Chest CT for triage during COVID-19 on the emergency department: myth or truth?

PURPOSE: We aimed to investigate the diagnostic performance of chest CT compared with first RT-PCR results in adult patients suspected of COVID-19 infection in an ED setting. We also constructed a predictive machine learning model based on chest CT and additional data to improve the diagnostic accuracy of chest CT. METHODS: This study's cohort consisted of 319 patients who underwent chest CT and RT-PCR testing at the ED. Patient characteristics, demographics, symptoms, vital signs, laboratory tests, and chest CT results (CO-RADS) were collected. With first RT-PCR as reference standard, the diagnostic performance of chest CT using the CO-RADS score was assessed. Additionally, a predictive machine learning model was constructed using logistic regression. RESULTS: Chest CT, with first RT-PCR as a reference, had a sensitivity, specificity, PPV, and NPV of 90.2%, 88.2%, 84.5%, and 92.7%, respectively. The prediction model with CO-RADS, ferritin, leucocyte count, CK, days of complaints, and diarrhea as predictors had a sensitivity, specificity, PPV, and NPV of 89.3%, 93.4%, 90.8%, and 92.3%, respectively. CONCLUSION: Chest CT, using the CO-RADS scoring system, is a sensitive and specific method that can aid in the diagnosis of COVID-19, especially if RT-PCR tests are scarce during an outbreak. Combining a predictive machine learning model could further improve the accuracy of diagnostic chest CT for COVID-19. Further candidate predictors should be analyzed to improve our model. However, RT-PCR should remain the primary standard of testing as up to 9% of RT-PCR positive patients are not diagnosed by chest CT or our machine learning model.

Guideline adherence of mediastinal staging of non-small cell lung cancer: A multicentre retrospective analysis.

OBJECTIVES: Mediastinal lymph node staging of NSCLC by initial endosonography and confirmatory mediastinoscopy is recommended by the European guideline. We assessed guideline adherence on mediastinal staging, whether staging procedures were performed systematically and unforeseen N2 rates following staging by endosonography with or without confirmatory mediastinoscopy. MATERIAL AND METHODS: We performed a multicentre (n = 6) retrospective analysis of NSCLC patients without distant metastases, who were surgical candidates and had an indication for mediastinal staging in the year 2015. All patients who underwent EBUS, EUS and/or mediastinoscopy were included. Surgical lymph node dissection was the reference standard. Guideline adherence was based on the 2014 ESTS guideline. RESULTS: 330 consecutive patients (mean age 69 years; 61% male) were included. The overall prevalence of N2/N3 disease was 42%. Initial mediastinal staging by endosonography was done in 84% (277/330; range among centres 71-100%; p < .01). Confirmatory mediastinoscopy was performed in 40% of patients with tumour negative endosonography (61/154; range among centres 10%-73%; p < .01). Endosonography procedures were performed 'systematically' in 21% of patients (57/277) with significant variability among centres (range 0-56%; p < .01). Unforeseen N2 rates after lobe-specific lymph node dissection were 8.6% (3/35; 95%-CI 3.0-22.4) after negative endosonography versus 7.5% (3/40; 95% CI 2.6-19.9) after negative endosonography and confirmatory mediastinoscopy. CONCLUSION: Although adherence to the European NSCLC mediastinal staging guideline on initial use of endosonography was good, 30% of endosonography procedures were performed insufficiently. Confirmatory mediastinoscopy following negative endosonography was frequently omitted. Significant variability was found among participating centres regarding staging strategy and systematic performance of procedures. However, unforeseen N2 rates after mediastinal staging by endosonography with and without confirmatory mediastinoscopy were comparable.

T helper 17 cells are involved in the local and systemic inflammatory response in community-acquired pneumonia.

BACKGROUND: Recent findings in mouse models suggest that T helper (Th)17 cells, characterised by production of interleukin (IL)-17A and IL-22, are involved in the immunopathogenesis of pneumonia. OBJECTIVE: In this study, we aimed to identify the involvement of Th17 cells in human community-acquired pneumonia (CAP). DESIGN: Within 24 h of admission, T cells from peripheral blood (n=39) and bronchoalveolar lavage (BAL, n=20) of CAP patients and of 10 healthy individuals were analysed by intracellular flow cytometry for the production of various cytokines, including IL-17A and IL-22. Peripheral blood T cells were also analysed 7 and 30 days after admission. Th17 cytokine profiles were correlated with pneumonia severity index and microbial aetiology. RESULTS: In the BAL of CAP patients, proportions of IL-17A and IL-22 single positive, as well as IL-17A/IL-22 double positive CD4 T cells were significantly increased compared with healthy individuals. Significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells in BAL were found in non-severe and severe CAP patients, as well as in pneumococcal and non-pneumococcal CAP. In the peripheral blood of CAP patients upon admission, we found significantly increased proportions of IL-17A/IL-22 double positive CD4 T cells. One week after admission, the proportions of these double positive cells were still significantly increased in CAP patients compared with healthy individuals. CONCLUSIONS: These data indicate that Th17 cells are engaged in the local and systemic immune response in human pneumonia. Especially, IL-17A/IL-22 double positive Th17 cells may be involved in the immunopathogenesis of CAP.

Local and systemic cytokine profiles in nonsevere and severe community-acquired pneumonia.

Local inflammatory responses in community-acquired pneumonia (CAP) remain insufficiently elucidated, especially in patients with nonsevere CAP. In this study we determined local and systemic cytokine responses in CAP patients and correlated these with disease severity and other clinical parameters. Levels of interleukin (IL)-6, IL-8, IL-10, IL-1ß, tumour necrosis factor-α, interferon (IFN)-γ, IL-22, IL-17A and IL-4 were determined in bronchoalveolar lavage fluid and serum of 20 CAP patients upon admission and 10 healthy individuals. Systemic cytokine levels were also measured on days 7 and 30. In bronchoalveolar lavage fluid of CAP patients, levels of IL-6, IL-8 and IFN-γ were significantly increased compared with healthy individuals, but no correlations with disease severity were found. Systemic levels of IL-6, IL-10 and IFN-γ were significantly higher in severe CAP patients than in nonsevere CAP patients and healthy individuals. Moreover, these cytokines showed a significant correlation with the pneumonia severity index. In the total group of CAP patients, systemic IL-8 and IL-22 levels were also increased compared with healthy individuals. We therefore conclude that IL-6, IL-10 and IFN-γ are important cytokines in CAP, although differences in disease severity upon admission are only reflected by systemic levels of these cytokines.

Molecular diagnostics of a single multifocal non-small cell lung cancer case using targeted next generation sequencing.

Histological and molecular subtyping of non-small cell lung cancer (NSCLC) is important for predicting survival and drug response in these patients. Up to 8 % of NSCLC are multifocal and these tumor foci are often clonally related. Multiple foci can however also represent different primary tumors, with prognostic and therapeutic consequences. We describe a patient with multifocal NSCLC from which we obtained tissue from two separate lesions. With routine conventional molecular determinations, the clonal relationship between the two lesions was determined. In addition, targeted next generation sequencing with the Ion Torrent Personal Genome Machine (PGM) was performed to explore the accuracy and additional value of this relatively new technique. The two tumors of this patient showed different activating epidermal growth factor receptor (EGFR) mutations, EGFR amplification status, TP53 mutation status, and loss of heterozygosity patterns. With the PGM, all conventional detected mutations were confirmed, and an additional variant of unknown significance in ATM was detected in one of the tumors. The multifocal NSCLC of this patient represents two unrelated primary tumors. Our results suggest that multifocal NSCLC should be considered as potentially multiple primary tumors. As the presence of activating EGFR mutations has important therapeutic consequences, EGFR testing should be performed on all tumor foci present. In the present case, targeted next generation sequencing using the PGM appeared to be accurate and comparable with conventional molecular determinations. However, the application of the PGM in routine pathology molecular diagnostics needs validation in larger series of cases.