Oscillometry-Defined Small Airway Dysfunction in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: The prevalence of small airway dysfunction (SAD) in patients with chronic obstructive pulmonary disease (COPD) across different ethnicities is poorly understood. This study aimed to estimate the prevalence of SAD in stable COPD patients. METHODS: We conducted a cross-sectional study of 196 consecutive stable COPD patients. We measured pre- and post-bronchodilator (BD) lung function and respiratory impedance. The severity of COPD and lung function abnormalities was graded in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. SAD was defined as either difference in whole-breath resistance at 5 and 19 Hz > upper limit of normal or respiratory system reactance at 5 Hz < lower limit of normal. RESULTS: The cohort consisted of 95.9% men, with an average age of 66.3 years. The mean forced expiratory volume 1 second (FEV1) % predicted was 56.4%. The median COPD assessment test (CAT) scores were 14. The prevalence of post-BD SAD across the GOLD grades 1 to 4 was 14.3%, 51.1%, 91%, and 100%, respectively. The post-BD SAD and expiratory flow limitation at tidal breath (EFLT) were present in 62.8% (95% confidence interval [CI], 56.1 to 69.9) and 28.1% (95% CI, 21.9 to 34.2), respectively. COPD patients with SAD had higher CAT scores (15.5 vs. 12.8, p<0.01); poor lung function (FEV1% predicted 46.6% vs. 72.8%, p<0.01); lower diffusion capacity for CO (4.8 mmol/min/kPa vs. 5.6 mmol/min/kPa, p<0.01); hyperinflation (ratio of residual volume to total lung capacity % predicted: 159.7% vs. 129%, p<0.01), and shorter 6-minute walk distance (367.5 m vs. 390 m, p=0.02). CONCLUSION: SAD is present across all severities of COPD. The prevalence of SAD increases with disease severity. SAD is associated with poor lung function and higher symptom burden. Severe SAD is indicated by the presence of EFLT.

Association of the C allele of rs479200 in the EGLN1 gene with COVID-19 severity in Indian population: a novel finding.

The present study investigated two single nucleotide polymorphisms (SNPs)-rs479200 and rs516651 in the host EGLN1/PHD2 gene for their association with COVID-19 severity. A retrospective cohort of 158 COVID-19 patients from the Indian population (March 2020 to June 2021) was enrolled. Notably, the frequency of C allele (0.664) was twofold higher than T allele (0.336) in severe COVID-19 patients. Here, we report a novel finding that the C allele of rs479200 in the EGLN1 gene imparts a high risk of severe COVID-19 (odds ratio-6.214 (1.84-20.99) p = 0.003; 9.421 (2.019-43.957) p = 0.004), in additive inheritance model (adjusted and unadjusted, respectively).

Exploring the Immunodominant Epitopes of SARS-CoV-2 Nucleocapsid Protein as Exposure Biomarker.

Background The nucleocapsid protein (N protein) of SARS-CoV-2 is undeniably a potent target for the development of diagnostic tools due to its abundant expression and lower immune evasion pressure compared to spike (S) protein. Methods Blood samples of active COVID-19 infections (n=71) and post-COVID-19 (n=11) were collected from a tertiary care hospital in India; pre-COVID-19 (n=12) sera samples served as controls. Real-time reverse transcriptase-PCR (rRT-PCR) confirmed pooled sera samples (n=5) were used with PEPperCHIP® SARS-CoV-2 Proteome Microarray (PEPperPRINT GmbH, Germany) to screen immunodominant epitopes of SARS-CoV-2. Highly immunodominant epitopes were then commercially synthesized and further validated for their immunoreactivity by dot-blot and ELISA. Results The lowest detectable concentration (LDC) of the N1 peptide in the dot-blot assay was 12.5 µg demonstrating it to be fairly immunoreactive compared to control sera. IgG titers against the contiguous peptide (N2: 156AIVLQLPQGTTLPKGFYAEGS176) was found to be significantly higher (p=0.018) in post-COVID-19 compared to pre-COVID-19 control sera. These results suggested that N2-specific IgG titers buildup over time as expected in post-COVID-19 sera samples, while a non-significant immunoreactivity of the N2 peptide was also observed in active-COVID-19 sera samples. However, there were no significant differences in the total IgG titers between active COVID-19 infections, post-COVID-19 and pre-COVID-19 controls. Conclusion The N2-specific IgG titers in post-COVID-19 samples demonstrated the potential of N protein as an exposure biomarker, particularly in sero-surveillance studies.

Respiratory morbidities and lung function abnormalities in survivors of Bhopal Gas Disaster: A cross-sectional study.

BACKGROUND: Respiratory morbidities remained significant for the last four decades among the survivors of the Bhopal gas disaster. We hypothesized that lung function abnormalities, especially small airway dysfunctions, were responsible for the ongoing respiratory morbidities. METHODS: We conducted a cross-sectional study between 2018 and 2020 in the severely exposed cohort of the Bhopal gas disaster. A standardized questionnaire was used to record their respiratory symptoms. The forced oscillometry (FOT) and spirometry were utilized for assessing lung functions. Univariate and multivariate logistic regression analyses were used to examine the association. RESULTS: Of 916 enrolled individuals (men: 442, mean age: 55.2 ± 12.3 years), 558 participated in lung function assessments. Breathlessness was the most common complaint (71.7%), followed by cough (15.1%). The R5 > upper limit of normal (ULN), R5-19 > ULN, and X5 < lower limit of normal (LLN) were observed in 29.3%, 23.3%, and 21.2% participants, respectively. Normal, obstructive, and restrictive spirometry was observed in 46.2%, 26.1%, and 27.7%, participants, respectively. FOT parameters were abnormal in 25.3% individuals with normal spirometry. Individuals with obstructive spirometry had the highest risk of having abnormal FOT parameters (adjusted odds ratio [adj OR]:3.93, 95% confidence interval [CI]: 2.24-6.89). Breathlessness showed a significant association with abnormal R5 (adj OR: 1.81; 95% CI: 1.13-2.91) and obstructive spirometry (adj OR: 2.26; 95% CI: 1.29-3.95). CONCLUSIONS: Assessment of small airway functions along with spirometry are useful to identify complex lung function abnormalities in cases of toxic inhalation.

Oxidative biomarkers of exhaled breath condensate in adults exposed to traffic-related air pollution: a case-control study.

Traffic-related air pollution exposure (TRAP) is a major public health problem. The effects of TRAP exposure on the oxidative biomarkers of exhaled breath condensate (EBC) of adults are seldom studied. We compared the oxidative EBC biomarkers in a group of individuals exposed to TRAP with those of individuals unexposed to TRAP. We conducted a case-control study in Bhopal City (Madhya Pradesh, India). Adults with a history of exposure to TRAP were enrolled as cases and adults with less exposure to TRAP were used as a control. Based on respiratory symptoms and smoking habits, study subjects were stratified into six subgroups. EBC was collected by TURBO14 (Medivac SRL, Italy) at -5 °C. The EBC pH was measured after gas standardization with argon. EBC hydrogen peroxide (H2O2), cystenine leukotrienes (Cys-LTs), 8-isoprostane were measured by commercial ELISA kit. A total of 250 consecutive adult (male: 194) subjects were recruited. Among them, 133 were TRAP-exposed (male: 128) and 117 were non-TRAP-exposed (male: 66). The respiratory symptoms between TRAP-exposed and non-TRAP-exposed subjects were not different. The post-gas standardized EBC pH (median: 7.72; interquartile range (IQR): 7.15-7.94 vs. median: 7.60, IQR: 6.72-7.87;p= 0.09) and EBC H2O2(median: 2.20µmol l-1; IQR: 1.46-3.51 vs. median: 1.99, IQR: 1.41-3.10;p= 0.29) in TRAP-exposed subjects were statistically not different from the non-TRAP-exposed subjects. The EBC Cys-LTs (median: 69.81; IQR: 57.0-83.38 vs. median: 47.21 pg ml-1; IQR: 39.90-54.87,p< 0.001) and EBC 8-isoprostane (median: 12.55 pg ml-1; IQR: 5.51-18.09 vs. median: 7.12; IQR: 4.60-16.04,p= 0.026) in TRAP-exposed subjects were higher compared to those in non-TRAP-exposed subjects. The subgroup analysis showed that TRAP-exposed subjects, irrespective of their smoking habits and respiratory symptoms, had higher EBC Cys-LTs compared to the non-TRAP-exposed subjects. TRAP exposure increases oxidative biomarkers of the EBC in adults.

Elevated serum matrix metalloprotease (MMP-2) as a candidate biomarker for stable COPD.

BACKGROUND: The increasing trend of Chronic Obstructive Pulmonary Disease (COPD) in becoming the third leading cause of deaths by 2020 is of great concern, globally as well as in India. Dysregulation of protease/anti-protease balance in COPD has been reported to cause tissue destruction, inflammation and airway remodelling; which are peculiar characteristics of COPD. Therefore, it is imperative to explore various serum proteases involved in COPD pathogenesis, as candidate biomarkers. COPD and Asthma often have overlapping symptoms and therefore involvement of certain proteases in their pathogenesis would render accurate diagnosis of COPD to be difficult. METHODS: Serum samples from controls, COPD and Asthma patients were collected after requisite institutional ethics committee approvals. The preliminary analysis qualitatively and quantitatively analyzed various serum proteases by ELISA and mass spectrometry techniques. In order to identify a distinct biomarker of COPD, serum neutrophil elastase (NE) and matrix metalloprotease-2 (MMP-2) from COPD and Asthma patients were compared; as these proteases tend to have overlapping activities in both the diseases. A quantitative analysis of the reactive oxygen species (ROS) in the serum of controls and COPD patients was also performed. Statistical analysis for estimation of p-values was performed using unpaired t-test with 95% confidence interval. RESULTS: Amongst the significantly elevated proteases in COPD patients vs the controls- neutrophil elastase (NE) [P < 0.0241], caspase-7 [P < 0.0001] and matrix metalloprotease-2 (MMP-2) [P < 0.0001] were observed, along with increased levels of reactive oxygen species (ROS) [P < 0.0001]. The serum dipeptidyl peptidase-IV (DPP-IV) [P < 0.0010) concentration was found to be decreased in COPD patients as compared to controls. Interestingly, a distinct elevation of MMP-2 was observed only in COPD patients, but not in Asthma, as compared to controls. Mass spectrometry analysis further identified significant alterations (fold-change) in various proteases (carboxy peptidase, MMP-2 and human leukocyte elastase), anti-proteases (Preg. zone protein, α-2 macroglobulin, peptidase inhibitor) and signalling mediators (cytokine suppressor- SOCS-3). CONCLUSION: The preliminary study of various serum proteases in stable COPD patients distinctly identified elevated MMP-2 as a candidate biomarker for COPD, subject to its validation in large cohort studies.

Long-term ambient air pollution exposure and respiratory impedance in children: A cross-sectional study.

OBJECTIVES: The present study was aimed to compare the respiratory impedance of children residing in areas with different ambient air pollution (AAP). METHODS: A comparative cross-sectional pilot study was carried out in healthy school children of two cities in India i.e. Agra and Bhopal. Agra is one of the most polluted cities of India and AAP of Agra is much higher as compared to Bhopal, the reference city in the present study. The respiratory impedance was measured at 5, 11, and 19 Hz by forced oscillation technique (FOT). The anthropometric parameters, respiratory resistance at 5 Hz (R5), small airway resistance (R5-19), and reparatory reactance at 5 Hz (X5) of children from above two cities were compared by Student's t-test. RESULTS: A total 114 children (57 boys) from Agra and 151 children (76 boys) from Bhopal aged 9-16 years were recruited. The children from Agra were younger (11.9 ±â€¯1.9 yr vs. 13.1 ±â€¯2.2 yr, p < 0.001) as compared to Bhopal, though their anthropometric parameters were comparable. The magnitude of R5 (5.53 ±â€¯1.81 cmH20/L/s vs. 5.10 ±â€¯1.77 cmH20/L/s, p = 0.05), X5 (-1.46 ±â€¯0.65 cmH20/L/s vs. -1.17 ±â€¯0.63 cmH20/L/s, p < 0.001), and R5-19 (0.79 ±â€¯0.79 cmH20/L/s vs. 0.56 ±â€¯0.78 cmH20/L/s, p = 0.023) in children of Agra were higher as compared to children of Bhopal. The differences in impedance were significantly higher between boys, but not between girls. CONCLUSIONS: The present study demonstrates a higher magnitude of small airway dysfunction in children exposed to high AAP. A future study involving larger samples and longitudinal measurements of respiratory impedance will provide better insights.

Regression equations of respiratory impedance of Indian adults measured by forced oscillation technique.

BACKGROUND: Forced oscillation technique (FOT) is a technique to measure the mechanical properties of the lung. The present study was aimed to develop regression equations of within- and whole-breath respiratory impedance (Zrs) of healthy Indian adults. METHODS: Total 323 adults were sequentially screened. Smokers, individuals with respiratory symptoms or diseases, and unable to perform acceptable FOT were excluded. Within- and whole-breath resistance (Rrs) and reactance (Xrs) were measured at 5, 11, and 19 Hz by Resmon Pro® Full device. The regression equations of within- and whole-breath Rrs and Xrs were generated separately for men and women by multiple linear regression models. RESULTS: The FOT data of 253 individuals (122 men) aged 18-81 years were included in the analysis. The magnitudes of whole-breath Rrs at 5 Hz (4.53 ± 1.05 cmH2O/L/s in women vs. 3.26 ± 1.05 cmH2O/L/s in men; P = 0.000) and whole-breath Xrs at 5 Hz (-1.23 ± 0.66 cmH2O/L/s in women vs. -1.00 ± 0.54 cmH2O/L/s in men; P = 0.003) of women were significantly of higher magnitude as compared to men. The standing height was the best determinant of Zrs, followed by body weight; the effect of age was negligible and was observed in men only. The magnitudes of both Rrs and Xrs decrease with an increase in standing height of both men and women. CONCLUSIONS: The present study provides regression equations of within- and whole-breath respiratory impedance of Indian adults.

Regression Equations of Respiratory Impedance Measured by Forced Oscillation Technique for Indian Children.

OBJECTIVE: To develop regression equations of within and whole-breath respiratory impedance for Indian children aged 5 to 17 y. METHODS: A prospective cross-sectional study was carried out in 5 to 17 y old school children of Bhopal, India. Healthy children were identified by physical examination and by administering questionnaire. The respiratory system resistance (Rrs) and reactance (Xrs) were measured at frequency of 5, 11, and 19 Hz by forced oscillation technique (FOT). The regression equations of within and whole-breath Rrs and Xrs were developed separately for boys and girls by multiple linear regression models. RESULTS: Total 336 children were recruited and data of 320 healthy children (boys - 159), standing height of 146.1 ± 16.6 cm and body mass index of 17.2 ± 2.9 kg/m2 were included in the analysis. The mean respiratory system resistance at 5 Hz (R5) and respiratory system reactance at 5 Hz (X5) of the children, irrespective of gender were 5.46 ± 2.10 cmH2O/L/s and - 1.43 ± 0.85 cmH2O/L/s respectively. Boys of age 16 y and older had significantly smaller Rrs as compared to girls of corresponding age (p < 0.05). The standing height of children had the highest predictive power, followed by age in the regression model. With an increase in standing height, the magnitude of both Rrs and Xrs values of children decrease. The bodyweight of children had a negligible contribution to the regression models. CONCLUSIONS: The regression equations of within- and whole-breath Rrs and Xrs of Indian children aged 5 to 17 y are presented for the first time. The R5 values of Indian children were comparable to children of other ethnicities.

Respiratory Morbidity of Roadside Shopkeepers Exposed to Traffic-related Air Pollution in Bhopal, India.

BACKGROUND: Traffic-related air pollution (TRAP) is a major source of ambient air pollution in urban areas. Shopkeepers of heavily trafficked roadside shops are persistently exposed to high levels of TRAP. OBJECTIVES: To estimate the prevalence of respiratory morbidity in shopkeepers of shops in heavily trafficked roadside areas in Bhopal city (India) and to determine any association with long term exposure to TRAP. METHODS: This cross-sectional study was conducted among 251 shopkeepers working in roadside shops of three major traffic corridors in Bhopal city. The demographic profile and prevalence of respiratory morbidity were collected by administering a validated questionnaire. The total exposure period (TEP) to TRAP was calculated for each individual by multiplying their work duration (in years) and average working hours per day. Odds ratios were calculated to estimate the association of TEP with respiratory morbidity. RESULTS: The age of the study population was 44.8±13.5 years old and 95% were male. Nearly 55% of the shopkeepers reported at least one respiratory symptom. The prevalence of bronchial asthma, chronic bronchitis, breathlessness, and cough was 3.6% (95% confidence interval (CI): 1.9-6.7), 13.9% (95% CI: 10.2-18.8), 41.8% (95% CI: 35.9-48.0), and 18.3% (95% CI: 14.0-23.6), respectively. The adjusted risk ratios of bronchial asthma 2.17 (95% CI: 0.35-13.41), chronic bronchitis 1.42 (95% CI: 0.58-3.48), breathlessness 1.71 (95% CI: 0.94-3.11), and cough 0.97 (95% CI: 0.47-2.03) for those with a TEP over 100. CONCLUSIONS: Shopkeepers working in heavily trafficked roadside shops suffer from respiratory morbidity and the risk increases with higher TEP. Total exposure period is a valuable indicator to estimate the effects of long-term TRAP exposure. INFORMED CONSENT: Obtained. ETHICS APPROVAL: The study was approved by the Institutional Ethics Committee of the National Institute for Research in Environmental Health (Bhopal, India). COMPETING INTERESTS: The authors declare no competing financial interests.

Role of Proteases in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is generally associated with progressive destruction of airways and lung parenchyma. Various factors play an important role in the development and progression of COPD, like imbalance of proteases, environmental and genetic factors and oxidative stress. This review is specifically focused on the role of proteases and their imbalance in COPD. There are three classes (serine, mettalo, and cysteine) of proteases involved in COPD. In serine proteases, neutrophil elastase, cathepsin G, and proteinase-3 are involved in destruction of alveolar tissue. Matrix-mettaloproteinase-9, 12, 13, plays an influential role in severity of COPD. Among cysteine proteases, caspase-3, caspases-8 and caspase-9 play an important role in controlling apoptosis. These proteases activities can be regulated by inhibitors like α-1-antitrypsin, neutrophil elastase inhibitor, and leukocyte protease inhibitor. Studies suggest that neutrophil elastase may be a therapeutic target for COPD, and specific inhibitor against this enzyme has potential role to control the disease. Current study suggests that Dipeptidyl Peptidase IV is a potential marker for COPD. Since the expression of proteases and its inhibitors play an important role in COPD pathogenesis, therefore, it is worth investigating the role of proteases and their regulation. Understanding the biochemical basis of COPD pathogenesis using advanced tools in protease biochemistry and aiming toward translational research from bench-to-bedside will have great impact to deal with this health problem.

CD14 C-159T polymorphism and its association with chronic lung diseases: A pilot study on isocyanate exposed population of Central India.

CONTEXT: CD14 functions as a multifunctional receptor for bacterial cell wall components including endotoxin and lipopolysaccharide and is likely to influence the cytokine profile and subsequent immunoglobulin E production in response to antigen/allergen contact in allergic phenotypes. AIMS: The present study was to investigate genetic polymorphism in CD14 gene - 159C/T, which may be one of the risk factor for increased prevalence of Chronic Lung Diseases in the Central India. SETTINGS AND DESIGN: Survivors of Methyl isocyanates toxicity in Bhopal still suffering from various respiratory ailments were examined. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism was performed to determine the polymorphism of C-159T. RESULTS: The genotype and allelic frequencies were in Hardy-Weinberg's equilibrium. Prevalence of CC, CT, and TT were 5.5%, 22.2% and 9.25% respectively in asthmatics; 16.6%, 20.3% and 5.5% respectively in chronic obstructive pulmonary disease (COPD) patients and 5.5%, 14.8% and 1.85 respectively among interstitial lung disorder (ILD) patients; whereas the control cohort with no methyl isocyanate exposure displayed (CC, CT, and TT) cytosine, thymine as 2%, 1.6% and 2% respectively. Increased risk of Asthma among those carrying TT genotype and T allele (odds ratio [OR] =2.61 and 2.02 respectively). CONCLUSION: COPD risk significantly found among those with CC genotype and C allele (OR = 2.81 and 1.50 respectively), whereas ILD risk found significantly among CT genotype and C allele (OR = 1.75 and 1.40 respectively). Therefore, single nucleotide polymorphism (SNP) C-159T polymorphism in CD14 gene might be a risk factor for development of CLD in this population.

Annual change in spirometric parameters among patients affected in Bhopal gas disaster: A retrospective observational study.

BACKGROUND: The involvement of respiratory system due to inhalation of methyl isocyanate (MIC) during Bhopal gas disaster was particularly severe. We retrospectively evaluated the annual changes in spirometric parameters among those who were affected in this disaster (exposed survivors) and had respiratory symptoms. MATERIALS AND METHODS: Spirometry reports of exposed survivors that were carried out in our institution were retrospectively reviewed and we identified 252 subjects who had performed spirometry at least twice with interval of more than one year. The annual changes in spirometric indices of them were calculated. RESULTS: The average age of study population was 55.7 years and 72% were male. Annual decline of FEV1 ≥ 40 ml/yr was observed among 48% exposed survivors. The mean annual decline of FEV1 among symptomatic exposed survivors with initial normal spirometry was 91 ml (95% CI: 52 ml to 130 ml) and this was more than the patients with initial obstructive pattern. Among fifty four patients with initial normal spirometry, ten patients (18.5%) developed obstructive and two patients (5%) developed restrictive lung function abnormalities during follow up spirometry. CONCLUSION: The exposed survivors with chronic respiratory symptoms had accelerated decline in lung function and they are at higher risk of developing obstructive lung function.

An HIV1/2 point of care test on sputum for screening TB/HIV co-infection in Central India - Will it work?

OBJECTIVE: To determine whether the OraQuick® HIV-1/2 Assay (OraSure Technologies, Inc., Bethlehem, PA, USA) in sputum is a valid tool for HIV surveillance among TB patients. METHODS: A cross sectional study was carried out on sputa of patients diagnosed with tuberculosis. Sputa were tested for antibodies to HIV using OraQuick® HIV-1/2 Assay (OraSure Technologies, Inc., Bethlehem, PA, USA). The results were compared with results of serum ELISA. RESULTS: Compared to serum ELISA, the OraQuick® HIV-1/2 Assay in sputum specimens reported 90% sensitivity (9/10) and 100% specificity (307/307), with a positive predictive value of 100% (95%CI: 66.37%-100.00%) and a negative predictive value of 99.68% (95%CI: 98.20%-99.99%). CONCLUSIONS: This testing method may provide a useful strategy for conducting HIV surveillance in possible co-infected TB patients at peripheral centres. Since there is no investment on infrastructure, it may be possible for paramedical health professionals to carry out the test, particularly in areas with low HIV endemicity.

Subjective assessment of quality of sleep in chronic obstructive pulmonary disease patient and its relationship with associated depression.

BACKGROUND: The quality of sleep in chronic obstructive pulmonary disease (COPD) patient from India has not been studied. Aim of this study was evaluation of subjective assessment of sleep quality in stable COPD patients and its relationship with associated depression. MATERIALS AND METHODS: Forty clinically stable COPD patients were recruited from outpatient department and their disease status was classified as per Global Initiative for Chronic Obstructive Lung Disease guideline. Presence of depression was assessed by administering Patient Health Questionnaire (PHQ)-9 and subjective quality of sleep was measured by Pittsburgh Sleep Quality Index (PSQI). RESULTS: All study subjects were male and mean age of study population was 62.2 ± 9.2 years, 12 patients (30%) in stage II, 19 patients (47.5%) in stage III and 9 patients (22.5%) in stage IV were enrolled. All subjects had poor sleep quality with the median global Pittsburgh Sleep Quality Index score 11. PHQ-9 score was significantly correlated with daytime function and global PSQI score (P<0.01). No correlation of global PSQI score with severity of COPD was observed. CONCLUSION: The prevalence of poor sleep quality among COPD patients is high. Irrespective of severity of airflow obstruction, the presence of depression in COPD is a risk factor for poor sleep quality.