Anti‐mitochondrial protein antibodies in a serum from a patient with systemic lupus erythematosus: Specificity and comparison with other anti‐mitochondrial antibodies

Anti-mitochondrial antibodies present in a serum from a systemic lupus erythematosus patient have been characterized by indirect immunofluorescence of cultured transformed human amnion cells, and by two-dimensional gel electrophoresis and immunoblotting. The antibodies which stained mostly mitochondria in transformed human amnion cells reacted with four mouse brain cortex mitochondrial proteins. These proteins, which have been termed a, b, c and d, exhibited apparent molecular weights of 66 000, 49 000, 49 000 and 44 000, respectively. Proteins a and c exhibited charge variants. Surprisingly, most of the proteins recognized by this serum also reacted with sera from a patient with liver cirrhosis and idiopathic pulmonary fibrosis.