title: Performance of creatinine and cystatin C GFR estimating equations in an HIV-positive population on antiretrovirals.
abstract: OBJECTIVE
  To evaluate the performance of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine, cystatin C, and creatinine-cystatin C estimating equations in HIV-positive patients.
  
  
  METHODS
  We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) Study and CKD-EPI creatinine 2009, CKD-EPI cystatin C 2012, and CKD-EPI creatinine-cystatin C 2012 glomerular filtration rate (GFR) estimating equations compared with GFR measured using plasma clearance of iohexol in 200 HIV-positive patients on stable antiretroviral therapy. Creatinine and cystatin C assays were standardized to certified reference materials.
  
  
  RESULTS
  Of the 200 participants, median (IQR) CD4 count was 536 (421) and 61% had an undetectable HIV viral load. Mean (SD) measured GFR (mGFR) was 87 (26) mL/min per 1.73 m. All CKD-EPI equations performed better than the MDRD Study equation. All 3 CKD-EPI equations had similar bias and precision. The cystatin C equation was not more accurate than the creatinine equation. The creatinine-cystatin C equation was significantly more accurate than the cystatin C equation, and there was a trend toward greater accuracy than the creatinine equation. Accuracy was equal or better in most subgroups with the combined equation compared to either alone.
  
  
  CONCLUSIONS
  The CKD-EPI cystatin C equation does not seem to be more accurate than the CKD-EPI creatinine equation in patients who are HIV-positive, supporting the use of the CKD-EPI creatinine equation for routine clinical care for use in North American populations with HIV. The use of both filtration markers together as a confirmatory test for decreased estimated GFR based on creatinine in individuals who are HIV-positive requires further study.
authors: Tufts Medical Center, Boston, MA, USA. linker@tuftsmedicalcenter.org
authors: Lesley A
authors: LA
authors: Inker
authors: Christina
authors: C
authors: Wyatt
authors: Rebecca
authors: R
authors: Creamer
authors: James
authors: J
authors: Hellinger
authors: Matthew
authors: M
authors: Hotta
authors: Maia
authors: M
authors: Leppo
authors: Andrew S
authors: AS
authors: Levey
authors: Aghogho
authors: A
authors: Okparavero
authors: Hiba
authors: H
authors: Graham
authors: Karen
authors: K
authors: Savage
authors: Christopher H
authors: CH
authors: Schmid
authors: Hocine
authors: H
authors: Tighiouart
authors: Fran
authors: F
authors: Wallach
authors: Zipporah
authors: Z
authors: Krishnasami
mesh_terms: D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects / Q000502:physiology; D006679:HIV Seropositivity / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007472:Iohexol / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000209:etiology
chemical_list: D019380:Anti-HIV Agents; D015415:Biomarkers; D055316:Cystatin C; D007472:Iohexol; D003404:Creatinine