Pediatric systemic multi-inflammatory diseases in Italy during SARS-COV-2 epidemic: From Kawasaki disease to Kawacovid

Introduction: Italy was affected by the SARS-CoV-2 epidemic after its outbreak in China With a 4-weeks delay after the peak in adults, we observed an abnormal number of patients with characteristics of a multi-inflammatory disease and similarities with Kawasaki Disease (KD) Others reported similar cases, defined PIMS-TS or MIS-C 1,2 Objectives: To better characterize clinical features and treatment response of PIMS-TS and to explore its relationship with KD Methods: We conducted an observational, retrospective, multicenter study On April 24th-2020 the Rheumatology Study Group of the Italian Pediatric Society launched a national online survey, to enroll patients diagnosed with KD or with a multisystem inflammatory disease between February 1st 2020 and May 31st The population was then divided into two different groups: 1) Classical and incomplete KD, named Kawasaki Disease Group (KDG);2) KD-like multi-inflammatory syndrome, named KawaCOVID (KCG) An expert panel of pediatric rheumatologists re-analyzed every single patient to ensure appropriate classification Data were collected with an online database Results: 149 cases were studied, 96 with KDG and 53 with KCG The two population significantly differed for clinical characteristics (see table 1) Lymphopenia, higher CRP levels, elevated Ferritin and Troponin-T characterized KCG such as lower WBC and platelets (all p values<0,05) KDG received more frequently immunoglobulins (IVIG) and acetylsalicylic acid (ASA) (81,3% vs 66%;p=0 04 and 71,9% vs 43,4%;p=0 001 respectively) as KCG more often received glucocorticoids (56,6% vs 14,6%;p<0 0001) SARS-CoV-2 assay more often resulted positive in KCG than in KDG (75,5% vs 20%;p<0 0001) Short-term follow data on KCG showed minor complications while on KDG a majority of patients had persistence of CAA Comparing KDG with a KD-Historical Italian cohort (598 patients), no statistical difference was found in terms of clinical manifestations and laboratory data between the two groups Conclusion: Our study would suggest that SARS-CoV-2 infection might determine two distinct inflammatory diseases in children: KD, possibly triggered by SARS-CoV-2, and PIMS-TS Older age at onset and clinical peculiarities, like the occurrence of myocarditis, characterize this multiinflammatory syndrome Our patients had an optimal response to treatments and a good outcome, with few complications and no deaths