Overview: Glutamine Synthetase Immunohistochemistry TestIntroduction: The Glutamine Synthetase Immunohistochemistry Test detects glutamine synthetase to diagnose liver tumors, causing jaundice or pain. Following 2023 AASLD guidelines, it uses immunohistochemistry for high specificity, supporting cancer screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in histopathology for patients with suspected hepatocellular carcinoma or other liver tumors.
Other Names: GS IHC Assay, Liver Tumor IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: Glutamine synthetase testing began in the 2000s with liver cancer research. Immunohistochemistry-based methods improved diagnostic precision for hepatic tumors.
Purpose: Detects glutamine synthetase to diagnose liver tumors, guides treatment, and evaluates patients with jaundice or pain.
Test Parameters: 1. Glutamine Synthetase Protein
Pretest Condition: No fasting required. Collect tissue via liver biopsy or surgical resection. Report history of jaundice, abdominal pain, or liver dysfunction.
Specimen: 0.5-2 cma³ tissue (FFPE). Transport in a biohazard container.
Sample Stability at Room Temperature: 7 days
Sample Stability at Refrigeration: Not refrigerated
Sample Stability at Frozen: Not frozen
Medical History: Document jaundice, abdominal pain, liver dysfunction, or family history of liver tumors. Include current medications, especially chemotherapy.
Consent: Written consent required, detailing the tests purpose, cancer implications, and risks of biopsy or surgery.
Procedural Considerations: Uses immunohistochemistry to detect glutamine synthetase in liver tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for liver tumor diagnosis.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive glutamine synthetase staining suggests hepatocellular carcinoma, guiding surgery or targeted therapy. Negative staining may require further marker testing.
Specialist Consultation: Consult a hepatologist or oncologist for result interpretation and treatment planning.
Additional Supporting Tests: AFP IHC, HepPar1 IHC, or liver imaging (e.g., CT/MRI) to confirm liver tumor diagnosis.
Test Limitations: Not specific to hepatocellular carcinoma; other liver tumors may express glutamine synthetase. Clinical correlation is needed.
References: AASLD Hepatocellular Carcinoma Guidelines, 2023; American Journal of Surgical Pathology, Shafizadeh N, 2022.
