Comparison of neutrophil CD64 and monocytic HLA-DR with existing biomarkers for the diagnosis and prognosis of sepsis

BACKGROUND: We measured the expression of serum procalcitonin (PCT), quantitative C-reactive protein (QCRP), neutrophil CD64 (nCD64) and monocytic HLA-DR (mHLA-DR) sequentially in patients admitted to the intensive care unit (ICU) and correlated the expression of these biomarkers to predict development of sepsis and its outcome. METHODS: Consenting adult patients of more than 18 years of age, who developed sepsis during an observation period of 20 days with a sequential organ failure assessment score (SOFA) score ≥ 2 or those who already had sepsis at admission to the ICU were included. SOFA score, serum PCT, QCRP, nCD64 and mHLA-DR assays were recorded on the first and third day of admission to the ICU. A total of 27 sepsis cases and 24 controls (all admitted to the ICU) were included in the study. RESULTS: SOFA score, serum PCT, QCRP, nCD64 were significantly higher and mHLA-DR was significantly lower in cases compared to controls, both on day 1 and day 3. There was no significant difference in any of the parameters between day 1 and day 3. PCT and nCD64, both with sensitivity of 77.8% and specificity of 70.8% (95% CI, 0.73–0.95), had the best predictive value for diagnosing sepsis. Lower mHLA-DR (< 5000/cell) was associated with higher mortality among cases. CONCLUSIONS: Serum PCT and nCD64 are the best biomarkers with similar sensitivity and specificity in detecting sepsis. mHLA-DR could have a role in prognosis as lower levels were associated with higher mortality.