system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 37-year-old man presents to his gastroenterologist due to a transaminitis found by his primary care physician (PCP). He reports currently feeling well and has no acute concerns. Medical history is significant for ulcerative colitis treated with 5-aminosalicylate. He recently went on a trip to Mexico and experienced an episode of mild diarrhea. The patient is 5 ft 4 in and weighs 220 lbs (99.8 kg). His temperature is 98°F (36.7°C), blood pressure is 138/88 mmHg, pulse is 90/min, and respirations are 18/min. Physical examination is unremarkable. Laboratory testing demonstrates:

Leukocyte count: 7,200 /mm^3
Alkaline phosphatase: 205 U/L
Aspartate aminotransferase (AST): 120 U/L
Alanine aminotransferase (ALT): 115 U/L
Perinuclear antineutrophil cytoplasmic antibody (pANCA): Positive
Antimitochondrial antibody: Negative

Which of the following is most likely the diagnosis?
assistant
Primary sclerosing cholangitis