Liver panel and follow-up testing lead to primary biliary cholangitis diagnosis
Clinical cases: Gastroenterology
Situation
A 54-year-old woman presented with fatigue and pruritus. Initial labs showed ALP/GGT dominant elevation, elevated IgM, and normal IgG. Ultrasound showed no obstruction, and all other common causes for her symptoms were excluded upon examination.
Results
ALDG2 test results:
- AMA-M2 IgG: 0.4 U Positive
- HEp-2 IFA: <1:80 Negative
- SMA screen: Negative
Algorithm branch: AMA positive only
Next steps
Based on ALDG2 results, perform PBC2 test.
PBC2 test results:
- SP100 IgG: 65 U Positive
- gp210 IgG: 12 U Negative
- dsDNA IgG: 43 IU/mL Negative
- Smith IgG: 0.3 U Negative
Working interpretation: Primary biliary cholangitis (PBC) diagnosis strongly favored.
Teaching points
- AMA-only pattern follows the PBC/myositis/SLE differentiation branch. AMA+SP100 provide serological support for PBC diagnosis but do not stage disease.
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