Neonatal infections in Lubumbashi, in the Democratic Republic of Congo: Correlation between C-reactive protein (CRP), interleukin-6 (IL-6) and procalcitonin (PCT)

Introduction: The study focuses on Neonatal Infections in Lubumbashi, DRC , a major public health concern due to their high prevalence and impact on newborn health. Early diagnosis is crucial , but difficult due to non-specific symptoms and the dilemma of antibiotic therapy. Biological markers of inflammation, which must be early, sensitive, specific, and inexpensive , are essential to aid diagnosis. C-Reactive Protein (CRP), Interleukin-6 (IL-6), and Procalcitonin (PCT) are three markers used, each with a different kinetic of action (IL-6 very early, PCT early/specific to bacteria, CRP later/for follow-up). This research aims to assess the correlation between these three markers in newborns suspected of infection.

Materials and Methods: This was a prospective cohort study conducted at the Dee Service medical laboratory in Lubumbashi. The sample included 75 newborns (0 to 28 days) hospitalized in Lubumbashi and presenting with suspected or confirmed neonatal infection. Serum concentrations of CRP, IL-6, and PCT were measured from blood samples using immunofluorescence analyzers (SK-1000, Ichroma 2, Fine care Wondfo) with specific kits. Statistical analysis used the Pearson correlation coefficient and Student's t-test, with R Studio and Excel software.

Results: The mean serum concentrations were 46.46±37.23 mg/L for CRP, 25.61±23.72 mg/L for IL-6, and 8.01±6.28 mg/L for PCT. Correlation analysis revealed a poor correlation between CRP and PCT (rxy​=0.57). The correlation between PCT and IL-6 was inverse (rxy​=−0.17). Finally, the correlation between CRP and IL-6 was also poor (rxy​=0.10).

Conclusion: The correlation coefficients suggest an overall poor correlation between CRP, IL-6, and Procalcitonin in infected newborns in Lubumbashi, with results ranging from poor to inverse. These results emphasize that, although individually useful in diagnosis, these markers have distinct induction mechanisms and kinetics. The study confirms the relevance of integrating multiple markers to optimize the diagnosis and monitoring of neonatal infections , as the inflammatory syndrome is not specific to a precise cause.