Potential and promising marker for serious bacterial infections in children: Delta neutrophil index.

AIM: This study aimed to evaluate the usefulness and accuracy of the delta neutrophil index (DNI), an index expressing the number of immature granulocytes as a proportion of the total, as an inflammatory marker in predicting serious bacterial infections (SBIs). METHODS: Paediatric patients admitted to our hospital with fever were divided into four groups: SBI, non-SBI, COVID-19 and control group. White blood cell count, absolute neutrophil count, C-reactive protein and the DNI were recorded, and their accuracy in predicting SBI was evaluated. RESULTS: Mean DNI was 4.96 ± 8.38 in the SBI group (150 patients), 0.67 ± 1.68 in the non-SBI group (397 patients), 0.29 ± 0.99 in the COVID-19 group (112 patients) and 0.14 ± 0.21 in the control group (102 patients). The DNI was significantly higher in the SBI group compared with the non-SBI (P < 0.001); the non-SBI group also had higher levels than the COVID-19 group (P = 0.005). One percent increase in the DNI increased the SBI rate 1.36 times (odds ratio 1.36 (95% confidence interval 1.23-1.49), P < 0.001). Based on the determined cut-off value (>2.5%), the DNI (odds ratio 6.27 (95% confidence interval 3.85-10.21), P < 0.001) significantly predicted SBIs with 90.4% specificity and 47.7% sensitivity. CONCLUSIONS: SBIs in childrenare associated with an increase in DNI levels. Compared to other biomarkers, the DNI had higher specificity in predicting SBIs. The DNI may also be usefulin differentiating bacterial and non-bacterial infections in individualclinical syndromes. Currently, there is no evidence that serum DNI aids indifferentiating COVID-19 and upper respiratory tract infection.

Positive Role of Delta Neutrophil Index (DNI) as a Prodiagnostic Marker in Cecal Ligation and Puncture (CLP)-Induced Sepsis Murine Model.

Sepsis is an emergent infectious disease and a leading cause of death despite immediate intervention. While Delta neutrophil index (DNI) and myeloperoxidase (MPO) are known as a prodiagnostic marker of sepsis, the preclinical evidence of the best marker of sepsis is unclear. For this, using a well-designed cecal ligation and puncture (CLP)-induced sepsis mouse model, we comparatively measured the level and cost-effectiveness of sepsis biomarkers such as DNI, myeloperoxidase (MPO), procalcitonin (PCT), and tumor necrosis factor-alpha (TNF-α). First, we found that the optimal time point for early detection is at 6 h, 24 h post-CLP. Strikingly, the peak level and fold change of DNI was revealed at 24 h, further showing the best fold change as compared with other biomarker levels. Given the fold change at 6, 24 h, PCT was next to DNI. Third, a cost-effectiveness survey showed that DNI was the best, with PCT next. Further, DNI level was moderate positively associated with PCT (ρ = 0.697, p = 0.012) and TNF-α (ρ = 0.599, p = 0.040). Collectively, these data indicate that DNI in CLP-induced sepsis mice is as effective as the existent inflammatory biomarkers such as MPO, PCT and TNF-α to predict the prognosis of sepsis. This might have clinically important implications that DNI is cost effective, thus quickly and rationally applying to diverse types of imminent sepsis regardless of species. This might be the first report on the validity of DNI in preclinical CLP-induced murine sepsis.

Delta neutrophil index and C-reactive protein: a potential diagnostic marker of multisystem inflammatory syndrome in children (MIS-C) with COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening hyperinflammation syndrome emerging after COVID-19. The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is evaluated in infection and inflammation. The aim of this study is to evaluate the usefulness of DNI as a diagnostic marker in patients with MIS-C and to assess its role in determining the severity of MIS-C. This retrospective, observational study included 83 patients with MIS-C and 113 patients with COVID-19, and 102 healthy controls. C-reactive protein (CRP), the absolute neutrophil count (ANC), absolute lymphocyte count (ALC), DNI, and the platelet count were recorded. The DNI levels were 4.60 ± 5.70% in the MIS C group, 0.30 ± 0.99% in the COVID group, and 0.20 ± 0.56% in the control group (p < 0.001). According to the severity of MIS-C, the DNI level was found to be 1.22% in mild MIS-C, 4.3% in moderate MIS-C, and 5.7% in severe MIS-C. There was a statistically significant correlation between DNI levels and the severity of MIS-C. The cutoff value of DNI for predicting MIS-C was 0.45%. In the analysis of the diagnostic performance of DNI compared with CRP, ANC, ALC and platelet counts, sensitivity, specificity, positive predictive value, and negative predictive value were found to be 79.5%, 97.1%, 95.7%, and 85.3%, respectively.Conclusions: The delta neutrophil index was identified as a diagnostic marker for MIS-C such as ANC, ALC, platelet count, and CRP. DNI levels in hemogram analysis may guide clinicians in determining the diagnosis and severity of MIS-C. What is Known: • Although CRP, sedimentation, ALC, ANC, platelet count, sodium, and albumin are used as first step tests, there is no specific laboratory marker used in the diagnosis of MIS C. • The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is elevated in infection and inflammation. What is New: • DNI is a promising and easily accessible marker that can be used with other markers in the diagnosis and determines the severity of MIS C. • DNI is an easily accessible, inexpensive, and dynamic marker and its levels in simple hemogram analysis will guide pediatricians in determining the diagnosis and severity in MIS C.

The role of haematological parameters in patients with COVID-19 and influenza virus infection.

SARS-CoV-2, the causative agent of coronavirus disease 19 (COVID-19), was identified in Wuhan, China. Since then, the novel coronavirus started to be compared to influenza. The haematological parameters and inflammatory indexes are associated with severe illness in COVID-19 patients. In this study, the laboratory data of 120 COVID-19 patients, 100 influenza patients and 61 healthy controls were evaluated. Lower lymphocytes, eosinophils, basophils, platelets and higher delta neutrophil index (DNI), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were found in COVID-19 and influenza groups compared to healthy controls. The eosinophils, lymphocytes and PLR made the highest contribution to differentiate COVID-19 patients from healthy controls (area under the curves (AUCs): 0.819, 0.817 and 0.716, respectively; P-value is <0.0001 for all). The NLR, the optimal cut-off value was 3.58, which resulted in a sensitivity of 30.8 and a specificity of 100 (AUC: 0.677, P < 0.0001). Higher leucocytes, neutrophils, DNI, NLR, PLR and lower lymphocytes, red blood cells, haemoglobin, haematocrit levels were found in severe patients at the end of treatment. Nonsevere patients showed an upward trend for lymphocytes, eosinophils and platelets, and a downward trend for neutrophils, DNI, NLR and PLR. However, there was an increasing trend for eosinophils, platelets and PLR in severe patients. In conclusion, NLR and PLR can be used as biomarkers to distinguish COVID-19 patients from healthy people and to predict the severity of COVID-19. The increasing value of PLR during follow-up may be more useful compared to NLR to predict the disease severity.