Early kidney disease is asymptomatic and strongly associated with morbidity
and mortality, hence an accurate estimation of kidney function is crucial for its
diagnosis. In turn, an appropriate diagnosis and treatment of chronic and acute kidney
disease depends on early detection. Currently markers like blood concentrations of
creatinine and Cystatin-C are used to estimate glomerular filtration rate, and others as
proteinuria help to assess renal damage, but all of these have different limitations
indicating the need for new biomarkers that can discriminate and detect damage,
especially in the most critical situation during the development of kidney disease. Given
that kidneys are the most important excretory organ, changes in blood concentration
levels of a wide variety of metabolites can be a reflection of reduction of
kidney function and renal damage. An ideal biomarker for renal disease has to be able
to predict early diagnosis of kidney disease, allowing for identification of the type and
etiology of the lesion, as well as initiation and monitoring of treatments. In this chapter,
we describe the most relevant eGFR equation and biomarkers for kidney diseases.
Keywords: ADMA, AKI, BTP, CKD, Creatinine, Cystatin-C, FGF-23, GFR equations,
IL-18, KIM-1, Kidney disease, L-FABP, Microalbumin, NAG, NGAL,
Uric acid.
