From the Guidelines
Elevated Lactate Dehydrogenase (LDH) levels are associated with a worse prognosis and increased mortality in various conditions, including cancer and liver disease, as evidenced by studies such as 1 and 1. The implications of elevated LDH levels are significant, as they can indicate tissue damage or death in various parts of the body. LDH is an enzyme found in nearly all body tissues, and its elevation is a general marker of tissue damage rather than a diagnostic test for a particular disease.
Common Causes of Elevated LDH Levels
- Heart attack
- Liver disease
- Certain cancers
- Hemolysis (red blood cell destruction)
- Muscle damage
- Severe infections
Prognostic Value of LDH
Elevated LDH levels have been associated with poor outcomes in patients with osteosarcoma, as shown in a study of 1421 patients with osteosarcoma of the extremity, where high LDH levels were correlated with lower 5-year disease-free survival rates 1. Similarly, in patients with cutaneous melanoma, elevated LDH levels are associated with worse survival and are incorporated into the AJCC melanoma staging system for the classification of stage IV disease 1.
Clinical Significance
In clinical practice, elevated LDH levels should prompt further investigation to determine the underlying cause, as treatment focuses on addressing the underlying condition rather than the LDH elevation itself. The degree of elevation can provide clues about the severity of tissue damage, with very high levels often indicating significant tissue destruction.
Recent Evidence
A recent study published in 2024 found that serum lactate, which is associated with LDH, is a predictor of mortality in critically ill patients with cirrhosis, and that a model incorporating MELD and lactate (MELD-LA) is an excellent predictor of in-hospital mortality 1.
Key Takeaways
- Elevated LDH levels are associated with tissue damage and poor outcomes in various conditions
- LDH is a general marker of tissue damage rather than a diagnostic test for a particular disease
- Further investigation is necessary to determine the underlying cause of elevated LDH levels
- Treatment focuses on addressing the underlying condition rather than the LDH elevation itself.
From the Research
Implications of Elevated Lactate Dehydrogenase (LDH) Levels
Elevated LDH levels have been associated with various clinical implications, including:
- Diagnostic value in the preclinical stage of malignant lymphoma 2
- Prognostic significance in patients with idiopathic pulmonary arterial hypertension, with higher levels correlating with increased severity and mortality 3
- Association with features of advanced disease and inferior survival in patients with multiple myeloma 4
- Pejorative predictive criteria, with levels superior to 10-fold the normal rate indicating a higher mortality rate 5
Clinical Outcomes and LDH Levels
Studies have shown that:
- Elevated LDH levels are strongly associated with HeartMate II pump thrombosis and poor clinical outcomes 6
- Early intervention for elevated LDH can improve clinical outcomes, with resolution of symptoms and reduced incidence of death or pump thrombosis 6
- LDH level elevations are associated with therapeutic failure, while normalization of LDH levels is attributable to effective treatment 5
LDH Levels and Disease Severity
Research has demonstrated that:
- Higher LDH levels are associated with increased disease severity and mortality in patients with idiopathic pulmonary arterial hypertension 3
- Elevated LDH levels can identify subgroups of patients with multiple myeloma who have a worse outcome 4
- LDH levels superior to 10-fold the normal rate are associated with a higher mortality rate, regardless of the underlying etiology 5