Liver diseases are commonly diagnosed using serum enzyme assays, particularly for aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), and 5'-nucleotidase (5'-NT). While elevated levels of these enzymes are typically associated with liver and bile duct injuries, subnormal levels can also indicate various pathologies. This review consolidates current knowledge on diseases linked with subnormal liver enzyme levels, focusing on their pathogenesis, specificity, and treatment implications.
Aminotransferases: ALT and AST, critical for amino acid metabolism, are mainly found in hepatocytes but also exist in renal, cardiac, and skeletal tissues. ALT is more specific to the liver, while AST is present in both cytoplasm and mitochondria. Subnormal aminotransferase levels can result from deficiencies in pyridoxal 5'-phosphate (PLP, vitamin B6), often seen in conditions such as:
Alkaline Phosphatase (ALP): ALP, a membrane-bound glycoprotein involved in phosphate metabolism, has several isozymes (intestinal, placental, germ-cell, tissue-nonspecific). Subnormal ALP levels are associated with:
Gamma Glutamyl Transferase (GGT): GGT is important in glutathione metabolism and is a marker for bile duct function. Subnormal levels are noted in:
5'-Nucleotidase (5'-NT): This enzyme is involved in nucleotide metabolism. Low levels can indicate:
Subnormal serum levels of liver enzymes are clinically significant and can indicate a variety of underlying conditions. Recognizing these patterns can aid in the early diagnosis and management of diseases such as vitamin B6 deficiency, chronic kidney disease, and specific genetic disorders. Understanding the pathophysiological mechanisms behind these enzyme deficiencies is crucial for developing targeted treatments and improving patient outcomes. The diagnostic approach to patients presenting with subnormal liver enzyme levels should include a thorough clinical history, dietary assessment, and consideration of potential genetic and acquired conditions. This comprehensive understanding will facilitate more effective patient care and treatment strategies.
Full text
https://www.xiahepublishing.com/2310-8819/JCTH-2023-00446
The study was recently published in the Journal of Clinical and Translational Hepatology .
The Journal of Clinical and Translational Hepatology (JCTH) is owned by the Second Affiliated Hospital of Chongqing Medical University and published by XIA & HE Publishing Inc. JCTH publishes high quality, peer reviewed studies in the translational and clinical human health sciences of liver diseases. JCTH has established high standards for publication of original research, which are characterized by a study’s novelty, quality, and ethical conduct in the scientific process as well as in the communication of the research findings. Each issue includes articles by leading authorities on topics in hepatology that are germane to the most current challenges in the field. Special features include reports on the latest advances in drug development and technology that are relevant to liver diseases. Regular features of JCTH also include editorials, correspondences and invited commentaries on rapidly progressing areas in hepatology. All articles published by JCTH, both solicited and unsolicited, must pass our rigorous peer review process.
Follow us on X: @xiahepublishing
Follow us on LinkedIn: Xia & He Publishing Inc.
Journal of Clinical and Translational Hepatology
Subnormal Serum Liver Enzyme Levels: A Review of Pathophysiology and Clinical Significance
18-Mar-2024