Endogenous markers for kidney function in children: a review

Abstract

Although glomerular filtration rate (GFR) in children can be measured using a gold-standard technique following injection of an exogenous marker, this invasive and cumbersome technique is not widely available and GFR is commonly estimated using serum levels of endogenous markers. Creatinine, urea, cystatin C, beta-trace protein, and beta-2 microglobulin are well-established endogenous markers of kidney function. These markers differ in site of production and effects of diet and medication, as well as renal-tubular handling and extra-renal elimination. For each marker, different methods are available for measurement. Importantly, the measurements of creatinine and cystatin C have recently been standardized with the introduction of international reference standards. In order to allow estimation of GFR from serum marker concentrations, different equations for estimated GFR (eGFR) have been developed in children, using simple or more complex regression strategies with gold standard GFR measurements as a dependent variable. As a rule, estimation strategies relying on more than one marker - either by calculating the average of single parameter equations or by using more complex equations incorporating several parameters - outperform eGFR estimations using only a single marker. This in-depth review will discuss the physiology, measurement and clinical use of creatinine, urea, cystatin C, beta-trace protein, and beta-2 microglobulin in children. It will also address the generation of eGFR equations in children and provide an overview of currently available eGFR equations for the pediatric age group.

Biochemical and Histological Changes Associated with Azo Food Dye (Tartrazine) in Male Albino Rats

“…In assessing the renal functional integrity, biochemical parameters such as urea and creatinine are used [19]. Creatinine is nitrogen containing by-product formed by the actions of creatine-kinase on creatine which is synthesized in the liver from arginine, glycine and methionine [21]. Diet and state of hydration or dehydration does not influence creatinine much compared to urea.…”

“…Diet and state of hydration or dehydration does not influence creatinine much compared to urea. An elevated level of plasma creatinine is usually associated with renal dysfunction [21]. Tartrazine at a dose above ADI have been reported to induce renal dysfunction in rats even though there are still contradictory scientific review reports.…”

Choosing the Optimal Method for Measuring Glomerular Filtration Rate in Pediatric Intensive Unit

“…Иные экзогенные маркеры также обладают высокой ПЕДИАТРИЧЕСКАЯ ФАРМАКОЛОГИЯ /2018/ ТОМ 15/ № 3 точностью в определении СКФ [1,9], однако и они не наш-ли применения в клинической практике. Использование для расчета СКФ цистатина С -эндогенного, более точного маркера по отношению к креатинину [10,11], существенно ограничено по причине относительно высо-кой стоимости его определения [12]. Таким образом, на сегодняшний день наиболее часто учитываемым эндогенным маркером измерения СКФ как у детей, так и у взрослых остается креатинин [13].…”

“…На концентрацию креати-нина в сыворотке крови влияют общий объем попереч-нополосатой мышечной ткани, функция печени, общий метаболизм в организме, а также диета [10,13,15,16]. При рождении у детей (в особенности у недоношенных) первоначальная концентрация креатинина обусловле-на не столько собственной продукцией, сколько объ-емами, накопленными в пренатальном периоде при передаче от матери через плаценту [17].…”

Determination of glomerular filtration rate using cystatin C in healthy Nigerian newborns

“…Furthermore, jaundice is a common clinical condition in the newborns that tends to affect serum creatinine measured with the Jaffe reaction method [5]. Also, there is significant variation in the levels of day to day creatinine [6]. In contrast, cystatin C is a non-glycated basic protein with a molecular weight of 13.3 kDa and functions as an inhibitor of cysteine proteinase [4].…”