Neonatal multisystem inflammatory syndrome during acute SARS-COV-2 infection

Introduction. During the development and spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic, a new inflammatory response syndrome arised in newborns and was designated as the multisystem inflammatory syndrome in neonates (MISN). Case report. A term infant girl with fever and diagnosed SARS-CoV-2 infection was admitted to hospital. In laboratory findings lactate dehydrogenase, ferritin, interleukin-6, and D-dimer values were elevated. Upon admission, dual parenteral antibiotic therapy (ceftazidime, vancomycin) and low molecular weight heparin (LMWH) therapy was started. After 5 days of febrility with negative microbiological analyses and further deterioration of laboratory findings, intravenous immunoglobulin (IVIg) therapy was administered at a dose of 2 g/kg for one day, then methylprednisolone at a dose of 1 mg/kg/day for 4 days, after which the reduction of corticosteroid therapy was performed with prednisone. One day after IVIg administration, the newborn became afebrile, with the gradual normalization of laboratory findings. The newborn was discharged after 16 days of hospitalization. Two weeks after discharge, the use of LMWH was stopped. After seven days, the D-dimer value increased significantly. The anticoagulant therapy was restarted. After a month of LMWH administration, the D-dimer value completely normalized, and the therapy was stopped. Conclusion. In this case after the applied therapy for multisystem inflammatory syndrome in children, there was cessation of febrility and gradual normalization of laboratory parameters, which confirms that the newborn in this case probably had MIS-N. The prolonged elevated Ddimer value was most probably a consequence of inflammation as part of the multisystem inflammatory syndrome.