PH Grand Rounds: Interferon-Associated Pulmonary Arterial Hypertension

Abstract

Presentation: A woman aged 54 years with multiple sclerosis (MS), chronic obstructive pulmonary disease (COPD), and hypertension presented with progressive exertional dyspnea and fatigue noted over 8 months. Multiple sclerosis was diagnosed 15 years earlier and treated with subcutaneous interferon-β for 10 years with subjective and clinical benefits. She described gradual fatigue and breathlessness with walking, climbing stairs, and performing activities of daily living but denied exertional chest pain, syncope, or lower extremity edema. She attributed her symptoms to worsening MS, however, her treating neurologist did not identify clinical or magnetic resonance imaging (MRI) indicative of worsening progressive MS. Because she was a daily smoker, her exertional dyspnea was attributed to COPD, and pulmonary function testing confirmed a diagnosis of airflow limitation with a decreased diffusion capacity; results were FEV1: 2.22 L (85% predicted), FVC: 3.44 L, FEV1/FVC: 0.65, DLCO: 9.0 mL/min/ mm Hg. In addition, an arterial blood gas (FiO 2 : 0.21) revealed 7.41/39/80. Yet, despite use of nebulized albuterol every 6 hours, her exertional dyspnea was not relieved, and she was referred for further assessment of exertional dyspnea.