Evaluation of Immature Granulocyte Count as the Earliest Biomarker for Sepsis

Abstract

Background 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. Patients and methods 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. Results 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. Conclusion 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. How to cite this article 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.

The Clinical Utility of Automated Immature Granulocyte Measurement in the Early Diagnosis of Bacteremia

“…A [10]. Similarly, receiver operating characteristic curves in our study showed that IGC and IG% are better predictors of infection with AUC of 0.75 and 0.79, respectively.…”

Neutrophil Reactivity Intensity and misclassification of immature granulocytes

“…Van der Geest et al 4 found the optimal IG% cutoff to identify infection to be 0.4%. And Bhansaly et al 1 reported an optimal IG% cutoff as low as 0.7% to prospectively predict sepsis within 24 hours with AUC of 0.818. Ideally, we should evaluate IG misclassification in similarly low IG% levels.…”

“…However, these findings are limited to our smear practice and patient population and NEUT‐RI may thus be of significant value in other laboratory settings for identification of misclassified results. Also, considerations should be made to whether NEUT‐RI values ≥56 or the presence of the Abnormal WBC scattergram flag should affect the release of the preliminary Sysmex result prior to the completion of the smear analysis, as crucial clinical decisions regarding infection status and sepsis may be made in the meantime 1–4,7 …”

“…The number and percentage of circulating immature granulocytes (IG and IG%) rise in response to severe infection and high values predict sepsis. [1][2][3][4] Precise estimation of neutrophil maturity is needed to make a proper clinical evaluation of the patient's immune status.…”

Endometriyal Kanserde Delta Nötrofil İndeksinin Öngörücü Potansiyeli: Tanı için Yeni Bir Biyobelirteç

“…One such biomarker that has shown promise in the diagnosis and prognosis of EC is delta neutrophil index (DNI) (8,9). DNI is a laboratory parameter that measures the difference between the fraction of immature granulocytes and mature granulocytes in the bloodstream (8)(9)(10). DNI is a sensitive marker of systemic inflammation and infection and has been shown to be a promising prognostic biomarker in various cancers, including EC (10)(11)(12)(13)(14).…”