Assessing kidney function in HIV infection

Chronic kidney disease often goes unrecognized, and the NIH encourages clinical laboratories to report glomerular filtration rate (GFR) estimates when they report serum creatinine levels. Chronic kidney disease based on estimated GFRs below 60 mL/min/1.73m2 is seen in as many as 10% of persons with HIV infection and even more frequently when urinary protein excretion is measured. The Cockcroft-Gault formula and Modification of Diet in Renal Disease (MDRD) equation are the most widely used to estimate GFR. Although which estimate is more reliable is still debated, both are superior to serum creatinine levels alone for evaluating kidney function. The Cockcroft-Gault formula is the standard FDA measure for recommended renal dose adjustment; the MDRD equation is considered the most reliable predictor of GFR within the range of 20 to 60 mL/min/1.73m2. Neither equation has been validated in HIV or other special populations. Patients with proteinuria or a reduced GFR should undergo further evaluation and referral to a nephrologist.