Evaluation Of Serum Il-8 Levels as A Diagnostic Biomarker for Neisseria Gonorrhoeae Infection

Abstract

Background: Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae, often presenting at urogenital and extragenital sites. Interleukin-8 (IL-8) is a key chemokine involved in neutrophil recruitment and inflammatory response. Evaluating serum IL-8 levels may provide insight into infection severity and offer diagnostic utility. Methods: This case–control study enrolled 52 patients aged 20–50 years diagnosed with gonorrhea at Hussein Teaching Hospital in Karbala City, Iraq, from April 2024 to March 2025. Patients were categorized by infection site: urogenital, anorectal, and pharyngeal. Forty healthy individuals served as controls. Serum IL-8 concentrations were measured by ELISA. Results: Mean serum IL-8 levels were significantly elevated in patients (92.6 ± 18.4 pg/ml) compared to controls (34.7 ± 10.2 pg/ml; p < 0.001). IL-8 concentrations differed by infection site: urogenital (96.8 ± 17.5 pg/ml), anorectal (84.3 ± 15.2 pg/ml), and pharyngeal (71.6 ± 13.8 pg/ml) (F = 8.47, p < 0.001). ROC analysis revealed excellent diagnostic accuracy (AUC = 0.91), with a cut-off of 60.5 pg/ml yielding 88.5% sensitivity and 85.4% specificity. Conclusions: Serum IL-8 is markedly elevated in gonorrhea patients and varies by infection site. It demonstrates high diagnostic accuracy, supporting its potential role as a non-invasive biomarker for identifying and stratifying gonococcal infection.

Keywords:

Interleukin-8, Gonorrhea, Sensitivity, Specificity, AUC

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