Although the CG and MDRD equations are widely used in HIV infection, they were derived from HIV-negative persons with

acute illnesses or ongoing CKD. The CG formula includes weight but not race, although it is known, for example, that African Americans have a higher muscle mass than Caucasians, while the MDRD and CKD-EPI formulae do not include weight, which may make it the equation of choice in observational studies if this variable is not measured for all patients. The CKD-EPI equation was derived in a less selected, but HIV-negative, population, Adriamycin in vivo and was found to be more accurate than existing estimates in the normal range [6]. None of the equations has yet been validated in HIV-positive persons. Comparison of the different equations has been

based on small numbers to date and results have been contradictory. In one small study, eGFR values derived using CG and MDRD were highly correlated [9], in another, MDRD was found to have the greatest accuracy [10], while another suggested CG was the best estimate of GFR in HIV-infected patients, as they are typically younger [11]. A comparison of the CG and MDRD equations in African patients enrolled in the Development of Antiretroviral Therapy trial suggested that the prevalence of moderate CKD was higher using MDRD compared with CG [12]. The difficulties do not end with having decided which method to use for calculating eGFR. In HIV-infected persons, the HIV Medicine Association of the Infectious Diseases Society of America has proposed five Palbociclib manufacturer SPTLC1 stages of CKD (see Table 1) [13] based on the National Kidney Foundation Kidney Disease Outcomes

Quality Initiative [14]. CKD is defined as either kidney damage (pathologic abnormalities or markers of damage) or GFR<60 mL/min/1.73 m2 for >3 months. An eGFR>60 mL/min/1.73 m2 is generally considered too inaccurate for routine clinical use and has been discouraged [15] with a recommendation that stages 1 and 2 are not used, in part because eGFR is particularly imprecise at low serum creatinine levels (normal to high GFR) [16]. In persons not infected with HIV, the staging system probably overestimates the prevalence of CKD and potentially misclassifies persons as having CKD in the absence of clinically relevant kidney disease [15]. There is little understanding of or research into outcomes following CKD in HIV-infected patients, or the prevalence of advanced (stage IV or V) CKD. Preliminary data from the EuroSIDA study suggested that up to one-third of patients resolved CKD [defined as either confirmed (≥3 months apart) eGFR≤60 mL/min/1.73 m2 for patients with baseline eGFR>60 mL/min/1.73 m2 or confirmed 25% decline in eGFR for patients with baseline eGFR≤60 mL/min/1.