Figure 1.

Proposed diagnostic algorithm for patients with suspected AIH. Antibodies are detected in >95% of patients if testing strictly adheres to the guidelines. In cases with acute severe AIH (AS-AIH), a trial with corticosteroid administration may be justified before obtaining the results, as autoimmune serology testing may be quite time-consuming.

*IgG may also be within normal levels in about 39% of AS-AIH

**ANA and SMA can also be evaluated by IFA on HEp2 cells or ELISAs (for details and rules see text and Table 6) [5]. All labs should strictly adhere to the guidelines in terms of the techniques used and the cutoffs considered for reactivity

IgG, immunoglobulin G; ULN, upper limit of normal; AIH, autoimmune hepatitis; IFA, immunofluorescence assay; anti-SLA/LP, antibodies against soluble liver antigens/liver pancreas; ELISA, enzyme-linked immunosorbent assay; ANA, antinuclear antibodies; SMA, smooth muscle antibodies; anti-LKM1, anti–liver kidney microsomal type-1 antibodies; anti-LC1, anti–liver cytosol type-1 antibodies; pANNA, perinuclear anti-neutrophil nuclear antibodies; anti-dsDNA, antibodies against double stranded DNA; anti-LKM3, anti–liver kidney microsomal type-3 antibodies; anti-F actin, antibodies against filamentous actin; anti-Ro52, antibodies against Ro52 autoantigen; pIgG, polyreactive IgG; NMR, nuclear magnetic resonance