Biochemical and cardiovascular predictors of PIMS-TS risk in children after COVID-19 recovery: preliminary results of the LATE-COVID-Kids Study

INTRODUCTION: We aimed to characterize biochemical and cardiovascular predictors of the paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) risk based on the data from the LATE-COVID-Kids study. METHODS: 148 consecutive COVID-19 convalescents hospitalized for the clinical evaluation after the acute phase of COVID-19 were classified into two groups related to symptoms: 33 children finally diagnosed with PIMS-TS and 115 children without PIMS-TS (control group). RESULTS: PIMS-TS children were significantly younger (6.79 ±4.57 vs. 9.10 ±4.94 years). After adjustment, in comparison to those without, PIMS-TS children had a higher level of antithrombin III (111 ±9.30 vs. 105 ±11.4), higher heart rate (HR)/min (100 (89.0–111) vs. 90 (79.7–100)) and sinus rhythm (p = 0.03) but lower PQ interval (p = 0.02) on admission to hospital. The lymphocytes (absolute count and percentage) were significantly higher in children with PIMS-TS, and the opposite results were obtained for IgA and neutrophils. Furthermore, children with PIMS-TS had a higher level of thyroid stimulating hormone (2.76 (2.16–4.18) vs. 2.36 (1.73–2.83)) and red cell distribution width (p < 0.005) compared to those without. CONCLUSIONS: It is the first data on the possible predictors of PIMS-TS risk in the Long-COVID period. These results need to be further validated to next create the PIMS SCORE algorithm, which might enable the effective prediction of children with the risk of PIMS-TS occurrence after COVID-19 recovery.