SP100 and primary biliary cholangitis: Indeed, four investigations of 6-month intervals during the follow-up period showed the following positive titres of anti-sp100 (ANA-PBC-specific antibodies; 37, 21, 58 and 69 Units) and anti-M2 IgG antibodies (AMA; 80, 65.6, 98.5 and 89.4 Units), although the cholestatic enzymes were within normal limits.