Procalcitonin as a Biomarker for Bacterial Infections: Clinical Applications
Kalsitonin sebagai Biomarker untuk Infeksi Bakteri: Aplikasi Klinis
Keywords:
Procalcitonin, Bacterial Infection, Hematological Parameters, Inflammation, ELISAAbstract
Bacterial infections can induce substantial inflammatory responses that are often mirrored by alterations in hematological parameters and serum biomarkers, such as procalcitonin. The identification of reliable biomarkers plays a critical role in facilitating early diagnosis and assessing disease severity. This study was designed to assess the diagnostic significance of serum procalcitonin levels alongside hematological indicators in patients with confirmed bacterial infections, comparing these findings with values obtained from healthy individuals. Conducted as a case-control observational study in Southern Iraq between January and April 2024, the research included 150 participants—100 with laboratory-confirmed bacterial infections and 50 healthy controls. Blood samples were collected from all participants to perform complete blood count (CBC) analysis and to determine serum procalcitonin concentrations using enzyme-linked immunosorbent assay (ELISA). Sociodemographic variables including age, gender, body mass index (BMI), and smoking status were statistically comparable between both groups. However, patients with bacterial infections showed significantly elevated procalcitonin levels (mean 5.68 ± 2.74 ng/ml) compared to controls (mean 0.39 ± 0.21 ng/ml), with a p-value of less than 0.001. Moreover, there was a direct correlation between infection severity and procalcitonin concentration. Hematological alterations in the patient group included increased white blood cell (WBC) counts, neutrophilia, lymphopenia, decreased levels of hemoglobin and hematocrit, and a marked rise in platelet counts. Interestingly, procalcitonin levels did not differ significantly by gender, suggesting that sex-based variation may not influence its diagnostic utility. These findings reinforce the clinical value of procalcitonin as a biomarker for both diagnosing bacterial infections and monitoring their severity. Additionally, associated hematological changes provide complementary information reflecting the systemic inflammatory response, thereby enhancing the effectiveness of combined biomarker-based assessment in clinical settings.
Highlights:
- Diagnostic Value: Procalcitonin levels significantly rise in bacterial infections, making it a reliable biomarker for diagnosis and severity assessment.
- Clinical Correlation: A strong correlation exists between procalcitonin levels and white blood cell count, enhancing its diagnostic precision.
- No Gender Bias: Procalcitonin levels are consistent across genders, indicating its universal applicability in both male and female patients.
Keywords: Procalcitonin, Bacterial Infection, Hematological Parameters, Inflammation, ELISA
References
[1] R. E. Nelson, D. Hyun, A. Jezek, and M. H. Samore, “Mortality, Length of Stay, and Healthcare Costs Associated With Multidrug-Resistant Bacterial Infections Among Elderly Hospitalized Patients in the United States,” Clin. Infect. Dis., vol. 74, no. 6, pp. 1070–1080, Mar. 2022.
[2] R. E. Nelson et al., “National Estimates of Healthcare Costs Associated With Multidrug-Resistant Bacterial Infections Among Hospitalized Patients in the United States,” Clin. Infect. Dis., vol. 72, Suppl. 1, pp. S17–S26, Jan. 2021.
[3] H. Fongang, A. T. Mbaveng, and V. Kuete, “Global Burden of Bacterial Infections and Drug Resistance,” Adv. Bot. Res., 2023.
[4] Y. Chen et al., “Serum Procalcitonin and C-Reactive Protein Levels as Diagnostic Markers for Distinguishing Bacterial Infections From Lupus Flares,” Int. Immunopharmacol., vol. 101, p. 108304, Dec. 2021.
[5] M. Tao et al., “Diagnostic Value of Procalcitonin for Bacterial Infections in Hemodialysis Patients,” Ren. Fail., 2022.
[6] U. M. AlJarhi et al., “Evaluation of Biomarkers for Differentiating Bacterial Infection From Disease Activity in Lupus,” Clin. Rheumatol., vol. 40, pp. 1861–1869, May 2021.
[7] A. H. de Nooijer et al., “Inflammatory Biomarkers to Predict Prognosis of Infections,” J. Crit. Care, 2023.
[8] L. Essmann et al., “Tailoring Anti-Infective Therapy Through Procalcitonin and Specific Biomarkers,” Expert Rev. Mol. Diagn., vol. 23, no. 9, pp. 739–752, Sep. 2023.
[9] S. Mohammad, A. Mohsen, and I. Jalil, “Prevalence of Bacterial Vaginosis Among Infertile Women in Iraq,” Infect. Epidemiol. Microbiol., vol. 10, no. 4, 2024.
[10] N. Foulon et al., “Procalcitonin Levels in Septic and Nonseptic Subjects With AKI and ESKD,” Crit. Care, vol. 29, no. 1, p. 171, Apr. 2025.
[11] S. Han et al., “Diagnostic Roles of Biomarkers in AKI Patients,” Diagnostics, vol. 13, no. 4, p. 777, Feb. 2023.
[12] G. Fu et al., “Procalcitonin and AKI in Bacterial Septic Shock,” Blood Purif., vol. 50, no. 6, pp. 790–799, Sep. 2021.
[13] D. E. Luhulima, R. Ronny, and R. Amelia, “Procalcitonin as a Marker of Sepsis,” J. Complement. Altern. Med. Res., vol. 18, no. 2, pp. 66–76, Jun. 2022.
[14] Z. Q. M. Hilo, A. Mahmood, and O. A. Mohsein, “Genomic Insights Into Staphylococcus aureus,” Eur. J. Ecol. Biol. Agric., vol. 1, no. 5, pp. 29–48, 2024.
[15] H. Kim, Y. H. Roh, and S. H. Yoon, “Procalcitonin as Diagnostic Marker in Pediatric Meningitis,” Diagnostics, 2021.
[16] P. Schuetz, “How to Use Procalcitonin in Infections,” Clin. Chem. Lab. Med., 2023.
[17] M. Vassallo et al., “PCT and CRP/PCT Ratio as Infection Markers in Solid Tumors,” Front. Med., vol. 8, p. 627967, Mar. 2021.
[18] D. Cleland and A. Eranki, “Procalcitonin,” StatPearls, 2023.
[19] K. Tong-Minh et al., “High PCT and ICU Admission in COVID-19 Patients,” BMC Infect. Dis., vol. 22, p. 165, Feb. 2022.
[20] M. A. Ismail et al., “Genetic Variability of E. coli in UTIs,” Cent. Asian J. Med. Nat. Sci., vol. 6, no. 1, pp. 179–191, 2024.
[21] F. Heidari-Beni et al., “Procalcitonin in Severe COVID-19 Patients,” in Clin. Biol. Mol. Aspects COVID-19, pp. 277–286, 2021.
[22] H. G. Xu, M. Tian, and S. Y. Pan, “Clinical Utility of Procalcitonin,” Crit. Rev. Clin. Lab. Sci., vol. 59, no. 2, pp. 93–111, Feb. 2022.
[23] M. Kabak, B. Çil, and I. Hocanlı, “Blood Parameters and PCR Positivity,” Int. Immunopharmacol., 2021.
[24] R. Q. Taha et al., “Bacterial Aetiologies of Otitis Media,” Int. J. Biosci., vol. 6, no. 1, pp. 94–99, 2024.
[25] W. Zhang et al., “Hematological Markers in Sepsis Diagnosis,” Ann. Transl. Med., vol. 9, no. 22, p. 1680, Nov. 2021.
[26] E. Çil et al., “Relationships Between PCT and NLR/PLR in Pneumonia,” Eur. Rev. Med. Pharmacol. Sci., vol. 26, no. 9, pp. 3200–3205, May 2022.
[27] J. S. Kim and C. E. Park, “CRP and CBC Changes by Procalcitonin Level,” Korean J. Clin. Lab. Sci., 2022.
[28] R. Q. Taha et al., “Genomic Landscape of MDR Klebsiella pneumoniae,” 2025.
[29] A. Hussain et al., “Serum PCT as Predictive Biomarker in COVID-19,” Cureus, vol. 14, no. 8, e27816, Aug. 2022.
[30] T. Tian, B. Wei, and J. Wang, “CRP, PCT, and Immune Cell Ratios in Sepsis,” BMC Emerg. Med., 2021.
[31] Y. Li, L. Min, and X. Zhang, “PCT, CRP, WBC in Differential Diagnosis,” BMC Pulm. Med., 2021.
[32] W. Zhou and J. Tan, “Clinical Significance of Eosinophils, PCT, CRP in AECOPD,” Am. J. Transl. Res., 2021.
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