Abstract:
Background: Olfactomedin 4 is a glycoprotein encoded by the gene, OLFM4 and found in
various tissues including pancreatic β-cells. It involves various pathways of innate immunity,
inflammation, and malignancies. However, the clinical significance of its expression in
Chronic Kidney Disease (CKD) was not studied so far.
Objective: To identify the OLFM4 gene expression in CKD patients with comorbidities of
diabetes (DM), hypertension (HT), and other causes (O) and its association with disease
progression.
Methods & Materials: Total RNA was extracted from the urine samples of the study
population (n=43): CKD + DM (n=8); CKD + HT (n=16); CKD + DM and HT (n=7); CKD +
O (n=6), and healthy volunteers (n=6). Reverse transcription-quantitative polymerase chain
reaction was carried out using gene-specific primers. Normalization was carried out using
reference gene, β-2 microglobulin, and Fold Changes (FC) were calculated using the relative
quantification method. OLFM4 expression in early (n=15) and late-stage of CKD (n=23) was
also analyzed irrespective of the etiology. Log2normalized fold changes were compared with
existing biomarkers: serum creatinine and estimated Glomerular Filtration Rate (eGFR) of
CKD.
Results: OLFM4 gene was upregulated at 10.47±2.62-fold in CKD patients while the highest
upregulation was found in CKD patients with both DM and HT (FC: 12.26) compared to other
study categories. However, the upregulation of OLFM4 was significantly high in the late-stage
of CKD than the early-stage (p<0.05). OLFM4 expression in CKD subjects poorly correlated
with serum creatinine (r=0.22; p>0.05) and eGFR (r=0.015; p>0.05).
Conclusion: Both diabetes and hypertension enhance the expression of the OLFM4 gene and
it could be used as a candidate biomarker for CKD progression. However further validation is
required with more samples before clinical application.
