Inclusion Criteria:  Age ≥ 18 Recipient of a transplanted kidney Planned visit to the outpatient nephrology clinic of University Hospital Ostrava, Czech Republic, between 1.5. and 30.7.2021 for enrolment Planned blood collection and available results of blood tests from planned inspections from 18.1.2021. Signed consent to the use of anonymous data for scientific purposes and publications.  Exclusion Criteria:  disagreement with participation in the study and data analysis