ESPE Abstracts

Introduction: Paediatric Inflammatory Multisystem Syndrome Temporarily associated with SARS-CoV-2 (PIMS-TS) was first reported by our hospital in the UK. Vitamin D₃(25(OH)D) has important roles in cardiac function, immunomodulation, and inflammation. It therefore may be an important biomarker for severity in PIMS-TS, however 25(OH)D status and treatment guidance in PIMS-TS are lacking. We report serum 25(OH)D levels on admission and associations with disease severity. We outline our initial treatment strategy and subsequent modification to obtain a rapid and safe correction of serum levels of 25(OH)D to optimal levels (>75 nmol/l).

Methods: Retrospective data analysis of children aged 1-18 years with PIMS-TS admitted to a tertiary paediatric hospital in London between 16 April 2020 and 31 January 2021. Baseline 25(OH)D serum levels were measured prior to treatment with cholecalciferol and associations with indicators of severity were assessed. Early in the pandemic a single dose of 100,000 IU cholecalciferol was administered on admission, but on subsequent review this was modified to 200,000 IU. Post-treatment 25(OH)D serum levels were taken to assess efficacy.

Results: The median age of the cohort (n = 109) was 8.9 years, 68 (62.4%) were male, and 53 (48.6%) were of black or Asian race. Median baseline 25(OH)D level was 36 nmol/l and levels <50 nmol/l were present in 69% children (75/109). Associations with lower baseline levels included: markers of inflammation (P < 0.001) including ferritin (426mcg/l IQR 227-861), D-Dimer (2.3mg/l IQR 1.5-6.7), and lymphocyte count (1.3x10⁹/L IQR 0.7-2.4); paediatric intensive care unit admission (P < 0.001); and fractional shortening on echocardiography <29% (P < 0.001). There was no significant difference in the baseline 25(OH)D levels between the 100,000 IU and 200,000 IU treatment groups but the post-dose levels were >75 nmol/l in 30% (8/27) and 89% (17/19) children, respectively. No adverse effects of supplementation were reported.

Conclusions: PIMS-TS is associated with low 25(OH)D levels and a high proportion of children had vitamin D deficiency on presentation which could be effectively treated with a single dose 200,000 IU cholecalciferol. Serum 25(OH)D levels are a valuable biomarker of severity, but further studies are needed to establish if effective supplementation can modify outcomes.