Serum levels of TNF-α, IL-1β, and IL-33 in patients with ascending pyelonephritis: A case-control study in Al-Najaf City

Abstract

Objective: Ascending pyelonephritis (APN) is a serious upper urinary tract infection that may lead to immune-mediated inflammation. This study aimed to compare the serum levels of three cytokines, tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-33 (IL-33), in patients with pyelonephritis versus healthy individuals. The study also assessed differences between acute and chronic pyelonephritis cases and evaluated the diagnostic utility of these cytokines using receiver operating characteristic (ROC) analysis.

Methodology: A case-control study was conducted from September 2024 to January 2025, enrolling 120 participants: 60 patients with pyelonephritis (30 acute, 30 chronic) and 60 healthy controls. Serum levels of TNF-α, IL-1β, and IL-33 were measured using enzyme-linked immunosorbent assay (ELISA).

Results: TNF-α levels were significantly elevated in patients compared to controls (36.23 ± 64.12 pg/ml vs. 21.68 ± 18.52 pg/ml; p = 0.023). IL-1β levels also showed a significant increase (15.17 ± 27.82 pg/ml vs. 8.04 ± 7.00 pg/ml; p = 0.001). Similarly, IL-33 levels were higher in patients (23.19 ± 36.88 pg/ml) compared to controls (12.52 ± 8.96 pg/ml; p = 0.001). Chronic cases exhibited significantly higher cytokine levels than acute cases. ROC analysis revealed that TNF-α and IL-1β had strong diagnostic potential, while IL-33 demonstrated limited utility.

Conclusion: TNF-α and IL-1β are promising biomarkers for the diagnosis and monitoring of pyelonephritis, whereas IL-33 may have limited diagnostic relevance. TNF-α and IL-1β may serve as adjunct biomarkers for diagnosing pyelonephritis, particularly in chronic cases.