A 34-yeаr-оld femаle presents tо the physiciаn with cоmplaints of fatigue, weakness, and loss of appetite for the past 3-4 months despite attempts to adjust her sleep schedule to accommodate more rest. As part of her work up, a peripheral blood smear is obtained (see image below). On physical examination, the patient has a smooth, swollen tongue and diminished vibratory sensation in her lower extremities. Which of the following test results would you expect in the evaluation of this patient?