The Diagnostic Power Of IL-6 In the Diagnosis of Acute Cholecystitis

Abstract

Background: Cholecystitis is an inflammatory condition of the gallbladder that varies in severity and is associated with elevated inflammatory markers such as interleukin-6 (IL-6). Understanding the relationship between IL-6 levels and disease severity may improve diagnosis and management.

Methods:
This case–control study enrolled 68 patients aged 22 to 45 years diagnosed with cholecystitis at Nasiriyah Teaching Hospital, Thi‑Qar City, Iraq, from March 2024 to February 2025. Patients were classified into mild, moderate, and severe groups based on clinical and imaging criteria. Forty healthy patients without gallbladder disease served as controls. Exclusion criteria included recent antimicrobial treatment, chronic illnesses, pregnancy, and lactation. Serum IL-6 levels were measured by ELISA following standardized protocols.

Results:
Mean serum IL-6 concentration was significantly higher in patients (85.2 ± 21.4 pg/ml) compared to controls (32.7 ± 12.6 pg/ml) (p < 0.001). IL-6 levels progressively increased with cholecystitis severity: mild (64.3 ± 12.8 pg/ml), moderate (83.7 ± 14.5 pg/ml), and severe (106.5 ± 18.2 pg/ml), with statistically significant differences among groups (ANOVA, F = 18.46, p < 0.001). Post hoc analysis confirmed that each severity group differed significantly in IL-6 levels. Receiver operating characteristic (ROC) curve analysis showed excellent diagnostic accuracy for IL-6 with an area under the curve of 0.914. At a cut-off value of 58.0 pg/ml, IL-6 achieved a sensitivity of 89.6% and specificity of 82.4% for distinguishing cholecystitis patients from healthy controls (p < 0.001).

Conclusions:
Serum IL-6 is markedly elevated in patients with cholecystitis and correlates strongly with disease severity. IL-6 demonstrates high diagnostic accuracy and may serve as a valuable biomarker for identifying and stratifying cholecystitis in clinical settings.