Immunoglobulin G4(+) B-cell receptor clones distinguish immunoglobulin G 4-related disease from primary sclerosing cholangitis and biliary/pancreatic malignancies.
Doorenspleet ME., Hubers LM., Culver EL., Maillette de Buy Wenniger LJ., Klarenbeek PL., Chapman RW., Baas F., van de Graaf SF., Verheij J., van Gulik TM., Barnes E., Beuers U., de Vries N.
UNLABELLED: Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) of the biliary tree and pancreas is difficult to distinguish from sclerosing cholangitis and biliary/pancreatic malignancies (CA). An accurate noninvasive test for diagnosis and monitoring of disease activity is lacking. We demonstrate that dominant IgG4(+) B-cell receptor (BCR) clones determined by next-generation sequencing accurately distinguish patients with IgG4-associated cholangitis/autoimmune pancreatitis (n = 34) from those with primary sclerosing cholangitis (n = 17) and CA (n = 17). A novel, more affordable, and widely applicable quantitative polymerase chain reaction (qPCR) protocol analyzing the IgG4/IgG RNA ratio in blood also achieves excellent diagnostic accuracy (n = 125). Moreover, this qPCR test performed better than serum IgG4 levels in sensitivity (94% vs. 86%) and specificity (99% vs. 73%) and correlates with treatment response (n = 20). CONCLUSIONS: IgG4(+) BCR clones and IgG4/IgG RNA ratio markedly improve delineation, early diagnosis, and monitoring of IgG4-RD of the biliary tree and pancreas. (Hepatology 2016;64:501-507).