Accuracy of Xpert(®) MTB/RIF assay compared with AdvanSure™ TB/NTM real-time PCR using bronchoscopy specimens.

BACKGROUND: The performance of Xpert(®) MTB/RIF assay, an automated nucleic acid amplification test (NAAT) that was developed for the detection of tuberculosis (TB), has been evaluated in various clinical settings. However, few studies have compared Xpert with other NAATs, especially its performance using lower respiratory tract specimens (LRTS). OBJECTIVE: To compare the practical diagnostic performance of the Xpert assay with that of the AdvanSure™ TB/NTM RT-PCR kit in the detection of pulmonary TB (PTB), using LRTS obtained through bronchoscopy. RESULTS: Of 249 patients included, 105 had culture-confirmed PTB. Using culture as reference, the overall sensitivity of Xpert and AdvanSure was respectively 92.4% and 83.8%. When acid-fast bacilli smear results were taken into consideration, the sensitivity of Xpert for smear-positive and smear-negative LRTS was respectively 100% and 88.9%, while that of the AdvanSure was 100% and 76.4%. Xpert showed better results than AdvanSure in terms of sensitivity in smear-negative LRTS (P = 0.012), but no difference in smear-positive LRTS. CONCLUSIONS: Xpert may be advantageous in the detection of PTB using LRTS, particularly in low microbiological burden settings.

Alteration of cell growth and morphology by overexpression of transforming growth factor beta type II receptor in human lung adenocarcinoma cells.

TGF-beta is a potent inhibitory regulator of cell growth, which is transduced through interaction between type I (RI) and type II (RII) receptors that form heteromeric kinase complexes. Abnormal expression of these receptors has been identified in several human epithelial cancers and has been shown to be highly associated with resistance to TGF-beta. In this study, we investigated the expression of RI and RII in 13 human non-small cell lung cancer cell lines (NSCLCs) and demonstrated decreased or loss of RII expression in five lung cancer cell lines, but not of RI. Of these cell lines, the role of RII in NCI-H358 adenocarcinoma, which lacks RII and is insensitive to TGF-beta, was investigated by transducing this cell line with a recombinant retrovirus expressing full-length TGF-beta RII. Stably transfected cells showed significant increase in RII mRNA and protein expression. These cells responded to exogenous TGF-beta1 with suppressed proliferation in a dose-dependent manner and G1 arrest accompanied by morphological change distinct from control cells. We also investigated whether overexpression of dominant-negative RII (dnRII) in NCI-H441 adenocarcinoma, which is sensitive but expresses low levels of RII, could block signaling through the receptor complex. The overexpression of this kinase-domain-truncated RII by expressing the retroviral dnRII construct led to loss of the ability to respond to TGF-beta1 and an exhibition of uncontrolled growth. These results suggest a close association between the loss of the expression of wild-type TGF-beta RII and carcinogenesis in human lung cancer cells.

Endobronchial tuberculosis with expectoration of tracheal cartilages.

A case of endotracheal tuberculosis with expectorations of the lateral one-third of the multiple tracheal cartilages is reported. Fibreoptic bronchoscopy revealed caseous materials and loosening of the tracheal cartilages. The patient expectorated cartilaginous material several times before and after fibreoptic bronchoscopy. In spite of the loss of tracheal cartilages, tracheal lumen was maintained with a mild airflow limitation. The remaining two-thirds of the tracheal cartilage rings seemed to be strong enough to support the tracheal lumen opening during the respiratory cycle. Although rare, expectoration of bronchial cartilage can be one of the clinical features of endobronchial tuberculosis.

Pulmonary lymphangioleiomyomatosis in Korea.

BACKGROUND: Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease occurring in women of reproductive age and leading to progressive respiratory failure in spite of treatment. In Korea the first case was reported in 1984 and by 1997 a total of 23 cases had been reported. The clinical findings of these Korean cases are reviewed. METHODS: The details of 10 cases of LAM on file at Seoul National University Hospital were reviewed together with those of 13 cases previously reported from other Korean institutes. Two, including the only one to be reported in a man, were excluded after reviewing the clinical, radiological, and pathological findings, leaving a total of 21 cases in the present study. RESULTS: All 21 patients were women and in all cases the disease was proven pathologically. The mean (SD) age at onset of symptoms was 32 (8.6) years. The most common symptoms were dyspnoea and pneumothorax which were seen in 19 (90%) and 13 (76%) patients, respectively. Pulmonary function tests showed decreased transfer factor (TLCO) (100%) and airflow limitation (67%). All the cases had characteristic cysts on high resolution computed tomographic (HRCT) scanning. The overall severity score based on HRCT scans correlated with the percentage predicted TLCO/VA (p = 0.03) and FEV1/FVC (p = 0.02). The patients were all treated with medroxyprogesterone and/or tamoxifen. Follow up was possible in 10 cases. Two of these patients appeared to stabilise with no appreciable change clinically or in lung function on medroxyprogesterone and/or tamoxifen, but the remaining patients all deteriorated with two dying of respiratory insufficiency and one of infection following lung transplantation. CONCLUSIONS: As in other countries, in Korea LAM occurs exclusively in women and progresses despite hormonal treatment.