The goal of this observational study is detailed examination of endothelial glycocalyx in kidney transplantation. Researchers will evaluate markers of degradation of EG in blood and urine; and also perform direct visualisation of EG with sidestream dark field imaging (SDF) in both donors and recipients of kidney transplantation.

The aim is to summarize the current knowledge and to point out the importance of EG in kidney transplantation.

The endothelial glycocalyx (EG) is a thin layer on the surface of the endothelium that plays an important role for microcirculation and tissue metabolism. The role of EG is diverse - it acts as a protection of the endothelium against shear stress which is mediated on the intracellular structures of endothelial cells, allows the interaction of blood elements and endothelium, prevents the formation of uncontrolled thrombosis and excessive oxidative stress by free radicals. EG dysfunction can occur with partial or complete loss of its components, resulting in impaired vascular regulation and increased vascular permeability. Disruption or dysfunction of EG has been associated with disease states such as diabetes, chronic kidney disease, inflammatory conditions, sepsis, hypernatraemia, hypervolaemia and ischaemia/reperfusion injury. Enzymes such as hyaluronidase and metalloproteinases can degrade the components of EG. Damage to EG leads to the release of breakdown products into the bloodstream which can be detected. There are also direct methods of visualization of EG. Thanks to advances in the study of EG in kidney transplantation a comprehensive relationship in this field and specific clinical aspects can be assessed. In the future exploring potential therapeutic options to protect EG may have implications for better graft function and survival.

Inclusion Criteria:

• Patients undergoing kidney transplantation

Exclusion Criteria:

• Patients who don't sign the informed consent

Group 1: Donors after brain death, Donors after circulatory death Group 2: Patients with end-stage renal disease who are eligible for kidney transplantation