Seronegative autoimmune hepatitis in childhood

Table 1 The antibodies and target antigens in autoimmune hepatitis

Antibody	Target antigen
ANA	Single-stranded/double-stranded DNA, ribonucleoproteins
ASMA	Filamentous actin, vimentin, desmin
LKM	Cytochrome P450 2D6 (CYP2D6)
anti-SLA	UGA serine transfer RNA associated protein
LC-1	Formiminotransferase cyclo-deaminase
pANCA	Nuclear lamina proteins
ASGP-R	Asialoglycoprotein receptor

ANA: Anti-nuclear antibody; ASMA: Anti-smooth muscle antibody; LKM: liver-kidney microsomal antibody; LC-1: Liver cytosol type-1 antibody; SLA: Anti-soluble liver antigen/liver–pancreas antigen; ASGP-R: Asialoglycoprotein receptor; pANCA: Perinuclear anti-neutrophil cytoplasmic antibody.

Table 2 The differences between seropositive and seronegative autoimmune hepatitis

Seropositive individuals	Seronegative individuals
High IgG	Normal IgG (may be high)
Presents with an acute or chronic course of disease	Generally, presents with acute manifestations
Does not show bone marrow abnormality	Lymphopenia may accompany (generally initially) and bone marrow failure may develop
Autoantibodies are detectabl on admission	Autoantibody positivity may develop after immunosuppressive therapy
Disease onset is usually in the second decade for type 1 AIH and at any age in the first decade for type 2	Disease onset is similar to type 2 AIH (may be at any age)
Treatment response is generally good	Treatment response is generally good
Immunosuppressant withdrawal possible (Recurrence rate is higher in type 2 AIH than type 1)	Immunosuppressant withdrawal possible (Recurrence rate is unknown)

IgG: Immunoglobulin G; AIH: Autoimmune hepatitis.