CKDx – chronische Nierenerkrankung unklarer Ursache
摘要
Chronic kidney disease of unexplained cause (CKDx) describes a form of CKD in which no clear etiology can be identified despite a structured, comprehensive and contemporary diagnostic evaluation. Therefore, CKDx is a diagnosis of exclusion and, according to current registry and cohort data, affects approximately 16–20% of all patients with CKD. Despite its clinical relevance, there is still no uniform definition or standardized recommendations for diagnostic evaluation and reporting. The consensus paper by the European Renal Association (ERA) working group Genes & Kidney establishes CKDx as a process-based concept that transparently addresses diagnostic uncertainty and counteracts premature nonspecific diagnoses. The diagnosis of CKDx requires a structured evaluation including medical history, family history, laboratory and urine diagnostics, imaging as well as histological and genetic investigations, depending on the clinical context. Genetic testing in particular is becoming increasingly more important, as modern sequencing technologies enable a causal diagnosis in a relevant proportion of cases. In addition, a standardized reporting system is proposed to transparently document histological and genetic findings. Therefore, CKDx should not be understood as a diagnostic endpoint but more as a dynamic classification aimed at regular re-evaluation. The concept thus provides the basis for the further development of cause-oriented, precision medicine approaches in nephrology.