Evaluation of 25 OH Vitamin D in chronic renal failure and end stage renal disease subjects

Analysis of laboratory samples from chronic renal failure (CRF) and end stage renal disease (ESRD) patients can be problematic. Current HPLC and RIA methods for the determination of 25 OH Vitamin D involve sample extraction. However, the differences between a normal and CRF or ESRD matrix can lead to interference or inaccuracy in non-extracted, automated methods now available. The objective of this study was to assess the accuracy of the non-extracted LIAISON 25 OH Vitamin D assay in the analysis of CRF and ESRD samples as compared against RIA as reference. Samples were collected from regional reference laboratories and analyzed in both the LIAISON 25 OH Vitamin D assay and the DiaSorin 25 OH Vitamin D RIA. By Student's t test, no significant difference was observed between the RIA values and the LIAISON values (P = 0.07 CRF; P = 0.28 ESRD). The linear regression analysis resulted in the equations: CRF: LIAISON = 0.91 (RIA) + 0.6; r = 0.82 and ESRD: LIAISON = 0.93 (RIA) - 0.6; r = 0.78. From these data we conclude that the LIAISON 25 OH Vitamin D assay correctly assesses the 25 OH Vitamin D status of CRF and ESRD patients.     

Reduced glomerular filtration rate, inflammation and HDL cholesterol as main determinants of superoxide production in non-dialysis chronic kidney disease patients

Enhanced oxidative stress partly resulting from an over-production of superoxide anion (O(2)(?-)) represents a novel and particular risk factor in chronic kidney disease (CKD) patients. This study was therefore designed to evaluate O(2)(?-) determinants in this population. O(2)(?-) production was evaluated using chemiluminescence method in 136 CKD patients (79M/57F, median age: 69.5 [27.4-94.6]). Renal function (evaluated by the glomerular filtration rate using modification of diet in renal disease (MDRD)), inflammation, lipids, nutritional and bone mineral as well as clinical parameters were evaluated. Potential relationships between O(2)(?-) and these clinico-biological parameters were investigated to identify main determinants of such a pathological process. Enhanced O(2)(?-) production has been observed at the pre-dialysis phase: stages 4 and 5 of CKD (p = 0.0065). In multivariate analysis, low eGFR (MDRD <30 mL/min/1.73 m(2); p = 0.046), high fibrinogen (≥3.7 g/L; p = 0.044) and abnormal HDL cholesterol (<1.42 mmol/L and ≥ 1.75 mmol/L; p = 0.042) were the main determinants of O(2)(?-) production in CKD patients.