Uremic toxins (UTs)

Uremic toxins are a heterogeneous group of compounds that accumulate in the blood and tissues of patients with chronic kidney disease (CKD) due to impaired renal clearance [1]. A significant subset of these toxins, including indoxyl sulfate and p-cresyl sulfate, are generated in the gastrointestinal lumen through the bacterial fermentation of dietary proteins like tryptophan and tyrosine [2]. These gut-derived toxins are particularly problematic because they are often protein-bound, which makes them difficult to remove via standard hemodialysis [1]. Targeting these toxins within the gastrointestinal tract using oral sorbents like AST-120 allows for their sequestration and subsequent fecal excretion before they can enter the systemic circulation [3]. This therapeutic approach aims to reduce the systemic uremic burden, which is linked to the progression of renal fibrosis, cardiovascular disease, and systemic inflammation [2,4]. Beyond sorbents, other strategies include the use of prebiotics and probiotics to modulate the gut microbiome and decrease the initial production of these toxic metabolites [4]. Clinical management of these toxins is a critical component of slowing CKD progression and improving patient outcomes in end-stage renal disease [3]. (Citations: [1] Vanholder R, et al. Kidney Int. 2003; [2] Niwa T. Biomark Med. 2010; [3] Schulman G, et al. Am J Kidney Dis. 2014; [4] Ramezani A, et al. J Am Soc Nephrol. 2014).

Other names

Uremic retention solutesGut-derived uremic toxinsNephrotoxinsIndoxyl sulfatep-Cresyl sulfateTrimethylamine N-oxide (TMAO)Indoxyl sulfate (IS)p-Cresyl sulfate (PCS)

Adsorption and physical sequestration within the gastrointestinal lumen to prevent systemic absorption and promote fecal excretion, or modulation of gut microbiota to reduce toxin synthesis.