Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder of uncertain etiology. Recognition of this disease as a distinct entity stemmed from investigation into autoimmune pancreatitis (AIP), which was ultimately found to be part of a larger, systemic process. Prior studies on AIP have revealed 8 associated autoantigens including carbonic anhydrase (CA) isoforms 1, 2 and 4, lactoferrin (LAF), trypsin (PRSS2), trypsin inhibitor (SPINK1), E3 ubiquitin protein ligase (UBR2) and amylase-2A (AMY). While many AIP patients have IgG4-RD, these studies did not exclude type 2 AIP (non-IgG4 related), did not include patients with other manifestations of IgG4-RD and did not fully explore the B cell response. Our aim was to examine these autoantigens among a large and diverse cohort of systemic IgG4-RD patients.
Methods: Six of these autoantigens were commercially available in a recombinant form (CA-1, CA-2, CA-4, LAF, PRSS2, SPINK1). IgG4-RD patients (n = 100) were recruited between January 2012 and June 2016 and plasma samples frozen at -20°C until use. All samples had active disease at the time of collection. Disease controls (n = 25) included ANCA-associated vasculitis, rheumatoid arthritis and systemic lupus erythematosus. Healthy donors (n = 40) were used as negative controls. All proteins were studied by ELISA using a series of secondary antibodies (IgG, IgG1, IgG2, IgG3, and IgG4). Our cohort was powered to evaluate the correlation between autoantibody positivity and the presence of salivary gland, lymph node, pancreatic, lacrimal gland, lung, and retroperitoneal involvement.
Conclusion: Autoantibodies previously reported in association with AIP were observed among a large cohort of systemic IgG4-RD patients. The presence of these autoantibodies did not correlate to pancreatic involvement nor were they specific for IgG4-RD. This finding of promiscuous autoreactivity likely represents a breach in tolerance in IgG4-RD providing support for an autoimmune etiology to this disease.
To cite this abstract in AMA style:Perugino CA, Awan I, Rosenberg I, Mahajan V, Stone JH, Pillai S. Autoimmune Pancreatitis-Associated Autoantigens Among 100 IgG4-Related Diseases Patients [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/autoimmune-pancreatitis-associated-autoantigens-among-100-igg4-related-diseases-patients/. Accessed November 30, 2020.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/autoimmune-pancreatitis-associated-autoantigens-among-100-igg4-related-diseases-patients/