Table 1.

Non-classical phenotypes of autoimmune hepatitis

Non-classical phenotype	Salient features
Acute severe disease	Corticosteroids effective in 36%-100%[49]
	Protracted treatment can be complicated by infection[49]
	High mortality if no better within 2 wk of therapy[85]
	MELD score ≥ 12 identifies 97% of treatment failures[58]
Asymptomatic mild hepatitis	Common (25%-34%) but unstable state[20,21,22,87,88,89]
	Symptoms develop in 26%-70%[20,21]
	Progression possible if untreated[20,21,22,87]
	Improves quickly with therapy[22]
Atypical histological features	Centrilobular necrosis is an early acute form[18,33,34,35,36,37,92]
	Transition to interface hepatitis possible[35]
	Coincidental biliary changes lack cholestatic profile[41]
	Fatty changes may co-exist[58,94]
Absent or variant serological markers	Seronegativity possible in 13%[31]
	Other features and treatment outcome similar[31,32,100]
	Non-standard autoantibodies possible[101,102,103,104]
	Conventional autoantibodies may be expressed later[30]
	Screen for celiac disease[105,106,107,108]
Concurrent cholangiographic changes	Abnormal cholangiograms in 44% with CUC[116]
	Poor outcome if biliary changes and CUC[121,122,123,124]
	MRC abnormalities in 8% adults without CUC[117]
	MRC abnormalities may be associated with fibrosis[119]
Male gender	0.2-0.5 cases/100 000 per year[127,128]
	Low frequency of concurrent immune diseases[130,131,132]
	No diversity of HLA DRB1*04 alleles[130,131,132]
	Better survival than women[136]
Non-Caucasian	Cholestatic features may be common[45,141,142,143]
	Male predominance possible[47]
	Socioeconomic factors important[137,138,146,147]

MELD: Model of End Stage Liver Disease; MRC: Magnetic resonance cholangiography; CUC: Chronic ulcerative colitis; HLA: Human leukocyte antigen.