Indirect immunofluorescence and ELISA for testing of antimitochondrial antibodies -Which is better?-

For Antimitochondrial antibodies (AMA) testing, both indirect immunofluorescense (IF) and ELISA (M2) are currently used. Herein we aimed to suggest which is better for AMA testing in clinical setting. Recent nation-wide surveillances for PBC demonstrated that AMA testing with M2 has been prevailed instead of IF. On the other hand, 3-5% of PBC patients had M2-negative but IF-positive AMA, and these patients might not be diagnosed as PBC if only M2 would have been tested. In another PBC cohort at our hospital we failed to detect any difference between patients with only IF-positive and those with M2-positive. Therefore, M2 should be used for screening for AMA, and if M2 was negative AMA should be reexamined with IF.