Functional immune responses after the use of immune-modulatory therapy for Paediatric Inflammatory Multisystem Syndrome temporally associated with SARS-CoV2 (PIMS-TS)

During the first few months of the SARS-CoV2 pandemic, a new paediatric syndrome was described: Paediatric Inflammatory Multisystem Syndrome temporally associated with SARS-CoV2 (PIMS-TS), whereby children presented with fever and multisystem inflammation ranging from mild symptoms to critical illness with multi-organ failure. For mild cases supportive treatment appears to be sufficient, however more severe cases have been treated with a range of immune-modulators including intravenous immunoglobulin, systemic glucocorticoids, tumour-necrosis-factor blockade, interleukin-6 and/or interleukin-1Ra inhibitors. Although largely effective in reducing the inflammation and resolving acute cardiovascular impairment, the medium and long-term outcomes of the use of these therapies is not well-described, and there is clinical equipoise about which agent is most best-suited to treat future cases of PIMS-TS. In addition PIMS-TS/COVID in itself may have medium/long lasting impact on the immune system. An improved understanding of the extent and duration of immune-suppression caused by the immune-modulatory agents used to treat PIMS-TS will help guide clinicians to appropriate follow-up, further investigations and potentially interventions such as vaccine boosters, shielding or even the use of antimicrobial prophylaxis. It may also help to differentiate between different agents and their medium-long term impact on the child's immune system, and this may inform treatment strategies. The three main paediatric centres for the management of PIMS-TS in London are: Great Ormond Street Hospital, Evelina Children's Hospital and St Mary's Hospital, and this study proposes to recruit children from these centres to examine the functional immune responses during the recovery from PIMS-TS and following their treatment with immune-modulatory therapy.