The primary biochemical markers for the diagnosing and evaluating stages of chronic kidney disease (CKD) are serum creatinine and the estimated glomerular filtration rate (GFR). For diagnosing CKD, the GFR needs to be <60 mL/min/1.73 m2 for more than 3 months. Less frequently used endogenous marker for estimating the GFR is cystatin C. Alternatively, exogenous markers that can be used include inulin, iotalamat, and iohexol if clarity is not achieved with creatinine or cystatin C. Globally, urinary albumin and albumin-creatinine ratio are the recommended tests from a spot collection to estimate the kidney damage. Urinary protein estimate’s use is declining, especially 24-hour collections. There are several other markers discussed in brief that may be a useful adjunct in identifying causes and likely management strategies for CKD. Finally, pitfalls of the primary methodologies for the above tests are provided to guide readers in better understanding the results and their use in patient care decisions.
Part of the book: Chronic Kidney Disease