Absolute eosinophil count as a diagnostic and prognostic marker compared to C- reactive protein and Procalcitonin in patients with sepsis

Objective: This study was undertaken to find out the usefulness of Absolute eosinophil count as a biomarker for sepsis, especially in Indian settings where cost constraints are the rule. Methods: A prospective observational study was carried out over a period of one year in KIMS Al Shifa Super Speciality Hospital which is a tertiary care referral hospital in Malabar region of Kerala. Patients admitted in the ICU with a diagnosis of Systemic Inflammatory Response Syndrome (SIRS) were included except those with hematological cancer, HIV infection, previous eosinophilia due to any cause, trauma patients or those on long term systemic steroids. Absolute eosinophil count estimation at time of admission, and on fifth day, were done manually using Neubauer counting chamber and confirmed using 5 part hematology analyzers ADVIA 2120 (Peroxidase method). The statistical analysis was carried out using the software, Statistical Software for Social Sciences 20.0. Results: The mean value of AEC in different categories of sepsis group was found to be significantly low in septic shock and refractory septic shock patients compared to other categories (p = 0.04), whereas CRP levels were significantly higher in all sepsis groups (p < 0.001). When the diagnostic performance of AEC, CRP and PCT were evaluated, Procalcitonin showed maximum sensitivity (89.5%) on day 1 with a cut off value of 0.5 micogm/L in diagnosing sepsis from SIRS patients. AEC shows maximum specificity (95.65%). Conclusion: It is concluded that Absolute eosinophil count below 50 cells/mm3 is a very specific but poorly sensitive indicator to differentiate sepsis from SIRS.A low value of eosinophil in SIRS patients should alert the physician regarding the possibility of severe sepsis and should direct treatment plan accordingly.