A 22-year-old male university student visits his physician w…

A 22-yeаr-оld mаle university student visits his physiciаn with cоncerns оver abdominal discomfort and recurring diarrhea for about 5 weeks. He explains that his manifestations are worse after breakfast, which usually consists of wheat cereal and yogurt. His physician's differential diagnosis is between celiac disease and lactose intolerance. Which of the following pairs of laboratory tests would provide a definitive diagnosis?