Real-time and non-invasive acute lung rejection diagnosis using confocal LASER Endomicroscopy in lung transplant recipients: Results from the CELTICS study

BACKGROUND AND OBJECTIVE

Traditionally, the diagnosis of acute rejection (AR) relies on invasive transbronchial biopsies (TBBs) to obtain histopathological samples. We aimed to evaluate the diagnostic yield of probe-based confocal laser endomicroscopy (pCLE) as a complementary and non-invasive tool for ACR screening, comparing its results with those obtained from TBBs.

METHODS

Between January 2015 and April 2022, we conducted a retrospective study of all lung transplant recipients aged over 18 years at Toulouse University Hospital (France). All patients who underwent bronchoscopies with both TBBs and pCLE imaging were included. Two experienced interpreters (TV and MS) reviewed the pCLE images independently, blinded to all clinical information and pathology results.

RESULTS

From 120 procedures in 85 patients, 34 abnormal histological samples were identified. Probe-based confocal laser endomicroscopy revealed significant associations between both alveolar (ALC) and perivascular (PVC) cellularities and abnormal histological samples (p<0.0001 and 0.003 respectively). Alveolar cellularity demonstrated a sensitivity (Se) of 85.3 %, specificity (Spe) of 43 %, positive predictive value (PPV) of 37.2 % and negative predictive value (NPV) of 88.1 %. For PVC, Se was 70.6 %, Spe 80.2 %, PPV 58.5 % and NPV 87.3 %. Intra-interpreter correlation (TV) was 88.3 % for the number of vessels (+/-1), 98.3 % for ALC and 90 % for PVC. Inter-interpreter correlation (TV and MS) was 80 % for vessels (+/-1), 97.5 % for ALC and 83.3 % for PVC.

CONCLUSION

Our study demonstrates the feasibility of incorporating pCLE into clinical practice, demonstrating good diagnostic yield and reproducible outcomes in the screening of AR in lung transplant recipients.

[Bronchoscopic management of malignant central airway obstructions]

Up to 30% of lung cancer patients suffer from central airway obstruction, resulting in major deterioration in prognosis and quality of life. Interventional bronchoscopy combines a number of invasive techniques used during rigid bronchoscopy. It is designed to rapidly improve symptoms, primarily dyspnea. Applied according to very precise indications, this technique requires careful patient selection and needs to be incorporated into the multimodal oncological management in combination with systemic treatments, radiation therapy and surgery.

[Bronchial thermoplasty for severe asthma]

Bronchial thermoplasty has been developed over the past fifteen years and is the first endoscopic technique approved in the management of severe asthma. This procedure uses radiofrequency applied to the airway wall to target bronchial smooth muscle. Patients treated in randomized controlled trials have experienced significant decreases in the use of rescue medications, urgent care visits, and exacerbations rate. The lack of reliable predictive markers of response to this expensive, minimally-invasive technique currently makes it a last-line treatment option. We review the principles and supposed mechanisms of action of this treatment, the results from the main trials and clinical registry data and discuss the place of bronchial thermoplasty in the current management of severe asthma. We also discuss perspectives to better characterize the mechanisms of action and identify the responder phenotype, the main challenge of current studies.