The Role Of CRP, Serum Amyloid A, And Haptoglobin Levels in Immune Response Against Proteus Infections

Abstract

The Proteus species are significant nosocomial pathogens for urinary tract infection, wound infections and other systemic problems. Mediated through their production of urease, swarming motility and biofilm formation they have the potential to add additional impact on tissue damage and driving robust innate immune activity. Acute-phase proteins (APPs) are some of the first factors whose levels change that suggest a response to inflammation and could offer further insight into the host–pathogen interplay in Proteus infections. The objective of this study was to evaluate the levels of three major APPs including C-reactive protein (CRP), serum amyloid A (SAA) and haptoglobin in serum of patients with confirmed Proteus infections compared to healthy individuals. Sixty patients with a positive culture for Proteus infection, and 50 healthy subjects were recruited at Al-Najaf General Hospital, Iraq from February 2024 to March 2025. Patients on antibiotics in the last 3 months, chronic inflammatory diseases, pregnancy and lactation were excluded. Serum CRP, SAA, and haptoglobin measurements were performed using the ELISA. Data revealed increased levels of all acute-phase proteins in patients. CRP levels were significantly higher in the patients (mean ≈26 mg/L), when compared to controls, with p < 0.03. SAA presented a clear increase in infected subjects (mean ≈ 32 mg/L) with p < 0.02 while haptoglobin also exhibited an increased tendency (mean ≈ 1.9 g/L), with p < 0.04. These elevations suggest robust induction of early innate immune pathways and increased hepatic synthesis of APPs following Proteus-associated inflammation. The results of this study indicate that CRP, SAA, and haptoglobin are significantly elevated in Proteus infections and could be used as good complementary biomarkers to evaluate inflammation response, monitor disease activity, and assess diagnosis in patients with Proteus species infection.

Keywords:

Interleukin-17, Vaginitis, Bacteria, Candida, Trichomonas.

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