Severe pulmonary hypertension in adult pulmonary Langerhans cell histiocytosis: the effect of sildenafil as a bridge to lung transplantation.

Severe pulmonary hypertension (PH) often develops in patients with pulmonary Langerhans cell histiocytosis (PLCH). Supplemental oxygen treatment is often used, whereas pulmonary arterial hypertension-specific vasodilators are generally considered hazardous because of the possible development of pulmonary edema and deterioration of hypoxia. In the present report, we herein describe a PLCH patient with severe PH in whom sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, substantially improved the pulmonary hemodynamics before lung transplantation. An immunohistochemical study of the resected lung revealed positive staining for PDE5 on the diseased pulmonary arteries. These observations suggest that sildenafil can be a promising therapeutic option for PH in patients with PLCH.