Immature granulocytes: Innovative biomarker for SARS‑CoV‑2 infection

Abstract

Immature granulocytes (IGs) include metamyelocytes, myelocytes and promyelocytes, and are the precursors of neutrophils. Increased IG counts found in peripheral blood indicate an enhanced bone marrow activity. In addition, IGs have been evaluated in numerous clinical conditions, such as severe acute pancreatitis, systemic inflammatory response syndrome and infectious complications following open-heart surgery under cardiopulmonary bypass. Neutrophils are considered to play a crucial role in the host defense during bacterial and fungal infections, and are involved in the antiviral immune response. Numerous studies have reported the role of neutrophils in coronavirus disease 2019 (COVID-19) infection, concluding that the percentage of neutrophils may be a predictor of the severity of COVID-19 infection. There has been limited research regarding the role of neutrophil precursors in viral infections, including severe acute respiratory syndrome coronavirus 2 infection. The present thus aimed to evaluate the role of the IG count in patients hospitalized due to COVID-19 infection. The patients were predominantly infected with the alpha variant and were all unvaccinated. The IG count was measured and was found to be associated with disease severity, with patient outcomes, with the duration of hospitalization and with the development of complications. The IG count was a significantly associated with the severity of COVID-19 infection, with greater IG count values being detected in severe and critical cases. In addition, greater IG count values were associated with a longer duration of hospitalization. Furthermore, the IG count was found to be an independent prognostic biomarker of intubation and mortality in patients with COVID-19, according to multivariate logistic regression analysis, including age, the male sex and the presence of comorbidities as confounders.

Evaluation of Hemogram Parameters in the Diagnosis of Pulmonary Embolism: Immature Granulocytes and Other New Tips

“…IG are neutrophil precursors including metamyelocytes, myelocytes, and promyelocytes and high IG values indicate an enhanced bone marrow activity. 10 , 11 It has been previously investigated as a prognostic inflammatory parameter in sepsis, acute respiratory distress syndrome, pancreatitis, coronavirus disease 2019 (COVID-19). 11 – 13 Kong et al 14 found that immature granulocytes were associated with early mortality in PE.…”

Factors predicting poor outcomes of patients treated with tocilizumab for COVID‑19‑associated pneumonia: A retrospective study

“…For example, the existence of monoallelic vs. biallelic ACE2 and Toll-like receptor 7 genes on the X chromosome may help to explain the greater risk of COVID-19 infection in males compared to females (37). Several studies have reported laboratory parameters, such as eosinophils, lymphocytes, PLTs, immature granulocytes, ferritin and liver enzymes as biomarkers of poor outcomes in patients with COVID-19 (36,(38)(39)(40)(41)(42). Of note, only a few studies have evaluated laboratory data as biomarkers of poor outcomes in tocilizumab-treated patients with COVID-19 (29)(30)(31)(32)(33)(34)(43)(44)(45).…”

Onodera's prognostic nutritional index: Comparison of its role in the severity and outcomes of patients with COVID‑19 during the periods of alpha, delta and omicron variant predominance

“…In COVID-19, the imbalance of the immune response and excessive inflammation is a major component of its pathogenesis (9). Several immune and inflammatory indicators, including the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, eosinophil-to-lymphocyte ratio, immature granulocytes, ferritin, fibrinogen, C-reactive protein, interleukin (IL)-6 and lactate dehydrogenase, have been shown to be associated with disease severity and mortality in patients with COVID-19 (10)(11)(12)(13)(14).…”