Anti-mitochondrial antibody

Anti-mitochondrial antibodies (AMA) are antibodies (immunoglobulins) formed against mitochondria,^[1] primarily mitochondria in cells of the liver. The presence of AMAs in the blood or serum of a person is indicative of a disease called primary biliary cirrhosis (PBC)^[2] (a scarring of liver tissue, confined primarily to the bile duct drainage system of the liver). It is present in about 95% of cases.^[3]

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Primary biliary cirrhosis is seen primarily in middle-aged women, and in those afflicted with other autoimmune diseases. PBC is an autoimmune disorder, a condition in which the human body's immune defense system mistakenly attacks the body's own cells, or in this case parts of the cells.

Cause of AMAs is postulated that xenobiotic-induced and/or oxidative modification of mitochondrial autoantigens is a critical step leading to loss of tolerance. In acute liver failure AMA are found against all major liver antigens.^[4]

• pyruvate dehydrogenase, E2 subunits
• 2-oxo-glutarate dehydrogenase
• branched chain 2-oxo-acid dehydrogenase

Anti-cardiolipin antibodies are another type of AMA, cardiolipin is found on the inner mitochondrial membrane.

Correlation with non-mitochodrial antigens

Fifty seven percent of acute liver failure patients had elevated anti-transglutaminase antibodies (anti-tTG), which correlate with gluten-sensitive enteropathy (see coeliac disease, Gluten-sensitive enteropathy associated conditions).^[4] The inflamation produced by gluten-sensitive cellular immunity may cause the oxidative stress resulting in the modification of mitochondrial antigens and acute liver failure. Anti-gp210 antibodies are also found in 47% of PBC patients.^[5][6]

See also

• Mitochondrion
• Antibodies

References

1. ^ MedlinePlus Encyclopedia 003529
2. ^ GI111 at FPnotebook
3. ^ Oertelt S, Rieger R, Selmi C, Invernizzi P, Ansari A, Coppel R, Podda M, Leung P, Gershwin M (2007). "A sensitive bead assay for antimitochondrial antibodies: Chipping away at AMA-negative primary biliary cirrhosis". Hepatology 45 (3): 659-65. PMID 17326160.
4. ^ ^{a b} Leung PS, Rossaro L, Davis PA, et al (2007). "Antimitochondrial antibodies in acute liver failure: Implications for primary biliary cirrhosis". doi:10.1002/hep.21828. PMID 17657817.
5. ^ Nickowitz RE, Worman HJ (1993). "Autoantibodies from patients with primary biliary cirrhosis recognize a restricted region within the cytoplasmic tail of nuclear pore membrane glycoprotein Gp210". J. Exp. Med. 178 (6): 2237-42. PMID 7504063.
6. ^ Bauer A, Habior A (2007). "Measurement of gp210 autoantibodies in sera of patients with primary biliary cirrhosis". J. Clin. Lab. Anal. 21 (4): 227-31. doi:10.1002/jcla.20170. PMID 17621358.