lung (control patients). The expression of somatostatin receptors was evaluated in vivo using 111In-octreotide scintigraphy. We evaluated the relationship between 111In-octreotide uptake and the activity of pulmonary fibrosis as assessed by lung function tests, bronchoalveolar lavage (BAL) cellularity, and high-resolution CT (HRCT) of the chest. Planar images and thoracic SPECT (24 h) were performed after injection of 222 MBq of 111In-octreotide. Lung uptake was quantified using the lung-to-background ratio (L/B). In addition, the expression of sst2 was evaluated in vitro, in frozen lung-tissue samples using autoradiography, and in human cultures of lung fibroblasts using a ligand-binding assay.

RESULTS

Compared with lung uptake in control patients (median L/B, 1.25; range, 1.14-1.49), lung uptake was increased in all 11 IPF patients (median L/B, 2.63; range, 1.59-3.13; P < 0.001) and in 4 of 6 SSc patients (median L/B, 1.68; range, 1.42-2.16). The L/B was lower in SSc patients than in IPF patients (P = 0.011). Increased uptake correlated with the alteration of lung function (carbon monoxide diffusing capacity [rho = -0.655; P = 0.038], diffusing capacity for carbon monoxide and alveolar volume ratio [rho = -0.627; P = 0.047], vital capacity [rho = -0.609; P = 0.054], and total lung capacity [rho = -0.598; P = 0.058]) and with the intensity of alveolitis (total BAL cellularity [rho = 0.756; P = 0.045], neutrophil counts [rho = 0.738; P = 0.05]), and HRCT fibrosis score (rho = 0.673; P = 0.007). Autoradiography suggested that vascular structures were a prominent binding site. Lung fibroblasts expressed somatostatin receptors in vitro as measured by binding assay.

CONCLUSION

Our preliminary results identified an increased expression of sst2 in (mainly idiopathic) pulmonary fibrosis. Lung uptake correlates with the alteration of lung function and with the intensity of alveolitis.

Defect of Pro-Hepatocyte Growth Factor Activation by Fibroblasts in Idiopathic Pulmonary Fibrosis

RATIONALE AND OBJECTIVES

Hepatocyte growth factor (HGF) protects against lung fibrosis in several animal models. Pro-HGF activation to HGF is subjected to regulation by its activator (HGFA), a serine protease, and HGFA-specific inhibitors (HAI-1 and HAI-2). Our hypothesis was that fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) had an altered capacity to activate pro-HGF in vitro compared with control fibroblasts.

METHODS

We measured the kinetics of pro-HGF activation in human lung fibroblasts from control subjects and from patients with IPF by Western blot. HGFA, HAI-1, and HAI-2 expression was evaluated by immunohistochemistry, RNA protection assay, and Western blot. We evaluated the effect of TGF-beta(1) and PGE(2) on pro-HGF activation and HGFA, HAI-1, and HAI-2 expression.

MAIN RESULTS

Lung fibroblasts activated pro-HGF in vitro. Pro-HGF activation was inhibited by serine protease inhibitors, by an anti-HGFA antibody, as well as by HAI-1 and HAI-2. Pro-HGF activation by IPF fibroblasts was reduced compared with control fibroblasts. In IPF fibroblasts, HGFA expression was lower and HAI-1 and HAI-2 expression was higher compared with control fibroblasts. PGE(2) stimulated pro-HGF activation through increased expression of HGFA and decreased expression of its inhibitor HAI-2. In contrast, TGF-beta(1) reduced the ability of lung fibroblasts to activate pro-HGF through decreased expression of HGFA and increased expression of its inhibitors.

CONCLUSIONS

IPF fibroblasts have a low capacity to activate pro-HGF in vitro via a low level of HGFA expression and high levels of HAI-1 and HAI-2 expression, and PGE(2) is able to partially correct this defect.

Cutting Edge: Nonproliferating Mature Immune Cells Form a Novel Type of Organized Lymphoid Structure in Idiopathic Pulmonary Fibrosis

Ectopic formation of secondary lymphoid tissue is initiated by the local attraction of naive T and B cells. In this study, we describe a novel type of organized lymphoid structure in the lung of human idiopathic pulmonary fibrosis, with key features of lymphoid neogenesis, including: 1) recently activated CD40 ligand (CD40L)+ T cells; 2) variable numbers of activated CD40+/CD40L+ B cells, sometimes organized in follicles; 3) fully mature dendritic cells (DC) expressing CD40, CD83, CD86, and DC-lysosome-associated membrane protein; 4) the expression of the chemokine CCL21; 5) the presence of vessels with characteristics of high endothelial venules; and 6) a dense network of follicular DC. Surprisingly, these structures are devoid of CCR7+ naive T cells, proliferating lymphocytes, and germinal centers, suggesting that newly recruited activated DC and Ag-experienced lymphocytes can drive lymphoid neogenesis and that factors present within the lymphoid aggregates, such as CD40L, are essential to induce DC maturation.

Effects of diesel particles on the control of intracellular mycobacterial growth by human macrophagesin vitro

Changes that may modify the capacity of macrophages to control mycobacterial growth could favour the reactivation of bacillary proliferation within protective granulomas developed in response to mycobacterial infection. There is increasing evidence that diesel exhaust particles (DEPs) could suppress some macrophage functions, but it is not known whether DEPs may alter macrophage mycobactericidal activity. The aim of this study was to assess the effect of DEPs on the mycobactericidal activity of human mononuclear phagocytes in vitro. Human monocytes from healthy donors were cultured for 3 days in the presence or absence of DEPs or carbon black particles (CBPs), and then infected with a Mycobacterium bovis bacillus Calmette-Guérin reporter strain expressing luciferase activity. DEPs were rapidly internalized by monocyte-derived macrophages without cytotoxic effect. Mycobactericidal activity of cells exposed to DEPs was not different from that of cells cultured in their absence or in the presence of CBPs. Although our study was restricted to the mycobactericidal activity of human macrophages in vitro, the results indicate that DEPs do not directly influence the first line of defence against microorganisms. Whether exposure to DEPs influences the adaptive immune response against mycobacterial infections remains to be determined.