SERUM MICRORNA AS POTENTIAL BIOMARKER FOR ASSESSING SEVERITY IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Abstract

Background: Chronic kidney disease (CKD) is a progressive disorder characterized by irreversible decline in renal function and increased risk of cardiovascular morbidity and mortality. Conventional biomarkers such as serum creatinine, blood urea, and estimated glomerular filtration rate (eGFR) have limitations in accurately reflecting ongoing molecular injury and disease severity. MicroRNAs (miRNAs), particularly miRNA-21 and miRNA-29, have emerged as promising non-invasive biomarkers due to their involvement in renal fibrosis, inflammation, and disease progression.

Methods: A case-control cohort study was conducted in the Department of Medicine and Intensive Care Unit at Dr. D. Y. Patil Medical College, Hospital and Research Institute, Kolhapur, over a period of 18 months. A total of 127 participants were enrolled, including 98 CKD patients and 29 healthy controls. Patients were categorized according to CKD stage based on eGFR. Serum miRNA-21 and miRNA-29 expression levels were measured and correlated with renal function parameters including eGFR, serum creatinine, and serum urea. Statistical analysis was performed to assess differences between groups and correlations with disease severity.

Results: CKD patients demonstrated significantly reduced eGFR (16.86 ± 13.56 vs. 104.90 ± 20.05 mL/min/1.73 m²; p=0.001) and significantly elevated serum creatinine (5.54 ± 2.68 vs. 0.79 ± 0.18 mg/dL; p=0.001) and serum urea (109.61 ± 41.84 vs. 32.65 ± 15.56 mg/dL; p=0.001) compared with controls. Mean serum miRNA-21 expression was significantly higher in CKD patients than controls (4.42 ± 1.43 vs. 1.45 ± 0.29; p<0.001), while mean serum miRNA-29 expression was significantly lower (0.25 ± 0.11 vs. 0.99 ± 0.13; p<0.001). Stage-wise analysis showed progressive elevation of miRNA-21 from 2.38 ± 0.98 in Stage 2 to 5.33 ± 0.95 in Stage 5 CKD, whereas miRNA-29 progressively declined from 0.63 ± 0.01 in Stage 2 to 0.18 ± 0.03 in Stage 5 CKD (p=0.001). miRNA-21 showed strong negative correlation with eGFR (r = -0.806, p<0.001) and positive correlations with serum creatinine (r = 0.953, p<0.001) and serum urea (r = 0.831, p<0.001). Conversely, miRNA-29 demonstrated a strong positive correlation with eGFR (r = 0.995, p<0.001) and negative correlations with serum creatinine (r = -0.784, p<0.001) and serum urea (r = -0.702, p<0.001).

Conclusion: Serum miRNA-21 and miRNA-29 are significantly associated with CKD severity. miRNA-21 acts as a positive marker of disease progression, while miRNA-29 behaves as an inverse marker reflecting preserved renal function. These findings support the potential utility of serum miRNA-21 and miRNA-29 as non-invasive biomarkers for assessing disease severity and monitoring progression in patients with chronic kidney disease.