Determination of High-Sensitivity C-reactive protein in Chronic Kidney Disease Patients in Al-Hawija General Hospital in Kirkuk City-Iraq

Chronic kidney disease (CKD) is a serious worldwide health problem due to the gradual and irreversible damage it causes. Although hemodialysis (HD) is an essential renal replacement treatment, little is known about its effectiveness and prevalence in Iraq. This study aimed to determine high- sensitivity c-reactive protein(hs-CRP), interleukin-6(IL-6), complement components C3 and C4, and the novel renal biomarker fibroblast growth factor-23 (FGF-23) in Iraqi patients with CKD, alongside selected biochemical parameters including estimated glomerular filtration rate (eGFR), serum creatinine, phosphate, albumin, sodium, potassium. The study was conducted at Al-Hawija General Hospital during September 2024 and May 2025, and included 160 participants: 80 CKD patients (aged 35–65 years) and 80 age- and sex-matched healthy controls. Spectrophotometry was used for biochemical measurements, ELISA for IL-6, C3, C4, and FGF-23, and immunoturbidimetry for CRP. The majority of CKD patients were in the 35–65-year age group (mean 46.08 ± 6.29 years), with females constituting 71.25%. Diabetes mellitus was the most common comorbidity (24%). Inflammatory and complement assays revealed significantly higher levels of hs-CRP and IL-6 in CKD patients. Serum C3 levels were significantly elevated, while C4 showed no significant difference. FGF-23 levels were significantly elevated in CKD patients and demonstrated a strong negative correlation with estimated eGFR. Compared with controls, CKD patients had significantly lower eGFR, serum albumin and serum sodium. In contrast, serum creatinine, serum phosphate and serum potassium were significantly higher. ROC curve analysis indicated that FGF-23 had the highest diagnostic performance (AUC = 0.92, sensitivity = 91.2%, specificity = 90.5%), followed by IL-6 (AUC = 0.85), CRP (AUC = 0.78), and C3 (AUC = 0.74).These findings indicate that integrating inflammatory markers (CRP, IL-6), complement components (C3, C4), and the novel renal biomarker (FGF-23) provides a broader pathophysiological assessment of CKD and could enhance early detection, risk stratification, and potentially guide anti-complement therapeutic approaches in nephropathy within the Iraqi healthcare setting.