3650 – Anti-GP2 Iso 1 IgA

Intended Purpose

The Anti-GP2 Iso 1 IgA is a quantitative immunoassay for the determination of IgA antibodies against glycoprotein 2 (GP2) isoform 1 in human serum. The Anti-GP2 Iso 1 IgA is intended as an aid in the diagnosis of primary sclerosing cholangitis in conjunction with other clinical and laboratory findings. The immunoassay is designed for manual professional in vitro diagnostic use.

Diagnostic Relevance

Primary sclerosing cholangitis (PSC) is a slowly developing disease of the gall bladder that predominantly affects young adults up to middle age and in a significant proportion of cases leads to inflammation of the liver in the final stage. Disease-related complications can severely affect patients’ quality of life, but even asymptomatic patients are at risk of progressive changes in the biliary tract and the occurrence of cholangiocarcinoma. The prevalence of cholangiocarcinoma in PSC patients is 5-10%, and about half of the cases are detected within 2 years of the initial PSC diagnosis. There is currently no effective pharmacological therapy and liver transplantation remains the only curative treatment. However, recurrence of PSC after surgery is not an uncommon phenomenon.

Glycoprotein 2 (GP2) is predominantly expressed in the exocrine pancreas. A total of four human GP2 isoforms have been identified (GP2 1-4). Both anti-GP2 IgA and IgG autoantibodies were first detected in inflammatory bowel disease. Later, an association between GP2 antibodies and certain PSC phenotypes with poor prognosis was demonstrated, particularly in relation to the development of cholangiocarcinoma.

IgA antibodies against glycoprotein 2 isoforms 1 and 4 are associated with liver dysfunction. IgA antibodies against isoform 4 have been shown to be predictive of cholangiocarcinoma, while IgA antibodies against isoform 1 indicate a poor prognosis of the disease with low survival. The low prevalence and lack of clinical significance of anti-GP2 IgG antibodies in PSC suggest that anti-GP2 IgA may play a pathogenic role in PSC.