Table 2.
Analytical performance of biomarker quantification.
| Precision | Linearity | Trueness | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Adult Low | Pediatric Low | Adult Normal | |||||||
| Mean (µmol/L) | CV (%) | Mean (µmol/L) | CV (%) | Mean (µmol/L) | CV (%) | Low (µmol/L) | High (µmol/L) | Pearson Correlation | |
| creatinine | 189.1 | 6.4 | 108.3 | 6.2 | 107.9 | 7.0 | 21 | 928 | 0.993 |
| dimethyl sulfone | 12.6 | 13.4 | 12.2 | 19.8 | 8.5 | 20.7 | 4 | 90 | 0.983 |
| myo-inositol | 110.5 | 11.1 | 78.5 | 11.2 | 68.5 | 14.2 | 39 | 441 | 0.991 |
| valine | 418.0 | 1.5 | 310.6 | 1.9 | 437.8 | 3.8 | 27 | 1250 | 0.998 |
| GFRNMR | 43.5 | 9.5 | 68.3 | 6.0 | 82.4 | 4.2 | n.a. | n.a. | 0.84 |
Precision is determined in three different pooled sera (adult low GFR, pediatric low GFR, and adult normal GFR). For linearity, upper and lower limits of the linear range are given. For dimethyl sulfone and myo-inositol, trueness was determined by spike recovery. For creatinine and valine, clinical chemistry methods were used.