Autoimmune hepatitis in childhood: a 20-year experience

Area of Science:

• Pediatric Gastroenterology and Hepatology
• Immunology
• Clinical Biochemistry

Background:

• Autoimmune hepatitis (AIH) is a chronic liver disease of unknown etiology.
• Childhood AIH presents with diverse clinical, biochemical, and histological features.
• Distinguishing between AIH subtypes is crucial for prognosis and management.

Purpose of the Study:

• To delineate the clinical, biochemical, histological features, and outcomes of childhood AIH.
• To compare anti-nuclear and/or smooth muscle antibody (ANA/SMA) positive AIH with liver/kidney microsomal antibody (LKM-1) positive AIH.
• To identify predictors of outcome in pediatric AIH.

Main Methods:

• Retrospective review of medical records for 52 children diagnosed with AIH.
• Categorization into ANA/SMA positive (32) and LKM-1 positive (20) groups.
• Analysis of clinical presentation, biochemical markers, histological findings, HLA associations, treatment response, and long-term outcomes.

Main Results:

• LKM-1 positive AIH patients were younger with higher bilirubin and AST levels at presentation.
• ANA/SMA positive AIH patients showed a higher frequency of HLA A1/B8/DR3/DR52a and a greater proportion were cirrhotic at diagnosis.
• While both subtypes had similar severity and long-term outcomes, immunosuppression withdrawal was successful only in ANA/SMA positive cases.

Conclusions:

• Childhood ANA/SMA positive and LKM-1 positive AIH exhibit distinct clinical and biochemical profiles.
• Despite differences, both subtypes share comparable disease severity and long-term prognosis.
• Baseline bilirubin and INR are key predictors of outcome in pediatric AIH.