SALIVARY AND URINARY METABOLOMICS STUDY IN IGA NEPHROPATHY PATIENTS

7 Feb 2025 12 a.m. 12 a.m.

WCN25-AB-1709, Poster Board= FRI-159

Introduction:

Immunoglobulin A nephropathy (IgAN) is the most common form of glomerulonephritis worldwide with a strong autoimmune component. Metabolites will allow us to evaluate such diseases by analyzing body fluids. We aim to evaluate the disease from a different perspective including saliva and differences between healthy people and IgAN patients. And show the correlation between saliva and urine of the IgAN patients.

Methods:

This study was based on two groups as healthy control and IgAN patients groups which presented Bezmialem Vakıf University. Stimulated salivary samples and spot urine samples were collected from both groups. Collected samples were processed to full metabolome analysis in Liquid Chromatography-Mass Spectrometry (LC-MS/MS) device. Also general demographic information of participants including serum urea, serum creatinine, urine creatinine, proteinuria and eGFR results were collected.

Results:

16 participants whose mean age was 54.31±6.651 for IgAN group and 10 participants whose mean age were 41.46±6.009 for the healthy control group were enrolled in this study. Metabolomic analysis identified 42 metabolites in saliva samples and 4 were significantly dysregulated in IgAN patients (Table 1). And 138 urinary metabolites were identified and 19 of them were significantly dysregulated in IgAN patients (Table 2). The metabolic pathway analysis of saliva samples showed an impairment in pentose phosphate pathway while the urinary pathway metabolite analysis showed an impairment in ABC transporters, Arginine biosynthesis, Purine metabolism, Histidine metabolism, Aminoacyl-tRNA biosynthesis, D-amino acid metabolism, Glutamatercig synapse and GABAergic synapse.

Table 1. fold-change values, p-value and adjusted p-value for dysregulated saliva metabolites from the analysis results Table 2. fold-change values, p-value and adjusted p-value for dysregulated urine metabolites from the analysis results

Conclusions:

Results showed an metabolite which is N-Acetylneuraminic acid was dysregulated both in urine and saliva samples. N-Acetylneuraminic acid was significantly downregulated in saliva and upregulated in urine compared to the healthy controls (p=0,048729 and p=0,000941653). Review of the known literature suggests that this pattern contradicts the metabolomic results that belong to chronic kidney disease. So this pattern could be a possible marker that differentiates IgAN from other chronic kidney disease and healthy people. Also purine metabolism, glutamatergic synapse and GABAergic synapse which were impaired in saliva samples of IgAN patients, the metabolites that belong to these pathways which are Uric acid and L-glutamine were found downregulated in urine samples. Further studies with greater numbers of participants with multiple sample collections in different times will be beneficial to showing affected and changed metabolites and pathways as the course of the disease changes.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.