Final answer:
Anti-mitochondrial antibodies (AMAs) are the primary antibodies present in primary biliary cirrhosis, found in about 90-95% of cases, and are crucial for diagnosis.
Step-by-step explanation:
The antibodies present in primary biliary cirrhosis (PBC) are primarily anti-mitochondrial antibodies (AMAs). These autoantibodies are very specific to PBC and are found in approximately 90-95% of cases. PBC is an autoimmune disease characterized by the progressive destruction of the small bile ducts within the liver, leading to cholestasis and eventually liver cirrhosis. Alongside AMAs, other non-specific autoantibodies may also be present, such as antinuclear antibodies (ANAs).
Diagnosis of primary biliary cirrhosis typically involves testing for these autoantibodies and is supported by increased levels of alkaline phosphatase (ALP) as a reflection of cholestasis and damage to the bile ducts.