Antimitochondrial antibody-negative primary biliary cirrhosis with secondary Sjogren syndrome: a case report

Introduction and importance

Primary biliary cholangitis (PBC) is a rare immune-mediated liver disease characterized by the destruction of intrahepatic bile ducts and a positive antimitochondrial antibody (AMA), which is considered a serological hallmark for the diagnosis. Rarely, AMA can be absent/nondetectable in a few cases and is referred to as 'AMA-negative'.

Case presentation

The authors present such an uncommon case of AMA-negative PBC in a 39-year-female with Sjogren's syndrome who presented with fatigue, pruritus, and dry eyes.

Clinical discussion

Previously published studies state that approximately only about 5% of patients with PBC are 'AMA-negative'. For patients negative for AMA, the diagnosis has to be based on typical pathological features of this disease. Once a diagnosis of PBC is established, regardless of whether it is positive or negative for AMAs, ursodeoxycholic acid is a widely accepted treatment.

Conclusion

The presence/absence of AMAs is associated with similar clinical, biochemical, and histopathological characteristics in PBC. The identification of AMAs alone should not impact the diagnosis or treatment of PBC.

The Prevalence of Anti-Hexokinase-1 and Anti-Kelch-Like 12 Peptide Antibodies in Patients With Primary Biliary Cholangitis Is Similar in Europe and North America: A Large International, Multi-Center Study

Primary biliary cholangitis (PBC), formerly known as primary biliary cirrhosis, is present worldwide. Autoantibodies, in particular anti-mitochondrial antibodies (AMA) detected by indirect immunofluorescence assays or newer solid phase immunoassays can detect most, but not all individuals with PBC. Detection of antibodies to the anti-nuclear antigens sp100 and gp210 can identify additional PBC patients, but some seronegative patients remain, often resulting in delayed diagnosis and treatment. Antibodies to kelch-like 12 (KLHL12) and hexokinase 1 (HK-1) were recently identified as new biomarkers for PBC and notably identify patients who are negative for conventional autoantibodies. To become globally adopted, it is important to validate these new biomarkers in different geographic areas. In the present study we evaluated the prevalence of anti-KLHL12 (measured by a KLHL12-derived peptide referred to as KL-p) and anti-HK-1 antibodies by ELISA at five sites within Europe and North America and demonstrated the presence of these antibodies in patients with PBC in all geographies.