Standard Pulmonary Function Tests Research Articles

Design and Evaluation of a Novel Venturi-Based Spirometer for Home Respiratory Monitoring.

The high cost and limited availability of home spirometers pose a significant barrier to effective respiratory disease management and monitoring. To address this challenge, this paper introduces a novel Venturi-based spirometer designed for home use, leveraging the Bernoulli principle. The device features a 3D-printed Venturi tube that narrows to create a pressure differential, which is measured by a differential pressure sensor and converted into airflow rate. The airflow is then integrated over time to calculate parameters such as the Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1). The system also includes a bacterial filter for hygienic use and a circuit board for data acquisition and streaming. Evaluation with eight healthy individuals demonstrated excellent test-retest reliability, with intraclass correlation coefficients (ICCs) of 0.955 for FVC and 0.853 for FEV1. Furthermore, when compared to standard Pulmonary Function Test (PFT) equipment, the spirometer exhibited strong correlation, with Pearson correlation coefficients of 0.992 for FVC and 0.968 for FEV1, and high reliability, with ICCs of 0.987 for FVC and 0.907 for FEV1. These findings suggest that the Venturi-based spirometer could significantly enhance access to spirometry at home. However, further large-scale validation and reliability studies are necessary to confirm its efficacy and reliability for widespread use.

Novel Surface Topographic Assessment of Lung Volume and Pulmonary Function Tests in Idiopathic Scoliosis: A Preliminary Study.

Severe spinal deformity results in restrictive pulmonary disease from thoracic distortions and lung-volume limitations. Though spirometry and body plethysmography are widely accepted tests for pulmonary function tests (PFTs), they are time-consuming and require patient compliance. This study investigates whether surface topographic [surface topography (ST)] measurements of body volume difference (BVD) and torso volume difference between maximum inhale and exhale correlate to values determined on PFTs. This study included patients with idiopathic scoliosis and thoracic/thoracolumbar curves ≥40 degrees. Patients received ST scans, clinical examinations, and EOS biplanar radiographs on the same day. PFTs were performed within 3 months of ST/radiographic analysis. Univariate linear regression analysis was used to examine relationships between BVD, PFT values, and mean curves. Sixteen patients (14.6 ± 2.2 y, 69% females) with idiopathic scoliosis and mean thoracic/thoracolumbar curves of 62 degrees ± 15˚ degrees (45 degrees to 93 degrees) were assessed. BVD displayed statistically high-positive positive correlations with forced vital capacity ( R = 0.863, P < 0.0001), forced expiratory volume in 1 second ( R = 0.870, P < 0.001), vital capacity ( R = 0.802, P < 0.0001), and TLC ( R = 0.831, P < 0.0001. Torso volume difference showed similarly high positive correlations to forced vital capacity, forced expiratory volume in 1 second, vital capacity, and TLC, but not residual volume. No correlations emerged between the mean thoracic/thoracolumbar curve and BVD or PFT values. This study strongly endorses further investigation into ST scanning as an alternative to traditional PFTs for assessing pulmonary volumes. The noncontact and noninvasive nature of ST scanning presents a valuable alternative method for analyzing thoracic volume, particularly beneficial for patients unable to cooperate with standard PFTs. Level II-prognostic.

Assessing pulmonary function in ALS using electrical impedance tomography

Objective We sought to determine whether thoracic electrical impedance tomography (EIT) could characterize pulmonary function in amyotrophic lateral sclerosis (ALS) patients, including those with facial weakness. Thoracic EIT is a noninvasive, technology in which a multi-electrode belt is placed across the chest, producing real-time impedance imaging of the chest during breathing. Methods We enrolled 32 ALS patients and 32 age- and sex-matched healthy controls (HCs) without underlying lung disease. All participants had EIT measurements performed simultaneously with standard pulmonary function tests (PFTs), including slow and forced vital capacity (SVC and FVC) in upright and supine positions and maximal inspiratory and expiratory pressures (MIPs and MEPs, respectively). Intraclass correlation coefficients (ICCs) were calculated to assess the immediate reproducibility of EIT measurements and Pearson’s correlations were used to explore the relationships between EIT and PFT values. Results Data from 30 ALS patients and 27 HCs were analyzed. Immediate upright SVC reproducibility was very high (ICC 0.98). Correlations were generally strongest between EIT and spirometry measures, with R values ranging from 0.64 to 0.82 (p < 0.001) in the ALS cohort. There were less robust correlations between EIT values and both MIPs and MEPs in the ALS patients, with R values ranging from 0.33 to 0.44. There was no significant difference for patients with and without facial weakness. There were no reported adverse events. Conclusion EIT-based pulmonary measures hold the promise of providing an alternative approach for lung function assessment in ALS patients. Based on these early results, further development and study of this technology are warranted.

Screening and staging of chronic obstructive pulmonary disease with deep learning based on chest X-ray images and clinical parameters

BackgroundChronic obstructive pulmonary disease (COPD) is underdiagnosed with the current gold standard measure pulmonary function test (PFT). A more sensitive and simple option for early detection and severity evaluation of COPD could benefit practitioners and patients.MethodsIn this multicenter retrospective study, frontal chest X-ray (CXR) images and related clinical information of 1055 participants were collected and processed. Different deep learning algorithms and transfer learning models were trained to classify COPD based on clinical data and CXR images from 666 subjects, and validated in internal test set based on 284 participants. External test including 105 participants was also performed to verify the generalization ability of the learning algorithms in diagnosing COPD. Meanwhile, the model was further used to evaluate disease severity of COPD by predicting different grads.ResultsThe Ensemble model showed an AUC of 0.969 in distinguishing COPD by simultaneously extracting fusion features of clinical parameters and CXR images in internal test, better than models that used clinical parameters (AUC = 0.963) or images (AUC = 0.946) only. For the external test set, the AUC slightly declined to 0.934 in predicting COPD based on clinical parameters and CXR images. When applying the Ensemble model to determine disease severity of COPD, the AUC reached 0.894 for three-classification and 0.852 for five-classification respectively.ConclusionThe present study used DL algorithms to screen COPD and predict disease severity based on CXR imaging and clinical parameters. The models showed good performance and the approach might be an effective case-finding tool with low radiation dose for COPD diagnosis and staging.

Calculated Maximal Volume Ventilation (cMVV) as a Marker of Early Respiratory Failure in Amyotrophic Lateral Sclerosis (ALS).

Respiratory failure assessment is among the most debatable research topics in amyotrophic lateral sclerosis (ALS) clinical research due to the wide heterogeneity of its presentation. Among the different pulmonary function tests (PFTs), maximal voluntary ventilation (MVV) has shown potential utility as a diagnostic and monitoring marker, able to capture early respiratory modification in neuromuscular disorders. In the present study, we explored calculated MVV (cMVV) as a prognostic biomarker in a center-based, retrospective ALS population belonging to the Piemonte and Valle d'Aosta registry for ALS (PARALS). A Spearman's correlation analysis with clinical data and PFTs showed a good correlation of cMVV with forced vital capacity (FVC) and a moderate correlation with some other features such as bulbar involvement, ALSFRS-R total score, blood oxygen (pO2), carbonate (HCO3-), and base excess (BE), measured with arterial blood gas analysis. Both the Cox proportional hazard models for survival and the time to non-invasive ventilation (NIV) measurement highlighted that cMVV at diagnosis (considering cMVV(40) ≥ 80) is able to stratify patients across different risk levels for death/tracheostomy and NIV indication, especially considering patients with FVC% ≥ 80. In conclusion, cMVV is a useful marker of early respiratory failure in ALS, and is easily derivable from standard PFTs, especially in asymptomatic ALS patients with normal FVC measures.

Impulse Oscillometry as an Alternative Lung Function Test for Hospitalized Adults.

Impulse oscillometry (IOS) is a noninvasive technique that measures lung physiology independently of patient effort. In the present study, we aimed to investigate the utility of IOS parameters in comparison with pulmonary function testing (PFT) among hospitalized subjects, with emphasis on obstructive and small airway diseases. Sixty-one subjects hospitalized either with unexplained dyspnea or for pre-surgery evaluation were included in the study. All subjects underwent PFTs and IOS test. The correlation between IOS results and PFTs was examined in different subgroups. The ability of IOS parameters to predict abnormal PFTs was evaluated using the area under the receiver operating characteristic (ROC) curve, and optimal cutoff values were calculated. IOS results were found to correlate with PFT values. Subgroup analysis revealed that these correlations were higher in younger (age < 70) and non-obese (body mass index < 25kg/m2) subjects. The resonant frequency was an independent predictor and had the best predictive ability for abnormal FEV1/FVC (area under the ROC curve 0.732 [95% CI 0.57-0.90], optimal cutoff 17 Hz, 87% sensitivity, 62% specificity) and abnormal forced expiratory flow during the middle half of the FVC maneuver (area under the ROC curve 0.667 [95% CI 0.53-0.81], optimal cutoff 15 Hz, 77% sensitivity, 54% specificity). Area of reactance and the difference in respiratory resistance at 5 Hz and 20 Hz also showed a good predictive ability for abnormal FEV1/FVC (area under the ROC curve 0.716 and 0.730, respectively). We found that the IOS performed well in diagnosing small airway and obstructive diseases among hospitalized subjects. IOS might serve as an alternative to standard PFTs in non-cooperative or dyspneic hospitalized patients.

Is Lung Function Measured by Oscillometry Useful in Interstitial Lung Diseases?

IntroductionThe role of oscillometry in interstitial lung disease (ILD) is still unclear. The main objective of our study was to describe the parameters determined by oscillometry in these patients and compare them with those obtained in conventional respiratory function tests. Material and methodsThis was a cross-sectional observational study. Patients with no respiratory disease and patients being followed up for ILD in the specialist unit of Hospital Universitario de Getafe, Madrid were included. ResultsA total of 45 individuals were analyzed. Fifteen had no respiratory disease, 15 were ILD patients with mild functional impairment, and another 15 were ILD patients with severe impairment. None of the participants had an obstructive pattern on spirometry.Comparison between the three groups showed statistically significant differences in the values of R5-19, reactance at 5Hz and reactance at 11Hz. No differences were observed between the three groups in Delta Xrs. The study showed a strong correlation between total and inspiratory reactance at 5Hz and forced vital capacity and diffusing capacity for carbon monoxide. ConclusionsOur results suggest that the findings in ILD are characteristic of this disease and that they differ from those found in other diseases such as chronic obstructive pulmonary disease. It also seems that there are differences according to the degree of functional impairment of the patients. The results show a strong correlation with standard pulmonary function tests, so oscillometry could be a useful tool in patients with ILD who are unable to perform it, and could provide additional information.

Application of 3D computed tomography in emphysematous parenchyma patients scheduled for bronchoscopic lung volume reduction.

Bronchoscopic lung volume reduction (BLVR) is a feasible, safe, effective and minimally invasive technique to significantly improve the quality of life of advanced severe chronic obstructive pulmonary disease (COPD). In this study, three-dimensional computed tomography (3D-CT) automatic analysis software combined with pulmonary function test (PFT) was used to retrospectively evaluate the postoperative efficacy of BLVR patients. The purpose is to evaluate the improvement of lung function of local lung tissue after operation, maximize the benefits of patients, and facilitate BLVR in the treatment of patients with advanced COPD. All the reported cases of advanced COPD patients treated with BLVR with one-way valve were collected and analysed from 2017 to 2020. Three-dimensional-CT image analysis software system was used to analyse the distribution of low-density areas <950 Hounsfield units in both lungs pre- and post- BLVR. Meanwhile, all patients performed standard PFT pre- and post-operation for retrospective analysis. We reported six patients that underwent unilateral BLVR with 1 to 3 valves according to the range of emphysema. All patients showed a median increase in forced expiratory volume in 1 second (FEV1) of 34%, compared with baseline values. Hyperinflation was reduced by 16.6% (range, 4.9%-47.2%). The volumetric measurements showed a significant reduction in the treated lobe volume among these patients. Meanwhile, the targeted lobe volume changes were inversely correlated with change in FEV1/FEV1% in patients with heterogeneous emphysematous. We confirm that 3D-CT analysis can quantify the changes of lung volume, ventilation and perfusion, to accurately evaluate the distribution and improvement of emphysema and rely less on the observer.

Validation of CT-based ventilation and perfusion biomarkers with histopathology confirms radiation-induced pulmonary changes in a porcine model

Imaging biomarkers can assess disease progression or prognoses and are valuable tools to help guide interventions. Particularly in lung imaging, biomarkers present an opportunity to extract regional information that is more robust to the patient’s condition prior to intervention than current gold standard pulmonary function tests (PFTs). This regional aspect has particular use in functional avoidance radiation therapy (RT) in which treatment planning is optimized to avoid regions of high function with the goal of sparing functional lung and improving patient quality of life post-RT. To execute functional avoidance, detailed dose–response models need to be developed to identify regions which should be protected. Previous studies have begun to do this, but for these models to be clinically translated, they need to be validated. This work validates two metrics that encompass the main components of lung function (ventilation and perfusion) through post-mortem histopathology performed in a novel porcine model. With these methods validated, we can use them to study the nuanced radiation-induced changes in lung function and develop more advanced models.

P197 A pilot study to determine whether normative values of specialised pulmonary function tests differ in children from non-Caucasian, ethnic minority backgrounds

Standard pulmonary function tests, like spirometry, are routinely performed in clinical care to detect and monitor the progression of lung disease. Reference ranges are used to determine what is normal for an individual, and are derived by performing these tests on healthy controls to establish normative values. For specialist pulmonary function tests such as multiple breath washout (MBW), Fractional exhaled Nitric Oxide (FeNO) and Nasal Nitric Oxide (nNO) reference ranges are limited or derived from small sample sizes. Furthermore, these values are often primarily based on Caucasian individuals with even less literature on normative values for ethnic minorities. This is now particularly relevant in the CF community, as there is growing identification of CF within ethnic minorities, which are over-represented in the group without access to CFTR modulator drugs. Therefore, there is utility in identifying if there are normative difference between Caucasian and ethnic minorities. If differences do exist, use of inappropriate ‘normal’ ranges could lead to disease being missed or overdiagnosed in these populations, contributing to health inequalities.

Impulse Oscillometry as a Diagnostic Test for Pulmonary Emphysema in a Clinical Setting.

Body plethysmography (BP) is the standard pulmonary function test (PFT) in pulmonary emphysema diagnosis, but not all patients can cooperate to this procedure. An alternative PFT, impulse oscillometry (IOS), has not been investigated in emphysema diagnosis. We investigated the diagnostic accuracy of IOS in the diagnosis of emphysema. Eighty-eight patients from the pulmonary outpatient clinic at Lillebaelt Hospital, Vejle, Denmark, were included in this cross-sectional study. A BP and an IOS were performed in all patients. Computed tomography scan verified presence of emphysema in 20 patients. The diagnostic accuracy of BP and IOS for emphysema was evaluated with two multivariable logistic regression models: Model 1 (BP variables) and Model 2 (IOS variables). Model 1 had a cross-validated area under the ROC curve (CV-AUC) = 0.892 (95% CI: 0.654-0.943), a positive predictive value (PPV) = 59.3%, and a negative predictive value (NPV) = 95.0%. Model 2 had a CV-AUC = 0.839 (95% CI: 0.688-0.931), a PPV = 55.2%, and an NPV = 93.7%. We found no statistically significant difference between the AUC of the two models. IOS is quick and easy to perform, and it can be used as a reliable rule-out method for emphysema.

Deep learning using multilayer perception improves the diagnostic acumen of spirometry: a single-centre Canadian study

RationaleSpirometry and plethysmography are the gold standard pulmonary function tests (PFT) for diagnosis and management of lung disease. Due to the inaccessibility of plethysmography, spirometry is often used alone but...

Postural changes in lung volumes in patients with heart failure and Cheyne-Stokes respiration: Relationship with sleep apnea severity

Background and aimIt has been proposed that the increased severity of sleep apnea frequently observed in heart failure (HF) patients with Cheyne-Stokes respiration (CSR) when sleeping in the supine compared to the lateral position, may be caused by the concomitant reduction in functional residual capacity (FRC). We assessed positional changes in FRC in patients with CSR and investigated the relationship between these changes in the laboratory and corresponding changes in CSR severity during sleep. MethodsAfter a diagnostic polysomnography, 18 HF patients with dominant CSR and an apnea-hypopnea index (AHI)≥15 events/h underwent a standard pulmonary function test in the sitting position. Measurements were repeated in the supine, left lateral and right lateral. The latter two measurements were averaged to obtain a single lateral measurement. ResultsThe FRC in the seated position was 3.0 ± 0.5 L (85 ± 13% of predicted), decreased to 2.3 ± 0.3 L (−21 ± 8%, p < 0.0001) in the supine position, and increased to 2.8 ± 0.4 L (+21 ± 12%, p < 0.0001) from the supine to the lateral position (−5±8% vs seated, p = 0.013). During sleep, the AHI and the apnea index (AI) decreased from 47 ± 15 events/h to 26 ± 12 events/h (−46 ± 20%, p < 0.0001) and from 29 ± 21 events/h to 12 ± 10 events/h (−61 ± 40%, p < 0.001) from the supine to the lateral position. Changes in the AI were significantly correlated with corresponding changes in FRC (ρ = −0.55, p = 0.032). ConclusionIn patients with HF and CSR, lying in the supine position causes a significant reduction in FRC in the context of a chronically reduced FRC. The negative correlation between postural changes in FRC and AI supports the hypothesis that the reduction in lung gas stores in the supine position may promote/exacerbate respiratory control instability.

Imaging biomarkers of lung ventilation in interstitial lung disease from 129Xe and oxygen enhanced 1H MRI

PurposeTo compare imaging biomarkers from hyperpolarised 129Xe ventilation MRI and dynamic oxygen-enhanced MRI (OE-MRI) with standard pulmonary function tests (PFT) in interstitial lung disease (ILD) patients. To evaluate if biomarkers can separate ILD subtypes and detect early signs of disease resolution or progression. Study typeProspective longitudinal. PopulationForty-one ILD (fourteen idiopathic pulmonary fibrosis (IPF), eleven hypersensitivity pneumonitis (HP), eleven drug-induced ILD (DI-ILD), five connective tissue disease related-ILD (CTD-ILD)) patients and ten healthy volunteers imaged at visit 1. Thirty-four ILD patients completed visit 2 (eleven IPF, eight HP, ten DIILD, five CTD-ILD) after 6 or 26 weeks. Field strength/sequenceMRI was performed at 1.5 T, including inversion recovery T1 mapping, dynamic MRI acquisition with varying oxygen levels, and hyperpolarised 129Xe ventilation MRI. Subjects underwent standard spirometry and gas transfer testing. AssessmentFive 1H MRI and two 129Xe MRI ventilation metrics were compared with spirometry and gas transfer measurements. Statistical testTo evaluate differences at visit 1 among subgroups: ANOVA or Kruskal-Wallis rank tests with correction for multiple comparisons. To assess the relationships between imaging biomarkers, PFT, age and gender, at visit 1 and for the change between visit 1 and 2: Pearson correlations and multilinear regression models. ResultsThe global PFT tests could not distinguish ILD subtypes. Percentage ventilated volumes were lower in ILD patients than in HVs when measured with 129Xe MRI (HV 97.4 ± 2.6, CTD-ILD: 91.0 ± 4.8 p = 0.017, DI-ILD 90.1 ± 7.4 p = 0.003, HP 92.6 ± 4.0 p = 0.013, IPF 88.1 ± 6.5 p < 0.001), but not with OE-MRI. 129Xe reported more heterogeneous ventilation in DI-ILD and IPF than in HV, and OE-MRI reported more heterogeneous ventilation in DI-ILD and IPF than in HP or CTD-ILD. The longitudinal changes reported by the imaging biomarkers did not correlate with the PFT changes between visits. Data conclusionNeither 129Xe ventilation nor OE-MRI biomarkers investigated in this study were able to differentiate between ILD subtypes, suggesting that ventilation-only biomarkers are not indicated for this task. Limited but progressive loss of ventilated volume as measured by 129Xe-MRI may be present as the biomarker of focal disease progresses. OE-MRI biomarkers are feasible in ILD patients and do not correlate strongly with PFT. Both OE-MRI and 129Xe MRI revealed more spatially heterogeneous ventilation in DI-ILD and IPF.

USING 6-MINUTE WALKING DISTANCE AND FRAILTY MEASURES TO PREDICT RISK OF POSTSTEM CELL TRANSPLANT PULMONARY COMPLICATIONS AND MORTALITY

USING 6-MINUTE WALKING DISTANCE AND FRAILTY MEASURES TO PREDICT RISK OF POSTSTEM CELL TRANSPLANT PULMONARY COMPLICATIONS AND MORTALITY

An a Priori Approach to Small Airway Dysfunction in Pediatric Asthmatics.

Small airway dysfunction remains a stepchild in the pediatric asthma care pathway. In brief, elements of the pulmonary function test (PFT) concerning smaller airway data remain less utilized. To further the value of the standard PFT we underwent a prospective Proof of Concept (POC) project, utilizing the outpatient performance of PFT tests in children 6–18 years during a 15-month period. The goal of the study was to determine if a priori the PFT represented a small airway disease pattern or not. Only the pulmonary function was used to make that distinction. Children 6–18 years with asthma who completed a PFT had their PFT as being characterized with or without a small airway dysfunction (SAD) designation, coded in the electronic medical record as an a priori decision using the code J98.4 (other disorders of lung) as a marker for electronic medical records retrieval. Subsequently, the results were analyzed between a group of 136 children designated (a priori) as having no small airway dysfunction in comparison to 91 children a priori designated as having small airway dysfunction. The a priori designation groups were post hoc compared for large and smaller airway function differences. Both large and smaller airway dysfunction were highly significantly different between the 2 groups, based solely on the initial division of the total group based on the decision the PFT represented a small airway pattern. We concluded the baseline pulmonary function test used in the evaluation of pediatric asthma has readily identifiable information regarding the presence of small airway dysfunction, and we characterized what was unique on the PFT based on that SAD classification

Pulmonary function in patient with ulcerative colitis

Aim: To determine the type and frequency of pulmonary involvement in patients with UC and to determine the distribution of pulmonary dysfunction in patients with UC. Methods: A total of 39 cases of UC, were enrolled consecutively in this study from the Department of Gastroenterology. The age, sex, family history, duration of disease, biochemical parameters (CRP, ESR, blood routine test, etc.), lung function, chest X-ray, diagnoses, and treatments were collected. Patients and controls underwent standard pulmonary function testing. Comparisons of rates among multiple groups were done with Fisher exact test, continuous variables were compared with one-way ANOVA. Results: According to the true love index, the severity of active UC was moderate and severe among 36.7% and 63.3% of subjects respectively. The pulmonary function test “FCV” showed reduced mean FCV among subjects with active UC (2.86±0.77 litres) and inactive UC (3.91±0.62 litres) as compared to controls (4.04±1.14 litres). Among the patients with deranged PFT, 1 (7.6%) had obstructive, 7 (53.8%) had small airway disease and 5 (38.6%) had a restrictive pattern of lung involvement. Conclusion: Subclinical pulmonary dysfunction is frequent in UC and dependent on disease activity. Some alterations were sub-clinical and some of the patients showed troublesome pulmonary symptoms.

Assessment of Multi-Layer Perceptron Neural Network for Pulmonary Function Test’s Diagnosis Using ATS and ERS Respiratory Standard Parameters

The aim of the research work is to investigate the operability of the entire 23 pulmonary function parameters, which are stipulated by the American Thoracic Society (ATS) and the European Respiratory Society (ERS), to design a medical decision support system capable of classifying the pulmonary function tests into normal, obstructive, restrictive, or mixed cases. The 23 respiratory parameters specified by the ATS and the ERS guidelines, obtained from the Pulmonary Function Test (PFT) device, were employed as input features to a Multi-Layer Perceptron (MLP) neural network. Thirteen possible MLP Back Propagation (BP) algorithms were assessed. Three different categories of respiratory diseases were evaluated, namely obstructive, restrictive, and mixed conditions. The framework was applied on 201 PFT examinations: 103 normal and 98 abnormal cases. The PFT decision support system’s outcomes were compared with both the clinical truth (physician decision) and the PFT built-in diagnostic software. It yielded 92–99% and 87–92% accuracies on the training and the test sets, respectively. An 88–94% area under the receiver operating characteristic curve (ROC) was recorded on the test set. The system exceeded the performance of the PFT machine by 9%. All 23 ATS\ERS standard PFT parameters can be used as inputs to design a PFT decision support system, yielding a favorable performance compared with the literature and the PFT machine’s diagnosis program.

Associations of HIV persistence, cigarette smoking, inflammation, and pulmonary dysfunction in people with HIV on antiretroviral therapy.

We aimed to investigate the relationship between measures of HIV persistence with antiretroviral therapy (ART) and cigarette smoking, systemic markers of inflammation, and pulmonary function.Retrospective study of 82 people with HIV (PWH) on ART for a median of 6.9 years (5.6–7.8) and plasma HIV RNA levels <50 copies/mL.HIV DNA and cell-associated HIV RNA (CA-RNA) were measured in peripheral blood mononuclear cells (PBMC) and plasma HIV RNA was measured by single-copy assay (SCA). Plasma levels of 17 inflammatory mediators were measured by Bio-Plex, and standard pulmonary function tests (PFT) were performed in all participants.Median age was 52 years and 41% were women. Most had preserved CD4+ T cell counts (median (IQR) 580 (361–895) cells/mm3). Median plasma HIV RNA was 1.3 (0.7–4.6) copies/mL, and median levels of HIV DNA and CA-RNA in PBMC were 346 (140–541) copies and 19 (3.7–49) copies per 1 million PBMC, respectively. HIV DNA was higher in smokers than in nonsmokers (R = 0.3, P < 0.05), and smoking pack-years positively correlated with HIV DNA and CA-RNA (R = 0.3, P < 0.05 and R = 0.4, P < 0.01, respectively). HIV DNA, CA-RNA, and plasma HIV RNA were not significantly associated with any measure of pulmonary function or inflammation.Cigarette smoking was associated with HIV DNA and CA-RNA levels in blood, but measures of HIV persistence were not associated with pulmonary function or inflammation.

Correlation of respiratory oscillometry with CT image analysis in a prospective cohort of idiopathic pulmonary fibrosis

BackgroundMarkers of idiopathic pulmonary fibrosis (IPF) severity are based on measurements of forced vital capacity (FVC), diffusing capacity (DLCO) and CT. The pulmonary vessel volume (PVV) is a novel quantitative...