[Selected proteins as biomarkers of kidney injury used in the nephrological diagnosis].

Acute kidney injury (AKI) is an important clinical entity, developing in hospitalized patients due to rapid deterioration of the kidney function, while chronic, progressive glomerulopathies, tubulointerstitial damage, recurrent pyelonephritis, long-lasting nephrolithiasis or systemic diseases affecting kidneys (hypertension, diabetes), result in chronic kidney disease (CKD) development. Early AKI detection enables the implementation of appropriate therapy, which in some cases prevents the irreversible complications, leading to patient's death. Similarly, the correct biochemical assessment allows for monitoring CKD course, which reduces the risk of chronic complications and the development of symptomatic, chronic kidney failure. Therefore, novel laboratory parameters are still sought, endowed with the high sensitivity and specificity, which allow for the reliable AKI diagnosis or estimation of the CKD advancement. The paper focuses on discussing the role of the four proteins: cystatin C, neutrophil gelatinase-associated lipocalin-1 (NGAL), kidney injury molecule-1 (KIM-1) and αKlotho as novel biomarkers in AKI/CKD diagnosis.