Multisystem inflammatory syndrome in neonates (MIS-N): a systematic review

Area of Science:

• Neonatal Medicine
• Infectious Diseases
• Pediatric Cardiology

Background:

• Multisystem inflammatory syndrome following SARS-CoV-2 infection (MIS-C) has been observed in adults and children.
• Reports of a similar condition in neonates, termed multisystem inflammatory syndrome in neonates (MIS-N), have emerged globally since late 2020.

Purpose of the Study:

• To systematically review the clinical characteristics, laboratory parameters, treatment, and outcomes of neonates diagnosed with MIS-N.
• To identify patterns and risk factors associated with MIS-N in the neonatal population.

Main Methods:

• A systematic review was conducted using multiple electronic databases (MEDLINE, EMBASE, PubMed, SCOPUS, Google Scholar, Web of Science) from January 2020 to September 2022.
• Data from 27 studies involving 104 neonates were analyzed, focusing on clinical presentation, laboratory findings, treatment modalities, and patient outcomes.

Main Results:

• MIS-N predominantly affected late preterm males, with cardiovascular system involvement in 83.65% and respiratory system in 64.42%. Fever was uncommon (20.2%).
• Elevated inflammatory markers included IL-6 (86.7%) and D-dimer (81.1%). Echocardiography revealed ventricular dysfunction (35.8%) and dilated coronary arteries (28.3%).
• Maternal SARS-CoV-2 infection was present in 100% of cases. Early MIS-N showed a higher proportion of preterm and low birth weight infants compared to late MIS-N.

Conclusions:

• MIS-N is an emerging condition in neonates, characterized by significant cardiovascular involvement and a predilection for late preterm males.
• Diagnosis can be challenging due to overlapping symptoms with other neonatal morbidities, necessitating a high index of suspicion.
• Effective treatments include steroids and IVIg, with a high discharge rate, though mortality remains a concern (8.2%).