Premium Nahrungsergänzungsmittel | artgerecht

Glutamate Pyruvate Transaminase (GPT) – Liver Enzyme

Glutamate pyruvate transaminase (GPT) is a liver enzyme measured in blood tests to assess liver function and detect liver cell damage.

Regular tips about health Regular tips about health

Things worth knowing about "Glutamate Pyruvate Transaminase"

Glutamate pyruvate transaminase (GPT) is a liver enzyme measured in blood tests to assess liver function and detect liver cell damage.

What is Glutamate Pyruvate Transaminase?

Glutamate pyruvate transaminase (GPT), also known as alanine aminotransferase (ALT) or SGPT (serum glutamate pyruvate transaminase), is an enzyme found primarily in liver cells (hepatocytes). Smaller amounts are present in the kidneys, heart muscle, skeletal muscle, and pancreas. Under normal conditions, GPT is detectable in the blood only at very low concentrations.

Measuring the GPT level in the blood is a key component of liver function testing and is one of the most commonly ordered laboratory tests in clinical medicine.

Function and Mechanism of Action

GPT catalyzes a biochemical reaction in amino acid metabolism: it transfers an amino group from alanine to alpha-ketoglutarate, producing pyruvate and glutamate. This reaction plays an important role in both energy metabolism and the urea cycle within the liver.

Because this enzyme is predominantly located inside liver cells, its blood level rises significantly when liver cells are damaged and release their contents into the bloodstream. GPT is therefore considered a liver-specific marker of cell injury.

Clinical Significance and Diagnosis

GPT is measured as part of a blood test (liver panel). Reference ranges may vary slightly between laboratories, but typical values are:

Women: up to approximately 35 U/L (units per liter)
Men: up to approximately 45 U/L

Elevated GPT levels indicate damage or inflammation of liver cells. The degree of elevation and the clinical context help determine the underlying cause and severity.

Causes of Elevated GPT Levels

Viral hepatitis (e.g., hepatitis A, B, C): marked elevation, often more than ten times the upper limit of normal
Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH): mild to moderate elevation
Alcoholic liver disease: moderate elevation, often combined with elevated AST (GOT)
Liver cirrhosis: variable levels depending on disease activity
Drug-induced liver injury: e.g., from paracetamol, statins, or antibiotics
Liver tumors or metastases
Congestive heart failure with hepatic congestion
Intense physical exercise or muscle disorders (less common, as GPT is also present in muscle tissue)

AST/ALT Ratio (De Ritis Ratio)

In clinical practice, GPT (ALT) is frequently evaluated together with GOT (glutamate oxaloacetate transaminase, AST). The AST/ALT ratio, known as the De Ritis ratio, provides important diagnostic clues:

A ratio below 1 (ALT higher than AST) is more suggestive of viral hepatitis or fatty liver disease.
A ratio above 2 (AST markedly higher than ALT) is more indicative of alcoholic liver disease.

When Should GPT Be Measured?

Testing for GPT levels is appropriate in the following situations:

Suspected liver disease (e.g., jaundice, upper abdominal pain, unexplained fatigue)
Follow-up monitoring in patients with known liver conditions
Monitoring patients on medications with known hepatotoxic potential
Screening in high-risk groups (e.g., obesity, excessive alcohol consumption, type 2 diabetes)
Routine health check-ups

Management of Elevated GPT Levels

Treatment always targets the underlying cause. Elevated GPT is not a diagnosis in itself but a signal of possible liver injury. Depending on the cause, management may include:

Alcohol abstinence in alcohol-related liver disease
Weight loss and dietary changes in fatty liver disease
Antiviral therapy for viral hepatitis
Discontinuation or adjustment of hepatotoxic medications
Regular monitoring of liver enzyme levels over time

References

Longo DL et al. - Harrison's Principles of Internal Medicine, 20th edition (2018), McGraw-Hill Education.
European Association for the Study of the Liver (EASL) - EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis (2021). Journal of Hepatology, 75(3), 659-689.
Schiff ER, Maddrey WC, Reddy KR - Schiff's Diseases of the Liver, 12th edition (2018), Wiley-Blackwell.

Building Blocks for a Healthy Life

As an integrated manufacturer, we develop & produce evidence-based, patented, and non-patented formulations. We work exclusively with plant and natural extracts according to the strictest purity & quality standards.
The combination of science & modern technology with the laws of nature creates solutions consistently tailored to humans – for the highest good: health.