S5539 Detection of Primary Biliary Cholangitis in the Absence of Persistently Elevated Alkaline Phosphatase

Introduction: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the progressive destruction of interlobular biliary ducts with a high risk of progression to cirrhosis. In the US, PBC occurs more often in women. Up to 50% of cases identified in early stages develop cirrhosis within 4 years without treatment. Current diagnostic criteria require 2 of the 3: a positive serology such as anti-mitochondrial antibody (AMA) or PBC specific antinuclear antibodies, an elevated alkaline phosphatase (ALP) above 1.5 times the upper limit of normal for 24 weeks, or a biopsy demonstrating chronic non-suppurative destructive cholangitis. The majority of cases are identified because of persistently elevated ALP. We report an unusual case of a male with possible PBC without persistently elevated ALP. Case Description/Methods: A 43-year-old man with type 2 diabetes complicated by end-stage renal disease, now status-post renal and pancreatic transplant, was noted to have 1.5 years of an intermittent mildly elevated alkaline phosphatase (ALP) with only one >1.5 times normal peaking at 198 IU/L. A right upper quadrant ultrasound was unrevealing. The subsequent AMA level was positive at 40.9 units with normalized ALP. The patient had no hepatobiliary symptoms. Hepatology consult recommended multidisciplinary management for possible PBC due to complicated treatment strategy required due to his prior renal and pancreas transplantation. Discussion: Cases such as these, with a positive AMA in the absence of a persistently elevated ALP pose a diagnostic challenge. This patient is particularly complicated due to co-morbidities, including prior transplantation and maintenance on immunosuppressants. To fulfill current diagnostic criteria a biopsy is recommended. In a review of 82 biopsy-confirmed PBC cases, 29.2% with early histological stages (stage 1 and 2) had an ALP within normal limits. Approximately 80-84.6% of patients with a positive AMA and normal ALP had liver histology consistent with PBC. Given the progressive nature of PBC and the availability of a treatment that can improve prognosis, it is crucial to diagnose and treat PBC in early stages. The evidence that the early stage PBC may not be associated with persistently elevated ALP demonstrates the need to assertively pursue the diagnosis with the presence of a positive AMA. This patient’s complicated clinical circumstances requires multispecialty involvement to ensure optimal clinical outcome.