In search of novel uremic toxins: a proteomics-based pilot ELISA study.

Novak, Ruđer; Paulić, Lana; Pintarić, Klara; Babić, Klaudia; Plaftak, Tin; Udiljak, Ivan; Salai, Grgur; Hrkač, Stela; Vojtušek, Ivana Kovačević; Grgurević, Lovorka

Introduction: Uremic toxins are harmful metabolites that accumulate in the body of patients in parallel with the loss of renal function. Based on the results from a previous shotgun proteomics study that identified lumican, matrix remodeling associated 5 (MXRA5), neuropilin 1 (NRP1), and leucine-rich alpha-2-glycoprotein (LRG) as potential uremic toxins, we conducted a small pilot study in order to determine their expression levels in plasma and urine across the stages of chronic kidney disease (CKD). Materials and methods: We conducted a cross-sectional study in which participants were divided into six subgroups (CKD1-5 and healthy controls). We determined the expression levels of lumican, MXRA5, NRP1 and LRG from blood plasma and expression levels of MXRA5, NRP1 and LRG from urine using enzyme-linked immunosorbent assays. Results: This study included a total of N=40 participants, divided across 6 subgroups. We found no statistically significant differences in blood plasma expression levels between the subgroups for any of the assessed protein. However, we found that urinary concentration of NRP1 and LRG to be statistically significantly higher in the CKD stages 2-5 group as compared to the healthy CKD1, with arithmetic mean of NRP1 being 3.2 times higher and arithmetic mean of LRG 19.4 times higher in the CKD stages 2-5 comparing to healthy CKD1. Conclusions: We did not find that any of the assessed proteins followed the expected kinetics which would be expected for uremic toxins. However, urinary LRG and NRP1 could potentially be new biomarker candidates for CKD – but further research is needed.

CHRONIC kidney failure; ENZYME-linked immunosorbent assay; BLOOD plasma; ARITHMETIC mean; KIDNEY physiology

Rad Hrvatske Akademije Znanosti i Umjetnosti. Medicinske Znanosti, 2024, Vol 565, Issue 68/69, p14

1330-5301

Academic Journal

10.21857/yvjrdcdjgy