quiz of month

A 60-year-old male is seen in the pulmonary clinic for evaluation of dyspnea. He underwent single-lung transplantation 3 years ago for idiopathic pulmonary fibrosis and did well until the last 5 months,
when he noted that his exercise tolerance had decreased as a result of shortness of breath. He denies fevers, chills, weight loss, or medication noncompliance. The patient does have an occasional dry cough. His current medications include immune supressant, trimethoprim-sulfamethoxazole (TMP-SMX), pantoprazole, diltiazem, and mycophenolate mofetil. He has past history of tobacco use. Physical examination show dry crackles on the side of the origin lung and decreased breath sounds on the side of the transplanted lung. Review of pulmonary function testing shows an FEV1/FVC ratio of 55% of the predicted value and an FEV1 of 0.90 L. Additionally, FEV1 has fallen by 31% progressively over the last 1-1/2 year. Which of the following can ameliorate the fall in FEV1 in this patient?
A. Augmented immunosuppression
B. Reduced immunosuppression
C. Antifungal therapy
D. Antiviral therapy
E. Administration of α1 antitrypsin
F. None of the above