A 68-Year-Old HIV-Negative Man Comes to the Physician Due to 5

A 68-year-old HIV-negative man comes to the physician due to 5 months of worsening cough with an associated 4.5-kg (10-lb) weight loss.  He also reports fatigue and decreased appetite.  He has no recent travel history, sick contacts, new medications, or exposure to new environmental agents.  The patient's other medical problems include moderate chronic obstructive pulmonary disease, hyperlipidemia, and type 2 diabetes mellitus.  His medications include fluticasone/salmeterol inhaler, albuterol, metformin, aspirin, and atorvastatin.  His immunizations are up to date.  The patient has a 30-pack-year smoking history but quit 5 years ago.  He drinks alcohol socially and does not use illicit drugs.
His temperature is 37.0 C (98.6 F) , blood pressure is 130/70 mm Hg, and respirations are 14/min.  Pulse oximetry shows 94% oxygen saturation on room air.  Lung examination shows crackles over the right lower lung with mild wheezes diffusely.  The remainder of the physical examination is within normal limits.
The patient's routine blood work shows normal chemistry and complete blood count.  CT scan of the chest obtained following an abnormal chest x-ray reveals an infiltrate in the right middle lobe and bronchiectasis and nodules in the right middle and upper lobe.  Two of 2 separate sputum cultures grow mycobacteria identified as Mycobacterium avium complex by a rapid nuclear acid probe.
Which of the following is the best management for this patient?

A) Antimycobacterial therapy with isoniazid-containing 4-drug regimen
B) Antimycobacterial therapy with macrolide-containing 3-drug regimen
C) Bronchoscopy with transbronchial needle biopsy
D) Discontinuation of fluticasone and clinical observation
E) Tuberculin skin testing