Review: Serum and urine biomarkers of kidney disease: A pathophysiological perspective

Abstract

The use of reliable biomarkers is becoming increasingly important for the improved management of patients with acute and chronic kidney diseases. Recent developments have identified a number of novel biomarkers in serum or urine that can determine the potential risk of kidney damage, distinguish different types of renal injury, predict the progression of disease and have the potential to assess the efficacy of therapeutic intervention. Some of these biomarkers can be used independently while others are more beneficial when used in combination with knowledge of other clinical risk factors. Advances in gene expression analysis, chromatography, mass spectrometry and the development of sensitive enzyme-linked immunosorbent assays have facilitated accurate quantification of many biomarkers. This review primarily focuses on describing new and established biomarkers, which identify and measure the various pathophysiological processes that promote kidney disease. It provides an overview of some of the different classes of renal biomarkers that can be assessed in serum/plasma and urine, including markers of renal function, oxidative stress, structural and cellular injury, immune responses and fibrosis. However, it does not explore the current status of these biomarkers in terms of their clinical validation.

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“…5,[36][37][38][39] However, in our study, the influence of proteinuria was significant only in the univariate model, before adjusting for AST. Thus, urinary AST was superior to nonselected proteinuria for predicting progressive decline in KAG function.…”

Arterial Hypertension and Renal Disease

“…Albumin is the most abundant protein in the circulation and during normal kidney function very little intact albumin is excreted by the kidney (<30 mg/day in humans) (Tesch, 2010). It is known that a slight increase of urinary albumin excretion (microalbuminuria) is a predictor of renal and cardiovascular events in hypertensive patients (Hillege, 2002).…”

“…It is known that a slight increase of urinary albumin excretion (microalbuminuria) is a predictor of renal and cardiovascular events in hypertensive patients (Hillege, 2002). Albuminuria is frequently used as an early marker of renal injury because it often precedes a decline in renal function (Tesch, 2010). In arterial hypertension, an increased transglomerular passage of albumin may result from several mechanisms-hyperfiltration, glomerular basal membrane abnormalities, endothelial dysfunction, and nephrosclerosis (Redon, 2002).…”

“…Blood urea nitrogen and creatinine clearance are well-established biomarkers of kidney function that can be measured cheaply and easily (Tesch, 2010). Increases levels of serum creatinine are the main manifestations of hypertension-associated renal dysfunction.…”

Urine biomarkers in renal allograft

“…Such assays may prove useful for determining the nature of renal injury or the stage of disease in patients. [42] Novel multiplex technologies such as Biomarker Panel Array (BPA) may provide a new perspective for diagnosis and prognosis of renal rejection after kidney transplantation; more importantly, these technologies could significantly improve the sensitivity and specificity in reflecting the clinical manifestations. It is important to note that the advancement of proteomics technologies may become a critical drive for the discovery of novel urinary biomarkers which could specifically and accurately reflect underlying molecular events of allograft rejection.…”