MCC950 Ameliorates Acute Exogenous Lipoid Pneumonia Induced by Sewing Machine Oil in Rats via the NF-κB/NLRP3 Inflammasome Pathway

BACKGROUND/AIM

Acute exogenous lipoid pneumonia (AELP) is a rare disorder caused by intake of lipid formulations and is often underdiagnosed. Meanwhile, the mechanism of AELP is still underlying. MCC950, was previously found to significantly suppress the release of inflammatory cytokines IL-18 and IL-1β. However, the effect of MCC950 on AELP induced by sewing machine oil has not been reported.

MATERIALS AND METHODS

The NLRP3, NF-[Formula: see text]B p65, caspase-1 and IL-1β expression in lung tissues were compared between a rat model of AELP and control rats using western blotting and real-time quantitative assay. Moreover, haematoxylin and eosin (H&E) staining was performed to elucidate the mechanisms by which MCC950 ameliorates sewing machine oil-induced AELP in vivo.

RESULTS

MCC950 reduced the expression of NF-[Formula: see text]B p65 in the lung samples of the treatment group and further down-regulated the NLRP3 and caspase-1 levels while inhibited the production of IL-1β. Besides, decreases in inflammatory cell infiltration in the lung were shown using H&E staining.

CONCLUSION

MCC950 ameliorates sewing machine oil-induced acute exogenous lipoid pneumonia in rats through inhibition of the NF-[Formula: see text]B/NLRP3 inflammasome pathway.

Interstitial Lung Disease in Adulthood Associated with Surfactant Protein C Gene Mutation in a Patient with a History of Lipoid Pneumonia in Infancy

Mutations in the surfactant protein C gene (SFTPC) are responsible for hereditary interstitial lung disease (ILD), which is a rare disease. We herein report a patient with a clinical history of endogenous lipoid pneumonia in infancy who developed diffuse progressive pulmonary fibrosis in adulthood associated with SFTPC mutations. A surgical lung biopsy and genetic sequencing revealed fibrotic interstitial pneumonia and two SFTPC mutations (c.215G>A and c.578C>A). Based on these findings, we diagnosed the series of lung diseases as sporadic ILD caused by SFTPC mutations. Physicians should suggest genetic sequencing in patients with early-onset ILD.

Complicated pneumonia due to exogenous toxic substances in children

BACKGROUND

Toxic substances may be inhaled or aspirated not always by patients themselves but sometimes by healthcare providers unintentionally by nasogastric administrations or medications. Aspirated toxic particles may cause injury in the pulmonary epithelium at various levels of the respiratory tract, leading to a spectrum varying from simple symptoms to severe chronic disease. Imaging features of substances are different depending on their structure and are not well known. Moreover, on follow-up, radiologic findings are not well correlated with clinical findings which progress or recover more rapidly.

CASE

In this case series, we report three different chemical pneumonitis due to aspiration of exogenous substances of paint thinner, activated charcoal and liquid paraffin. We present three cases with chest radiographs, distinctive computed tomography findings and follow-up images.

CONCLUSIONS

Aspiration of exogenous materials reveals typical imaging findings such as the metallic density of charcoals, fat attenuation of liquid paraffin and necrotic areas within consolidation in hydrocarbon poisoning. Recognition of imaging findings is very important for the diagnosis and characterization of toxic substances.

[Exogenous lipoid pneumonia induced by long-term usage of compound menthol nasal drops: a case report]

Here we reported a case of exogenous lipoid pneumonia from Peking University Third Hospital. A 62-year-old male presented with chronic cough and expectoration for 8 years, without chest pain, hemoptysis or short of breath. He was an ex-smoker. In his past medical history, the patient reported chronic rhinitis sicca for 20 years. Chest computed tomography (CT) showed patchy ground glass opacities in his bilateral lower lobe. In recent 3 years, his symptoms showed slowly deteriorative changes, as did his chest CT findings. No improvement of the patient's symptoms was observed, although he had been treated with many antibiotics. Then he was referred to our hospital for a detailed investigation for interstitial lung disease. On admission, the physical examination showed no abnormal findings except for inspiratory fine crackles in his bilateral lower lung field on auscultation. The results of the laboratory analysis, including complete blood cell count, biochemistry, arterial blood gas, urinalysis, antinuclear antibody (ANA), antineutrophil cytoplasmic antibody (ANCA) and tumor markers were all within normal ranges. To exclude the possibility of infectious or malignant conditions, bronchoscopy was performed. Secretions from the left lower lobe bronchus were collected for bacterial, fungal and fast-acid cultures, which were all negative. A bronchoalveolar lavage (BAL) was performed in the left lower lobe with a 30% recovery. The total cell count of the BAL fluid was 6.5×10⁴/mL, and the cellularity differential revealed increased neutrophils (20%) and lymphocytes (17%). The cytological examination in the BAL fluid showed no malignant cells. All the clinical data above did not reveal any conclusive information. However, the pathological findings of his transbronchial lung biopsy (TBLB) were highlighted with lipid-laden macrophages engulfed by large vacuoles occupying almost completely the cytoplasm of the cells, which were consistent with those of exogenous lipoid pneumonia. Given these findings, it emerged that the patient was taking twice daily inhalations of a compound menthol nasal drops (essential oil of camphor, menthol and liquid paraffin) for his chronic rhinitis sicca for at least 10 years. Then he discontinued oil nasal sprays and showed gradual improvement 3 months later without intensive treatment. The presenting case report emphasizes the fact that chronic inhalation of nasal sprays and decongestants containing mineral oils was a cause of exogenous lipoid pneumonia, and clinicians should bear it in mind.