Investigating the appropriate adenosine deaminase cutoff value for the diagnosis of tuberculous pleural effusion in a country with decreasing TB burden.

As the burden of tuberculosis (TB) in South Korea decreases while that of malignancy increases with an aging society, the composition of etiology for pleural effusion is changing. The aim of this study was to investigate the diagnostic value of adenosine deaminase (ADA) for diagnosis of tuberculous pleural effusion (TPE) in this circumstance. Medical records of patients who underwent medical thoracoscopy from May 2015 to September 2020 in Incheon St. Mary Hospital, Korea were retrospectively reviewed. TPE was diagnosed if one of the following criteria was met: (1) granuloma in pleura, (2) positive TB polymerase chain reaction or culture in pleural fluid or tissue with non-specific pathologic findings in pleura, or (3) bacteriologically confirmed pulmonary TB with non-specific pathologic findings in pleura. A total of 292 patients, including 156 with malignant pleural effusion (MPE), 52 with TPE, and 84 with other benign effusion, were analyzed. Among 206 patients with lymphocyte dominant pleural effusion, the area under receiver characteristic curve of ADA for diagnosis of TPE was 0.971. The sensitivity and specificity of a current cutoff value of 40 IU/L were 1.00 and 0.61, respectively, whereas those of a raised cutoff value of 70 IU/L were 0.93 and 0.93, respectively. Among 54 patients with ADA levels of 40-70 IU/L, 30 (55.6%) patients were diagnosed as MPE, 21 (38.9%) as other benign effusion, and only 3 (5.6%) as TPE. Caution is needed in clinical diagnosis of TPE with current ADA cutoff value in countries with decreasing TB incidence, due to many false positive cases.

Factors associated with discrepancy between fresh frozen and permanent biopsy from medical thoracoscopy: single center analysis of 172 medical flexible thoracoscopy cases.

BACKGROUND: Frozen sections prepared during medical thoracoscopy (MT) have precise diagnostic ability in pleural pathology and may assist in decision-making before pleurodesis. The present study evaluated the diagnostic sensitivity of frozen sections from flex-rigid MT, and further evaluated clinical parameters for their association with a discrepancy between frozen sections and permanent paraffin sections. METHODS: This retrospective study evaluated 172 patients who underwent flex-rigid MT between February 2017 and November 2019 at Incheon Saint Mary's Hospital. RESULTS: Of the 172 patients, 85 were pathologically diagnosed with malignancy based on permanent paraffin sections. An accurate diagnosis by fresh frozen section was feasible in 88.2% of the cases compared to the permanent paraffin sections. Among the 85 patients, 75 had malignancies in frozen sections, while 10 patients showed otherwise. In the 85 malignant cases, age, sex, the volume of effusion, thoracoscopic findings, as well as the final pathological diagnosis (lung vs. non-lung origin) were included in univariate analysis for an association with non-malignant frozen section results. High adhesion grade and malignancy other than lung cancer were significant factors associated with frozen section negative cases in a multivariable analysis. CONCLUSIONS: Taking fresh frozen sections during MT using a flex-rigid bronchoscope is a useful diagnostic modality with reliable sensitivity for malignancy. However, if the pre-procedural diagnosis is likely to be a malignancy other than lung cancer, and if severe adhesions are present in the pleural cavity, the final pathological confirmation should be determined based on permanent paraffin sections, not only on fresh frozen sections.

Interstitial pneumonia with autoimmune features show better survival and less exacerbations compared to idiopathic pulmonary fibrosis.

BACKGROUND: Patients with interstitial lung disease (ILD) who show features related to autoimmunity without meeting criteria for a defined connective tissue disease are categorized as interstitial pneumonia with autoimmune features (IPAF). The present study compared clinical characteristics and clinical outcomes of patients with IPAF to patients with connective tissue disease related-interstitial lung disease (CTD-ILD) and patients with idiopathic pulmonary fibrosis (IPF). METHODS: ILD patients who were consecutively enrolled in a single institution ILD cohort between 2008 and 2015 were evaluated for the study. Clinical data had been prospectively collected, while radiologic imaging and pathologic findings were re-reviewed for the present study. RESULTS: Out of 305 patients with ILD, 54 (17.7%) patients met the classification of IPAF, 175 (57.4%) patients had IPF, and 76 (24.9%) patients were diagnosed with CTD-ILD. Compared to IPF, incidences of acute exacerbations in 1,3 and 5 years were significantly less in the IPAF group (p = 0.022, p = 0.026 and p = 0.007, respectively). From multivariate analysis for mortality, age (p = 0.034, HR 1.022, 95% CI: 1.002-1.044), FVC (p < 0.001, HR 0.970, 95% CI: 0.955-0.984), ILD exacerbation (p = 0.001, HR 2.074, 95% CI: 1.366-3.148), and ILD type (p = 0.047, HR 0.436, 95% CI: 0.192-0.984 (IPAF vs IPF), respectively) showed significant association. CONCLUSIONS: Compared to the other ILD groups, IPAF showed distinct clinical characteristics. The IPAF group showed better survival and less episodes of exacerbation when compared to the IPF group.