This review aims to discuss the current evidence about the role of two biomarkers in pediatric acute kidney injury (AKI)-uromodulin (UMOD) and YKL-40 (a glycoprotein whose name is derived from the three N-terminal amino acids present on the secreted form and its molecular size of 40 kDa). Several novel biomarkers have been used in the diagnostic and prognostic evaluation of AKI. UMOD and YKL-40 or chitinase 3-like protein 1 have recently attracted scientific interest as potential biomarkers in the disease. Although UMOD has long been recognized as a marker of tubular health, it was only in the recent past that its functional role in health and disease began to be understood. The finding of low levels of the biomarker in AKI supports the recent discovery that it plays a protective rather than an instigatory role in the disease. Evidence synthesized from the reviewed studies suggests that urine UMOD levels are negatively correlated with AKI risk. Moreover, increased serum UMOD may also be used as a prognostic biomarker for recovery from AKI. On the other hand, YKL-40 (although a multidisease biomarker) has been shown to play a predictive and prognostic role in AKI, its levels being positively correlated with disease risk. Large prospective studies are however required to confirm these results and to assess the clinical utility of estimating UMOD and YKL-40 levels as well as the therapeutic implications of their altered levels.

Urinary tract infection (UTI) is one of the common causes of hospital visit in infants and children. Vesicoureteral reflux (VUR) predisposes to UTI and renal scarring. VUR is usually diagnosed after an episode of UTI. VUR is the most common underlying etiology responsible for febrile UTIs or pyelonephritis in children. Along with the morbidity of pyelonephritis, long-term sequelae of recurrent renal infections include renal scarring, proteinuria, and hypertension. Treatment is directed toward the prevention of recurrent infection through the use of continuous antibiotic prophylaxis during a period of observation for spontaneous resolution or by surgical correction. In children, bowel and bladder dysfunction (BBD) plays a significant role in the occurrence of UTI and the rate of VUR resolution. Effective treatment of BBD leads to higher rates of spontaneous resolution and decreased risk of UTI.

Chronic kidney disease (CKD) is characterized by progressive loss of renal function. Although the burden of CKD in India cannot be assessed accurately, its approximate prevalence is believed to be 800 per million populations (pmp), and the incidence of end-stage renal disease (ESRD) is 150–200 pmp. Diabetic nephropathy is a leading cause of ESRD worldwide. Another cause of ESRD is dyslipidemia, which is one of the most common quantitative lipid abnormalities in patients with CKD. In diabetes, the total cholesterol and triglyceride levels rise as the albumin excretion rate increases, leading to renal injury. Oxidative stress generated by hyperglycemia increases reactive oxygen species production, which causes cellular dysfunction and damage, and ultimately results in diabetic micro- and macro-vascular complications. Therefore, lipids may represent a useful clinical tool for not only identifying patients at a high risk of developing CVD but also assessing the development and progression of renal disease. In this review, we summarize the effects of lipid abnormalities and oxidative stress in patients with diabetes and nephropathy.