What is eGFR in pathology results and how does it differ from GFR? What is the normal limits for it?

Post date: May 2, 2012
A glomerular filtration rate (GFR) is the amount of a marker substance that is filtered by all of the glomeruli in the kidney and not reabsorbed by any of the tubules that ends up in the urine. To measure this exactly requires the administration of a marker substance such as inulin, iothalamate or other chemical marker that will exactly measure glomerular filtration rate (GFR). These tests are research tests done usually in a research laboratory. Rather than do research tests, we employ a chemical substance naturally in the blood such as urea, creatinine or Cystatin C, then enter this concentration into an equation that estimates glomerular filtration rate (eGFR). The normal GFR in generally given as 120 milliliters per minute per 1.73 meters squared for a young individual. When we use estimating equations, we suggest that a normal eGFR is greater than 60 milliliters per minute per 1.73 meters squared because of the inexact nature of the estimating equations.