Related Experiment Video
Updated: Aug 22, 2025
11:47
Using 2-Photon Microscopy to Quantify the Effects of Chronic Unilateral Ureteral Obstruction on Glomerular Processes
Published on: March 4, 2022
2.3K
The Medium Cut-Off Membrane Does Not Lower Protein-Bound Uremic Toxins
Yang Gyun Kim1, Sang Ho Lee1, Su Woong Jung1
1Division of Nephrology, Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul 05278, Korea.
Toxins
|November 10, 2022
Summary
Medium-cutoff membranes show promise for removing protein-bound uremic toxins (PBUT) in dialysis patients, with varying efficacy across different dialysis modalities for specific toxins.
Area of Science:
- Nephrology
- Cardiovascular Medicine
- Membrane Science
Background:
- Protein-bound uremic toxins (PBUT) accumulation correlates with cardiovascular risks in dialysis patients.
- The effectiveness of medium-cutoff (MCO) membranes for PBUT removal requires further clarification.
- Dialysis modality impacts uremic toxin clearance.
Purpose of the Study:
- To evaluate the efficacy of PBUT clearance across different dialysis modalities: high-flux hemodialysis (HF-HD), post-dilution online hemodiafiltration (post-OL-HDF), and MCO-HD.
- To compare the removal rates of specific uremic toxins, including urea, beta 2-microglobulin (B2MG), lambda free light chain (λ-FLC), indoxyl sulfate (IS), and p-cresyl sulfate (pCS).
Main Methods:
- A prospective, cross-over study involving 22 patients undergoing thrice-weekly maintenance hemodialysis.
- Patients were assessed on HF-HD, post-OL-HDF (average convection volume 21.4 L/session), and MCO-HD over three weeks.
- Measurement of uremic toxin levels and reduction rates (RR) in plasma and dialysate.
Main Results:
- Post-OL-HDF demonstrated a higher RR for B2MG compared to MCO-HD and HF-HD.
- MCO-HD achieved the highest RR for λ-FLC, followed by post-OL-HDF and HF-HD.
- No significant differences in post-dialysis plasma levels or clearance rates were observed for IS and pCS across the modalities.
Conclusions:
- MCO membranes show potential for enhanced removal of certain protein-bound toxins like λ-FLC.
- Dialysis modality influences the clearance of specific uremic toxins, necessitating tailored treatment approaches.
- Further research is needed to fully elucidate the role of MCO membranes in managing PBUT and cardiovascular risk.
More Related Videos
Related Concept Videos
01:22Drug Elimination by Renal Route: Tubular Reabsorption
3.5K
During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, lipophilic, and nonionized undergo passive reabsorption from the tubular fluid into the surrounding peritubular capillaries. This reabsorption process restricts their elimination through the kidneys. However, the majority of drugs are either weak acids or weak bases, and their ionization level is dependent on pH. By altering the pH of urine, the...
3.5K
01:15Drug Elimination by Renal Route: Tubular Secretion
2.5K
Once the process of glomerular filtration is completed, blood carrying unfiltered drug molecules traverses through efferent arterioles and makes its way into the peritubular capillaries in the proximal tubule. A variety of carriers play a pivotal role in actively secreting drugs from these peritubular capillaries into the tubular fluid. The organic anion transporter transfers acidic drugs, against an electrochemical gradient, from the peritubular capillaries into the renal tubule cells and...
2.5K
01:29Drug Distribution: Plasma Protein Binding
6.0K
Drugs predominantly attach to plasma proteins, with only a small percentage remaining unbound. The unbound portion can be calculated as one minus the bound fraction. Acidic drugs form large, inactive complexes by reversibly binding to plasma albumin, which prevents them from diffusing across biological barriers. These drug-protein complexes act as reservoirs for the drugs. As the concentration of unbound drugs decreases, these complexes quickly dissociate to release the free drug, maintaining...
6.0K
01:28Renal Drug Excretion: Tubular Secretion
252
Active tubular secretion is a robust, energy-demanding process that utilizes carrier systems to transport drugs into renal tubules. The active renal secretion systems include the organic anion transporter (OAT) for weak acids and the organic cation transporter (OCT) for weak bases. Structurally similar drugs can compete for the same transporter, potentially leading to drug accumulation and toxicity. However, this principle can be exploited therapeutically. One example is probenecid (Probalan),...
252
01:15Dialysis
769
Dialysis is a diffusion-based purification process that separates analyte molecules from a complex matrix. This is accomplished by allowing molecules in the solution to pass through a semipermeable membrane into a liquid on the other side. The membrane is usually made of cellulose acetate or cellulose nitrate, and the second liquid must be miscible with the solution. Ions (e.g., chloride or sodium) or organic molecules (e.g., glucose) can pass through the membrane pores, which generally have...
769
01:09Hepatic Drug Clearance: Effect of Protein Binding
274
Hepatic clearance is influenced by protein binding based on the drug's extraction ratio. Drugs with high extraction ratios are considered flow-limited and remain unaffected by protein binding during hepatic clearance. On the other hand, drugs with low extraction ratios may be impacted by plasma protein binding, although the extent of this influence depends on the fraction of the drug bound.
For low-extraction-ratio drugs that are less than 80% protein-bound, minor changes in protein binding...
For low-extraction-ratio drugs that are less than 80% protein-bound, minor changes in protein binding...
274