Extrinsic lipoid pneumonia due to chronic polyethylene glycol consumption: A case report.

Extrinsic lipoid pneumonia (ELP) results from the aspiration of lipid-containing substances. Tissue or cell histopathology after Oil-Red-O staining can confirm the diagnosis, which requires proper tissue handling and preparation during bronchoscopy. Here, we report a case of ELP in a quadriplegic patient with a long history of dysphagia and polyethylene glycol consumption. Computed tomography (CT) of the chest revealed multiple, progressively enlarging, fat-attenuated, nodular pulmonary lesions. Bronchoscopy with bronchoalveolar lavage (BAL) and a transbronchial forceps biopsy confirmed the diagnosis of lipoid pneumonia. We discuss the clinical, radiological, and pathological features of ELP and highlight the preparatory steps required for obtaining a successful diagnosis.

Inflammatory impact of IFN-γ in CD8+ T cell-mediated lung injury is mediated by both Stat1-dependent and -independent pathways.

Influenza infection results in considerable pulmonary pathology, a significant component of which is mediated by CD8(+) T cell effector functions. To isolate the specific contribution of CD8(+) T cells to lung immunopathology, we utilized a nonviral murine model in which alveolar epithelial cells express an influenza antigen and injury is initiated by adoptive transfer of influenza-specific CD8(+) T cells. We report that IFN-γ production by adoptively transferred influenza-specific CD8(+) T cells is a significant contributor to acute lung injury following influenza antigen recognition, in isolation from its impact on viral clearance. CD8(+) T cell production of IFN-γ enhanced lung epithelial cell expression of chemokines and the subsequent recruitment of inflammatory cells into the airways. Surprisingly, Stat1 deficiency in the adoptive-transfer recipients exacerbated the lung injury that was mediated by the transferred influenza-specific CD8(+) T cells but was still dependent on IFN-γ production by these cells. Loss of Stat1 resulted in sustained activation of Stat3 signaling, dysregulated chemokine expression, and increased infiltration of the airways by inflammatory cells. Taken together, these data identify important roles for IFN-γ signaling and Stat1-independent IFN-γ signaling in regulating CD8(+) T cell-mediated acute lung injury. This is the first study to demonstrate an anti-inflammatory effect of Stat1 on CD8(+) T cell-mediated lung immunopathology without the complication of differences in viral load.