Verificamos o comportamento e a associação dos auto-anticorpos à atividade inflamatória na hepatite auto-imune (HAI). 95 pacientes tinham HAI-1 com antinúcleo (AAN) e/ou antimúsculo liso (AAML) e /ou antiactina (AAA) e, 14, o antiantígeno hepático solúvel (AAASH). 17 pacientes tinham HAI-2 com antimicrossoma de fígado e rim (AAMFR) e 5 anticitosol hepático (AACH). 5 apresentavam apenas o AAASH. O AAML/AAA não apareceu no seguimento em pacientes inicialmente negativos ao contrário do AAN em 6 pacientes. AAN, AAMFR, AACH e AAAHS não foram associados à atividade inflamatória. O AAML (>1/80) e o AAA (1>1/40) foram associados à ausência de resposta histológica (100 por cento e 100 por cento) (p<0,001) / The behavior and significance of autoantibodies in the course of autoimmune hepatitis (AIH) were assessed by comparing their occurrence and titers with disease activity. 95 patients had AIH type 1, 17 had AIH type 2 and 5 subjects had only anti-soluble liver antigen (anti-SLA). Anti-muscle (SMA) and anti-actin antibodies (AAA) did not appear in the course of AIH. Anti-nuclear (AAN) appears de novo in 6 patients. AAN, liver kidney microsome, liver cytosol and anti-SLA were not associated with disease activity. On the other hand, only the persistence of SMA (>1:80) and AAA (>1:40) were associated with histological activity (100 per cen and 100 per cent) (p<0,001) and may be useful in the clinical management...