Evaluation of the exercise capacity and mechanisms responsible for exercise limitation in patients with pulmonary Langerhans cell Histiocytosis

Abstract

Pulmonary Langerhans Histiocytosis Cells (PLCH) is characterized by infiltration of Langerhans cells and formation of loose granulomas with lymphocytic infiltrate and formation of nodular and cystic lesions on chest CT, and is often associated with smoking. Functionally, there may be obstructive and / or restrictive defect, with reduced carbon monoxide diffusing capacity. Dyspnea and lower exercise tolerance are common in PLCH, but exercise capacity in this disease is poorly understood and has not been compared to controls. Besides, the mechanisms involved in limiting exercise are poorly understood and cover multiple factors such as change in gas exchange, pulmonary hypertension (PH), dynamic hyperinflation, physical deconditioning and left heart failure. The involvement of pulmonary circulation in PLCH has unknown prevalence, but contributes to the symptoms. In the PH classification, PLCH belongs to the group 5, of multifactorial etiology. The definition of the presence and contribution of dyspnea mechanisms in different severities of PLCH is important to understanding the disease and individualization of treatment. The objective of the study is to evaluate the exercise capacity of patients with HCLP, and determinate mechanisms of dyspnea and lower exercise tolerance beyond its impact on quality of life. (AU)