AUTHOR=Prader Seraina , Ritz Nicole , Baleydier Frédéric , Andre Maya C. , Stähli Noémie , Schmid Kevin , Schmid Hanna , Woerner Andreas , Diesch Tamara , Meyer Sauteur Patrick M. , Trück Johannes , Gebistorf Fabienne , Opitz Lennart , Killian Michael P. , Marchetti Tommaso , Vavassori Stefano , Blanchard-Rohner Géraldine , Mc Lin Valerie , Grazioli Serge , Pachlopnik Schmid Jana TITLE=X-Linked Lymphoproliferative Disease Mimicking Multisystem Inflammatory Syndrome in Children—A Case Report JOURNAL=Frontiers in Pediatrics VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2021.691024 DOI=10.3389/fped.2021.691024 ISSN=2296-2360 ABSTRACT=

Most children with a SARS-CoV-2 infection are asymptomatic or exhibit mild symptoms. However, a small number of children develop features of substantial inflammation temporarily related to the COVID-19 also called multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS), clinically similar to Kawasaki disease, toxic shock syndrome and hemophagocytic lymphohistiocytosis (HLH). It is well-known that genetic pre-disposition plays an important role in virally-triggered diseases such as Epstein-Barr virus (EBV)-associated HLH, while this has not yet been established for patients with MIS-C. Here we describe a male patient fulfilling the diagnostic criteria of MIS-C, who was initially treated according to current consensus guidelines. Presence of hypofibrinogenemia, normal lymphocyte counts and C-reactive protein, but substantial hyperferritinemia distinguish this patient from others with MIS-C. The clinical course following initial presentation with acute respiratory distress syndrome was marked by fatal liver failure in the context of EBV-associated HLH despite treatment with steroids, intravenous immunoglobulins, interleukin (IL)-1 receptor blockade and eventually HLH-directed treatment. X-linked lymphoproliferative disease type 1 (XLP1), a subtype of primary HLH was diagnosed in this patient post-mortem. This case report highlights the importance of including HLH in the differential diagnosis in MIS-C with severe disease course to allow specific, risk-adapted treatment and genetic counseling.