Elevated lactate:pyruvate ratio

What it means

An abnormal increase in the molar ratio of lactate to pyruvate in the blood circulation.

The lactate:pyruvate (L:P) ratio reflects the equilibrium between the product and substrate of the reaction catalyzed by lactase dehydrogenase and indirectly reflects the NADH:NAD+ cytoplasmic redox state. When cellular respiration or mitochondrial oxidative metabolism is impaired, such as in inborn errors of components of the mitochondrial respiratory chain, there is an increase in reducing equivalents (excess NADH and absence of NAD+) which results in an elevated L:P molar ratio.

Rare diseases that can present with this2

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category