Korean J Lab Med.
2005 Apr;25(2):104-110.
Determination of Anti-mitochondrial Antibody with M2 Antigens
- Affiliations
-
- 1Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Korea. progreen@daunet.donga.ac.kr
- 2Department of Internal Medicine, Dong-A University College of Medicine, Busan, Korea.
Abstract
- BACKGROUND
Anti-mitochondrial antibodies (AMA) are a hallmark of primary biliary cirrhosis (PBC); however, low titers of AMA are also detected in some patients without PBC. We evaluated the clinical value of commercial rat kidney/stomach sections and an additional biochip coated with mitochondrial antigen M2 (pyruvate dehydrogenase complex). METHODS: A total of 124 patients who had been tested for AMA were evaluated. Results of AMA, antibodies to M2, and antinuclear antibody were reviewed retrospectively and searched for clinical and laboratory data to diagnose PBC. AMA and M2 antibody were assayed by an indirect immunofluorescence assay using EUROPLUS kit (Euroimmun, Luebeck, Germany). RESULTS: In 10 of the 124 patients, a diagnosis of PBC was established by AMA, liver function test or liver biopsy. The sensitivity and specificity of rat kidney/stomach section, M2 antibody, and coarse cytoplasmic fluorescent pattern of HEp-2 cell were 80.0, 75.0, 88.9% and 97.4, 98.2, 97.3%, respectively; however, these differences were not statistically significant. Six patients with coarse cytoplasmic pattern of HEp-2 cell at 1: 320 dilution were positive for both rat kidney/stomach sec-tion and M2 antibody. Two of five patients with coarse cytoplasmic pattern at below 1: 80 dilution were diagnosed as PBC, yet all of them were negative for M2 antibody. CONCLUSIONS: M2 biochip test would be convenient to test simultaneously with rat kidney/stomach section and it provided results similar to those of the preexisting serological tests for PBC.