CKD-EPI is the most reliable equation to estimate renal function in patients with systemic lupus erythematosus.
BACKGROUND
No study has determined the best equation for estimating renal function in patients with systemic lupus erythematosus (SLE), starting from a gold standard test.


OBJECTIVE
To evaluate the performance of cistatin/creatinine based equations for estimating renal function in patients with SLE.


METHODS
We conducted two phases: the first phase included 14 patients in which iothalamate clearance was used to determine the glomerular filtration rate (GFR) and compared with different equations based on cystatin C and/or creatinine. In the second phase, we used the best equation (a cystatin and creatinine-based equation) as "reference standard" to compare 5 creatinine-based equations in 55 patients with SLE.


RESULTS
In the first phase the equation developed by Stevens and colleagues (based on creatinine and cystatin C), was the best equation. In phase 2, the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation was the best equation with bias of -2. 1 ml/min/1.73, accuracy (P30) of 94.5% and precision (interquartile range of differences) of -2.1 ml/min/1.73.


CONCLUSIONS
Our data suggest that CKD-EPI is the best creatinine-based equation to estimate GFR in patients with SLE.
Regional Unit of Rheumatology and Osteoporosis, Hospital Central Dr. Ignacio Morones Prieto and Faculty of Medicine, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico. marcomtzmtz@hotmail.com
Marco U
MU
Martínez-Martínez
Peter
P
Mandeville
Lilia
L
Llamazares-Azuara
Carlos
C
Abud-Mendoza
D000293:Adolescent; D000328:Adult; D000368:Aged; D003404:Creatinine / Q000378:metabolism; D055316:Cystatin C / Q000378:metabolism; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests / Q000379:methods*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology*; D015203:Reproducibility of Results; D055815:Young Adult
D055316:Cystatin C; D003404:Creatinine