Head-to-Head Comparison between Xpert MTB/RIF Assay and Real-Time Polymerase Chain Reaction Assay Using Bronchial Washing Specimens for Tuberculosis Diagnosis.

BACKGROUND: With the introduction of Xpert MTB/RIF assay (Xpert), its incorporation into tuberculosis (TB) diagnostic algorithm has become an important issue. The aim of this study was to evaluate the performance of the Xpert assay in comparison with a commercial polymerase chain reaction (PCR) assay. METHODS: Medical records of patients having results of both Xpert and AdvanSure TB/NTM real-time PCR (AdvanSure) assays using the same bronchial washing specimens were retrospectively reviewed. RESULTS: Of the 1,297 patients included in this study, 205 (15.8%) were diagnosed with pulmonary TB. Using mycobacterial culture as the reference method, sensitivity of the Xpert assay using smear-positive specimens was 97.5%, which was comparable to that of the AdvanSure assay (96.3%, p=0.193). However, the sensitivity of the Xpert assay using smear-negative specimens was 70.6%, which was significantly higher than that of the AdvanSure assay (52.9%, p=0.018). Usng phenotypic drug susceptibility testing as the reference method, sensitivity and specificity for detecting rifampicin resistance were 100% and 99.1%, respectively. Moreover, a median turnaround time of the Xpert assay was 1 day, which was significantly shorter than 3 days of the AdvanSure assay (p<0.001). CONCLUSION: In comparison with the AdvanSure assay, the Xpert assay had a higher sensitivity using smear-negative specimens, a shorter turnaround time, and could reliably predict rifampin resistance. Therefore, the Xpert assay might be preferentially recommended over TB-PCR in Korean TB diagnostic algorithm.

Successful lung transplantation after prone positioning in an ineligible donor: a case report.

Atelectasis is a reversible factor in hypoxemia among brain-dead donors. In ineligible donors, prone positioning reverses atelectasis and improves oxygenation. We present a successful lung transplantation after salvaging a previously unviable lung. A 37-year-old woman presented with acute pontine hemorrhage that progressed to brain death. The initial partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio of the donor's lung was 342 mmHg. The PaO2/FiO2 ratio dropped to 49 mmHg due to atelectasis. There was no improvement despite recruitment maneuvers, bronchoscopy, and chest percussion. After placing the donor in the prone position for four hours, electrical impedance tomography showed improved atelectasis. The donor did not experience hemodynamic instability. The lung was transplanted into a patient with Kartagener's syndrome with situs inversus. The surgical procedure was uneventful. He was successfully weaned from the mechanical ventilator on the second-day post-transplantation and was discharged from the hospital after 4 weeks.