From the Guidelines
An autoimmune liver screen should be performed in patients with unexplained elevated liver enzymes, jaundice, fatigue, or other symptoms suggesting liver dysfunction without clear causes like alcohol use, medications, or viral hepatitis, as it is crucial for early diagnosis and treatment of autoimmune liver diseases, which can significantly improve morbidity, mortality, and quality of life. The screen typically includes tests for antinuclear antibodies (ANA), anti-smooth muscle antibodies (ASMA), anti-mitochondrial antibodies (AMA), anti-liver kidney microsomal antibodies (anti-LKM), and immunoglobulin levels (particularly IgG) 1. According to the most recent guidelines, if AIH is suspected, ANA and SMA are performed as screening tests, and anti-LKM1, anti-LC1, anti-SLA, or ANCA can be further examined if clinically necessary 1. Results must be interpreted alongside clinical presentation, liver function tests, and sometimes liver biopsy findings, as positive antibody tests don't always confirm disease but indicate the need for further evaluation 2, 3. Early diagnosis is crucial as autoimmune liver diseases respond well to immunosuppressive therapy, typically starting with prednisone and often adding azathioprine as a steroid-sparing agent, with the goal of normalizing liver enzymes and preventing progression to cirrhosis, and most patients requiring long-term maintenance therapy 3. Key considerations in the diagnosis and management of autoimmune hepatitis include integrating laboratory findings, the presence of autoantibodies, and compatible histologic findings, as well as considering the possibility of overlap syndromes such as AIH-PBC or AIH-PSC overlap syndrome 1. In clinical practice, the diagnosis and treatment of autoimmune liver diseases should be guided by the most recent and highest-quality evidence, with a focus on improving patient outcomes and quality of life 1. The use of a revised diagnostic scoring system or a simplified diagnostic scoring system can aid in the diagnosis of AIH, and liver biopsy can provide important prognostic information and help guide treatment decisions 2, 1. Overall, an autoimmune liver screen is a critical tool in the diagnosis and management of autoimmune liver diseases, and its use should be guided by the most recent and highest-quality evidence, with a focus on improving patient outcomes and quality of life.
From the Research
Autoimmune Liver Disease Screening
- Autoimmune liver diseases (ALD) are characterized by immune-mediated injury of bile ducts or hepatocytes, and include conditions such as primary biliary cirrhosis (PBC), primary sclerosing cholangitis, and autoimmune hepatitis 4.
- Serum autoantibodies, together with imaging and histology, are critical to the diagnostic process when ALD is suspected 4.
- The development of sensitive and specific tests for serum autoantibodies is a priority for researchers to ensure a more efficient noninvasive workup 4.
Diagnostic Tests
- Indirect immunofluorescence (IIF) on triple rodent tissue is still the gold standard screening procedure for liver-relevant autoantibodies 5.
- Assays based on purified or recombinant antigens are increasingly used, having the main advantage of being observer-independent 5.
- Anti-nuclear antibody (ANA), anti-smooth muscle antibody, and anti-liver kidney microsomal antibody are commonly used to diagnose autoimmune hepatitis 5.
- Anti-mitochondrial antibody is the hallmark of primary biliary cholangitis (PBC), being disease-specific and present in about 95% of PBC patients 5.
Clinical Significance
- Autoantibodies may be present in the context of viral hepatitides and other inflammatory liver diseases, making it important to exclude these conditions before diagnosing autoimmune liver disease 5.
- The presence of certain autoantibodies can be predictive of disease activity or prognosis in liver diseases 6.
- Treatment with interferon can initiate the production of autoantibodies in patients with chronic hepatitis C virus infection, which may postulate the treatment outcome 6.
- Oxidative stress has been linked to the production of autoantibodies in liver diseases 6.
Diagnosis and Therapy
- The diagnosis of autoimmune liver disease can be facilitated by sequential measurement of relevant autoantibodies, exclusion of other liver disease, ultrasound, ERCP, and liver histology 7.
- Immunosuppressive therapy has been shown to prevent or stop the development of cirrhosis and improve the prognosis of patients with autoimmune hepatitis 7.
- Ursodesoxycholic acid (UDCA) seems to slow disease progression in particular in early stages of PBC 7.
- Overlap syndromes of autoimmune liver diseases, such as AIH with PBC or PSC, may comprise up to 10% of cases, and variant syndromes such as antimitochondrial antibody-negative PBC also occur 8.