Optical Biopsies Using Probe-Based Confocal Laser Endomicroscopy for Autoimmune Pulmonary Alveolar Proteinosis.

INTRODUCTION: Increasing numbers of cases of mild asymptomatic pulmonary alveolar proteinosis (PAP) are being reported with the recent increase in chest computed tomography (CT). Bronchoscopic diagnosis of mild PAP is challenging because of the patchy distribution of lesions, which makes it difficult to obtain sufficient biopsy samples. Additionally, the pathological findings of mild PAP, particularly those that differ from severe PAP, have not been fully elucidated. This study aimed to clarify the pathological findings of mild PAP and the usefulness of optical biopsy using probe-based confocal laser endomicroscopy (pCLE). METHODS: We performed bronchoscopic optical biopsy using pCLE and tissue biopsy in 5 consecutive patients with PAP (three with mild PAP and two with severe PAP). We compared the pCLE images of mild PAP with those of severe PAP by integrating clinical findings, tissue pathology, and chest CT images. RESULTS: pCLE images of PAP showed giant cells with strong fluorescence, amorphous substances, and thin alveolar walls. Images of affected lesions in mild PAP were equivalent to those obtained in arbitrary lung lesions in severe cases. All 3 patients with mild PAP spontaneously improved or remained stable after ≥3 years of follow-up. Serum autoantibodies to granulocyte-macrophage colony-stimulating factor were detected in all 5 cases. CONCLUSION: Optical biopsy using pCLE can yield specific diagnostic findings, even in patients with mild PAP. pCLE images of affected areas in mild and severe PAP showed similar findings, indicating that the dysfunction level of pathogenic alveolar macrophages in affected areas is similar between both disease intensities.

Iris-derived induced pluripotent stem cells that express GFP in all somatic cells of mice and differentiate into functional retinal neurons.

When regenerated tissue is generated from induced pluripotent stem cells (iPSCs), it is necessary to track and identify the transplanted cells. Fluorescently-labeled iPSCs synthesize a fluorescent substance that is easily tracked. However, the expressed protein should not affect the original genome sequence or pluripotency. To solve this problem, we created a cell tool for basic research on iPSCs. Iris tissue-derived cells from GFP fluorescence-expressing mice (GFP-DBA/2 mice) were reprogrammed to generate GFP mouse iris-derived iPSCs (M-iris GFP iPSCs). M-iris GFP iPSCs expressed cell markers characteristic of iPSCs and showed pluripotency in differentiating into the three germ layers. In addition, when expressing GFP, the cells differentiated into functional recoverin- and calbindin-positive cells. Thus, this cell line will facilitate future studies on iPSCs.

Risk Factors of Infectious Complications After Endobronchial Ultrasound-Guided Transbronchial Biopsy.

BACKGROUND: Infectious complications after endobronchial ultrasound-guided transbronchial biopsy with a guide sheath (EBUS-GS-TBB) are serious in that they may delay or change scheduled subsequent therapy. The aim of this study was to identify risk factors for infection after EBUS-GS-TBB. RESEARCH QUESTION: What are the risk factors for infection after EBUS-GS-TBB? STUDY DESIGN AND METHODS: We retrospectively reviewed the medical records of 1,045 consecutive patients who had undergone EBUS-GS-TBB for peripheral lung lesions between January 2013 and December 2017 at Fujita Health University Hospital. We evaluated the following risk factors for infectious complications after EBUS-GS-TBB: relevant patient characteristics (age and comorbidities), lesion size, CT scan features of target lesion (intratumoral low-density areas [LDAs] and cavitation), stenosis of responsible bronchus observed by bronchoscopy, and laboratory data before EBUS-GS-TBB (WBC count and C-reactive protein concentration). RESULTS: Forty-seven of the study patients developed infectious complications (24 with pneumonia, 14 with intratumoral infection, three with lung abscess, three with pleuritis, and three with empyema), among whom the complication caused a delay in cancer treatment in 13 patients, cancellation of cancer treatment in seven patients, and death in three patients. Multivariate analysis showed that cavitation (P = .007), intratumoral LDAs (P < .001), and stenosis of responsible bronchus observed by bronchoscopy (P < .001) were significantly associated with infectious complications after EBUS-GS-TBB. Prophylactic antibiotics had been administered to 13 patients in the infection group. Propensity matched analysis could not show significant benefit of prophylactic antibiotics in preventing post-EBUS-GS-TBB infections. INTERPRETATION: Cavitation, LDAs for CT scan features of target lesions, and stenosis of responsible bronchus observed by bronchoscopy are risk factors of post-EBUS-GS-TBB infection. In the cohort, prophylactic antibiotics failed to prevent infectious complications.

Flow cytometric analysis of lymphocyte profiles in mediastinal lymphadenopathy of sarcoidosis.

Lymphocyte profiles in mediastinal lymph nodes may reflect the immune status of patients with sarcoidosis. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is useful for the diagnosis of diseases with mediastinal lymphadenopathy including sarcoidosis. The purpose of this study was to determine lymphocyte profiles of lymph nodes in sarcoidosis by analyzing EBUS-TBNA samples. We prepared single cell suspensions from EBUS-TBNA samples of mediastinal lymph nodes from patients with sarcoidosis or lung cancer and analyzed surface markers (CD3, CD4, CD8, CD19, CD25) and FoxP3 expression in the resultant lymphocytes using flow cytometry. We studied 26 patients with sarcoidosis and 16 with lung cancer with mediastinal lymph node metastases. In sarcoidosis, the CD4/CD8 ratio was significantly more elevated in lymph nodes than in bronchoalveolar lavage fluid (P<0.001), although both were strongly correlated. The CD4/CD8 ratio was significantly higher in stage I than in stage II both in the BAL fluid and lymph nodes. When compared with lung cancer lymph node metastasis, the CD4/CD8 ratio was significantly higher in sarcoidosis, whereas the CD3/CD19 ratio was significantly higher in lung cancer. The proportion of regulatory T cells (CD4+, CD25+, FoxP3 high) did not differ between sarcoidosis and lung cancer samples. Lymphocyte profiles in mediastinal lymphadenopathy can be analyzed by flow cytometry of EBUS-TBNA samples. These findings might help elucidate the immunopathology of sarcoidosis.