Eunhee Han1, Sung Jin Jo1, Hyeyoung Lee1, Ae-Ran Choi1, Jihyang Lim1, Eun-Sun Jung2, Eun-Jee Oh3. 1. Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. 2. Departments of Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. 3. Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: ejoh@catholic.ac.kr.
Abstract
BACKGROUND: Antimitochondrial antibody (AMA) is a specific serologic marker in primary biliary cirrhosis (PBC). The aim of this study was to evaluate the clinical relevance of combined AMA assays. METHODS: Sera were obtained from 79 patients with PBC and 108 patients with other liver disease. They were tested by indirect immunofluorescence (IIF) using rat kidney/stomach tissue and HEp2 cells as substrate, 4 AMA-M2 assays, anti-sp100, and anti-gp210 assays. RESULTS: Using IIF-AMA with cut-off titer of 1:40, the sensitivity and specificity for PBC were 88.6% and 87.0%, respectively. A cut-off titer of 1:80 improved the specificity to 93.5%. The 4 commercial assay kits using AMA-M2 autoantibodies showed sensitivity of 55.7-79.7% and specificity of 91.7-95.4% with moderate to good agreement. AMA-M2 assays using both native and recombinant E2 antigens had higher sensitivity. ANAs on HEp2 cells, anti-sp100, and anti-gp210 were detected in 67.1%, 13.9-15.2%, and 22.8-27.8% of PBC patients, respectively. Additional AMA-M2 specific assays in IIF-AMA negative and low titer positive (1:40) sera increased the sensitivity and specificity to 88.6% and 90.7%, respectively. CONCLUSIONS: Serological diagnosis for PBC using IIF with high titer cut-off and additional AMA-M2 specific tests by ELISA or LIA in IIF-negative sera should be used.
BACKGROUND: Antimitochondrial antibody (AMA) is a specific serologic marker in primary biliary cirrhosis (PBC). The aim of this study was to evaluate the clinical relevance of combined AMA assays. METHODS: Sera were obtained from 79 patients with PBC and 108 patients with other liver disease. They were tested by indirect immunofluorescence (IIF) using rat kidney/stomach tissue and HEp2 cells as substrate, 4 AMA-M2 assays, anti-sp100, and anti-gp210 assays. RESULTS: Using IIF-AMA with cut-off titer of 1:40, the sensitivity and specificity for PBC were 88.6% and 87.0%, respectively. A cut-off titer of 1:80 improved the specificity to 93.5%. The 4 commercial assay kits using AMA-M2 autoantibodies showed sensitivity of 55.7-79.7% and specificity of 91.7-95.4% with moderate to good agreement. AMA-M2 assays using both native and recombinant E2 antigens had higher sensitivity. ANAs on HEp2 cells, anti-sp100, and anti-gp210 were detected in 67.1%, 13.9-15.2%, and 22.8-27.8% of PBC patients, respectively. Additional AMA-M2 specific assays in IIF-AMA negative and low titer positive (1:40) sera increased the sensitivity and specificity to 88.6% and 90.7%, respectively. CONCLUSIONS: Serological diagnosis for PBC using IIF with high titer cut-off and additional AMA-M2 specific tests by ELISA or LIA in IIF-negative sera should be used.
Authors: Federica Gaiani; Roberta Minerba; Alessandra Picanza; Annalisa Russo; Alessandra Melegari; Elena De Santis; Tommaso Trenti; Lucia Belloni; Silvia Peveri; Rosalia Aloe; Carlo Ferrari; Luigi Laghi; Gian Luigi de'Angelis; Chiara Bonaguri Journal: J Clin Med Date: 2022-09-05 Impact factor: 4.964