Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare complication of Covid-19 and a potentially fatal condition. It affects the heart, lungs, kidneys, GI tract, CNS leading to multiorgan failure in due course of time. The pathophysiology of MIS-C is not well understood, but the underlying immune dysregulation and the cytokine syndrome are hypothesized to play a major role.

A study published in the December 2022 issue of the Journal of Paediatrics and Child Health attempted to investigate if cardiac involvement in children with Covid-19 could be predicted using complete blood count (CBC), a simple and easily available test.¹

A total of 292 children, aged 1 month to 18 years, with laboratory confirmed Covid-19 and hospitalized in the pediatric ED were enrolled in this single-center retrospective study from March 2020 to February 2021. None of the study subjects had any comorbid condition. 70 healthy children of the same age comprised the control group. There were 12 patients with MIS-C. The various hematological parameters examined were neutrophil to lymphocyte ratio (NLR), CRP, procalcitonin, proBNP, troponin-I and CKMB. These are established indicators of systemic inflammation. The study also defined the cut-off levels of these parameters.

The levels of CRP, procalcitonin, NLR, proBNP, troponin I were raised in Covid patients with MIS-C vs Covid patients without MIS-C vs controls.

The sensitivity of NLR value ≥5.03 in predicting MIS-C was 66.7%, while the specificity was 91.6%. The sensitivity and specificity of proBNP ≥329.5 ng/L were 91.7% and 95.6% respectively. CKMB ≥2.95 μg/L had a sensitivity of 100% and a specificity of 77.7%, while troponin I ≥0.03 μg/L had a sensitivity of 75% and a specificity of 99.2%.

On logistic regression analysis, patients with NLR value of ≥5.03 were found to be 19-times more likely to develop MIS-C. The risk increased 60-folds in patients with troponin-I value of ≥0.03 μg/L. A proBNP value of ≥329.5 ng/L increased the risk 238 folds. A procalcitonin level ≥ 0.165 μg/L increased the risk of MIS‐C by 7.5 times, while a CRP level ≥ 12.65 mg/L increased the risk by 142 times.

This study has delineated predictors of MIS-C in patients with Covid-19 infection. It has also demonstrated the high sensitivity and specificity of cut-off values of parameters such as proBNP, troponin-I and NLR in predicting the development of MIS-C in Covid patients. Hence, measuring these parameters at the time of hospitalization can help clinicians in the timely identification of at-risk patients.

Reference

1. Güllü UU, et al. Haematological parameters predicting cardiac involvement in children with COVID-19 infection. J Paediatr Child Health. 2022 Dec;58(12):2236-2242. doi: 10.1111/jpc.16203.