Use of the Archimedes navigation system to diagnose peripheral pulmonary lesions: preliminary Italian results.

Diagnosis of peripheral pulmonary lesions (PPL) is one of the most challenging fields in early lung cancer diagnosis. Despite novel techniques and new approaches to the periphery of the lung, almost 25% of PPL remains undiagnosed. Virtual bronchoscopy navigation (VBN) potentially allows to sample PPL previously not reachable with conventional bronchoscopy. In this preliminary report, we described nine cases of PPL (in which conventional bronchoscopy did not reach the lesion) sampled with VBN, from which we obtained a diagnosis in seven out of nine cases (77.8%), consistent with other reported results in literature. More large-scale data are needed to whether VBN can increase diagnostic yield (DY) of PPL.

Accuracy and Predictors of Success of EUS-B-FNA in the Diagnosis of Pulmonary Malignant Lesions: A Prospective Multicenter Italian Study.

BACKGROUND: The role of endoscopic ultrasound with bronchoscope fine-needle aspiration (EUS-B-FNA) in the diagnosis of suspected malignant pulmonary lesions adjacent to the esophagus has been poorly investigated. The aim of the present study was to assess the accuracy of EUS-B-FNA for the diagnosis and molecular profiling of paraesophageal pulmonary lesions, as well as its predictors of success. MATERIALS AND METHODS: Patients who underwent EUS-B-FNA for the diagnosis of paraesophageal lesions were consecutively enrolled in four Italian centers. Demographic, clinical, procedural, pathological, and molecular characteristics of the malignant samples were collected. The primary outcome was the diagnostic accuracy for pulmonary malignancies. Secondary outcomes were diagnostic yield and predictors of success for diagnosis and molecular profiling. RESULTS: 107 adult patients (60 [56.1%] males; median (interquartile range) age: 69 [60-70] years) were enrolled. The diagnostic accuracy of EUS-B-FNA was 95.3% in the overall cohort and 95.2% in the 99 patients with a final diagnosis of malignancy. Neither clinical nor procedural variables significantly affected the diagnostic accuracy, whereas rapid on-site evaluation (ROSE), performed by pathologists or trained pulmonologists, was a strong predictor for a complete molecular profiling (OR [95% CI]: 12.9 [1.2-137.4]; p value: 0.03). CONCLUSION: EUS-B-FNA is a safe and accurate method for the diagnosis of paraesophageal pulmonary lesions. The presence of ROSE is relevant for a complete molecular profiling in this selected cohort of patients with advanced lung cancer.

Statistical approach to mediastinal staging in NSCLC with M.E.S.S.i.a. software.

The exclusion of pathological involvement of mediastinal lymph nodes in patients affected by NSCLC plays a central role in assessing  their prognosis and operability. Ceron et al. developed a software - called M.E.S.S.i.a (Mediastinal Evaluation with Statistical Support; instan approach) - that allows the calculation of the residual probability of lymph node involvement after a certain number of tests has been done, by integrating every test result with the pre-test prevalence. M.E.S.S.i.a. bridges a gap of current American College of Chest Physicians (ACCP) guidelines, providing probability values of mediastinal metastasis for a correct clinical decision. We conducted a preliminary retrospective study in a series of 108 patients affected by non small cell lung cancer (NSCLC). Pathological staging was compared to the probability of nodal involvement calculated by M.E.S.S.i.a. software. Forty-two out of 108 subjects (39%) had a calculated post-test probability <8%; none of these had proven N2/N3 metastasis at surgical staging (negative predictive value, NPV: 100%). In 12/41 cases M.E.S.S.i.a. was able to avoid invasive procedures. The remaining 66 (61%) patients did not reach the surgical threshold; among these, 11 displayed N2 positivity at pathological staging. Receiving operator curve (ROC) analysis produced an area under curve (AUC) value of  0.773 (p<0.001). These preliminary data show high accuracy of M.E.S.S.i.a. software in excluding N2/N3 lymph node involvement in NSCLC. We have therefore promoted a prospective multicenter study in order to to get a validation of the calculator at different levels of probability of lymph node involvement. The recruitable subjects are potentially operable NSCLC patients; the gold standard for detection of mediastinal disease is the surgical lymph node dissection.

Competence in flexible bronchoscopy and basic biopsy technique.

Diagnostic bronchoscopy and tissue sampling techniques using forceps (endobronchial biopsy [EBB] and transbronchial biopsies [TBB]) or needle aspiration (transbronchial needle aspiration-TBNA), all performed with a flexible bronchoscope, are the basic elements of any interventional procedure. The flexible fibrobronchoscopy allows the visualization of the airways and is used both for diagnostic and therapeutic purposes. The working channel of both fibrobronchoscopes with optical fibers and videobronchoscopes, even if of relatively small diameter, allows the insertion of various diagnostic and therapeutic accessories. Fiber optic systems have been widely replaced by video cameras using a miniaturized charge-coupled device camera positioned at the end of the scope that provides electronic transmission of images to a monitor. The indications for both diagnostic and therapeutic fibrobronchoscopy derive from a correct evaluation of symptoms and objective signs of the patient and from the correct interpretation of imaging methods. Although bronchoscopy techniques keep evolving at a rapid pace, basic procedures such as bronchoalveolar lavage, transbronchial lung biopsy, and transbronchial needle aspiration still play a key role in pulmonary disease diagnostics, and therefore, these methods must still be part of the training of interventional pulmonologists. Trainees will acquire a thorough knowledge of thoracic anatomy and become skilled in the interpretation of thoracic imaging, after which they will be given a theoretical and practical training course on virtual reality simulators, on animal or cadaver models, the effectiveness of which has been fully demonstrated by scientific studies. Specific DOPS tests have been developed for a qualitative evaluation of procedures on simulators, on animal models and on the patient.

Competence in navigation and guided transbronchial biopsy for peripheral pulmonary lesions.

Options for non-surgical tissue diagnosis of the peripheral nodule include CT scan-guided TTNA, fluoroscopy-guided bronchoscopy, radial endobronchial ultrasound (EBUS), electromagnetic navigation bronchoscopy (ENB), and virtual bronchoscopy navigation (VBN). For physicians who choose to pursue non-surgical biopsy, the decision to perform CT scan-guided or ultrasound-guided TTNA, conventional bronchoscopy or bronchoscopy guided by EBUS, ENB, or VBN will depend on a number of factors. CT scan-guided TTNA is preferable for nodules located near the chest wall or for deeper lesions, provided that there is no need to go through the fissures and there is no surrounding emphysema. Ultrasound-guided TTNA requires contact between the lesion and the costal pleura. Bronchoscopic techniques are preferable for nodules ≥2 cm located near a patent bronchus, or in individuals at high risk for pneumothorax following TTNA. In most other situations, operator experience should guide the decision. Trainees must possess a perfect knowledge of anatomy and be fully competent in the interpretation of imaging (CT with contrast medium and PET) and have a thorough knowledge of navigation technology in all its complexities. Practical training can be performed on animal, cadaver or plastic models. In the last years, to improve diagnostic yield, navigational bronchoscopy has attracted significant attention.

Multicentre external validation of the BIMC model for solid solitary pulmonary nodule malignancy prediction.

OBJECTIVES: To provide multicentre external validation of the Bayesian Inference Malignancy Calculator (BIMC) model by assessing diagnostic accuracy in a cohort of solitary pulmonary nodules (SPNs) collected in a clinic-based setting. To assess model impact on SPN decision analysis and to compare findings with those obtained via the Mayo Clinic model. METHODS: Clinical and imaging data were retrospectively collected from 200 patients from three centres. Accuracy was assessed by means of receiver-operating characteristic (ROC) areas under the curve (AUCs). Decision analysis was performed by adopting both the American College of Chest Physicians (ACCP) and the British Thoracic Society (BTS) risk thresholds. RESULTS: ROC analysis showed an AUC of 0.880 (95 % CI, 0.832-0.928) for the BIMC model and of 0.604 (95 % CI, 0.524-0.683) for the Mayo Clinic model. Difference was 0.276 (95 % CI, 0.190-0.363, P < 0.0001). Decision analysis showed a slightly reduced number of false-negative and false-positive results when using ACCP risk thresholds. CONCLUSIONS: The BIMC model proved to be an accurate tool when characterising SPNs. In a clinical setting it can distinguish malignancies from benign nodules with minimal errors by adopting current ACCP or BTS risk thresholds and guiding lesion-tailored diagnostic and interventional procedures during the work-up. KEY POINTS: • The BIMC model can accurately discriminate malignancies in the clinical setting • The BIMC model showed ROC AUC of 0.880 in this multicentre study • The BIMC model compares favourably with the Mayo Clinic model.

Pneumomediastinum after transbronchial lung biopsy.

Pneumomediastinum is a rare complication of a transbronchial lung biopsy. Common symptoms are chest pain, dyspnea, dysphagia, and specific electrocardiographic changes. We report a case of pneumomediastinum after a transbronchial lung biopsy. During the in-hospital stay, the symptoms and clinical picture rapidly improved without invasive treatment; therefore, the patient could be discharged after a few days. Approximately 1 month later, chest computed tomography was performed, which showed a complete resolution of the pneumomediastinum.

Polypeptide substrate recognition by calnexin requires specific conformations of the calnexin protein.

Calnexin is an endoplasmic reticulum chaperone that binds to substrates containing monoglucosylated oligosaccharides. Whether calnexin can also directly recognize polypeptide components of substrates is controversial. We found that calnexin displayed significant conformational lability for a chaperone and that heat treatment and calcium depletion induced the formation of calnexin dimers and higher order oligomers. These conditions enhanced the chaperone activity of calnexin toward glycosylated and non-glycosylated major histocompatibility complex (MHC) class I heavy chains, and enhanced calnexin binding to MHC class I heavy chains. In contrast to these observations, calnexin binding to oligosaccharide substrates has been reported to be impaired under calcium-depleting conditions. Calnexin dimers were induced in HeLa cells upon heat shock and under calcium-depleting conditions, and heat shock enhanced calnexin binding to MHC class I heavy chains in HeLa cells. Virus-induced endoplasmic reticulum stress also resulted in the appearance of calnexin dimers. Tunicamycin treatment of HeLa cells induced a slow accumulation of calnexin dimers, the appearance of which correlated with enhanced calnexin binding to deglycosylated MHC class I heavy chains. In vitro, the presence of calnexin-specific oligosaccharides inhibited the formation of calnexin dimers and higher order structures. Together, these data indicate that polypeptide binding is favored by conditions that induce partial unfolding of calnexin monomers, whereas oligosaccharide binding is favored by conditions that enhance the structural stability (folding) of calnexin monomers. Conditions that induce the calnexin "polypeptide-binding" conformation also induce self-association of calnexin if the concentration is sufficiently high; however, calnexin dimerization/oligomerization per se is not essential for polypeptide substrate binding.

A polypeptide binding conformation of calreticulin is induced by heat shock, calcium depletion, or by deletion of the C-terminal acidic region.

It is widely believed that the chaperone activity of calreticulin is mediated by its ability to bind glycoproteins containing monoglucosylated oligosaccharides. However, calreticulin is also a polypeptide binding protein. Here we show that heat shock, calcium depletion, or deletion of the C-terminal acidic domain enhance binding of purified calreticulin to polypeptide substrates and enhance calreticulin's chaperone activity. These conditions also enhance calreticulin oligomerization, but oligomerization per se is not required for enhanced polypeptide binding. In cells, calreticulin oligomerization intermediates accumulate in response to conditions that induce protein misfolding (heat shock and tunicamycin treatments), and upon calcium depletion. Additionally, in cells, calreticulin binds to deglycosylated major histocompatibility complex class I heavy chains when significant levels of calreticulin oligomerization intermediates are induced. Thus, cell stress conditions that generate nonnative substrates of calreticulin also affect the conformational properties of calreticulin itself, and enhance its binding to substrates, independent of substrate glucosylation.

Calreticulin recognizes misfolded HLA-A2 heavy chains.

Our studies investigated functional interactions between calreticulin, an endoplasmic reticulum chaperone, and major histocompatibility complex (MHC) class I molecules. Using in vitro thermal aggregation assays, we established that calreticulin can inhibit heat-induced aggregation of soluble, peptide-deficient HLA-A2 purified from supernatants of insect cells. The presence of HLA-A2-specific peptides also inhibits heat-induced aggregation. Inhibition of heat-induced aggregation of peptide-deficient HLA-A2 by calreticulin correlates with a rescue of the HLA-A2 heavy chain from precipitation, by forming high-molecular-weight complexes with calreticulin. Complex formation between HLA-A2 heavy chains and calreticulin occurs at 50 degrees C but not 37 degrees C, suggesting polypeptide-based interactions between the HLA-A2 heavy chain and calreticulin. Once complexes are formed, the addition of peptide is not sufficient to trigger efficient assembly of heavy chain/beta2m/peptide complexes. Using a fluorescent peptide-based binding assay, we show that calreticulin does not enhance peptide binding by HLA-A2 at 37 degrees C. We also show that calreticulin itself is converted to oligomeric species on exposure to 37 degrees C or higher temperatures, and that oligomeric forms of calreticulin are active in inhibiting thermal aggregation of peptide-deficient HLA-A2. Taken together, these results suggest that calreticulin functions in the recognition of misfolded MHC class I heavy chains in the endoplasmic reticulum. However, in the absence of other endoplasmic reticulum components, calreticulin by itself does not enhance the assembly of misfolded MHC class I heavy chains with beta2m and peptides.