Biomarkers of Oxidative Stress and Inflammation in Chronic Kidney Disease: A Cross-Sectional Study of Vitamin C and Pentraxin 3 Dynamics During Hemodialysis.

INTRODUCTION

Chronic kidney disease (CKD) is a condition where there is a progressive decline in kidney function, which is characterized by an estimated glomerular filtration rate of less than 60 mL/min/1.73 m². Vitamin C is a strong antioxidant, and pentraxin 3 (PTX3) is an early reliable sign of vascular inflammation and cardiovascular risk. However, it is still not clear how these two markers interact with each other during hemodialysis. This study aimed to correlate vitamin C and pentraxin-3 levels pre- and post-dialysis among CKD patients.

METHODS

A prospective observational study was conducted at Dhanalakshmi Srinivasan Medical College and Hospital, involving 60 CKD patients aged more than 18 years who were on maintenance hemodialysis. After obtaining written informed consent, we collected the participants' demographic information, clinical data, and biochemical parameters from their medical records. We used high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) to check the levels of vitamin C and PTX3 in the blood sample taken 30 minutes before and after dialysis. Vitamin C levels were classified as deficient, low, or normal, and pentraxin 3 values were categorized as normal, mildly elevated, moderately elevated, and severely elevated. A paired t-test was used to assess pre- and post-dialysis variations among the blood biochemical parameters. Pearson's correlation analysis was done to determine the correlation between vitamin C and pentraxin 3 in hemodialysis patients.

RESULTS

The study population had a mean age of 52.88 ± 9.55 years, with 51 (85%) males. Vitamin C levels dropped significantly after dialysis from 0.24 ± 0.092 mg/dL to 0.19 ± 0.085 mg/dL (p = 0.001), but PTX3 levels increased from 4.64 ± 1.299 ng/mL to 6.63 ± 1.259 ng/mL (p = 0.001) after dialysis. A total of 40 (66.67%) study participants were found to have low vitamin C levels; vitamin C deficiency was present in 19 (31.67%) participants in a pre-dialysis state, and their condition worsened further post-dialysis. A total of 31 (51.67%) participants had severely elevated PTX 3 levels, which further increased post-dialysis. PTX3 levels were consistently higher in hypertensive and diabetic patients, highlighting the inflammatory burden in these populations. There exists a weak, nonsignificant negative correlation between vitamin C and PTX 3 levels both pre- (r = -0.137, p = 0.781) and post-dialysis (r = -0.141, p= 0.757).

CONCLUSION

Although this observational study cannot establish causality, it indicates that hemodialysis is associated with reduced antioxidant levels and increased inflammatory markers. These findings suggest a possible link between oxidative stress and inflammation in CKD patients. Further studies are needed to evaluate the therapeutic role of antioxidant supplementation in mitigating cardiovascular risks.