What Is a Lactate Dehydrogenase (LDH) Test?

This post was written with Consensus AI Academic Search Engine – please read our Disclaimer at the end of this article. Lactate dehydrogenase (LDH) is an enzyme found in almost all body tissues. It plays a crucial role in the conversion of lactate to pyruvate, a key step in cellular respiration. The LDH test measures the amount of LDH in the blood or other body fluids and is used to detect tissue damage and monitor certain conditions.

Purpose of the LDH Test

The LDH test is primarily used to:

• Diagnose and monitor diseases: Elevated LDH levels can indicate tissue damage and are associated with various conditions such as heart disease, liver disease, muscle injury, and certain cancers1 2 3.
• Evaluate prognosis: In conditions like nasopharyngeal carcinoma and melanoma, high LDH levels correlate with disease progression and poorer outcomes1 2.
• Monitor treatment efficacy: For patients undergoing treatments such as chemotherapy, changes in LDH levels can help assess the effectiveness of the therapy7 9.

Methodology

The LDH test involves collecting a blood sample, which is then analyzed in a laboratory. The normal range for LDH levels in the blood is typically between 109.0-245.0 U/L, but this can vary depending on the laboratory and the specific population being tested1.

Clinical Significance

Cancer Prognosis

High pretreatment LDH levels have been shown to predict inferior outcomes in various cancers. For instance, in nasopharyngeal carcinoma, elevated LDH levels are associated with lower overall survival and higher rates of disease relapse1. Similarly, in metastatic melanoma, high LDH levels combined with imaging findings can accurately predict survival outcomes9.

Monitoring Disease Progression

In high-risk melanoma patients, elevated LDH levels correlate with disease progression, although they are not as effective as other markers like protein S-100B in detecting early distant metastasis2. In paraquat poisoning, elevated LDH levels are a significant predictor of poor prognosis, indicating severe tissue damage3.

Other Conditions

LDH levels are also useful in assessing the severity of pregnancy-induced hypertension and its complications. Higher LDH levels in preeclamptic and eclamptic women indicate more severe disease and potential complications5. In newborns with hypoxic-ischemic encephalopathy, elevated LDH levels can serve as an early marker of central nervous system damage6.

Applications in Research

Research has explored various applications of LDH measurements:

• Oral Health: A study on the effects of a novel herbal toothpaste found that brushing with the test toothpaste significantly reduced salivary LDH levels, indicating improved cellular integrity and oral health4.
• Exercise Physiology: Interval training has been shown to affect LDH activity, with significant increases in young rats, suggesting enhanced lactate clearance and improved metabolic function8.

Conclusion

The LDH test is a valuable diagnostic and prognostic tool in clinical practice. It helps in diagnosing tissue damage, monitoring disease progression, and evaluating treatment efficacy across various medical conditions. Elevated LDH levels are often indicative of severe disease and poorer outcomes, making it an essential marker in both clinical and research settings.

Disclaimer

The content presented in this blog is generated by Consensus, an AI-powered academic search engine, and is based on publicly available scientific literature. While every effort is made to provide accurate, up-to-date, and well-researched information, the content is intended for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making any decisions regarding medical conditions, treatments, or medications. The AI system’s analysis may not cover all perspectives, emerging research, or individual cases, and it is not a substitute for professional expertise. Neither the blog publisher nor the developers of the AI-powered search engine are responsible for any actions taken based on the information provided in this content. Use of this information is at your own risk. Citations to the original scientific studies are included for reference, but these studies should be reviewed in full and interpreted with the guidance of a healthcare or research professional.

If you are experiencing a medical emergency, please seek immediate attention from a healthcare provider.