Novel immunoassays for detection of CUZD1 autoantibodies in serum of patients with inflammatory bowel diseases.
BACKGROUND
Pancreatic autoantibodies (PABs) are detected in patients with inflammatory bowel disease (IBD). Their prevalence is higher in Crohn's disease (CrD) than in ulcerative colitis (UC). Glycoprotein 2 (GP2) and, more recently, CUB and zona pellucida-like domain-containing protein 1 (CUZD1) have been identified as target autoantigens of PAB. The clinical utility of CUZD1 autoantibodies has only recently been assessed by indirect immunofluorescence (IIF) assays. In this study, we developed and validated novel immunoassays for the detection of CUZD1 autoantibodies.


METHODS
Recombinant CUZD1 protein was utilized as a solid-phase antigen for the development of two immunoassays for the detection of IgG and IgA CUZD1 autoantibodies. Serum samples from 100 patients with CrD, 100 patients with UC, 129 patients assessed for various autoimmune diseases (vADs) and 50 control individuals were analyzed.


RESULTS
Two immunofluorometric assays for the detection of IgG and IgA CUZD1-specific antibodies were developed. CUZD1 autoantibodies were detected in 12.5% (25/200) IBD patients, including 16% of patients with CrD and in 9% of patients with UC (CrD vs. UC, p<0.05), compared with 3.1% (4/129) patients suspected of having vADs (CrD vs. ADs, p<0.05; UC vs. ADs, p=0.08). CUZD1 autoantibody positivity was not found to be related to disease location, age of disease onset or disease phenotype.


CONCLUSIONS
This is the first study to describe novel IgA and IgG CUZD1 autoantibody enzyme-linked immunosorbent assay. These immunoassays agree well with standard IIF techniques and can be utilized in multicenter studies to investigate the diagnostic and clinical utility of CUZD1 autoantibodies.
.
Sofia
http://orcid.org/0000-0003-2554-1180
S
Farkona
.
Antoninus
A
Soosaipillai
.
Panagiota
P
Filippou
.
Christos
C
Liaskos
.
Dimitrios P
DP
Bogdanos
.
Eleftherios P
EP
Diamandis
.
Ivan M
IM
Blasutig
D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D003093:Colitis, Ulcerative / Q000175:diagnosis; D003424:Crohn Disease / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis*; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification
D001323:Autoantibodies; C488236:CUZD1 protein, human; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008565:Membrane Proteins; D011994:Recombinant Proteins
CUZD1; Crohn’s disease; ELISA; autoantibodies; autoimmune; immunoassay; inflammatory bowel disease; ulcerative colitis