Various volatile organic compounds (VOCs) are known to be toxic. Although exhaled VOC patterns change in obstructive sleep apnea (OSA) patients, individual VOC profiles are not fully determined. The primary outcome was VOC characterizations; secondary outcomes included their relationships with sleep and clinical parameters in OSA patients. We prospectively examined 32 OSA patients with an apnea-hypopnea index (AHI) ≥ 15 by full polysomnography, and 33 age- and sex-matched controls without obvious OSA symptoms. Nine severe OSA patients were examined before and after continuous positive airway pressure (CPAP) treatment. By applying a method which eliminates environmental VOC influences, exhaled VOCs were identified by gas chromatography (GC)-mass spectrometry, and their concentrations were determined by GC. Exhaled aromatic hydrocarbon concentrations (toluene, ethylbenzene, p-xylene, and phenylacetic acid) in the severe OSA groups (AHI ≥ 30) and exhaled saturated hydrocarbon concentrations (hexane, heptane, octane, nonane, and decane) in the most severe OSA group (AHI ≥ 60) were higher than those in the control group. Exhaled isoprene concentrations were increased in all OSA groups (AHI ≥ 15); acetone concentration was increased in the most severe OSA group. Ethylbenzene, p-xylene, phenylacetic acid, and nonane concentrations were increased according to OSA severity, and correlated with AHI, arousal index, and duration of percutaneous oxygen saturation (SpO2) ≤ 90%. Multiple regression analyses revealed these 4 VOC levels were associated with the duration of SpO2 ≤ 90%. Isoprene and acetone decreased after CPAP treatment. OSA increased some toxic VOCs, and some correlated with OSA severity. CPAP treatment possibly ameliorates these productions.
Nodular pulmonary amyloidosis, a subtype of pulmonary amyloidosis, is a unique disease that can mimic lung cancer on radiographic imaging and is related to lymphoproliferative disorders. In this report, we describe a case of a 76-year-old male who presented with a solitary nodule in his left lower lung lobe on computed tomography that increased from 6 mm to 13 mm in diameter over 40 months. Lung cancer was suspected; however, transbronchial lung biopsy revealed deposition of an eosinophilic and homogeneous amorphous substance, which showed apple-green birefringence under polarized light after Congo red staining, and immunohistochemistry analysis returned positive results for immunoglobulin lambda light-chain. Upper gastrointestinal endoscopy revealed a gastric mucosa-associated lymphoid tissue (MALT) lymphoma. These findings indicated that this was a case of nodular pulmonary amyloidosis that preceded a diagnosis of MALT lymphoma.
A 79-year-old woman presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome). A 99mTc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 25.5% in the supine position and 32.3% in the sitting position. A dynamic CT scan and a transoesophageal echocardiogram confirmed the presence of a shunt across an atrial septal defect (ASD). A percutaneous transcatheter closure of the defect significantly improved the patient's blood oxygenation levels when she was in the upright position. An ASD should therefore be included in the differential diagnosis of platypnea-orthodeoxia syndrome, regardless of the patient's age.
An 82-year-old woman with a history of chronic thromboembolic pulmonary hypertension (CTEPH) presented with malaise, left facial nerve paralysis and the positive seroconversion of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA). She was diagnosed with ANCA-associated vasculitis (AAV). Administration of corticosteroids significantly improved her symptoms, with a decline in the serum MPOANCA level. Ten months later than the initial presentation, she developed an AAV exacerbation with lung infiltration and pericardial effusion, which improved with high-dose corticosteroid therapy. To date, a limited number of AAV cases concomitant with pulmonary hypertension have been reported. The case report presented herein suggests a potential role for CTEPH in the development of AAV.
Background A subset of COPD patients have high levels of eosinophils in the distal airways (“airway eosinophilia”). Objectives To compare the gene expression of type 2 inflammation in airway epithelial brushings of COPD patients with and without airway eosinophilia and to investigate the changes after inhaled corticosteroids (ICS). Methods Post-hoc analyses of the DISARM randomised controlled trial investigated the expression of airway inflammation (type 1, 2, and 17), IL-13, and mast cell gene signatures at baseline and after 12-week ICS treatment. Gene signatures were generated from RNA sequencing of airway epithelial brushings. Airway eosinophilia was defined as eosinophils>1% of the total leukocyte count in bronchoalveolar lavage. Gene set enrichment analyses identified upregulated canonical pathways in airway eosinophilia. Results Among 58 COPD patients, 38% had airway eosinophilia at baseline. Patients with airway eosinophilia had more severe airflow obstruction and more radiographic emphysema than the non-eosinophilia group. Patients with airway eosinophilia showed a higher epithelial expression of type 2 airway inflammation and IL-13 and mast cell activation at baseline, but the expression of type 1 and type 17 airway inflammation was similar to patients without airway eosinophilia. The airway eosinophilia group showed an upregulation of canonical pathways related to type 2 immune response and asthma. Treatment with ICS for 12 weeks reduced the epithelial expression of type 2 inflammation and mast cell gene signatures in patients with airway eosinophilia, while this change was not significant in patients without airway eosinophilia. Conclusions Airway eosinophilia marks a subset of COPD patients with increased airway epithelial expression of type 2 inflammation and a response to ICS treatment.
Exhaled volatile organic compounds (VOC) are being considered as biomarkers for various lungs diseases, including cancer. However, the accurate measurement of extremely low concentrations of VOC in expired air is technically challenging. We evaluated the clinical contribution of exhaled VOC measured with a new, double cold-trap method in the diagnosis of lung cancer.Breath samples were collected from 116 patients with histologically confirmed lung cancer and 37 healthy volunteers (controls) after inspiration of purified air, synthesized through a cold-trap system. The exhaled VOC, trapped in the same system, were heat extracted. We analyzed 14 VOC with gas chromatography.The concentrations of exhaled cyclohexane and xylene were significantly higher in patients with lung cancer than in controls (p = 0.002 and 0.0001, respectively), increased significantly with the progression of the clinical stage of cancer (both p < 0.001), and decreased significantly after successful treatment of 6 patients with small cell lung cancer (p = 0.06 and 0.03, respectively).Measurements of exhaled VOCs by a double cold-trap method may help diagnose lung cancer and monitor its progression and regression.
