Autoimmune hepatitis in the context of systemic lupus erythematosus: A narrative review of overlap syndrome and lupus-associated hepatitis

Table 5 Autoantibody profile and discriminatory value in the diagnosis of autoimmune hepatitis vs lupus hepatitis in patients with systemic lupus erythematosus

Autoantibody	Sensitivity in AIH	Specificity for AIH	Prevalence in SLE	Discriminatory value in AIH-SLE	Clinical notes
ANA	80%	Low	95%-99%	None	Intrinsic to SLE; not useful for discrimination
Anti-SMA (VG/VGT)	63%	Moderate	Approximately 4.4%	High	VG/VGT immunofluorescence pattern strongly favours AIH; anti-F-actin ELISA: AUROC 0.88
Anti-SLA/LP	14%-20%	99%	Not reported	Very high	Only AIH-specific autoantibody; sole marker in 14%-20% of AIH; associated with higher biochemical response rates; target antigen: SepSecS
Anti-LKM1	3% (type 2 AIH)	High	Rare	High if present	Marker of type 2 AIH; predominantly paediatric; target antigen: CYP2D6
Anti-ribosomal P	0%	High for lupus hepatitis	10%-40%	High-favours lupus hepatitis	Present in 68.8% of lupus hepatitis vs 0% of primary AIH; OR approximately 5.4 for hepatic SLE involvement (meta-analysis)
Polyreactive IgG	75%-88% (including seronegative AIH)	High	Not studied	Potentially high	25%-14% higher specificity than ANA/SMA; present in 88% of seronegative AIH; returns to baseline on treatment; not studied in SLE-AIH overlap
Anti-MRPS27	61.8%	87.1%	Not studied	Unknown	Novel biomarker identified by human proteome microarray; titres unchanged with treatment; role in AIH-SLE overlap unexplored

AIH: Autoimmune hepatitis; SLE: Systemic lupus erythematosus; SMA: Smooth muscle antibody; ELISA: Enzyme-linked immunosorbent assay; AUROC: Area under the receiver operating characteristic curve; SLA: Soluble liver antigen; LP: Liver-pancreas; SepSecS: O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase; CYP2D6: Cytochrome P450 2D6; LKM1: Liver kidney microsomal antibody type 1; OR: Odds ratio; IgG: Immunoglobulin G; ANA: Antinuclear antibody; SMA: Smooth muscle antibody; MRPS27: Mitochondrial ribosomal protein S27.