The value of inflammatory markers in predicting the severity of the disease in children infected with Sars-Cov 2

In December 2019, a new type of coronavirus emerged with the detection of pneumonia cases in Wuhan, China. This epidemic, it was named COVID-19. COVID-19, which spread rapidly in many countries after China, was declared a pandemic by WHO on March 11, 2020. Little is still known about the epidemiological and clinical features of pediatric patients with COVID-19. Complete blood count parameters have been investigated in many diseases as an indicator of the inflammatory process. Low-cost and routinely studied in the laboratory, complete blood count parameters, CRP, and their ratios neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (TLR), mean platelet volume/lymphocyte ratio (MPR), derived-NLR (d-NLR) and systemic immune inflammation index (SII) may be helpful in evaluating the prognosis of the disease. In this study, we aimed to evaluate the importance of hematological parameters in predicting the clinical severity of the disease in COVID-19 PCR-positive children. Our study included all children (n=6893) aged 1 month-18 years COVID PCR positive children who applied to our hospital between 01 April 2020 - 01 April 2022. Patient data were obtained from retrospective patient files. From the hospital data, the files scanned, and demographic data as well as clinical, vital signs at the time of admission and laboratory results were recorded. All patients according to their clinical severity classified; asymptomatic, mild, moderate, severe and critical. Disease severity and hemogram in 903 patients who had blood tests parameters (lymphocyte, neutrophil, eosinophil, monocytes, mean platelet volume, immature granulocytes, RDW etc.), CRP values and the ratios of these values, NLR, TLR, d-NLR, MPR, SII were evaluated. All patients who were positive for COVID-PCR 50% (n=3433) were female and 50% (n=3430) were male. Their ages ranged from 1 to 216 months (18 years), with a mean of 139.09±58.90 months (11.5±4.9 years). The most common symptoms in children with positive COVID-PCR were fever in 36.6%, cough in 28.4%, sore throat in 21%, and headache in 13.4%. From all the cases had their severity classified: 31.2% asymptomatic, 66.5% mild, upper respiratory tract infection, 1.9% moderate, lower respiratory tract infection, 0.2% severe, severe pneumonia, 0.1% were critical, intensive care patient. When the asymptomatic, mild and moderate patient group was evaluated, a statistically 8 significant difference was observed in neutrophils, lymphocytes, eosinophils, platelets, Mean platelet volume, immature granulocytes, CRP, NLR, TLR, MPR, d-NLR, SII. . [(p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,036; p<0,05), (p=0,002; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01), (p=0,001; p<0,01)]. When severe and critical patients were evaluated, a statistically significant difference was observed in RDW and NLR measurements. [ (p=0,021; p<0,05),(p=0,026; p<0,05)]. The optimal cut-off value for NLR is ≥9.19. Sensitivity = 0.801, specificity = 0.877, and (1-specific) = 0.123. The optimal cut-off value for RDW(fL) is ≥43.90. Sensitivity = 0.800, specificity = 0.875, and (1-specific) = 0.125. This indicates that the need for intensive care may develop in patients with NLR ≥9.19 and RDW(fL) ≥43.90 when evaluated with the results of our study. In our study, NLR was found to be associated with the clinical severity of COVID-19 disease. It is thought that this parameter can be used as a good indicator to predict the severity of COVID-19 disease.