3650 – Anti-GP2 Iso 1 IgA

Highlights

• Use of recombinant human glycoprotein 2 isoform 1 (GP2)
• Ready-to-use (exception: conjugate and wash buffer) and barcoded reagents
• Quality assured handling in routine laboratories
• Incubation at room temperature
• Quantitative determination of IgA antibodies against GP2 isoform 1
• Calibrated with internal standard preparation
• Results expressed in IU/L
• Excellent diagnostic sensitivity and specificity
• High precision within the measurement range
• CE marked
• Automatable

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.

Role of Glycoprotein 2 (GP2)

The exocrine pancreas predominantly expresses glycoprotein 2 (GP2), which exists in four human isoforms (GP2 1–4). Researchers first detected anti-GP2 IgA and IgG autoantibodies in inflammatory bowel disease. Later studies linked GP2 antibodies to specific PSC phenotypes with poor prognosis, particularly regarding the risk of developing cholangiocarcinoma.

IgA antibodies against glycoprotein 2 isoforms 1 and 4 contribute to liver dysfunction. Researchers found that IgA antibodies against isoform 4 predict cholangiocarcinoma, while those against isoform 1 signal a poor prognosis 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.

Publications

• Xia et al., (2024) Loss of mucosal tolerance to glycoprotein 2 isoform 1 is a potential novel diagnostic biomarker for cholangiocarcinoma