BACKGROUND: Pulmonary function tests are vital for diagnosing lung diseases, assessing treatment responses, and monitoring respiratory health. Recent updates to interpretive standards by the European Respiratory and American Thoracic Societies (ERS/ATS) in 2022 introduced significant changes compared to the 2005 standards. They include incorporating lung volume measurements, non-specific and mixed disorders, introducing z-scores for functional abnormality assessment, reducing severity categories from five to three, and revising criteria for positive bronchodilator responses.
METHODS: We conducted a retrospective, multi-center study across four centers using spirometric data spanning from 2002 to 2022. We categorized spirometry results using both the 2005 and 2022 ATS/ERS standards and calculated predicted values following the GLI 2012 equation (Caucasian subset).
RESULTS: Among 79,039 subjects, we observed that 23% shifted from an obstructive diagnosis under the 2005 standard to a mixed pattern diagnosis under the 2022 standard, necessitating lung volume assessments. In the evaluation of bronchodilator responses among 59,203 tests, 12.3% of those initially classified as responders were reclassified as non-responders with the new standards. We found variations in severity categorization across age groups, with older patients tending to receive milder severity classifications and younger individuals receiving greater severity classifications under the 2022 standards.
CONCLUSIONS: The 2022 document emphasizes early lung volume assessment, potentially leading to increased utilization of more complex tests. Furthermore, the bronchodilator response was predominant in extreme age groups and among individuals with milder spirometric impairments. This shift may impact treatment decisions, potentially initiating medication in milder cases and de-escalating treatment in more severe cases.

BACKGROUND: The European Respiratory Society (ERS) and the American Thoracic Society (ATS) recommend using z-scores, and the ATS has recommended using Global Lung Initiative (GLI)- \"Global\" race-neutral reference equations for spirometry interpretation. However, these recommendations have been variably implemented and the impact has not been widely assessed, both in clinical and research settings.
OBJECTIVE: We evaluated the ERS/ATS airflow obstruction severity classification.
METHODS: In the COPDGene Study (n = 10,108), airflow obstruction has been defined as a forced expiratory volume in one second to forced vital capacity (FEV1/FVC) ratio <0.70, with spirometry severity graded from class 1 to 4 based on race-specific percent predicted (pp) FEV1 cut-points as recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). We compared the GOLD approach, using NHANES III race-specific equations, to the application of GLI-Global equations using the ERS/ATS definition of airflow obstruction as FEV1/FVC ratio < lower limit of normal (LLN) and z-FEV1 cut-points of -1.645, -2.5, and -4 (\"zGLI Global\"). We tested the four-tier severity scheme for association with COPD outcomes.
RESULTS: The lowest agreement between ERS/ATS with zGLI Global and the GOLD classification was observed in individuals with milder disease (56.9% and 42.5% in GOLD 1 and 2) and race was a major determinant of redistribution. After adjustment for relevant covariates, zGLI Global distinguished all-cause mortality risk between normal spirometry and the first grade of COPD (Hazard Ratio 1.23, 95% CI 1.04-1.44, p=0.014), and showed a linear increase in exacerbation rates with increasing disease severity, in comparison to GOLD.
CONCLUSIONS: The zGLI Global severity classification outperformed GOLD in the discrimination of survival, exacerbations, and imaging characteristics.

Interstitial lung diseases (ILD) unresponsive to medical therapy often require lung transplantation (LTx), which prolongs quality of life and survival. Ideal timing for referral for LTx remains challenging, with late referral associated with significant morbidity and mortality. Among other criteria, patients with ILD should be considered for LTx if forced vital capacity (FVC) is less than 80% or diffusion capacity for carbon monoxide (DLCO) is less than 40%. However, data on referral rates are lacking.
To evaluate referral rates for LTx based on pulmonary function tests (PFTs) and identify barriers associated with non-referral.
A single-center retrospective cohort study.
The study consisted of ILD patients who performed PFT between 2014 and 2020. Patients with FVC < 80% or a DLCO < 40% were included in the study. Patients with absolute contraindications to LTx were excluded. Referral rates were computed, and a comparison was made between referred and non-referred subjects.
Out of 114 ILD patients meeting criteria for referral to LTx, 35 were referred (30.7%), and 7 proceeded to undergo LTx. Median time from PFT to referral for assessment was 255 days [interquartile range (IQR) 35-1077]. Median time from referral to LTx was 89 days (IQR 59-143). Referred patients were younger (p = 0.003), had lower FVC (p < 0.001), DLCO (p < 0.001), and a higher rate of pulmonary hypertension (p = 0.04). Relatively better PFT, and older age, were significantly associated with non-referral of patients.
There is under-referral of ILD patients who are eligible for LTx, which is associated with severe disease and missed opportunities for LTx. Further research is required to validate these findings.
Lung transplants: addressing referral gaps for lung disease patientsPatients with severe lung diseases that are unresponsive to medical treatments often require lung transplants to enhance their quality of life and survival. Determining the optimal timing for considering a transplant is challenging, as delaying it can lead to complications. Our study aimed to assess how frequently individuals with lung problems, particularly interstitial lung diseases, were referred for lung transplants based on lung function tests. We conducted a retrospective analysis of medical records for patients with lung diseases who underwent lung function tests between 2014 and 2020. We selected patients whose test results indicated impaired lung function, excluding those who were ineligible for lung transplants due to other medical reasons. Subsequently, we examined the number of patients referred for a lung transplant and compared them to those who were not referred. Our findings revealed that out of 114 patients eligible for a lung transplant, only 35 were referred, representing a referral rate of approximately 31%. Among these, only 7 patients actually underwent the transplant procedure. The time elapsed between the lung function test and the referral for a transplant assessment was notably long, averaging around 255 days. Additionally, once referred, patients waited an average of 89 days for the transplant assessment. Referred patients tended to be younger and had more severe lung disease, characterized by lower lung function test results and a higher likelihood of pulmonary hypertension. Conversely, patients who were not referred generally enjoyed better overall health and were older. This discrepancy highlights the missed opportunities for patients to improve their health and quality of life through lung transplantation. Further research is essential to verify the accuracy of these findings, but this study represents a crucial step toward ensuring that individuals with lung diseases receive the appropriate care they require.

Pulmonary mechanics has been traditionally viewed as determined by lung size and physical factors such as frictional forces and tissue viscoelastic properties, but few information exists regarding potential influences of cytokines and hormones on lung function. Concentrations of 28 cytokines and hormones were measured in saliva from clinically healthy scholar children, purposely selected to include a wide range of body mass index (BMI). Lung function was assessed by impulse oscillometry, spirometry, and diffusing capacity for carbon monoxide, and expressed as z-score or percent predicted. Ninety-six scholar children (55.2% female) were enrolled. Bivariate analysis showed that almost all lung function variables correlated with one or more cytokine or hormone, mainly in boys, but only some of them remained statistically significant in the multiple regression analyses. Thus, after adjusting by height, age, and BMI, salivary concentrations of granulocyte-macrophage colony-stimulating factor (GM-CSF) in boys were associated with zR5-R20 and reactance parameters (zX20, zFres, and zAX), while glucagon inversely correlated with resistances (zR5 and zR20). Thus, in physiological conditions, part of the mechanics of breathing might be influenced by some cytokines and hormones, including glucagon and GM-CSF. This endogenous influence is a novel concept that warrants in-depth characterization.

BACKGROUND: Substance use is a problem that affects people all over the world and is prevalent in different age groups. The lungs in particular, with their unique exposure to the environment and the bloodstream, are vulnerable to damage from substance use and can affect lung function. Efforts have generally focused on cigarettes, while there is little research on different substances of use. The study aimed to detect changes in pulmonary function tests in different substance users.
METHODS: An analytical cross-sectional study was carried out among different substance users at the Abdalaal Elidridi Psychiatric Hospital. A total of 60 adults were included: 16 cannabis users, 16 heroin users, 16 methamphetamine users, and 12 alcohol users. Participants used only one substance. Height and weight were measured, and BMI was calculated. For each participant, pulmonary function tests (PFTs) including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio and peak expiratory flow rate (PEFR) were measured using an electronic spirometer, and the results were compared with normal reference values for Sudanese subjects matched for age, sex, and height.
RESULTS: A high prevalence of lung function abnormalities (100.0%) is seen in all abusers. Obstructive lung disease is found in 80.0% of patients, and restrictive lung disease is found in 20.0% of cases. The measured FEV1/FVC ratio in different substance groups was lower than the expected normal values of (88.2 ± 2.9%). The mean FEV1/FVC ratio of alcohol was (83.6 ± 7.6%), for heroin, it was (77.3 ± 15.8%), for methamphetamine, it was (77.7 ± 17.8%) and for cannabis, it was (71.03 ± 11.3%), the latter was significantly lower than the other two groups (P < 0.001). Duration of substance use was inversely correlated with the FEV1/FVC ratio (r = -0.378, P 0.001), indicating that a longer duration of substance use correlates with lower FEV1/FVC ratios.
CONCLUSIONS: Obstructive lung abnormalities are frequent in substance abusers. All types of substances have a major deleterious effect on PFTs and harm the respiratory system. More action should be taken to address the effects of substances on the lungs. Awareness, early detection, and intervention are essential.

UNASSIGNED: Air pollution is a significant contributor to respiratory illness globally, and in India, evidence is scarce on whether smoking exacerbates this problem.
UNASSIGNED: We aimed at assessing if being a smoker among public transit drivers increased risk for respiratory illnesses and affected performance of pulmonary function tests in a cross-sectional study in a metropolitan city of Gujarat, western state of India. We conducted a cross-sectional study among public transit drivers (those who were smoking and not smoking). Administration staff who were not smoking were considered as control group. We collected socio-demographic and medical history including occupational history (N = 296). We collected details of respiratory symptoms with standard tools and assessed pulmonary function tests (PFT) using spirometry. Group differences and regression analyses were conducted in R software.
UNASSIGNED: We found that respiratory symptoms among public transit drivers who smoked were higher than those who did not smoke and healthy controls. In PFT diagnosis, drivers who smoke displayed two times higher prevalence of obstructive pattern compared to drivers who did not smoke. There was a significant reduction in the larger as well as the smaller airway functions, reflected in reduction of FEV1/FVC ratio (p < 0.001) and FEF25-75% (p < 0.001), respectively, among drivers who smoked compared to controls. Our results indicate that being a driver with a smoking history leads to a 3.1% greater decrease in the FEV1/FVC ratio and about half a litre reduction in FEF25-75% compared to the drivers who did not smoke.
UNASSIGNED: We suggest there is a high need for smoking cessation programmes for public transit drivers as they are at higher risk for respiratory illnesses and reduced pulmonary functions when smoking is added to the existing vehicular exposure.

Background: Studies on post-COVID-19 condition (PCC) in adults have shown deterioration in pulmonary function tests (PFTs), mainly a diffusion limitation. Among the pediatric population, data are scarce. Aim: To characterize PFTs in children with PCC, including changes over time. Methods: A prospective longitudinal study of children with defined PCC and respiratory complaints who were referred to a designated multidisciplinary clinic from 11/2020 to 12/2022. Results: Altogether, 184 children with a mean age of 12.4 years (SD 4.06) were included. A mild obstructive pattern was demonstrated in 19/170 (11%) at presentation, as indicated by spirometry and/or positive exercise challenge test and/or reversibility post bronchodilators, only three had a previous diagnosis of asthma. Lung volumes and diffusion were normal in all but one patient (1/134, 0.7%). Exhaled nitric oxide levels were elevated in 32/144 (22%). A total of 33 children who had repeated PFTs had normal or near-normal PFTs on follow-up testing, including seven (21.2%) who had mild obstructive PFTs at presentation. Multivariate analysis identified older age [OR 1.36 (95% CI:1.07-1.75)], specific imaging findings (prominent bronchovascular markings (OR 43.28 (95% CI: 4.50-416.49)), and hyperinflation (OR 28.42, 95% CI: 2.18-370.84)] as significant predictors of an obstructive pattern on PFTs. Conclusions: In children with PCC and respiratory symptoms, the most common impairment was a mild obstructive pattern; most were without a history of asthma. Improvement was witnessed in long-term follow-up. In contrast to the adult population, no diffusion limitation was found. Empirical periodic inhaler therapy may be considered in children with factors associated with PFT abnormalities.

UNASSIGNED: People living with HIV (PLHIV) have a greater risk of developing respiratory disorders. The problems are linked to poor socio-economic status, high viral load, low CD4 counts, and antiretroviral therapy. Despite the high prevalence of respiratory disorders, the association between HIV infection and pulmonary function status, as well as the associated factors, is not well established in resource-limited countries.
UNASSIGNED: A comparative cross-sectional study was conducted from September 24 to October 15 2020 at Jimma Medical Center among people living with HIV who were arranged into an age-sex-matched comparison group. Data were collected using a pretested structured questionnaire administered via face-to-face interviews. The collected data included socio-demographic, respiratory, HIV infection, and substance use variables. Pulmonary function tests were conducted using an SP10 spirometer. The collected data were entered and analyzed using SPSS version 26. Independent t-test and multiple linear regressions were carried out to identify factors associated with the pulmonary function status of the study participants.
UNASSIGNED: A total of 96 PLHIV and 96 matched control individuals participated in the study. The mean of pulmonary function test parameters among the PLHIV respondents was FVC (l) (67.35 ± 19.12, p0.003), FEV1s (l) (61.76 ± 16.04, p0.001), and PEFR (50.14 ± 23.32, p0.001), with a significant lowering in the study group. Female sex, respiratory symptoms, duration of HIV, duration of treatment, and khat chewing were associated with lowered FEV1s (l) (p < 0.05) in HIV-positive respondents.
UNASSIGNED: PLHIV had significantly lower mean lung function parameters than HIV-uninfected participants. As a result, health providers should screen HIV-positive patients with respiratory symptoms, prolonged duration of HIV infection, prolonged treatment, and khat chewing for non-infectious lung disorders while treating them.

Angiotensin-converting enzyme (ACE) 1 gene polymorphisms have been associated with vascular permeability, alveolar endothelial dysfunction and fibroblast proliferation and have been studied in pulmonary diseases such as COPD and idiopathic pulmonary fibrosis. Similar mechanisms of ACE 1 polymorphisms have been seen in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD). We are presenting a retrospective observational study in patients with SSc-ILD and analysing the association of ACE 1 gene polymorphisms (DD, II and ID) with the features of SSc, changes in pulmonary function tests (PFTs) and lung HRCT over three different periods of time (at the time of the diagnosis, 5 and 10 years after the diagnosis). The aim of the study was to determine whether ACE 1 gene polymorphisms have an effect on the severity of SSc-ILD. We found no statistically significant differences in the development and severity of SSc-ILD and changes in PFTs between subgroups of ACE 1 gene polymorphism over the analysed periods (at the time of diagnosis HRCT changes p = 0.270, FEV1 p = 0.483, FVC p = 0.497, DLco p = 0.807, after 5 years HRCT changes p = 0.163, FEV1 p = 0.551, FVC p = 0.362, DLco p = 0.620 and 10 years of follow-up HRCT changes p = 0.853, FEV1 p = 0.589, FVC p = 0.328, DLco p = 0.992). However, patients with the ID genotype showed a significant reduction in FEV1 after 10 years of follow-up in comparison to baseline levels (91.0 (IR 80.0-105.0) at the time of diagnosis and 84.0 (IR 69.0-99.0) after 10 years, p = 0.014). Our study suggests that ACE 1 gene polymorphisms do not have a role in the severity of SSc-ILD. Further studies are needed to explain the exact role of ACE 1 gene polymorphisms in SSc-ILD and SSc in general.

OBJECTIVE: This study aimed to establish prediction models for respiratory-related mortality in microscopic polyangiitis (MPA) complicated by interstitial lung disease (ILD) using clinical characteristics.
METHODS: We enrolled patients with MPA with ILD between May 2005 and June 2021 in a multicentre cohort of Japanese patients with MPA (REVEAL cohort). We evaluated the demographic, clinical, laboratory, radiological findings, treatments and the presence of honeycombing 1 cm above the diaphragm using chest high-resolution CT (HRCT) on admission. We explored the risk factors predictive of respiratory-related mortality.
RESULTS: Of 115 patients, 26 cases died of respiratory-related diseases during a median follow-up of 3.8 years. Eighteen patients (69%) died due to respiratory infection, three (12%) had diffuse alveolar haemorrhage, and five (19%) had exacerbation of ILD. In univariate analysis, older age, lower percent forced vital capacity (%FVC), lower percent diffusing capacity of carbon monoxide (%DLCO), and the presence of honeycombing in the right lower lobe were identified as risk factors. Additionally, in multivariate analysis adjusted for age and treatment, %FVC, %DLCO and the presence of honeycombing in the right lower lobe were independently associated with respiratory-related mortality. We created prediction models based on the values of %FVC, %DLCO and presence of honeycombing on chest HRCT (termed \"MPF model\"). The 5-year respiratory-related death-free rate was significantly different between patients with MPA with ILD stratified by the number of risk factors based on the MPF model.
CONCLUSIONS: Our study indicates that the MPF model may help predict respiratory-related death in patients with MPA with ILD.