Table 2.
Characteristics of autoantibodies in AIH
| Autoantibody | Method of detection | Frequency | Characteristics |
|---|---|---|---|
| ANA | IFA | 75–95% | AIH-1 |
| ELISA/Immunoblot | Homogenous pattern in 2/3; speckled or nucleolar in 1/3 on HEp-2 cell using IFA | ||
| SMA | IFA | –75% | Strongly favors AIH-1, particularly when combined with ANA at high titers |
| ELISA/Immunoblot (Actin) | |||
| Anti-LKM1 | IFA | 70% in AIH-2 | AIH-2 after excluding hepatitis C |
| ELISA/Immunoblot | Titer correlates with disease activity. | ||
| Anti-LC1 | IFA | 30% in AIH-2 | AIH-2 after excluding hepatitis C |
| ELISA/Immunoblot | |||
| Anti-SLA | ELISA/Immunoblot | 20–30% in AIH-1 and AIH-2 | Specific for AIH |
| Associated with more severe disease | |||
| p-ANNA | IFA | 20–96% in AIH-1 | Detected as the only serological marker in suspected AIH-1 with negative ANA, SMA, and anti-SLA |
AIH-1, autoimmune hepatitis type 1; AIH-2, autoimmune hepatitis type 2; ANA, antinuclear antibody; anti-LC1, antibody to liver cytosol type 1; anti-LKM1, antibody to liver kidney microsome type 1; anti-SLA, antibody to soluble liver antigen; ELISA, enzyme-linked immunosorbent assay; IFA, indirect immunofluorescence assay; p-ANNA, perinuclear antineutrophil nuclear antibody; SMA, smooth muscle antibody.