A new study from researchers of CEDOC-NOVA Medical School and Instituto Gulbenkian de Ciência, led by Maria Paula Macedo and Carlos Penha-Gonçalves, respectively, showed that a molecule CD26/DPP-4 is involved in the regeneration of acute liver wounds and is a promising biomarker for hepatic disease.

It is known that DPP-4 regulates insulin secretion upon food intake. The regulation of the levels of "sugar in the blood" in type-2 diabetics is performed by therapeutic inhibition of enzymatic activity of the molecule CD26/DPP-4.

This approach has earned clinical relevance. Moreover, apart from its role in the control of the amount of sugar present in blood, the molecule DPP4 appears to be related to inflammatory reactions in various pathological processes.

Liver injury

liver injury, also known as liver laceration, is some form of trauma sustained to the liver. This can occur through either a blunt force such as a car accident, or a penetrating foreign object such as a knife. 

Liver injuries constitute 5% of all traumas, making it the most common abdominal injury. Generally, nonoperative management and observation are all that is required for a full recovery.

Diagnosing liver injury

Imaging, such as the use of ultrasound or a computed tomography scan, is the generally preferred way of diagnosis as it is more accurate and is sensitive to bleeding, however; due to logistics, this is not always possible. 

For a person who is hemodynamically unstable a focused assessment with sonography for trauma   (FAST) scan may take place which is used to find free floating fluid in the right upper quadrant and left lower quadrant of the abdomen

The role of CD26/DPP-4 during liver injury

In this study, the researchers explored the role of CD26/DPP-4 during injury of the hepatic tissue leading to an evident reduction of the main liver immune cell population (Kupffer cells).

It was shown that the blood levels of CD26/DPP-4 enzymatic activity are augmented when this population of liver immune cells is diminished, both in acute and chronic mouse models of liver injury.

Inversely, the levels of blood enzymatic activity decreased during the recovery of these cells. The authors observed that specific deletion of such immune liver cell population in the absence of liver tissue damage also lead to a significant increase in CD26/DPP4 blood enzymatic activity.

Thus, these results show the close relationship between functional changes in Kupffer cells associated with hepatic diseases and the molecule CD26/DPP-4. The relation between the liver immune cells and the enzymatic activity of CD26/DPP-4 in the blood, exhibited in this study, suggests that the level/amount of the enzymatic activity of the molecule CD26/DPP-4 in the blood might be used as a biomarker.

Moreover, it can become a valuable biochemical parameter for the evaluation of hepatic lesion or disorder since so far can this evaluation can only be performed using invasive techniques.