HardGastroenterologyPrimary Biliary Cholangitis (PBC)mrcp part 1ukmla
A 45-year-old woman presents with a 3-month history of generalised itching, worse at night and after hot baths. She denies any rash. Examination is unremarkable apart from some excoriations. Initial blood tests show: Hb 130 g/L, WCC 7.5x10^9/L, Plt 280x10^9/L, Urea 5.0 mmol/L, Creatinine 80 umol/L, ALT 45 IU/L (normal <35), ALP 350 IU/L (normal <130), Bilirubin 15 umol/L. What further blood test is most crucial for investigating the likely cause?