Kidney transplantation is the preferred treatment method for patients with chronic kidney disease. Standard parameters (estimated glomerular filtration, albuminuria) of renal function detection are limited by many factors, therefore they are considered insufficient. Urinary post-translationally modified fetuin A (uPTM-FeA) appears to be a promising biomarker for the early detection of impaired renal function. Increased values were detected in patients with diabetic kidney disease, acute kidney injury and interstitial fibrosis/tubular atrophy.

Patients after kidney transplantation will be included in our analysis, in which the value of uPTM-FeA at the time of kidney graft biopsy performing (indication/ protocolar) and 6th months after biopsy. The study will also include the patients with chronic kidney disease after renal biopsy, when the value of uPTM-FeA be examined and then 6 months after renal biopsy. The analysis will be correlated with the basic characteristics of the donor and recipient, with the results of protocol or indication biopsy, rejection, level and dose of immunosuppression and parameters detecting renal function. The analysis will be correlated with the histopatology result of kidney biopsy.

The study also include patients with chronic kidney disease or acute kidney injury, who undergo renal biopsy. The value of uPTM-FeA be examined at the time of kidney biopsy and then 6 months after and correlated with the basic laboratory parametres and the results biopsy.

The aim of our study is to confirm the reliability of uPTM-FeA as a marker of kidney graft failure with the perspective of including uPTM-FeA examination in routine examination methods. Early detection of kidney graft failure can help save not only the graft, but also prolong the patient's life. And the second aim is correlated the value of uPTM-FeA with the severity of acute kindey injury and diagnosis of chronic kidney disease.

Inclusion Criteria for patients with kidney transplatation:

• patient age > 18 years,
• primary kidney transplantation;
• at least 12 months after kidney transplantation;
• immunosuppression: calcineurin inhibitors, mycophenolic acid analogues and corticosteroids;
• living donor or donation after brain death (DBD) donor;
• patient cooperation;
• regular check-ups in Transplant-Nephrology surgery at University Hospital Martin;
• provision of a sample of the first-morning urine;
• signed informed consent.

Exclusion Criteria with kidney transplatation:

• • patient age < 18 years;

  • secondary/tertiary kidney transplantation;
  • kidney transplantation in the last 12 months;
  • absence of ≥1 of the basic immunosuppressants (calcineurin inhibitors, mycophenolic acid analogues and corticosteroids);
  • contaminated sample of the first-morning urine (for example, menstruation);
  • non-provision of a sample of the first-morning urine;
  • disagreement of the patient with the Examination and inclusion in the study.

Inclusion Criteria for patients without kidney transplatation:

• patient age > 18 years,
• chronic kidney injury or acute kidney injury
• performed renal biopsy
• patient cooperation;
• regular check-ups in Transplant-Nephrology surgery at University Hospital Martin;
• provision of a sample of the first-morning urine;
• signed informed consent.

Exclusion Criteria with kidney transplatation:

• patient age < 18 years;
• absence of renal biopsy or non-represenantative sample of renal biopsy
• contaminated sample of the first-morning urine (for example, menstruation);
• non-provision of a sample of the first-morning urine;
• disagreement of the patient with the Examination and inclusion in the study.

Patients after primary kidney transplantation, whose undergo protocolar or indication graft biopsy.

It is a monocenter pilot study