Lactate Dehydrogenase (LDH)

Lactate dehydrogenase (LDH) is an enzyme that can be present in elevated levels in blood serum in various diseases. Five different LDH isozymes can be distinguished, each consisting of the H and M subunits.

Lactate dehydrogenase is used primarily in the diagnosis of myocardial infarction.

An increase in LDH can be expected after 6 to 12 hours after infarct onset.The maximum is reached after 48 to 144 hours after infarct onset.Normalization occurs after approximately 7 to 15 days.

The procedure

Material needed

  • Blood serum

Preparation of the patient

  • Not known

Disruptive factors

  • Expeditious processing of the blood sample (avoid hemolysis! This leads to highly pathological elevation of LDH).
  • Abseren required for prolonged storage after blood collection.

Standard values

Normal value in U/l(new reference range) Normal value in U/l(old reference range)
Women 135-215 120-240
Men 135-225 120-240
Newborn 150-785
1-6 months 160-437
7-12 months 145-365
1-2 years 86-315
2-3 years 106-296
12-19 years 90-270

Indications

  • Suspected anemia (anemia of the blood)
  • Suspicion of pulmonary embolism
  • Suspicion of myocardial infarction (heart attack)
  • Suspicion of skeletal muscle disease

Interpretation

Interpretation of increased values

  • Acute hepatitis (inflammation of the liver).
  • Anemia (anemia)
  • Endocarditis (inflammation of the inner lining of the heart)
  • Genetic muscle diseases such as muscular dystrophy.
  • Cardiac arrhythmias
  • Infectious mononucleosis (Pfeiffer’s glandular fever; Epstein-Barr virus infection))
  • Infectious myositis – inflammatory muscle diseases.
  • Coronary heart disease (CHD)
  • Physical stress
  • Liver damage due to intoxication (poisoning)
  • Pulmonary embolism – occlusion of a pulmonary artery, resulting in a reduced supply to the affected section of the lung.
  • Muscle overuse
  • Myeloproliferative neoplasms (MPN) (formerly chronic myeloproliferative diseases (CMPE)): e.g.
    • Chronic myeloid leukemia (CML).
    • Osteomyelosclerosis (OMS)
    • Polycythaemia vera (PV; synonyms: polycythemia, polycythemia).
  • Myocardial infarction (heart attack).
  • Myocarditis (inflammation of the heart muscle)
  • Pericarditis (inflammation of the pericardium)
  • Muscle trauma (muscle injury)
  • Condition after surgery on the heart

Interpretation of decreased values

  • Not relevant to the disease

Further notes

  • If myocardial infarction is suspected, the following laboratory parameters should be determined:
    • Myoglobin
    • Troponin T (TnT)
    • CK-MB (creatine kinase myocardial type).
    • CK (creatine kinase)
    • Aspartate aminotransferase (AST, GOT)
    • LDH (lactate dehydrogenase)
    • HBDH (hydroxybutyrate dehydrogenase)