Comparison of glomerular filtration rate estimates vs. 24‐h creatinine clearance in HIV‐positive patients

Abstract

BackgroundGuidelines for kidney function monitoring and antiretroviral drug dosing are available and respectively refer to glomerular filtration rate and creatinine clearance (CrCl). ObjectiveThe aim of the study was to compare kidney function estimates vs. measured 24-h CrCl in HIVinfected subjects. MethodsA cross-sectional design was used, with comparison of Cockcroft-Gault (CG), original and simplified modification of diet in renal disease (MDRD) equations vs. measured 24-h CrCl. Subjects were HIVinfected, 18-70 years old, without pre-existing kidney disease. ResultsResults are presented as mean (AE standard deviation), unless otherwise stated. The study population consisted of 90 patients, of whom 71% were male, with a mean age of 45 years (AE 6.5 years). At the time of evaluation, the mean body mass index was 23 (AE 3.3); mean serum creatinine was 0.91 mg/dL (AE 0.2 mg/dL); and mean blood urea nitrogen (BUN) was 34.7 mg/dL (AE 10.6 mg/dL). Differences between paired methods were all significant (Po0.00001), except between CG and simplified MDRD (P 5 0.21; Pearson r 5 0.81). In univariate analysis, male gender, CD4 nadir, hepatitis B virus coinfection, BUN and current CD4 cell count showed a significant positive correlation (Po0.2) with the difference between measured 24-h CrCl and either CG or simplified MDRD estimates. In multivariate analysis, only BUN showed a significant positive correlation (Po0.05). ConclusionsEstimates were lower than the measurements of 24-h CrCl. Original MDRD estimates were lower than those with other equations. CG and simplified MDRD estimates showed a satisfactory correlation.

Risk Factors of Chronic Kidney Disease in HIV-infected Patients

“…In the United States HIV cohort, some discrepancies have been shown between Cockroft-Gault and MDRD, but no gold standard was applied to the population (38). In a recent Italian study, Cockroft-Gault and MDRD estimates (versus gold standard) showed a satisfactory correlation (36). Plasmatic and urinary cystatin C can be measured routinely and provide good information on serum creatinine clearance using the CKD-EPI estimation, as well as on tubular dysfunction using the serum/urinary ratio (39).…”

“…The eGFR is widely considered to be a direct measure of kidney function and reduces before the onset of symptoms of kidney failure (34,35). We chose to use MDRD evaluation of GFR because it has been previously shown to have a level of precision and accuracy sufficient for clinical decision making (36,37). All methods of GFR estimation have been discussed and compared in some studies with gold standard methods of creatinine clearance measurements.…”

Fatores de risco associados a alterações renais em pacientes infectados por HIV-1

“…A primeira fórmula tem sido usada desde 1976 e é a mais cotada na adequação de doses de antirretrovirais, de acordo com a maioria das diretrizes vigentes. A equação MDRD foi elaborada em 1999 e, posteriormente, simplificada em uma versão que tem sido recomendada como a mais fiel preditora da função renal, especialmente nos casos em que a mesma está reduzida em relação aos níveis normais 18 . Ela foi usada como variável preditiva da função renal.…”

“…O padrão ouro para determinação da proteinúria e mesmo da filtração glomerular, a coleta de urina de 24h, é considerado um método de difícil aplicabilidade no conjunto de pacientes na prática clínica, razão pela qual, diversos autores têm recomendado a utilização de fórmulas para estimar a função renal. Privilegiamos o uso da MDRD simplificada, por esta ter se mostrado com maior precisão em pacientes com algum déficit de função renal 18 . A importância de rastrear a alteração precoce da função renal se destaca…”

Monitoring of Renal Function among HIV-Infected Patients Receiving Tenofovir in a Resource-Limited Setting

“…There was a study reporting that the C-G and 4-variable MDRD eGFR were highly correlated, but both underestimated the 24-hour urine CrCl in HIV-infected adults without chronic kidney disease. 30 However, in some reports, the MDRD formula is considered to be more accurate than the C-G formula, which may overestimate renal function. 21,31 Using MDRD formula may still have a high level of bias, depending on creatinine assay calibration, and low precision, with approximately 80% of eGFR in the range of 70% to 130% of the measured GFR value.…”