LKM or liver-kidney microsomal antibody is any of the various antibodies that are detected in the serum who suffer from different kinds of acute or chronic liver diseases. It is used if you have liver diseases that have unknown causes or if you are suffering from autoimmune hepatitis. The LKM antibody test is generally used along with smooth muscle antibody (SMA) and antinuclear antibodies (ANA). You may be asked by your doctor to undergo the test if he or she wants to find out the different causes of liver disease/injury. Also, if you have certain symptoms like jaundice, enlarged liver and weakness, your doctor will ask you to go through the test.