Lipocalin-2 as a biomarker for diabetic nephropathy

Abstract

Diabetes is a major global public health issue. The prevalence of type 1 diabetes is comparatively static, as hereditary and genetic causes are involved, while type 2 diabetes (T2D) prevalence is increasing day by day. T2D is associated with chronic complications, including diabetic neuropathy (DN), nephropathy, retinopathy, and other complications like diabetic foot. DN is the main complication of both types of diabetes. DN can be diagnosed by routine laboratory tests, microalbuminuria > 300 mg/24 h, and a gradual decrease in glomerular filtration rate. As the appearance of microalbuminuria is a late manifestation, an early marker for renal damage is needed. Lipocalin-2, also known as neutrophil gelatinase-associated lipocalin (NGAL), is a small protein purified from neutrophil granules and a good marker for kidney disease. NGAL is a transporter protein responsible for many physiological processes, such as inflammation, generation of the immune response, and metabolic homeostasis. NGAL has been reported to depict the early changes in renal damage when urine microalbumin is still undetecable. Therefore, elucidating the role of NGAL in detecting DN and understanding its mechanism can help establish it as a potential early marker for DN.

Keywords: Type 1 diabetes; Type 2 diabetes; Diabetic nephropathy; Lipocalin-2; Early biomarkers for kidney disease; Acute kidney injury

Core Tip: Diabetic nephropathy (DN) is a chronic complication of diabetes. The mainstay markers for kidney injury are a gradual decrease in glomerular filtration rate and microalbuminuria. Microalbuminuria appears late in DN; thus, new biomarkers are required. Different researchers highlighted the role of lipocalin-2 (NGAL) in the early detection of nephropathy before the appearance of microalbumin in urine. In this review, we briefly describe the role of NGAL in various diseases and cancers and detail its role as an early biomarker in DN.