A case of eosinophilic granulomatosis with polyangiitis showing multiple white lichen lesions on the airway mucosa.

A 70-year-old man, treated for asthma for 2 years and chronic sinusitis for several months, presented with fever, numbness in the lower limbs, heaviness in the head, gross hematuria, and black stools. He also had eosinophilia, elevated serum IgG4 levels, high levels of myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA), and pulmonary infiltrative shadows. Bronchoscopy revealed multiple white flattened lesions (white moss) on the airway mucosa, suggesting mycobacterial infection or malignancy. A biopsy from tracheal mucosa revealed airway inflammation with marked eosinophil infiltration. The patient was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) and treated with steroids, and all findings improved. However, a year and a half after the initiation of treatment, eosinophils and IgE gradually increased; subjective symptoms, such as asthma symptoms and numbness in the lower limbs, worsened; and ANCA, which had been negative, turned positive. Therefore, we suspected disease relapse and anti-IL-5 antibody (mepolizumab) treatment was initiated. Thereafter, ANCA turned negative again, eosinophils and IgE normalized, and subjective symptoms decreased. The presence of airway mucosal lesions in EGPA is relatively rare, and we report this case as a valuable case owing to the interesting bronchoscopic findings that are worth comprehending as a respiratory physician.

[An autopsy case involving severe sepsis due to Capnocytophaga canimorsus infection].

Capnocytophaga canimorsus, a commensal bacterium from the carine mouth, causes septicemia in human beings through bites or scratches. We report a case of a 60-year-old man contracting septicemia due to C. canimorsus infection after a dog bite who died less than 12 hours after admission. We observed neutrophils with intracytoplasmic bacilli in the peripheral blood smear. We discuss clinical presentation and autopsy findings.

Expression of liver X receptor alpha and lipid metabolism in granulocyte-macrophage colony-stimulating factor-induced human monocyte-derived macrophage.

Liver X receptor (LXR) is a nuclear receptor that acts as a sterol sensor and metabolic regulator of cholesterol and lipid homeostasis. The foam cell transformation of macrophages (Mvarphi) is considered a critical process in atherosclerotic lesions. The relationship, however, of the foam cell transformation of Mvarphi and LXR is not fully understood. The purpose of the present study was to examine the expression of LXRalpha, retinoid X receptor (RXR)alpha, ATP-binding cassette transporter (ABCA1), and macrophage scavenger receptor A (MSR-A), and lipid accumulation in human monocyte-derived Mvarphi. The expression of LXRalpha, ABCA1, MSR-A in 7 day cultured granulocyte-macrophage colony-stimulating factor (GM-CSF)-induced Mvarphi (GM-Mvarphi) was significantly higher than that in 7 day cultured M-CSF-induced Mvarphi (M-Mvarphi). The expression levels of LXRalpha, ABCA1 and MSR-A protein decreased from 48 h to 5 days after the addition of lipopolysaccharide (LPS) in GM-Mvarphi, but only MSR-A protein decreased at 5 days after the addition of LPS in M-Mvarphi. Intracellular lipid accumulation was clearly observed when GM-Mvarphi was pre-stimulated with LPS for 48 h and incubated with oxidized LDL for an additional 5 days. These findings suggest that the inhibitory activity of LXRalpha, ABCA1 and MSR-A by LPS may be related to the transformation of Mvarphis, especially GM-Mvarphi into foam cells.

Expression of liver X receptor alpha in rat fetal tissues at different developmental stages.

The liver X receptor (LXR) is a nuclear receptor that acts as a sterol sensor and metabolic regulator of cholesterol and lipid homeostasis. Using a novel LXRalpha-specific antibody for immunohistochemistry, we evaluated cellular expression of LXRalpha in fetal rat tissues. In the fetal liver, LXRalpha-positive macrophages appeared at 12 days and their number peaked at 18 days of gestation. In contrast, hepatocytes expressed LXRalpha during the later stage of gestation, suggesting the functional development of the liver during ontogeny. Later, macrophages in spleen and thymus expressed LXRalpha, and some mononuclear cells in the vascular lumen compatible to primitive/fetal macrophages in the fetal circulation were found to express LXRalpha. In vitro, rat monocytes did not express LXRalpha, but monocyte-derived macrophages cultured in the presence of macrophage-colony stimulating factor revealed the distinct expression of LXRalpha in nucleoli. These findings suggest that LXRalpha plays a role in the differentiation of fetal macrophages, particularly hepatic macrophages, in rat development.

Expression of toll-like receptor 2 and 4 in lipopolysaccharide-induced lung injury in mouse.

Pattern recognition receptors, which include the toll-like receptors (TLRs), are considered to play an important role in the response against lipopolysaccharide (LPS). In this study, we performed a reverse transcriptase/polymerase chain reaction (RT-PCR) study, Western analysis, immunohistochemical staining, and RT-PCR-amplified in situ hybridization of TLR2 and TLR4 in the case of LPS-induced lung injury. The expression of TLR2 and TLR4 increased in the lung rapidly after LPS inhalation and peaked at 24 h, followed by a gradual decrease. TLR2 and TLR4 expression was observed on the bronchial epithelium and tissue macrophages. In the early hours after inhalation of fluorescein-isothiocyanate (FITC)-labeled LPS, LPS was detected mainly on the bronchial epithelium and on a few of tissue macrophages. One day after inhalation, the LPS signals disappeared in the lungs of the mice, except for a few alveolar macrophages. The expression of TLR2, TLR4, and CD14 was coincident with the signals of FITC-labeled LPS. Instillation of liposome-encapsulated dichloromethylene diphosphonate induced a significant decrease in alveolar macrophages. In the macrophage-depleted mice, however, expression of TLR2 and TLR4 mRNA or protein was slightly suppressed in the lung after LPS inhalation. These data suggest that the bronchial epithelium and macrophages play crucial roles in LPS-induced lung injury through TLR2 and TLR4.