Blood fibrocytes are associated with severity and prognosis in COVID-19 pneumonia.

Increased blood fibrocytes are associated with a poor prognosis in fibrotic lung diseases. We aimed to determine whether the percentage of circulating fibrocytes could be predictive of severity and prognosis during coronavirus disease 2019 (COVID-19) pneumonia. Blood fibrocytes were quantified by flow cytometry as CD45+/CD15-/CD34+/collagen-1+ cells in patients hospitalized for COVID-19 pneumonia. In a subgroup of patients admitted in an intensive care unit (ICU), fibrocytes were quantified in blood and bronchoalveolar lavage (BAL). Serum amyloid P (SAP), transforming growth factor-ß1 (TGF-ß1), CXCL12, CCL2, and FGF2 concentrations were measured. We included 57 patients in the hospitalized group (median age = 59 yr [23-87]) and 16 individuals as healthy controls. The median percentage of circulating fibrocytes was higher in the patients compared with the controls (3.6% [0.2-9.2] vs. 2.1% [0.9-5.1], P = 0.04). Blood fibrocyte count was lower in the six patients who died compared with the survivors (1.6% [0.2-4.4] vs. 3.7% [0.6-9.2], P = 0.02). Initial fibrocyte count was higher in patients showing a complete lung computed tomography (CT) resolution at 3 mo. Circulating fibrocyte count was decreased in the ICU group (0.8% [0.1-2.0]), whereas BAL fibrocyte count was 6.7% (2.2-15.4). Serum SAP and TGF-ß1 concentrations were increased in hospitalized patients. SAP was also increased in ICU patients. CXCL12 and CCL2 were increased in ICU patients and negatively correlated with circulating fibrocyte count. We conclude that circulating fibrocytes were increased in patients hospitalized for COVID-19 pneumonia, and a lower fibrocyte count was associated with an increased risk of death and a slower resolution of lung CT opacities.

Residual ground glass opacities three months after Covid-19 pneumonia correlate to alteration of respiratory function: The post Covid M3 study.

INTRODUCTION: Lung function in survivors of SARS-Co-V2 pneumonia is poorly known, but concern over the possibility of sequelae exists. METHODS: Retrospective study on survivors with confirmed infection and pneumonia on chest-CT. Correlations between PFT and residual radiologic anomalies at three months taking into account initial clinical and radiological severity and steroid use during acute phase. RESULTS: 137 patients (69 men, median age 59 (Q1 50; Q3 68), BMI 27.5 kg/m2 (25.1; 31.7)) were assessed. Only 32.9% had normal PFT, 75 had altered DLCO. Median (Q1; Q3) values were: VC 79 (66; 92) % pred, FEV1 81 (68; 89), TLC 78 (67; 85), DLCO 60 (44; 72), and KCO 89 (77; 105). Ground glass opacities (GGO) were present in 103 patients (75%), reticulations in 42 (30%), and fibrosis in 18 (13%). There were significantly lower FEV1 (p = 0.0089), FVC (p = 0.0010), TLC (p < 0.0001) and DLCO (p < 0.0001) for patients with GGO, lower TLC (p = 0.0913) and DLCO (p = 0.0181) between patients with reticulations and lower FVC (p = 0.0618), TLC (p = 0.0742) DLCO (p = 0.002) and KCO (p = 0.0114) between patients with fibrosis. Patients with initial ≥50% lung involvement had significantly lower FEV1 (p = 0.0019), FVC (p = 0.0033), TLC (p = 0.0028) and DLCO (p = 0.0003) compared to patients with ≤10%. There was no difference in PFT and residual CT lesions between patients who received steroids and those who did not. CONCLUSION: The majority of patients have altered PFT at three months, even in patients with mild initial disease, with significantly lower function in patients with residual CT lesions. Steroids do not seem to modify functional and radiological recovery. Long-term follow-up is needed.

Alteration of Diffusion Capacity After SARS-CoV-2 Infection: A Pathophysiological Approach.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected millions of people worldwide, and pneumonia affects 90% of patients. This raises the possibility of millions of people with altered lung function. Few data exist to date on pulmonary function after SARS-CoV-2 infection, but alteration of diffusion capacity of CO (D LCO) is the most frequently described abnormality. First, we present original data on lung function at 3 months after SARS-CoV-2 infection and discuss the effect of using European Coal and Steel Community (ECSC) or Global Lung Function Initiative (GLI) reference equations to diagnose diffusion capacity. Second, we review existing data on D LCO alteration after SARS-CoV-2 infection and discuss the implication of restrictive disorder in D LCO alteration. Last, we discuss the pathophysiology of D LCO alteration and try to disentangle vascular damage and fibrosis.

Hyperventilation: A Possible Explanation for Long-Lasting Exercise Intolerance in Mild COVID-19 Survivors?

Since the outbreak of the coronavirus (COVID-19) pandemic, most attention has focused on containing transmission and addressing the surge of critically ill patients in acute care settings. As we enter the second phase of the pandemic, emphasis must evolve to post-acute care of COVID-19 survivors. Persisting cardiorespiratory symptoms have been reported at several months after the onset of the infection. Information is lacking on the pathophysiology of exercise intolerance after COVID-19. Previous outbreaks of coronaviruses have been associated with persistent dyspnea, muscle weakness, fatigue and reduced quality of life. The extent of Covid-19 sequelae remains to be evaluated, but persisting cardiorespiratory symptoms in COVID-19 survivors can be described as two distinct entities. The first type of post-Covid symptoms are directly related to organ injury in the acute phase, or the complications of treatment. The second type of persisting symptoms can affect patients even with mild initial disease presentation without evidence of organ damage. The mechanisms are still poorly qualified to date. There is a lack of correlation between initial symptom severity and residual symptoms at exertion. We report exercise hyperventilation as a major limiting factor in COVID-19 survivors. The origin of this hyperventilation may be related to an abnormality of ventilatory control, by either hyperactivity of activator systems (automatic and cortical ventilatory control, peripheral afferents, and sensory cortex) or failure of inhibitory systems (endorphins) in the aftermath of pulmonary infection. Hyperventilation-induced hypocapnia can cause a multitude of extremely disabling symptoms such as dyspnea, tachycardia, chest pain, fatigue, dizziness and syncope at exertion.

Physiology of the lung in idiopathic pulmonary fibrosis.

The clinical expression of idiopathic pulmonary fibrosis (IPF) is directly related to multiple alterations in lung function. These alterations derive from a complex disease process affecting all compartments of the lower respiratory system, from the conducting airways to the lung vasculature. In this article we review the profound alterations in lung mechanics (reduced lung compliance and lung volumes), pulmonary gas exchange (reduced diffusing capacity, increased dead space ventilation, chronic arterial hypoxaemia) and airway physiology (increased cough reflex and increased airway volume), as well as pulmonary haemodynamics related to IPF. The relative contribution of these alterations to exertional limitation and dyspnoea in IPF is discussed.

Cystic lung disease in Sjögren's syndrome: An observational study.

OBJECTIVES: To analyze the prevalence, characteristics and outcome of cystic lung disease associated with Sjögren's syndrome (SS). METHODS: From June 2010 to February 2015, 90 consecutive SS patients [60.1±14.8years; 88 (97.8%) female, 75 (83.3%) primary SS] had a systematic chest CT-scan. The presence of thin-walled cysts was analyzed by one experienced radiologist. Demographic data, clinical history, laboratory findings, and pulmonary function tests were extracted retrospectively from medical records. RESULTS: Twenty-one (23.3%) patients had cysts on CT scan performed 40.5±54.5months after SS diagnosis. Cysts number ranged from 1 to 25 were often bilateral (52.4%) and mostly located in the middle lung zone (76.2%). Cysts were isolated (n=6, 28.6%) or associated with other lesions, including bronchiectasis (n=5, 23.8%), micronodules (n=5, 23.8%), ground-glass opacity (n=4, 19%) and/or air trapping (n=3, 14.3%). Most patients with cysts (57.1%) had no respiratory symptoms. When comparing SS patients with and without cysts, patients with cysts tended to be older (65.3±15.3 versus 58.5±14.4years, P=0.06). Smoking habits were similar in both groups. Anti-SSB antibodies were more frequently detected in patients with cysts (57.1% vs. 26.1%, P=0.02). Pulmonary function tests were normal or displayed only mild small airways obstruction and reduced diffusion capacity to carbon monoxide. Four (19%) patients with cysts had a past history of associated pulmonary disease, including interstitial lung disease. During follow-up (25.1±17.7months), no patient developed specific lung disease or lymphoproliferative disorders. CONCLUSIONS: Cystic lung disease is frequent, benign, associated with anti-SSB/La antibodies and has no impact on outcome in SS.

Increased volume of conducting airways in idiopathic pulmonary fibrosis is independent of disease severity: a volumetric capnography study.

Bronchiectasis, bronchiolectasis, and bronchiolisation of alveolar regions are salient features of idiopathic pulmonary fibrosis (IPF). We asked whether IPF was associated with physiological changes consistent with increases in the volume of conducting airways, and whether airway volume was related to the severity of lung fibrosis. Patients with IPF (N = 57, vital capacity-VC: 73 ± 20%), patients with non-IPF interstitial lung disease (non-IPF ILD, N = 24, VC = 78 ± 18%) and controls without lung disease (N = 51, VC = 112 ± 21%) underwent volumetric capnography for the determination of conducting airway volume using Fletcher's equal area method, reported to predicted total lung capacity to control for the effect of lung size (VDaw/TLCp, mL/L). VDaw/TLCp was higher in patients with IPF (45.3 ± 12.8 ml L(-1)) in comparison with controls (34.2 ± 11.0 ml L(-1), p < 0.0001) and patients with non-IPF ILD (39.5 ± 9.2 ml L(-1), p = 0.0496). The same differences were observed when analysis was restricted to subjects with moderate IPF (VC ⩾ 80% predicted). Among IPF patients, VDaw/TLCp was correlated with neither the mMRC dyspnea scale, nor VC, nor carbon monoxide transfer factor, nor computed tomography fibrosis scores. Volumetric capnography showed higher conducting airway volume in IPF patients in comparison with controls and non-IPF ILDs, independent of disease severity. This result is consistent with either anatomical predisposition or dilation/longitudinal growth of conducting airways in IPF.

The risk/benefit of inhaled corticosteroids in chronic obstructive pulmonary disease.

Although inhaled corticosteroids have a well defined role in asthma therapy, their use remains controversial in nonasthmatic, smoking-related chronic obstructive pulmonary disease (COPD). Some studies have shown an effect of inhaled corticosteroids on airway inflammation in COPD, but the clinical relevance of these results is unknown. Data from five long-term, large studies, provide evidence that prolonged treatment with inhaled corticosteroids does not modify the rate of decline of forced expiratory volume in one second (FEV1) in patients with COPD and no reversibility to short-acting beta(2)-agonists. FEV1 was slightly improved over the first six months of treatment and lower reactivity in response to methacholine challenge has been observed. Improvement of respiratory symptoms and health status were also reported. A reduction of exacerbations rate was observed in two studies. No survival benefit was demonstrated. Two recent reports suggest that long term use of inhaled corticosteroids in COPD patients improves quality-adjusted life expectancy and is cost-effective. Combination therapy with inhaled corticosteroids and long-acting beta(2)-agonists have proven benefit in four long term large studies compared to placebo for FEV1, exacerbation rate, symptoms and health status. However, only two studies found that combination therapy was more effective than long-acting beta(2)-agonists alone for symptoms and health status improvement. The long term safety of inhaled corticosteroids is not known in COPD patients but topical adverse effects, and systemic effects such as a decrease of bone density of lumbar spine and femur and cutaneous adverse effects, have been reported after three years of treatment. However, three recent observational studies found a slight increase in the risk of fractures (hip, upper extremities and vertebral) in association with high doses of inhaled corticotherapy.

Normal pulmonary capillary blood volume in patients with chronic infiltrative lung disease and high pulmonary artery pressure.

STUDY OBJECTIVES: Pulmonary capillary blood volume (Qc), a component of diffusing capacity of the lung for carbon monoxide (Dlco), is increased in postcapillary pulmonary hypertension due to valve disease, but is decreased in primitive and thromboembolic pulmonary hypertension. This study was performed to evaluate which way pulmonary Qc is affected in patients with chronic infiltrative lung disease according to the value of systolic pulmonary artery pressure (SPAP). PATIENTS AND METHODS: Twenty-four patients who were nonsmokers and had chronic infiltrative lung disease secondary to connective tissue disease (12 patients), asbestosis (1 patient), sarcoidosis (5 patients), or of unknown origin (6 patients), and 8 control subjects underwent pulmonary function tests and Doppler echocardiography. MEASUREMENTS AND RESULTS: Total lung capacity, alveolar-arterial oxygen pressure difference, Dlco, and conductance of the alveolar-capillary membrane (Dm) did not differ between patients with low SPAP (LPAP) [ie, < 30 mm Hg] or high SPAP (HPAP). Patients with LPAP, but not HPAP, experienced significant decreases in pulmonary Qc, whatever the cause of the disease. There was a strong positive correlation between SPAP and Qc scaled by Dm to account for infiltrative disease severity (r = 0.68; p < 0.001). CONCLUSIONS: We thus conclude that pulmonary Qc is not decreased as expected in patients with chronic infiltrative lung disease and high pulmonary artery pressure. A high Qc/Dm ratio should encourage the physician to look for HPAP compatible with pulmonary hypertension, whatever the etiology of lung infiltrative disease.

Benefits and risks of inhaled corticosteroids in chronic obstructive pulmonary disease.

Inhaled corticosteroids have a proven benefit in the management of asthma, but until recently, their efficacy in non-asthmatic, smoking-related chronic obstructive pulmonary disease (COPD) was not evidence-based. Airway inflammation in COPD differs from inflammation in asthma. Some studies have shown an effect of inhaled corticosteroids on airway inflammation in COPD but the clinical relevance of these results are unknown. Short-term studies evaluating the effect of inhaled corticosteroids in patients with COPD were associated with no or modest improvements in lung function. Data from five, long-term, large studies have provided evidence that prolonged treatment with inhaled corticosteroids does not modify the rate of decline of forced expiratory volume in one second (FEV(1)) in patients with COPD and no reversibility to short-acting beta(2)-adrenoceptor agonists. FEV(1) was slightly improved over the first 6 months of treatment in two studies and lower airway reactivity in response to methacholine challenge has been observed. Improvement of respiratory symptoms and health status was also reported in three studies. A reduction in the rate of exacerbations was observed in two studies. No survival benefit was demonstrated in any study. The advantage of using inhaled, rather than oral, corticosteroids is a reduction in adverse effects for the same therapeutic effect, because inhaled corticosteroids rely more on topical action than systemic activity. The long-term safety of inhaled corticosteroids is not known in patients with COPD. However, topical adverse effects, and systemic effects such as a decrease of bone density of lumbar spine and femur and cutaneous adverse effects, have been reported in patients with COPD after 3 years of treatment with inhaled corticosteroids.