Measuring serum total and free indoxyl sulfate and p-cresyl sulfate in chronic kidney disease using UPLC-MS/MS
Publication date: Available online 4 December 2018Source: Journal of Food and Drug AnalysisAuthor(s): Chia-Ni Lin, I-Wen Wu, Yun-Fen Huang, Shu-Yu Peng, Ya-Ching Huang, Hsiao-Chen NingAbstractChronic kidney disease (CKD) is a complex disorder that affects multiple organs and increases the risk of cardiovascular complications. CKD affects approximately 12% of the population in Taiwan. Loss of kidney function leads to accumulation of potentially toxic compounds such as indoxyl sulfate (IS) and p-cresyl sulfate (pCS), two protein-bound uremic solutes that can stimulate the progression of CKD. The aim of this study was to assess whether IS and pCS levels were correlated with CKD stage. We developed and validated a method for quantitating total and free IS and pCS in serum by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Serum samples were pretreated using protein precipitation with acetonitrile containing stable isotope-labeled IS and pCS as internal standards. After centrifugation, the supernatant was diluted and injected into a UPLC-MS/MS system. Analyte concentrations were calculated from the calibration curve and ion ratios between the analyte and the internal standard. The calibration curves were linear with a correlation coefficient of>0.999; the analytical measurement range was 0.05–5 mg/L. The limit of quantitation of this assay was 0.05 mg/L for both analytes. The reference interval was ≤0.05–1.15 mg/L for...
PMID: 30994543 [PubMed - in process]
Calcimimetics are widely used in patients on dialysis to treat secondary hyperparathyroidism. Our current view is that bone effects are only indirect through parathyroid hormone suppression. However, because bone cells express the calcium-sensing receptor, direct calcium-sensing receptor –mediated effects are also possible. New experimental data demonstrate direct anabolic bone actions of calcimimetics, independent of parathyroid hormone suppression. Because these effects could be clinically useful, further studies are necessary to confirm the validity of this observation.
Acid retention occurs early during the course of chronic kidney disease (CKD). Studies conducted in patients with CKD suggest that alkali supplementation may slow CKD progression. However, the diagnosis of acid retention is challenging when plasma bicarbonate concentration is still normal. In this issue, Goraya et al. suggest that urinary citrate may predict acid retention in eubicarbonatemic patients with stages 1 and 2 CKD . Although interesting, this claim yet requires confirmation by further studies.
Glomerular filtration rate (GFR) estimating equations are widely used, but their accuracy is limited by the need for race-ethnicity factors and imprecision of the estimated GFR. In this issue, Bukabau et al. evaluated the accuracy of GFR estimating equations and race-ethnicity factors in 2 centers in sub-Saharan Africa. The authors determined that the African American factor is not applicable and that newer equations are not more accurate than the Chronic Kidney Disease Epidemiology Collaboration equations recommended by current guidelines.
Discussions focused on the optimal means for measuring blood pressure (BP) as well as managing BP in CKD patients.
A 67-year-old man began hemodialysis at age 44 years after undergoing a right nephrectomy. Whereas a preoperative ultrasound had revealed mild renal atrophy in the absence of cysts, the histopathologic analysis of the excised kidney was consistent with nonspecific chronic kidney disease. During the following decade, the remaining kidney became severely polycystic (Figure 1a and b), and the liver was occupied by several microcysts in the absence of hepatocellular dysfunction or cholestasis based on serum measurements.
This cohort study was conducted between January 1, 2005, and December 31, 2009.
Conditions: Diabetes Mellitus, Type 2; Renal Insufficiency, Chronic Interventions: Drug: Metformin; Drug: Sulfonylurea; Drug: DPP-4 inhibitor; Drug: SGLT2 inhibitor; Drug: GLP1 receptor agonist Sponsors: Weill Medical College of Cornell University; Patient-Centered Outcomes Research Institute Not yet recruiting