A 26-year-old man has had difficulty breathing through his nose for 3 years, but this problem has become progressively worse over the past 2 months. Physical examination shows glistening, translucent, polypoid masses filling the nasal cavities. Histologic examination of the excised masses shows respiratory mucosa overlying an edematous stroma with scattered plasma cells and eosinophils. Which of the following laboratory findings is most likely to be present in this patient?

Inflammatory nasal polyps can be associated with recurrent allergic rhinitis, a form of type I hypersensitivity often called hay fever. Type I hypersensitivity is associated with high IgE levels in the serum. The elevated hemoglobin A1c level indicates diabetes mellitus. Diabetes is not a risk factor for polyp formation, but ketoacidosis can lead to nasopharyngeal mucormycosis. Epstein-Barr virus infection can be found in nasopharyngeal carcinomas. Autoimmune diseases are not associated with nasal polyp formation. Staphylococcus aureus often colonizes the nasal cavity, but it usually does not cause problems.