Aetna considers the RenalVysion test (Nephrocor, Glen Allen, VA) for diagnosing and monitoring kidney disease experimental and investigational because of insufficient evidence of its effectiveness.

An estimated 7 % of adults aged 20 or older (15.5 million adults) have physiological evidence of chronic kidney disease (CKD) as defined by a moderately or severely reduced glomerular filtration rate (GFR) (Coresh et al, 2007).  Patients with kidney disease have a variety of different clinical presentations.  Some have symptoms that are directly referable to the kidney (e.g., gross hematuria, flank pain) or to extra-renal sites of involvement (e.g., edema, hypertensive, signs of uremia).  Many patients, however, lack specific symptoms and are noted on routine examination to have an elevated plasma creatinine concentration or an abnormal urinalysis.

According to the National Institute for Clinical Excellence (NICE, 2008), 30 % of people with advanced kidney disease are referred late to nephrology services causing increased mortality and morbidity.  Strategies aimed at earlier identification and, where possible, prevention of progression to established renal failure are needed.

The National Kidney Foundation practice guidelines on CKD (2002) recommended identifying persons at increased risk for CKD to include persons with diabetes, hypertension, those with a family history of CKD, age greater than 60 years, and those with United States racial or ethnic minority status.  The guidelines stated that kidney damage can be detected by measuring the albumin-creatinine ratio in un-timed ("spot") urine specimens, and estimating the GFR from serum creatinine measurements by using prediction equations.  The estimated GFR comes from a formula that combines the creatinine level with the patient's age, race and gender.  Chronic kidney disease is defined as the presence of kidney damage or level of GFR less than 60 ml/min per 1.73 m² that is present for 3 or more months.

The indications for performing a renal biopsy varies among nephrologists, being determined in part by the presenting signs and symptoms.  A percutaneous renal biopsy is sometimes performed to obtain a diagnosis, help guide therapy, and ascertain the degree of active and chronic changes.  The routine evaluation of a percutaneous renal biopsy involves examination of the tissue under light, immunofluorescence, and electron microscopy. 

RenalVysion (Nephrocor, Glen Allen, VA), a urine-based test that integrates urine cytopathlogy with urine chemistries (i.e., creatinine, protein, beta-2 microglobulin, microalbumin), is being marketed as a 'liquid biopsy' for the early diagnosis and monitoring of kidney disease.  However, there are no published studies on the use of RenalVysion for kidney disease and no medical professional society recommends RenalVysion testing for diagnosing and monitoring kidney disease.  Chronic kidney disease can be readily detected with tests for proteinuria, hematuria, and estimated GFR.  Randomized controlled studies comparing RenalVysion to these standard methods for diagnosing and monitoring kidney disease are needed.