Elevated CA19-9 in IgG4-related disease

Résumé fourni par la source

Background IgG4-related disease (IgG4-RD) is an inflammatory disease that can clinically mimic pancreatic and hepatobiliary cancer. Serum carbohydrate antigen 19-9 (CA19-9) is a tumour marker that is frequently used to aid in the diagnosis of biliary cancer. There have been reported cases that patients with IgG4-RD also have elevated CA19-9. Methods This study has two components, first, a quality assurance component that observes paired IgG4 and CA19-9 measurements from patients with unknown diagnoses were compared to determine if serum IgG4 interferes with CA19-9 measurement. In addition, a mixing study is used to investigate if high levels of IgG4 interfered with CA19-9 measurements. Second, a retrospective chart review was performed to compare patients diagnosed with IgG4-RD with normal versus elevated CA19-9. Results Among 487 unique individuals with paired measurements, no association between CA19-9 and serum IgG4 was found. Mixing studies revealed no interference. Among 20 patients with IgG4-RD, 11 had elevated CA19-9 (median 150 kU/L) and nine had normal CA19-9. There was no difference in bilirubin between the two groups (63.2 µmol/L vs 39.4 µmol/L, P = .47). Conclusion There is no relationship between CA19-9 and serum IgG4. Patients with IgG4-RD and elevated CA19-9 did not have higher bilirubin than those with normal CA19-9. Together, these results suggest that elevated CA19-9 in IgG4-RD may be related to the disease rather than to interference from high serum IgG4 or from biliary obstruction.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.