A 40-year-old man presents with recurrent sinusitis for 2 years, associated with a bloody nasal discharge, intermittent cough and breathlessness. The response to antihistamines and antibiotics was poor. His medical and surgical histories are unremarkable and he is currently not on any medications. His full blood count shows a Hb level of 10.1 g/dL, and a leukocyte count of 13,500, with 85% neutrophils. His ESR is 110 mm in the first hour.