Diagnóstico

Não há um exame que confirme exatamente o diagnóstico. A partir de suspeita pelas queixas do paciente e pelo exame clínico, o médico solicita exames de sangue que visam excluir outras causas mais comuns de hepatite, como, por exemplo, as causadas por vírus.

Dentre os exames que induzem fortemente o diagnóstico estão os que detectam anticorpos sanguíneos anormais.

Ecografia e biópsia hepática (retirada com agulha de um pequeno fragmento do fígado) são usadas para elaboração do diagnóstico, podendo demonstrar desde inflamação leve e diferente da hepatite por vírus até cirrose.

Diagnostic Criteria for Autoimmune Hepatitis (AIH)

Requisites	Diagnostic Criteria
Requisites	Definite	Probable
No genetic liver disease	Normal alpha1 antitrypsin phenotype Normal serum ceruloplasmin, iron, and ferritin levels	Partial alpha1 antitrypsin deficiency Nonspecific serum copper, ceruloplasmin, iron, and/or ferritin abnormalities
No active viral infection	No markers of current infection with hepatitis A, B, and C viruses	No markers of current infection with hepatitis A, B, and C viruses
No toxic or alcohol injury	Daily alcohol < 25 g/d and no recent use of hepatotoxic drugs	Daily alcohol < 50 g/d and no recent use of hepatotoxic drugs
Laboratory features	Predominant serum aminotransferase abnormality Globulin, gamma-globulin or immunoglobulin G level >/= 1.5 times normal	Predominant serum aminotransferase abnormality Hypergammaglobulinemia of any degree
Autoantibodies	ANA, SMA, or anti-LKM1 >/= 1:80 in adults and >/=1:20 in children; no AMA	ANA, SMA, or anti-LKM1 >/= 1:40 in adults or other autoantibodies*
Histologic findings	Interface hepatitis No biliary lesions, granulomas, or prominent changes suggestive of another disease	Interface hepatitis No biliary lesions, granulomas, or prominent changes suggestive of another disease

Diagnostic Scoring System for Atypical Autoimmune Hepatitis in Adults

Category	Factor	Score
Gender	Female	+2
Alk Phos:AST (or ALT) ratio	>3 <1.5	-2 +2
Gamma-globulin or IgG (times above upper limit of normal)	>2.0 1.5-2.0 1.0-1.5 <1.0	+3 +2 +1 0
ANA, SMA, or anti-LKM1 titers	>1:80 1:80 1:40 <1:40	+3 +2 +1 0
AMA	Positive	-4
Viral markers of active infection	Positive Negative	-3 +3
Hepatotoxic drugs	Yes No	-4 +1
Alcohol	<25 g/d >60 g/d	+2 -2
Concurrent immune disease	Any nonhepatic disease of an immune nature	+2
Other autoantibodies*	Anti-SLA/LP, actin, LC1, pANCA	+2
Histologic features	Interface hepatitis Plasma cells Rosettes None of above Biliary changes Atypical features	+3 +1 +1 -5 -3 -3
HLA	DR3 or DR4	+1
Treatment response	Remission alone Remission with relapse	+2 +3
Pretreatment score Definite diagnosis Probable diagnosis Posttreatment score Definite diagnosis Probable diagnosis		>15 10-15 >17 12-17