[Laboratory tests for kidney disease].

Kidney diseases are among the most frequently reported diseases with a poor prognosis that are diagnosed too late. According to current Kidney Disease Improving Global Outcomes (KDIGO) guidelines, diagnosis and risk stratification are mainly based on functional markers (creatinine and cystatin C), which are used to determine the estimated glomerular filtration rate (eGFR) and the analysis of urinary albumin excretion as a marker of kidney damage. These methods have limitations that can complicate the interpretation of the results and can lead to a delay of the diagnosis as well as to a misinterpretation of the prognosis. Therefore, new damage markers are required that sensitively and specifically detect kidney damage and enable targeted treatment. Urinalysis complements the laboratory diagnostic spectrum of diseases of the kidneys and urinary tract. It is mainly used for screening and provides important information on localization (renal/postrenal) and differentiation of kidney diseases (glomerular/tubulointerstitial).