Acute cellular rejection (ACR) in lung transplant recipients requires demonstration of perivascular lymphocytic infiltration in alveolar tissue samples from transbronchial biopsies (TBBs). Probe-based confocal laser endomicroscopy (pCLE) allows in vivo observation of alveolar, vascular, and cellular microstructures in the lung with potential to identify ACR. The objective of our prospective, blinded, multicenter observational study was to identify pCLE findings in patients with ACR diagnosed histopathologically by TBB.
Lung transplant recipients undergoing diagnostic bronchoscopies within 1 year posttransplant for suspected ACR had pCLE video imaging obtained immediately prior to tissue sampling via TBB. Findings of 2 pCLE criteria, abundant alveolar cellularity and perivascular cellularity (PVC), were assessed by 4 investigators familiar with pCLE and compared to histopathologic criteria of ACR to derive sensitivity, specificity, area under the receiver operating characteristic curve, and accuracy. Interobserver agreement was assessed by calculating intraclass coefficient and Fleiss κ. Findings were analyzed before and after a consensus meeting of investigators on interpreting images.
Thirty pCLE procedures were performed on 24 patients, 8 showing ACR in TBB. Diagnostic performance and interobserver agreement using pCLE to identify PVC were significantly higher than those of abundant alveolar cellularity (P<.01). The number of blood vessels identified with PVC on pCLE was significantly correlated with histopathologic activity grading of ACR (P<.01). PVC agreement among investigators significantly improved after consensus meeting (P<.01)
When found on pCLE, PVC is a feasible and reproducible criterion for assessment of ACR in vivo, but there is a learning curve for image interpretation.
Department of Transplantation (Dr Keller) and Department of Laboratory Medicine & Pathology (Dr Khoor), Mayo Clinic, Jacksonville, Florida; Pulmonary Diseases and Critical Care Medicine Department (Dr Arenberg), University of Michigan, Ann Arbor, Michigan; Norton Thoracic Institute (Dr Smith), Saint Joseph’s Hospital and Medical Center, Phoenix, Arizona; and Interventional Pulmonology, Division of Pulmonary, Critical Care and Sleep (Dr Islam), The Ohio State University, Columbus, Ohio.
Reprints: Cesar A. Keller, MD, Lung Transplant Program, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 (email@example.com Phone: 904-956-3271 Fax: 904-956-3262
Presented at the American Thoracic Society 2017 International Conference on May 2017, in Washington DC.
Portions of this manuscript have been published in abstract form: Keller C, Arenberg DA, Smith M, Islam S. Probe-Based Confocal Laser Endomicroscopy in the Diagnosis of Acute Lung Rejection: Results of a Prospective Multicenter Trial. Am J Respir Crit Care Med. 2017;195:A7640
Author contributions: Dr. Keller contributed to conception and design; experiments; collection, analysis, and interpretation of the data; generation/collection of the figures and tables; and writing and critical revision of the article. Dr. Khoor contributed to analysis and interpretation of the data and critical revision of the article. Dr. Arenberg contributed to conception and design; experiments; collection, analysis, and interpretation of the data; collection of the images; and critical revision of the article. Dr. Smith contributed to conception and design; experiments; collection, analysis, and interpretation of the data; collection of the images; and critical revision of the article. Dr. Islam contributed to conception and design; experiments; collection, analysis, and interpretation of the data; collection of the images; and critical revision of the article.
Disclosures: None of the authors have disclosures pertaining to this study. Unrelated to the study, Dr. Smith serves as a VATS lobectomy course instructor for Ethicon Endosurgery, for which they contribute $1500 to Norton Thoracic Institute.
Funding: Mauna Kea Technologies, Paris, France