From the Guidelines
Low lactate dehydrogenase (LDH) levels are generally not considered clinically significant in the context of morbidity, mortality, and quality of life. When evaluating the significance of low LDH, it's essential to consider the context in which it's being measured. In the case of testicular cancer, LDH is a less-specific marker than alpha-fetoprotein (AFP) and β-human chorionic gonadotropin (β-HCG) 1.
- LDH is an enzyme found in many body tissues, and while elevated levels often indicate tissue damage or disease, low levels rarely cause concern in clinical practice.
- Low LDH may occasionally be seen in cases of genetic LDH deficiency, which is an extremely rare inherited condition that can affect how the body processes glucose for energy.
- Some patients with this deficiency may experience muscle pain or weakness during exercise, but many remain asymptomatic.
- Low LDH can also sometimes occur with certain medications, malnutrition, or extensive fluid administration that dilutes blood components. However, these findings typically don't require specific treatment unless accompanied by symptoms, and the focus is usually on elevated values rather than low ones, as high LDH levels are associated with numerous pathological conditions including tissue damage, hemolysis, certain cancers, and organ dysfunction 1. In clinical practice, the normal range for LDH varies by laboratory, but generally falls between 140-280 U/L for adults, and healthcare providers typically focus on elevated values rather than low ones.
From the Research
Significance of Low LDH
- Low LDH levels can be observed in certain cases of autoimmune hemolytic anemia (AIHA), as reported in a study published in 2, where 25% of AIHA patients had normal LDH levels.
- In the context of sickle cell anemia, low LDH levels may not be directly associated with the severity of the disease, as elevated LDH levels are more commonly linked to hemolysis and disease severity, as seen in 3.
- Low LDH levels are not typically considered a significant indicator of disease severity or progression in conditions like acute leukemia, where elevated LDH levels are more commonly associated with lymphoblastic leukemia, as reported in 4.
- In megaloblastic anemia, low LDH levels are not diagnostic, as total serum LDH levels above 3000 IU/L are considered diagnostic of this condition, according to 5.
- In diabetic patients, the significance of low LDH levels is not well-established, but determining LDH levels can help assess disease progression, as suggested in 6.