P1079 - A Rare Case of Antimitochondrial Antibody-Negative Primary Biliary Cholangitis With a Positive Cytoplasmic Pattern of Antinuclear Antibody

Padmavathi Mali, MD
Gundersen Health Systems, Lacrosse, WI

Introduction: Many cases of antimitochondrial antibody (AMA)–negative primary biliary cholangitis (PBC) have been reported, but we report a rare case in which a 62-year-old woman with negative AMA with positive cytoplasmic antinuclear antibody (ANA) with reflex AMA positivity. There have been no previous reports of AMA-negative PBC and positive cytoplasmic antinuclear antibody (ANA) with reflex positive testing for AMA

Case Description/Methods: Before having gastric bypass surgery 2 years prior, a 62-year-old woman had elevated liver test results prompting a liver biopsy, the results of which showed severe steatosis and steatohepatitis. Although our patient lost a lot of weight, her repeat liver tests showed elevated concentrations of ALP (546 U/L, reference interval 35-104), aspartate aminotransferase (AST) (76 U/L, reference interval 0-32), and alanine aminotransferase (ALT) (61 U/L, reference interval, 0-40). Workup showed AMA was negative, Anti-smooth muscle antibodies (ASMA) were normal at 1:20, as were soluble liver antigen and immunoglobulin levels. This prompted a liver biopsy showing portal hepatitis characterized by mild, portal lymphocytic inflammation with rare plasma cells and focal, minimal interface activity with no evidence of steatosis or steatohepatitis. In one portal area, nodular portal lymphohistiocytic inflammation was prominent, and there was lymphocytic cholangitis in the interlobular bile duct, suggestive of a florid duct lesion. She was started on ursodiol after the liver biopsy results confirmed PBC. Liver tests 3 months later showed an ALP of 181 U/L, with continued improvement 18 months later to 123 U/L, and an AST and ALT of 32 and 23 U/L, respectively. Repeat ANA 18 months after the biopsy showed a speckled pattern with a titer of 1:160, a cytoplasmic pattern, and reflex ANA testing showed AMA-positivity (titer 1:160)

Discussion: AMA are autoantibodies consisting of immunoglobulins formed against mitochondrial cells of the liver. In patients with high suspicion of PBC but negative AMA, a liver biopsy is needed to confirm the diagnosis. Our case is unusual in that even though AMA was negative, the cytoplasmic pattern of ANA was elevated. For cytoplasmic patterns of ANA elevation, the reflex test cascade is AMA and ASMA. In our patient’s case, reflex ANA testing was positive for AMA. This case highlights the importance of reflex ANA testing in all patients with signs suggestive of PBC to avoid liver biopsy


Disclosures:


Padmavathi Mali, MD. P1079 - A Rare Case of Antimitochondrial Antibody-Negative Primary Biliary Cholangitis With a Positive Cytoplasmic Pattern of Antinuclear Antibody, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.