Serum Reactivity Against Bacterial Pyruvate Dehydrogenase: Increasing the Specificity of Anti-Mitochondrial Antibodies for the Diagnosis of Primary Biliary Cirrhosis
| Autor: | Naomi Hosoya, M. Eric Gershwin, Carlo Selmi, Atsushi Tanaka, Takashi Kato, Toshihiro Goto, Norikazu Mataki, Kentaro Kikuchi, Junya Arai, Hiroshi Miyakawa |
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| Rok vydání: | 2006 |
| Předmět: |
lcsh:Immunologic diseases. Allergy
Serial dilution medicine.drug_class Immunology Pyruvate Dehydrogenase Complex Biology medicine.disease_cause Monoclonal antibody Autoantigens Cross-reactivity Primary biliary cirrhosis Antigen medicine Humans Immunology and Allergy Escherichia coli Autoantibodies Liver Cirrhosis Biliary General Medicine medicine.disease Molecular biology digestive system diseases Mitochondria Titer biology.protein Antibody lcsh:RC581-607 Research Article |
| Zdroj: | Clinical and Developmental Immunology Clinical and Developmental Immunology, Vol 13, Iss 2-4, Pp 289-294 (2006) |
| ISSN: | 1740-2530 1740-2522 |
| Popis: | Antimitochondrial antibodies (AMA) are the serum hallmark of primary biliary cirrhosis (PBC). However, AMA-positivity can be found in non-PBC sera when lower dilutions are used, thus raising issues about the specificity and sensitivity of the test. AMA reacts primarily with the lipoylated domains of pyruvate dehydrogenase-E2 (PDC-E2) which is highly conserved across species, including bacteria. We studied 77 serum samples, including 24 from patients with anti-PDC-E2-positive PBC and 53 controls (16 with autoimmune hepatitis (AIH), 10 with primary sclerosing cholangitis (PSC), and 27 healthy individuals) for their reactivities at serial dilutions (1:10, 1:20 and 1:40) against Escherichia coli DH5 alpha lysate overexpressing human PDC-E2 using immunoblotting (IB). A murine anti-human PDC-E2 monoclonal antibody (mAB) was used as control. We further studied positive sera using adsorption with a synthetic E. coli peptide sharing similarity with human PDC-E2. Finally, we verified whether a unique buffer for E. coli preparation could reduce non-specific serum reactivity. Results demonstrated that 100% of anti-PDC-E2-positive PBC and up to 38% of control sera at 1:10 dilution recognized E. coli PDC-E2 at IB while dilution tests indicated that the overall potency of PBC reactivity was 100-fold higher compared to controls. In fact, a subgroup (20-38%) of non-PBC sera were positive at low titers but lost the reactivity when absorbed with the synthetic E. coli peptide. Finally, our unique buffer reduced the reactivity of non-PBC sera as measured by ELISA. In conclusion, we demonstrated that weak cross-reactivity with E. coli PDC-E2 occurs in non-PBC sera at lower dilutions and that such reactivity is not due to AMA-positivity. The use of a specific buffer might avoid the risk of false positive AMA determinations when E. coli-expressed recombinant antigens are used. |
| Databáze: | OpenAIRE |
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