Contributions
Abstract: EP1214
Type: E-Poster Presentation
Session title: Sickle cell disease
Background
Renal complications can occur throughout the life of a patient with sickle cell disease (SCD), starting with hyperfiltration and impaired urinary concentration in early childhood, leading to chronic kidney disease (CKD) with advancing age. As patients with SCD survive longer, the risk of these changes progressing to end-organ damage rises. Currently, there is no reliable marker for detecting early renal disease in childhood. Routine estimation of glomerular filtration rate (GFR) in children is derived from the height/plasma creatinine formula and is dependent on the accuracy of the creatinine analytical method used.
Aims
The aim of this study was to evaluate different equation methods for estimating GFR in comparison to the gold standard measure of GFR using clinical and demographic variables and markers of renal function, including creatinine.
Methods
Children aged 5-16 years followed for SCD (homozygous HbSS and HbSb0/b+) were prospectively recruited. Specific renal biomarkers were measured: formal GFR was measured using plasma disappearance of Inutest/Ihexol, plasma creatinine was measured either by standard laboratory method or by tandem mass spectrometry (MS). Estimated GFR was then calculated by using the “Bedside Schwartz method” with the formula: [(constant × height) ÷ plasma creatinine ].
Results
A total of 79 patients (39 males, mean age 9.8±4.0 years) were enrolled. Anthropometric measures were collected: the mean height, weight and body surface area were 135.4±20.9 cm, 34±15 kg, and 1.1±0.3 m2, respectively. Height/plasma creatinine was significantly correlated with Inutest GFR, r=0.86 (p<0.001). A revised eGFR constant was calculated for Schwartz equation from the slope of the plot of height/plasma creatinine versus GFR forced through zero. The new constant was determined as 30.86, or 31 for convenience. Standard renal measurements were available for all children. Mean values for GFR and laboratory plasma creatinine were 132.7±32.1 ml/min/1.73m2 and 38.5±17.8 µmol/l, respectively. Mean values for eGFR derived from standard plasma creatinine was 122.4 ± 31.7 ml/min, with significant difference in comparison to GFR values (p=0.002). MS eGFR was calculated for 44 children, resulting with a mean of 120.5±34.4 ml/min, and there was no significant difference in comparison to GFR values (p=0.239).
Conclusion
In conclusion, in children with SCD the formula to calculate eGFR based on height and plasma creatinine determined with MS traceable creatinine methods provides a more reliable estimation of renal function in comparison to standard laboratory plasma creatinine derived values, as a possible effect of the hyperfiltration state of these patients.
Keyword(s): Pediatric, Renal impairment, Sickle cell disease
Abstract: EP1214
Type: E-Poster Presentation
Session title: Sickle cell disease
Background
Renal complications can occur throughout the life of a patient with sickle cell disease (SCD), starting with hyperfiltration and impaired urinary concentration in early childhood, leading to chronic kidney disease (CKD) with advancing age. As patients with SCD survive longer, the risk of these changes progressing to end-organ damage rises. Currently, there is no reliable marker for detecting early renal disease in childhood. Routine estimation of glomerular filtration rate (GFR) in children is derived from the height/plasma creatinine formula and is dependent on the accuracy of the creatinine analytical method used.
Aims
The aim of this study was to evaluate different equation methods for estimating GFR in comparison to the gold standard measure of GFR using clinical and demographic variables and markers of renal function, including creatinine.
Methods
Children aged 5-16 years followed for SCD (homozygous HbSS and HbSb0/b+) were prospectively recruited. Specific renal biomarkers were measured: formal GFR was measured using plasma disappearance of Inutest/Ihexol, plasma creatinine was measured either by standard laboratory method or by tandem mass spectrometry (MS). Estimated GFR was then calculated by using the “Bedside Schwartz method” with the formula: [(constant × height) ÷ plasma creatinine ].
Results
A total of 79 patients (39 males, mean age 9.8±4.0 years) were enrolled. Anthropometric measures were collected: the mean height, weight and body surface area were 135.4±20.9 cm, 34±15 kg, and 1.1±0.3 m2, respectively. Height/plasma creatinine was significantly correlated with Inutest GFR, r=0.86 (p<0.001). A revised eGFR constant was calculated for Schwartz equation from the slope of the plot of height/plasma creatinine versus GFR forced through zero. The new constant was determined as 30.86, or 31 for convenience. Standard renal measurements were available for all children. Mean values for GFR and laboratory plasma creatinine were 132.7±32.1 ml/min/1.73m2 and 38.5±17.8 µmol/l, respectively. Mean values for eGFR derived from standard plasma creatinine was 122.4 ± 31.7 ml/min, with significant difference in comparison to GFR values (p=0.002). MS eGFR was calculated for 44 children, resulting with a mean of 120.5±34.4 ml/min, and there was no significant difference in comparison to GFR values (p=0.239).
Conclusion
In conclusion, in children with SCD the formula to calculate eGFR based on height and plasma creatinine determined with MS traceable creatinine methods provides a more reliable estimation of renal function in comparison to standard laboratory plasma creatinine derived values, as a possible effect of the hyperfiltration state of these patients.
Keyword(s): Pediatric, Renal impairment, Sickle cell disease