Evaluation of Immature Granulocyte Count as the Earliest Biomarker for Sepsis

Diagnosing sepsis early is important for its successful management. Various biomarkers are being used currently, but mostly they are either expensive or not readily available. This study aims to evaluate usefulness of automated immature granulocyte count (IG#) and immature granulocyte percentage (IG%) as early diagnostic markers of sepsis and compares it to other established predictive markers.

In this prospective observational study, 137 eligible, critically ill, nonseptic intensive care unit patients were analyzed for automated IG#, IG%, serum procalcitonin (PCT), and blood lactate (Lac), daily for 7 days after recruitment. Patients were followed for the development of sepsis, defined by the new Sepsis-3 criteria. The study was divided into four time periods of 24 hours each with respect to the day of developing organ dysfunction. Using area under receiver operator characteristic and diagnostic odds ratio (DOR) methods, the best biomarker for the prediction of sepsis in each time period was calculated.

IG# and IG% were the earliest biomarkers to have a significant discriminating value with area under the curve of 0.81 and 0.82, respectively, as early as 24 hours before clinical sepsis is diagnosed by Sepsis-3 criteria. Both IG# and IG% have a high DOR of 34.91 and 18.11, respectively, when compared to others like PCT and Lac having a DOR of 27.06 and 4.78, respectively.

IG# and IG% are easily available, rapid, and inexpensive tools to differentiate between septic and nonseptic patients with high specificity and sensitivity. It is the earliest biomarker to show a significant rise in patients developing sepsis.

Bhansaly P, Mehta S, Sharma N, Gupta E, Mehta S, Gupta S. Evaluation of Immature Granulocyte Count as the Earliest Biomarker for Sepsis. Indian J Crit Care Med 2022;26(2):216-223.