A comparative study of IL-6, CRP and NT-proBNP levels in post-COVID multisystem inflammatory syndrome in children (MISC) and Kawasaki disease patients.

ABSTRACT

BACKGROUND: Post-COVID multisystem hyperinflammatory syndrome in children (MISC) has clinical and laboratory similarities with Kawasaki disease (KD). Inflammatory markers like C-reactive protein (CRP), interleukin 6 (IL6) as well as N-terminal probrain natriuretic peptide (NT-proBNP) are elevated in both. This study attempts a comparative analysis of the 3 markers in an attempt at early differentiation for planning appropriate management. METHODOLOGY: This analytical study conducted at the Institute of Child Health, Kolkata, India compared the levels of the above 3 markers at admission between 72 patients with KD, 30% of whom had coronary artery lesions (CALs) collected over a period of 18 months (Jan 2017-June 2018), with 71 MISC patients over a period of 6 months (July 2020-December 2020). The non-parametric Mann-Whitney U test was used to test for similarity in distributions of the samples of CRP, NT-proBNP and IL6 in KD and MISC patients using correction factor for similar ranks. The 3 parameters were compared using receiver operating characteristic (ROC) curve analysis. RESULTS: Mean IL6 value in KD was 83.22 pg/mL and in MISC 199.91 pg/mL, which was not found to be statistically significant (P = .322 > .05).However mean NT-proBNP (914.91 pg/mL) with CRP level (96.32 mg/L) in KD was significantly lower (P < .05 for both cases) than that in MISC (9141.16 pg/mL and 145.66 mg/L respectively). ROC analysis showed NT-proBNP has the best sensitivity and specificity in predicting MISC. CONCLUSION: NT-proBNP and CRP are significantly higher among MISC patients; ROC analysis shows levels >935.7 pg/mL and >99.55 mg/L respectively might act as a guide to differentiate between them.