Clinical and Laboratory Manifestation of Gastrointestinal Involvement in MIS-C: A Single-Center Observational Study

Background: Digestive symptoms and gastrointestinal issues in children with coronavirus 2019 disease (COVID-19) and Multisystem Inflammatory Syndrome in Children (MIS-C) are commonly reported in pediatric studies from different countries. Our retrospective observational study aimed to summarize the main digestive symptoms and objective data on gastrointestinal involvement in children with MIS-C. Methods: We present the clinical, laboratory, and imaging data of 51 children with MIS-C hospitalized in a single center from 25 November 2020 to 24 April 2021, focusing on gastrointestinal involvement. Results: A total of 46/51 children (90.2%) reported at least one abdominal symptom (abdominal pain (86%, N = 44), vomiting, nausea, diarrhea), predominantly at presentation. Most children were older than 5 years (N = 40, 78%), predominated by the male sex (N = 37, 72.5%), and with a mean age of 8.82 ± 4.16 years. We found a tendency for lymphopenia, neutrophilia, and higher levels of CRP, d-dimer, and ferritin in MIS-C patients with abdominal pain (R-squared 0.188, F-statistic vs. constant model: 11.9, p-value = 0.00122, 20% explanation of variation with p = 0.001). We found a statistically significant linear relationship (regression) between neutrophile percentage (NEU%) and hospital stay and a tendency for elevated transaminases to be more frequent in older children (27.3% under 5 years and 65% over 5 years; p = 0.0583). We found no significant associations between digestive symptoms and age or the predominant SARS-CoV-2 variant. Conclusions: Most of our MIS-C patients presented with abdominal pain, usually along with other GI symptoms, which could be applied in clinical practice to MIS-C in children visiting the emergency room with abdominal pain and evidence of recent COVID-19 contact or infection. Further information from larger cohorts of MIS-C patients is needed to better understand the epidemiology of gastrointestinal involvement in these patients.