Distinct Phenotypes of Smokers with Fixed Airflow Limitation Identified by Cluster Analysis of Severe Asthma.

RATIONALE: Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses. OBJECTIVES: To explore novel severe asthma phenotypes by cluster analysis when including smoking patients with asthma. METHODS: We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters. RESULTS: Five clinical clusters, including two characterized by low forced expiratory volume in 1 second/forced vital capacity, were identified. When characteristics of smoking subjects in these two clusters were compared, there were marked differences between the two groups: one had high levels of circulating eosinophils, high immunoglobulin E levels, and a high sinus score, and the other was characterized by low levels of the same parameters. Sputum analysis revealed intriguing differences of cytokine/chemokine pattern in these two groups. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 3 years later. CONCLUSIONS: This study reveals two distinct phenotypes with potentially different biological pathways contributing to fixed airflow limitation in cigarette smokers with severe asthma.

Distinct Phenotypes of Cigarette Smokers Identified by Cluster Analysis of Patients with Severe Asthma.

RATIONALE: Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses. OBJECTIVES: To explore novel severe asthma phenotypes by cluster analysis when including cigarette smokers. METHODS: We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Twelve clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters. MEASUREMENTS AND MAIN RESULTS: Five clinical clusters were identified, including two characterized by high pack-year exposure to cigarette smoking and low FEV1/FVC. There were marked differences between the two clusters of cigarette smokers. One had high levels of circulating eosinophils, high IgE levels, and a high sinus disease score. The other was characterized by low levels of the same parameters. Sputum analysis revealed increased levels of IL-5 in the former cluster and increased levels of IL-6 and osteopontin in the latter. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 1 year later. CONCLUSIONS: This study reveals two distinct phenotypes of severe asthma in current and former cigarette smokers with potentially different biological pathways contributing to fixed airflow limitation. Clinical trial registered with www.umin.ac.jp (000003254).

Large-cell neuroendocrine carcinoma in the thymus.

Large-cell neuroendocrine carcinoma in the thymus is a rare cancer that is more aggressive and leads to a poorer prognosis than other thymic epithelial tumors. A 67-year-old woman presented with an anterior mediastinal mass in the thymus. Histological examination after thymectomy revealed large-cell neuroendocrine carcinoma in the thymus. Although the patient received postoperative chemotherapy and radiotherapy, a distant relapse was detected 6 months after the surgery. We reviewed nine cases of this rare cancer that have been reported in Japan. There is no evidence of to support postoperative therapy for large-cell neuroendocrine carcinoma in the thymus. However, it is essential to accumulate and study these cases to understand this disease and prolong patient survival.

Pulmonary Langerhans' cell histiocytosis presenting with an endobronchial lesion.

A 19-year-old man visited our hospital complaining of cough, sputum and low-grade fever. Chest radiograph and computed tomography findings suggested that he was suffering from pulmonary Langerhans' cell histiocytosis (PLCH). Bronchoscopy revealed a whitish elevated lesion at the bifurcation of the right upper lobe bronchus, and a specimen of this lesion showed the same pathological findings as pulmonary parenchymal lesions. Although there have been only a few reports of endobronchial LCH without pulmonary parenchymal lesions, this is, to our knowledge, the first case of PLCH with an endobronchial lesion, which was confirmed by bronchoscopy, and disappeared several months later.