Procalcitonin and C-Reactive Protein: Valuable Biomarkers in Sepsis Patients Admitted to a Tertiary Care Centre

Abstract

Background: Sepsis is a critical condition characterized by dysregulated host response to infection, leading to organ dysfunction and high mortality. Reliable biomarkers are essential for early diagnosis, monitoring therapeutic response, and guiding clinical decision-making. Among several candidates, procalcitonin (PCT) and C-reactive protein (CRP) are the most widely studied.

Objective: This study aimed to evaluate the levels of PCT and CRP in patients with mild sepsis, severe sepsis, and septic shock, both at admission and after treatment, and to assess their diagnostic and monitoring utility.

Methods: An Observational follow up study was conducted on 52 patients diagnosed with sepsis at a tertiary care center. Serum PCT and CRP were measured before and after treatment. Continuous and categorical analyses were performed, and statistical significance was assessed using paired t-tests and McNemar’s test.

Results: At admission, PCT levels increased stepwise with severity (6.21 ng/mL mild sepsis, 8.95 ng/mL in mild sepsis, 10.82 ng/mL in septic shock). CRP showed a parallel increase (124.2 mg/L, 146.3 mg/L, 155.8 mg/L, respectively). Both markers declined significantly post-treatment (PCT: −7.24 ng/mL, CRP: −59.8 mg/L; p<0.001 for both). Normalization of PCT (<0.5 ng/mL) occurred in 55% of mild sepsis, 35.7% of severe sepsis, and 33.3% of septic shock patients. CRP normalization (≤10 mg/L) was less frequent (30%, 14.3%, and 5.6%, respectively). Monitoring analysis showed greater responsiveness of PCT (85.5% reduction) compared to CRP (42.2%), with 65.4% of patients meeting PCT response criteria versus 69.2% for CRP. Concordant response of both biomarkers was seen in 51.9% of cases.

Conclusion: Both PCT and CRP were elevated in proportion to sepsis severity and decreased significantly following treatment, confirming their value as monitoring biomarkers. PCT demonstrated superior sensitivity, faster normalization, and greater responsiveness compared to CRP, making it a more reliable marker for assessing disease severity and therapeutic response. Combined use of PCT and CRP may enhance clinical decision-making, but PCT alone appears particularly valuable for guiding timely interventions.