Delta Neutrophil Index: A Potential Diagnostic Marker of Multisystem Inflammatory Syndrome in Children (MIS-C)

Abstract

Background Multisystem inflammatory syndrome in children (MIS-C) is a life threatening hiperinflamation syndrome emerging after COVID-19. The serum delta neutrophil index (DNI), reflects the fraction of circulating immature granulocytes and elevated 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. Methods This retrospective, observational study included 83 patients of MIS-C and 113 patients of COVID-19 and control group. C-reactive protein, absolute neutrophil count, absolute lymphocyte count, DNI and platelet count were recorded. Results The DNI levels were 4.60 ± 5.70% in the MIS C group and 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 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 the DNI levels and the severity of MIS-C. The cutoff value of DNI for predicting MIS-C was 0.45%. In the correlation analysis of DNI with CRP, ANC, ALC and platelet count, sensitivity, specificity, positive predictive value and negative predictive value were found to be 79.5%, 97.1%, 95.7%, and 85.3%, respectively. Conclusions DNI was identified as a predictive factor for diagnosis of 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.