A Rapid Antigen Detection Test to Diagnose SARS-CoV-2 Infection Using Exhaled Breath Condensate by A Modified Inflammacheck® Device.

BACKGROUND: The standard test that identifies the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is based on reverse transcriptase-polymerase chain reaction (RT-PCR) from nasopharyngeal (NP) swab specimens. We compared the accuracy of a rapid antigen detection test using exhaled breath condensate by a modified Inflammacheck® device with the standard RT-PCR to diagnose SARS-CoV-2 infection. METHODS: We performed a manufacturer-independent, cross-sectional, diagnostic accuracy study involving two Italian hospitals. Sensitivity, specificity, positive (PLR) and negative likelihood ratio (NLR), positive (PPV) and negative predictive value (NPV) and diagnostic accuracy with 95% confidence intervals (95% CI) of Inflammacheck® were calculated using the RT-PCR results as the standard. Further RT-PCR tests were conducted on NP specimens from test positive subjects to obtain the Ct (cycle threshold) values as indicative evidence of the viral load. RESULTS: A total of 105 individuals (41 females, 39.0%; 64 males, 61.0%; mean age: 58.4 years) were included in the final analysis, with the RT-PCR being positive in 13 (12.4%) and negative in 92 (87.6%). The agreement between the two methods was 98.1%, with a Cohen's κ score of 0.91 (95% CI: 0.79-1.00). The overall sensitivity and specificity of the Inflammacheck® were 92.3% (95% CI: 64.0%-99.8%) and 98.9% (95% CI: 94.1%-100%), respectively, with a PLR of 84.9 (95% CI: 12.0-600.3) and a NLR of 0.08 (95% CI: 0.01-0.51). Considering a 12.4% disease prevalence in the study cohort, the PPV was 92.3% (95% CI: 62.9%-98.8%) and the NPV was 98.9% (95% CI: 93.3%-99.8%), with an overall accuracy of 98.1% (95% CI: 93.3%-99.8%). The Fagan's nomogram substantially confirmed the clinical applicability of the test in a realistic scenario with a pre-test probability set at 4%. Ct values obtained for the positive test subjects by means of the RT-PCR were normally distributed between 26 and 38 cycles, corresponding to viral loads from light (38 cycles) to high (26 cycles). The single false negative record had a Ct value of 33, which was close to the mean of the cohort (32.5 cycles). CONCLUSIONS: The modified Inflammacheck® device may be a rapid, non-demanding and cost-effective method for SARS-CoV-2 detection. This device may be used for routine practice in different healthcare settings (community, hospital, rehabilitation).

Exercise related ventilation dynamics and clinical correlates in patients with fibrotic idiopathic interstitial pneumonias.

Assessment of exercise performance is a key component in the management of interstitial lung diseases, as its limitation may occur very early. Aim of the present study was to assess ventilation dynamics in combination with pulse-oximetry changes in 54 clinically stable patients affected by idiopathic pulmonary fibrosis or idiopathic fibrotic nonspecific interstitial pneumonia. Testing was successfully performed with the Spiropalm 6-MWT Hand-held spirometer by the majority of cases (94%). End test oxygen saturation (SpO2) values <88% were common in most of patients (76%), with a mean distance walked of 403 meters. Ventilation significantly increased due to the contribution of the tidal volume and the respiratory frequency (RF). This finding was associated with a decrease of the end of test respiratory reserve (RR), that was <20% in 9 cases (17.6%). Lung function was inversely related to the end of test RF, while a positive correlation occurred with the end of test RR and the estimated maximal voluntary ventilation (MVV). RR was also a predictive factor of declining forced vital capacity and lung diffusion capacity for carbon monoxide (DLCO) over a 6-month period. Further factors of DLCO impairment were low SpO2 and MVV. Comparison with the cardio-pulmonary exercise test (CPET) showed that the 6-MWT end of test RR was inversely related to the CPET-derived peak RF and VE/VCO2 suggesting RR as pivotal in exercise limitation assessment. Our results open challenging perspectives in an unexplored field. Future research will include management of latent respiratory failure and monitoring of disease progression and therapy response.

High-intensity training and cardiopulmonary exercise testing in patients with chronic obstructive pulmonary disease and non-small-cell lung cancer undergoing lobectomy.

OBJECTIVES: Peak VO2, as measure of physical performance is central to a correct preoperative evaluation in patients with both non-small-cell lung cancer (NSCLC) and chronic obstructive pulmonary disease (COPD) because it is closely related both to operability criteria and the rate of postoperative complications. Strategies to improve peak VO2, as a preoperative pulmonary rehabilitation programme (PRP), should be considered favourably in these patients. In order to clarify the role of pulmonary rehabilitation, we have evaluated the effects of 3-week preoperative high-intensity training on physical performance and respiratory function in a group of patients with both NSCLC and COPD who underwent lobectomy. METHODS: We studied 40 patients with both NSCLC and COPD, age < 75 years, TNM stages I-II, who underwent lobectomy. Patients were randomly divided into two groups (R and S): Group R underwent an intensive preoperative PRP, while Group S underwent only lobectomy. We evaluated peak VO2 in all patients at Time 0 (T0), after PRP/before surgery in Group R/S (T1) and 60 days after surgery, respectively, in both groups (T2). RESULTS: There was no difference between groups in peak VO2 at T0, while a significant difference was observed both at T1 and T2. In Group R, peak VO2 improves significantly from T0 to T1: 14.9 ± 2.3-17.8 ± 2.1 ml/kg/min ± standard deviation (SD), P < 0.001 (64.5 ± 16.5-76.1 ± 14.9% predicted ± SD, P < 0.05) and deteriorates from T1 to T2: 17.8 ± 2.1-15.1 ± 2.4, P < 0.001 (76.1 ± 14.9-64.6 ± 15.5, P < 0.05), reverting to a similar value to that at T0, while in Group S peak VO2 did not change from T0 to T1 and significantly deteriorates from T1 to T2: 14.5 ± 1.2-11.4 ± 1.2 ml/kg/min ± SD, P < 0.00001 (60.6 ± 8.4-47.4 ± 6.9% predicted ± SD, P < 0.00001). CONCLUSIONS: PRP was a valid preoperative strategy to improve physical performance in patients with both NSCLC and COPD and this advantage was also maintained after surgery.