Association of perinatal exposition to xenobiotics with kidney volume at birth.

BACKGROUND AND HYPOTHESIS: The state of Aguascalientes has the highest prevalence of kidney failure in young adults. A low nephron endowment has been suggested as a possible etiology. This study aims to evaluate the association between exposure to xenobiotics and low kidney volume (KV) at birth. METHODS: This is a cross-sectional, observational, and descriptive study of at-term pregnant women, with no comorbidities. We collected the mother´s urine (MU), amniotic fluid (AF), and neonate´s urine (NU). Metals and non-metals were measured with inductively coupled plasma mass spectrometry, pesticides were determined with high-performance liquid chromatography, and fluoride by ion-selective potentiometry. The total KV adjusted by body surface area (TKVBS) was calculated based on the kidney ultrasound. RESULTS: Between March-2022 and July-2023, we included 299 women with an average of 24.2 years (± 5.1). 54.2% of neonates were male with an average weight of 3,266 gr (± 399).Factors associated with the TKVBS ≤ 5 percentile were female sex, weight gain during the pregnancy, glomerular filtration rate, methomyl concentration in AF (Odds ratio 7.41, 95% confidence interval 2.31 - 23.8, p= 0.001), 2,4-Dichlorophenoxyacetic (2,4-D) >10 ng/ml in AF (4.99, 1.58 - 15.7, p= 0.002), MU (6.1, 1.9 - 19.7, p= 0.002), and NU (5.1, 1.10 - 26.2, p= 0.023) and fluoride in MU (5.1, 1.10 - 23.5, p= 0.010), and AF (6.76, 1.28 - 35.7, p=0.024). In all matrices (MU, AF and NU) exposure to pesticides was also significantly associated with greater concentrations of electrolytes (Na, K, Ca, PO4 and Mg and oligo-elements (Zn and Fe). CONCLUSIONS: In neonates born to at-term women with no comorbidities, the presence of pesticides and fluoride was associated with low KV. The significant loss of electrolytes and oligoelements associated with pesticides suggests proximal tubulopathy.

Phenotypes and outcome of diffuse pulmonary non-amyloid light chain deposition disease.

BACKGROUND: Light chain deposition disease (LCDD) is a very rare entity. Clinical manifestations of LCDD vary according to the organs involved. Data on pulmonary LCDD are scarce and limited to small series or case reports. This study aimed to describe the characteristics and outcome of diffuse pulmonary non-amyloid LCDD localized to the lungs. STUDY DESIGN AND METHODS: A multicenter retrospective cohort study was conducted. Clinical characteristics were collected, and chest CTs were centrally reviewed. The diagnosis of pulmonary non-amyloid LCDD was confirmed by immunohistochemistry. RESULTS: Thirty-one cases were identified (68% female), with a median age at diagnosis of 50 years (IQR 20). Baseline FEV1/FVC was < 0.70 in 45% of patients. Mean (± SD) FEV1 and DLCO were 86% ± 26.2 and 52% ± 23.9, respectively. CT revealed peculiar patterns of thin-walled cysts (58%) and thin-walled cystic bronchiectases (27%). Increased serum kappa light chain was found in 87% of patients. Histological analysis showed kappa light chain deposits in all patients, except one with lambda chain deposits. Median annual FEV1 decline was 127 ml (IQR 178) and median DLCO decline was 4.3% (IQR 4.3). Sixteen patients received immunomodulatory treatment or chemotherapy; serum light chain levels decreased in 9 cases (75%), without significant improvement in FEV1 (p = 0.173). Overall, 48% of patients underwent bilateral lung transplantation. Transplant-free survival at 5 and 10 years were 70% and 30%, respectively. An annual FEV1 decline greater than 127 ml/year was associated with increased risk of death or transplantation (p = 0.005). CONCLUSIONS: Diffuse pulmonary LCDD is characterised by female predominance, a peculiar imaging pattern with bronchiectasis and/or cysts, progressive airway obstruction and severe DLCO impairment, and poor outcome. Lung transplantation is a treatment of choice.

Infections in autoimmune pulmonary alveolar proteinosis: a large retrospective cohort.

BACKGROUND: Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease, predisposing to an increased risk of infection. A complete picture of these infections is lacking. RESEARCH QUESTION: Describe the characteristics and clinical outcomes of patients diagnosed with aPAP, and to identify risk factors associated with opportunistic infections. METHODS: We conducted a retrospective cohort including all patients diagnosed with aPAP between 2008 and 2018 in France and Belgium. Data were collected using a standardised questionnaire including demographics, comorbidities, imaging features, outcomes and microbiological data. RESULTS: We included 104 patients, 2/3 were men and median age at diagnosis was 45 years. With a median follow-up of 3.4 years (IQR 1.7-6.6 years), 60 patients (58%), developed at least one infection, including 23 (22%) with opportunistic infections. Nocardia spp was the main pathogen identified (n=10). Thirty-five (34%) patients were hospitalised due to infection. In univariate analysis, male gender was associated with opportunistic infections (p=0.04, OR=3.88; 95% CI (1.02 to 22.06)). Anti-granulocyte macrophage colony-stimulating factor antibody titre at diagnosis was significantly higher among patients who developed nocardiosis (1058 (316-1591) vs 580 (200-1190), p=0.01). Nine patients had died (9%), but only one death was related to infection. INTERPRETATION: Patients with aPAP often presented with opportunistic infections, especially nocardiosis, which highlights the importance of systematic search for slow-growing bacteria in bronchoalveolar lavage or whole lung lavage.

Rituximab and mycophenolate mofetil combination in patients with interstitial lung disease (EVER-ILD): a double-blind, randomised, placebo-controlled trial.

BACKGROUND: Standard of care for interstitial lung disease (ILD) with a nonspecific interstitial pneumonia (NSIP) pattern proposes mycophenolate mofetil (MMF) as one of the first-step therapies while rituximab is used as rescue therapy. METHODS: In a randomised, double-blind, two-parallel group, placebo-controlled trial (NCT02990286), patients with connective tissue disease-associated ILD or idiopathic interstitial pneumonia (with or without autoimmune features) and a NSIP pattern (defined on NSIP pathological pattern or on integration of clinicobiological data and a NSIP-like high-resolution computed tomography pattern) were randomly assigned in a 1:1 ratio to receive rituximab (1000 mg) or placebo on day 1 and day 15 in addition to MMF (2 g daily) for 6 months. The primary end-point was the change in percent predicted forced vital capacity (FVC) from baseline to 6 months analysed by a linear mixed model for repeated measures analysis. Secondary end-points included progression-free survival (PFS) up to 6 months and safety. FINDINGS: Between January 2017 and January 2019, 122 randomised patients received at least one dose of rituximab (n=63) or placebo (n=59). The least-squares mean change from baseline to 6 months in FVC (% predicted) was +1.60 (se 1.13) in the rituximab+MMF group and -2.01 (se 1.17) in the placebo+MMF group (between-group difference 3.60, 95% CI 0.41-6.80; p=0.0273). PFS was better in the rituximab+MMF group (crude hazard ratio 0.47, 95% CI 0.23-0.96; p=0.03). Serious adverse events occurred in 26 (41%) patients of the rituximab+MMF group and in 23 (39%) of the placebo+MMF group. Nine infections were reported in the rituximab+MMF group (five bacterial infections, three viral infections, one other) and four bacterial infections in the placebo+MMF group. INTERPRETATION: Combination of rituximab and MMF was superior to MMF alone in patients with ILD and a NSIP pattern. The use of this combination must take into consideration the risk of viral infection.

Hemodynamic characteristics in patients with pulmonary hypertension and chronic obstructive pulmonary disease: A retrospective monocentric cohort study.

BACKGROUND: Pulmonary hypertension (PH) is a hemodynamic condition characterized by an abnormal elevation in pulmonary arterial pressures. Several pathophysiological pre-capillary and post-capillary mechanisms have been described. PH is a common complication of chronic obstructive pulmonary disease (COPD), however, the prevalence of each mechanism in the development of PH in patients with COPD has been hardly studied. METHODS: We reported the clinical, functional, hemodynamic characteristics and outcomes of patients diagnosed with COPD and PH among the expert PH center of Nancy between January 1st, 2015 and March 31st, 2021. RESULTS: 123 patients with COPD and PH were included. Most patients (n=122, 99%) had a pre-capillary mechanism, 9% (n=11) a post-capillary mechanism, and 1% (n=1) an unclassified mechanism. 111 (90%) patients had pure pre-capillary PH and 11 (9%) patients had combined pre- and post-capillary PH. Combined pre- and post-capillary PH group was characterized by higher prevalence of cardiovascular comorbidities and of sleep apnea-hypopnea syndrome, a higher body mass index, lower lung volumes, higher mean pulmonary arterial pressure, pulmonary arterial wedge pressure and right atrial pressure. At follow-up (median 30 months), 52 patients had died, and 11 had undergone lung transplantation. One-year, three-year and five-year transplant-free survival rates were 71%, 29% and 11% respectively. There was no difference on outcomes between groups. CONCLUSION: PH in COPD patients is mostly due to pre-capillary mechanism. However, the existence of various and numerous comorbidities in COPD, especially cardiovascular, can lead to the participation of post-capillary mechanisms in the development of PH. Further studies are needed to confirm these findings and to assess the impact on outcomes and management strategies in these different patients.

COVID-19 in patients with pulmonary alveolar proteinosis: a European multicentre study.

Adult PAP patients experience similar #COVID19 rates to the general population, and high rates of hospitalisation and deaths, underscoring their vulnerability and the need for measures to prevent infection. The impact of iGM-CSF must be considered. https://bit.ly/3M0wKnZ.

French practical guidelines for the diagnosis and management of idiopathic pulmonary fibrosis - 2021 update. Full-length version.

BACKGROUND: Since the latest 2017 French guidelines, knowledge about idiopathic pulmonary fibrosis has evolved considerably. METHODS: Practical guidelines were drafted on the initiative of the Coordinating Reference Center for Rare Pulmonary Diseases, led by the French Language Pulmonology Society (SPLF), by a coordinating group, a writing group, and a review group, with the involvement of the entire OrphaLung network, pulmonologists practicing in various settings, radiologists, pathologists, a general practitioner, a health manager, and a patient association. The method followed the "Clinical Practice Guidelines" process of the French National Authority for Health (HAS), including an online vote using a Likert scale. RESULTS: After a literature review, 54 guidelines were formulated, improved, and then validated by the working groups. These guidelines addressed multiple aspects of the disease: epidemiology, diagnostic procedures, quality criteria and interpretation of chest CT scans, lung biopsy indication and procedures, etiological workup, methods and indications for family screening and genetic testing, assessment of the functional impairment and prognosis, indication and use of antifibrotic agents, lung transplantation, management of symptoms, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis. CONCLUSION: These evidence-based guidelines are intended to guide the diagnosis and practical management of idiopathic pulmonary fibrosis.

Interstitial pneumonia with autoimmune features: Evaluation of connective tissue disease incidence during follow-up.

OBJECTIVES: Among interstitial pneumonia with autoimmune features (IPAF) patients, identifying those at risk to develop a connective tissue disease (CTD) during the disease course is a key issue. The aim of this study was to evaluate the incidence of definite CTD diagnosis in IPAF patients during follow-up. METHODS: We performed a multicentric cohort study of interstitial lung disease (ILD) from 2010 to 2017 in pneumology and immunology departments of tertiary care centers. Patients with a known cause of ILD (including established CTD) at diagnosis were excluded. Among patients with idiopathic ILD and at least three years of follow-up, two groups (IPAF and non-IPAF) were retrospectively analyzed at time of diagnosis. RESULTS: A total of 249 patients with ILD were enrolled, including 70 IPAF and 179 non-IPAF patients. After a mean follow-up time of 77 ± 44 months, 18/70 IPAF patients (26%) had a CTD diagnosis - 9 antisynthetase syndrome, 8 systemic sclerosis and 1 overlap myositis - compared with 4/179 non-IPAF patients (2%). IPAF patients were at higher risk of CTD occurrence at 3 years of follow-up compared to non-IPAF patients (HR 10.1, 95% CI 3.1-33.1, p < 0. 01). IPAF patients progressing to CTD tended to be younger, more often female and have more frequently puffy fingers, capillaroscopy abnormalities and antisynthetase antibodies at diagnosis. CONCLUSIONS: We found that a significant proportion of IPAF patients had associated CTD diagnosis during follow-up. Prospective studies are needed to confirm baseline predictive factors of CTD occurrence in IPAF patients.

Cyclophosphamide added to glucocorticoids in acute exacerbation of idiopathic pulmonary fibrosis (EXAFIP): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: The use of cyclophosphamide in patients with acute exacerbation of idiopathic pulmonary fibrosis (IPF) is unknown. Our study was designed to evaluate the efficacy and safety of four cyclophosphamide pulses in addition to high-dose methylprednisolone in this population. METHODS: In this double-blind, placebo-controlled trial done in 35 departments across 31 hospitals in France, adult patients (≥18 years) with acute exacerbation of IPF and those with suspected acute exacerbation of IPF were randomly assigned in a 1:1 ratio using a web-based system to receive either intravenous pulses of cyclophosphamide (600 mg/m2) plus uromitexan as haemorrhagic cystitis prophylaxis (200 mg/m2) at the time of cyclophosphamide administration and then again, 4 h later, or placebo at days 0, 15, 30, and 60. Random assignment was stratified according to the severity of IPF and was block-balanced with variable block sizes of four or six patients. Patients receiving mechanical ventilation, with active infection, with active cancer, or who were registered on the lung transplant waiting list were excluded. All patients received standardised high-dose glucocorticoids. The investigators, patients, and the sponsor were masked to the treatment assignments. The primary endpoint was 3-month all-cause mortality, analysed by a χ2 test adhering to an intention-to-treat principle. The trial is now complete and registered with ClinicalTrials.gov, NCT02460588. FINDINGS: Between Jan 22, 2016, and July 19, 2018, 183 patients were assessed for eligibility, of whom 120 patients were randomly assigned and 119 patients (62 [52%] with severe IPF) received at least one dose of cyclophosphamide (n=60) or placebo (n=59), all of whom were included in the intention-to-treat analysis. The 3-month all-cause mortality was 45% (27/60) in patients given cyclophosphamide compared with 31% (18/59) in the placebo group (difference 14·5% [95% CI -3·1 to 31·6]; p=0·10). Similar results were found after adjustment by IPF severity (odds ratio [OR] 1·89 [95% CI 0·89-4·04]). The risk of death at 3 months, independent of the treatment received, was higher with severe than non-severe IPF (OR 2·62 [1·12-6·12]) and was lower with the use of antifibrotic therapy (OR 0·33 [0·13-0·82]). Adverse events were similar between groups by 6 months (25 [42%] in the cyclophosphamide group vs 30 [51%] in the placebo group) and their proportion, including infections, did not differ. Overall infection was the main adverse event and occurred in 20 (33%) of 60 patients in the cyclophosphamide group versus 21 (36%) of 59 patients in the placebo group. INTERPRETATION: In patients with acute exacerbation of IPF, adding intravenous cyclophosphamide pulses to glucocorticoids increased 3-month mortality. These findings provide evidence against the use of intravenous cyclophosphamide in such patients. FUNDING: Programme Hospitalier de Recherche Clinique of the French Ministry of Health (PHRC 2014-502), Roche Pharmaceuticals.

Outcomes of patients with decreased arterial oxyhaemoglobin saturation on pulmonary arterial hypertension drugs.

BACKGROUND: Drugs approved for the treatment of pulmonary arterial hypertension (PAH) improve long-term outcomes. These drugs have pulmonary vasodilator properties which may potentially cause a decrease in arterial oxyhaemoglobin saturation (S aO2 ) in some patients. The present retrospective study of the French Pulmonary Hypertension Registry aimed to describe the clinical characteristics and outcomes of patients showing a ≥3% decrease in S aO2 while treated with PAH drugs. METHODS: We reviewed 719 PAH patients. The exclusion criteria were PAH associated with congenital heart disease and PAH with overt features of venous/capillaries involvement. RESULTS: 173 (24%) patients had a ≥3% decrease in S aO2 . At diagnosis, they were older with a lower diffusing capacity of the lung for carbon monoxide and a shorter 6-min walk distance compared with those who did not display a ≥3% decrease in S aO2 . The percentage of patients meeting the European Society of Cardiology/European Respiratory Society (ESC/ERS) low-risk criteria at re-evaluation was significantly lower in those with a ≥3% decrease in S aO2 and more patients started long-term oxygen therapy in this group (16% versus 5%; p<0.001). A ≥3% decrease in S aO2 was associated with a poorer survival (hazard ratio 1.81, 95% CI 1.43-2.34; p<0.0001). In a multivariate Cox analysis, a ≥3% decrease in S aO2 was a prognostic factor independent of age at diagnosis and ESC/ERS risk stratification at follow-up. CONCLUSIONS: When treated with PAH drugs, a large subset of patients experience a ≥3% decrease in S aO2 , which is associated with worse long-term outcomes and reduced survival.

Hemodynamic Response to Treatment and Outcomes in Pulmonary Hypertension Associated With Interstitial Lung Disease Versus Pulmonary Arterial Hypertension in Systemic Sclerosis: Data From a Study Identifying Prognostic Factors in Pulmonary Hypertension Associated With Interstitial Lung Disease.

OBJECTIVE: Patients with systemic sclerosis and both pulmonary hypertension and interstitial lung disease (SSc-PH-ILD) generally carry a worse prognosis than patients with SSc and pulmonary arterial hypertension (SSc-PAH) without ILD. There is no evidence of the efficacy of PAH therapies in SSc-PH-ILD. We undertook this study to compare survival of and response to treatment in patients with SSc-PH-ILD and those with SSc-PAH. METHODS: We analyzed 128 patients (66 with SSc-PH-ILD and 62 with SSc-PAH) from 15 centers, in whom PH was diagnosed by right-sided heart catheterization; they were prospectively included in the PH registry. All patients received PAH-specific therapy. Computed tomography of the chest was used to confirm or exclude ILD. RESULTS: At baseline, patients with SSc-PH-ILD had less severe hemodynamic impairment than those with SSc-PAH (pulmonary vascular resistance 5.7 Wood units versus 8.7 Wood units; P = 0.0005) and lower diffusing capacity for carbon monoxide (median 25% [interquartile range (IQR) 18%, 35%] versus 40% [IQR 31%, 51%]; P = 0.0005). Additionally, patients with SSc-PH-ILD had increased mortality (8.1% at 1 year, 21.2% at 2 years, and 41.5% at 3 years) compared to those with SSc-PAH (4.1%, 8.7%, and 21.4%, respectively; P = 0.04). Upon treatment with PAH-targeted therapy, no improvement in the 6-minute walk distance was observed in either group. Improvement in the World Health Organization functional class was observed less frequently in patients with SSc-ILD-PH compared to those with SSc-PAH (13.6% versus 33.3%; P = 0.02). Hemodynamics improved similarly in both groups. CONCLUSION: ILD confers a worse prognosis to SSc-PH. Response to PAH-specific therapy is clinically poor in SSc-PH-ILD but was not found to be hemodynamically different from the response observed in SSc-PAH.

Exercise Hemodynamics in the Prognosis of Patients with Pulmonary Arterial Hypertension.

BACKGROUND: Assessment of prognosis is of major importance when deciding on a therapeutic strategy in patients with pulmonary arterial hypertension (PAH). OBJECTIVES: The aim of this study was to investigate the prognostic value of pulmonary hemodynamics during exercise and changes during treatment in patients with PAH. METHODS: Consecutive incident patients (n = 49) with PAH undergoing right heart catheterization at rest and during a constant workload cycle exercise in supine position were included. Predictors of survival were identified at baseline using Cox proportional hazard regression models in a univariate analysis unadjusted and adjusted for age and gender. RESULTS: During a median follow-up period of 42 months, 13 (27%) of the 49 patients studied died. Two predictors of death were found: rest-to-exercise changes in heart rate and systolic pulmonary artery pressure. Adjusted hazard ratios were 0.92 (95% CI 0.86-0.99) and 0.93 (95% CI 0.88-0.99), respectively. These 2 variables were correlated with each other (r = 0.55, p < 0.001). CONCLUSIONS: Rest-to-exercise changes in heart rate and systolic pulmonary artery pressure measured at diagnosis are predictors of survival in patients with PAH. These measurements taken from an exercise test reflect right ventricular function.

Evolution and Predictive Factors of Improvement of Obstructive Sleep Apnea in an Obese Population After Bariatric Surgery.

STUDY OBJECTIVES: Our objectives were to determine in an obese population (body mass index > 35 kg/m²) the number of patients, after gastric bypass (GBP), who no longer met French Ministry of Health criteria for utilizing positive airway pressure (PAP), and the predictive factors of obstructive sleep apnea (OSA) improvement. METHODS: Between June 2012 and August 2014 we diagnosed OSA in 129 incident patients requiring PAP therapy before GBP. A postoperative sleep recording was undertaken for 44 of these patients after a weight loss of at least 10%. RESULTS: Most of the patients showed severe OSA with a mean [standard deviation] apnea-hypopnea index (AHI) of 52.8 [23.8] events/h. The body mass index was 46.1 [5.1] kg/m². All the patients were treated via PAP and most of them via auto-titrating PAP with a range of 4-16 cmH2O. Following the GBP, in 31 patients (70.5%) OSA was improved, allowing PAP to be stopped (AHI < 15 events/h). The Epworth Sleepiness Scale score, the modified Medical Research Council dyspnea scale, the loudness of snoring, and sleep structure were improved. AHI was decreased by a mean of 40.9 [22.4] events/h (P < .001). In a multivariate logistic regression model, age (P = .018) and sleep oxygen desaturation index (P = .049) appeared to predict improvement of OSA. CONCLUSIONS: After GBP, 70.5% of the patients no longer met French Ministry of Health criteria for utilizing PAP, allowing discontinuation of this treatment. At diagnosis, a younger age and a less severe sleep oxygen desaturation were predictive factors of this improvement.

Pulmonary arterial hypertension in patient treated for multiple sclerosis with 4-aminopyridine.

4-Aminopyridine (4-AP) is a recent treatment indicated to improve walking in patient with multiple sclerosis. We report the first case of pulmonary arterial hypertension (PAH) that we attribute to the use of 4-AP. A 64-year-old woman with multiple sclerosis presented with dyspnea. After excluding other secondary causes of pulmonary hypertension, a diagnosis of severe PAH due to 4-AP was made based on right heart catheterization. History revealed that the dyspnea began with the initiation of 4-AP. After discontinuation of 4-AP therapy and initiation of ambrisentan and tadalafil, dyspnea and pulmonary arterial pressure have improved significantly and one specific PAH treatment was stopped. 4-AP is an outward rectifying potassium channel blocker with a vasoconstrictor effect in animal's pulmonary artery. According to the chronological sequence of events, the lack of other etiology, and its pharmacological plausibility, 4-AP is highly suspected to have induced our patient's PAH.

Rituximab for auto-immune alveolar proteinosis, a real life cohort study.

BACKGROUND: Whole lung lavage is the current standard therapy for pulmonary alveolar proteinosis (PAP) that is characterized by the alveolar accumulation of surfactant. Rituximab showed promising results in auto-immune PAP (aPAP) related to anti-GM-CSF antibody. METHODS: We aimed to assess efficacy of rituximab in aPAP in real life and all patients with aPAP in France that received rituximab were retrospectively analyzed. RESULTS: Thirteen patients were included. No patients showed improvement 6 months after treatment, but, 4 patients (30%) presented a significant decrease of alveolar-arterial difference in oxygen after 1 year. One patient received lung transplantation and one patient was lost of follow-up within one year. Although a spontaneous improvement cannot be excluded in these 4 patients, improvement was more frequent in patients naïve to prior specific therapy and with higher level of anti-GM-CSF antibodies evaluated by ELISA. No serious adverse event was evidenced. CONCLUSIONS: These data do not support rituximab as a second line therapy for patients with refractory aPAP.

A diffuse lung emphysema, severe pulmonary hypertension and lack of airflow limitation.

Pulmonary veno-occlusive disease is characterized by remodeling of pulmonary arteries, capillaries and venules. We report a case of diffuse lung emphysema and pulmonary veno-occlusive disease with the characteristic of having no airflow limitation. A very low diffusing capacity for carbon monoxide and results of high-resolution computed tomography of the chest suggested pulmonary veno-occlusive disease. The diagnosis was confirmed on histological analysis after lung transplantation. The combination of results of the computed tomography of the chest and the histological analysis suggested a relationship between diffuse lung emphysema and remodeling of pulmonary vessels. A distinctive pattern of mild-to-moderate airflow limitation in patients with chronic obstructive pulmonary disease and severe pulmonary hypertension has been described. This observation of the combination of diffuse emphysema, pulmonary veno-occlusive disease and no airflow limitation supports further pathophysiological studies on severe pulmonary hypertension in chronic obstructive pulmonary disease.

Probing Rubber Cross-Linking Generation of Industrial Polymer Networks at Nanometer Scale.

We present improved analyses of rheometric torque measurements as well as (1)H double-quantum (DQ) nuclear magnetic resonance (NMR) buildup data on polymer networks of industrial compounds. This latter DQ NMR analysis allows finding the distribution of an orientation order parameter (Dres) resulting from the noncomplete averaging of proton dipole-dipole couplings within the cross-linked polymer chains. We investigate the influence of the formulation (filler and vulcanization systems) as well as the process (curing temperature) ending to the final polymer network. We show that DQ NMR follows the generation of the polymer network during the vulcanization process from a heterogeneous network to a very homogeneous one. The time variations of microscopic Dres and macroscopic rheometric torques present power-law behaviors above a threshold time scale with characteristic exponents of the percolation theory. We observe also a very good linear correlation between the kinetics of Dres and rheometric data routinely performed in industry. All these observations confirm the description of the polymer network generation as a critical phenomenon. On the basis of all these results, we believe that DQ NMR could become a valuable tool for investigating in situ the cross-linking of industrial polymer networks at the nanometer scale.

Lack of correlation between the ventilatory response to CO2 and lung function impairment in myotonic dystrophy patients: evidence for a dysregulation at central level.

Myotonic dystrophy Type 1 (DM1) is the most common muscular dystrophy in adults. Respiratory failure is common but clinical findings support a dysregulation of the control of breathing at central level, furthermore contributing to alveolar hypoventilation independently of the severity of respiratory weakness. We therefore intended to study the relationship between the ventilatory response to CO2 and the impairment of lung function in DM1 patients. Sixty-nine DM1 patients were prospectively investigated (43.5 ± 12.7 years). Systematic pulmonary lung function evaluation including spirometry, plethysmography, measurements of respiratory muscle strength, arterial blood gas analysis and ventilatory response to CO2 were performed. Thirty-one DM1 patients (45%) presented a ventilatory restriction, 38 (55%) were hypoxaemic and 15 (22%) were hypercapnic. Total lung capacity decline was correlated to hypoxaemia (p = 0.0008) and hypercapnia (p = 0.0013), but not to a decrease in ventilatory response to CO2 (p = 0.194). Ventilatory response to CO2 was reduced to 0.85 ± 0.67 L/min/mmHg and not correlated to respiratory muscle weakness. Ventilatory response to CO2 was neither different among restricted/non-restricted patients (p = 0.2395) nor among normoxaemic/hypoxaemic subjects (p = 0.6380). The reduced ventilatory response to CO2 in DM1 patients appeared independent of lung function impairment and respiratory muscle weakness, suggesting a central cause of CO2 insensitivity.

[Impact of COPD: from disability to exacerbations]. / Impact de la BPCO: du handicap aux exacerbations.

COPD is a common disease characterized by health status impairment and disability that is usually progressive. Exacerbations of COPD, an acute event in the course of the disease, have effects on symptoms and patient's quality of life. Assessment of symptoms and risk of exacerbations is useful to guide strategy management of the disease. COPD disability includes different aspects. Its assessment needs to consider the classification of severity of airflow limitation, symptoms, comorbidities and impairment of patient's health-related quality of life. The rate at which exacerbations occur varies between patients. History of previous exacerbations and severity of airflow limitation are the best predictors of the frequency and severity of exacerbations. Severity of the symptoms is associated with an increased risk of exacerbations. Exacerbations increase deterioration in health status and leads to severe disability, inducing a vicious circle from disability to exacerbations. At an individual patient level, an understanding of the impact of COPD requires to assess the patient's disability, the risk of future exacerbations, and the identification of comorbidities.