Abstract: TH-PO0470
Differences in Tryptophan Metabolites and Aryl Hydrocarbon Receptors Clearance by Hemodialysis and Hemodiafiltration
Session Information
- Hemodialysis: Novel Markers and Case Reports
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Zakrocka, Izabela Natalia, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Koziol, Malgorzata Maria, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Mlak, Radoslaw, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Wieckowska-Deron, Marta Klara, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Jaszek, Natalia Magdalena, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Nour Mohammadi, Amir, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Boczkowska, Sylwia Klaudia, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Kocki, Tomasz, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Olender, Alina, Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Urbanska, Ewa M., Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Zaluska, Wojciech T., Uniwersytet Medyczny w Lublinie, Lublin, Lublin Voivodeship, Poland
- Kronbichler, Andreas, Medizinische Universitat Innsbruck, Innsbruck, Tyrol, Austria
Background
End stage kidney disease (ESKD) puts patients with kidney failure at significantly higher risk of cardiovascular events. Hemodialysis (HD) and hemodiafiltration (HDF) have limited efficacy in reconstituting kidney filtration function.
Tryptophan (Trp) is mainly metabolized through the kynurenine (KYN) pathway, leading to formation of biologically active substances, in particular KYN, kynurenic acid (KYNA) and 3-OH kynurenine (3-OHKYN). KYN and KYNA are agonists of aryl hydrocarbon receptors (AhRs). Despite the crucial role of AhRs in physiological processes, recent data link these receptors with immune system activation and cardiovascular diseases.
The aim of this study was to analyze the predialysis and postdialysis concentrations of Trp, KYN, KYNA, 3-OHKYN and AhR in patients receiving dialysis procedures, in relation to presence of diabetes and dialysis technique used.
Methods
The study was conducted in 61 stable patients with ESKD, receiving either HD (62%) or HDF (38%). Serum concentration of Trp, KYN, KYNA and 3-OHKYN were measured before and after dialysis through high performance liquid chromatography, whereas ELISA assay kit was performed to assess the concentration of AhR.
Results
The serum concentration of Trp did not change from predialysis (8.56 µmol/l) to the measurement post-dialysis (8.58 µmol/l, p = 0.2). On the contrary, the concentrations of KYN (2.05 µmol/l vs 0.73 µmol/l, p<0.01), KYNA (409.90 nmol/l vs 223.28 nmol/l, p < 0.01) and 3-OHKYN (73.76 nmol/l vs 22.31 nmol/l, p < 0.01) significantly decreased after dialysis. Interestingly, AhRs serum concentration was significantly lower after dialysis (2.01 ng/ml vs 1.16 ng/ml, p < 0.01). In patients with diabetes there was a trend towards lower predialysis AhR (1.4 ng/ml vs 2.2 ng/ml, p = 0.05). HDF procedures were related with significantly higher removal rates for KYN compared to HD (67% vs 52.5%, p = 0.01).
Conclusion
Our study reveals a significant decrease in KYN, KYNA, 3-OHKYN and AhR concentration through dialysis procedures. In patients with diabetes, lower AhR concentration may reflect decreased pancreatic reserve. HDF may provide beneficial effects on KYN removal over HD.
Funding
- Government Support – Non-U.S.