Characteristics and outcomes of multisystem inflammatory syndrome in children: A multicenter, retrospective, observational cohort study in Mexico.

Introduction: Multisystem inflammatory syndrome in children associated with coronavirus disease 2019 (MIS-C), a novel hyperinflammatory condition secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is associated with severe outcomes such as coronary artery aneurysm and death. Methods: This multicenter, retrospective, observational cohort study including eight centers in Mexico, aimed to describe the clinical characteristics and outcomes of patients with MIS-C. Patient data were evaluated using latent class analysis (LCA) to categorize patients into three phenotypes: toxic shock syndrome-like (TSSL)-MIS-C, Kawasaki disease-like (KDL)-MIS-C, and nonspecific MIS-C (NS-MIS-C). Risk factors for adverse outcomes were estimated using multilevel mixed-effects logistic regression. Results: The study included 239 patients with MIS-C, including 61 (26%), 70 (29%), and 108 (45%) patients in the TSSL-MIS-C, KDL-MIS-C, and NS-MIS-C groups, respectively. Fifty-four percent of the patients were admitted to the intensive care unit, and 42%, 78%, and 41% received intravenous immunoglobulin, systemic glucocorticoids, and anticoagulants, respectively. Coronary artery dilatation and aneurysms were found in 5.7% and 13.2% of the patients in whom coronary artery diameter was measured, respectively. Any cause in-hospital mortality was 5.4%. Hospitalization after ten days of symptoms was associated with coronary artery abnormalities (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.0). Age ≥10 years (OR: 5.6, 95% CI: 1.4-2.04), severe underlying condition (OR: 9.3, 95% CI: 2.8-31.0), platelet count <150,000 /mm3 (OR: 4.2, 95% CI: 1.2-14.7), international normalized ratio >1.2 (OR: 3.8, 95% CI: 1.05-13.9), and serum ferritin concentration >1,500 mg/dl at admission (OR: 52, 95% CI: 5.9-463) were risk factors for death. Discussion: Mortality in patients with MIS-C was higher than reported in other series, probably because of a high rate of cases with serious underlying diseases.

Clinical presentation of pediatric patients with symptomatic SARS-CoV-2 infection during the first months of the COVID-19 pandemic in a single center in Mexico City.

Background: The clinical spectrum of COVID-19 is broad, from asymptomatic to severe cases and death. The objective of this study is to analyze the clinical course of patients attended during the first months of the SARS-CoV-2 pandemic in a third-level pediatric hospital. Methods: Design: prospective cohort study. Patients with viral respiratory disease or suspected cases of COVID-19 were evaluated at the Pediatric Hospital, National Medical Center XXI Century, Mexico City, from 21 March 2020 to 13 January 2021. Statistical analysis: Chi-square test and Fisher's exact test were used for comparisons; a logistic regression model was constructed to identify clinical or laboratory characteristics associated with critical disease. A p-value < 0.05 was considered statistically significant. Results: A total of 697 patients met the operational definition of viral respiratory disease or suspected cases of COVID-19 and underwent real-time reverse transcription polymerase chain reaction (rRT-PCR) SARS-CoV-2 testing. Patients with a positive result were included. Of the 181 patients (26%), 121 (66.8%) had mild disease and were treated as outpatients and 60 (33.1%) were hospitalized. A total of six patients met the criteria for multisystem inflammatory syndrome in children (MIS-C). Of the 60 inpatients, 65% were males, and 82% had one or more comorbidities. The main comorbidities were cancer (42%) and overweight (15%). The median hospital stay was 9 days. The inpatients had a higher frequency of fever, general malaise, dyspnea, chills, polypnea, and cyanosis than the outpatients (p < 0.05). Only 21.4% of the outpatients had one or more comorbidities, which were lower than in the hospitalized patients (p < 0.001). Laboratory data at admission were similar between critically ill and those with moderate and severe disease. The patients who developed pneumonia were at higher risk of critical disease, while older age was associated with a better prognosis. A total of 13 of the 60 inpatients died (mortality 7.1%). All but one had one or more comorbidities: four had cancer, four congenital heart disease, one chronic kidney disease and epilepsy, one Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis, one obesity, and one diabetes mellitus. Conclusion: Hospital mortality is high, especially in children with comorbidities. Despite 2 years having passed since the beginning of the COVID-19 pandemic, the epidemiological and clinical data on children are still helpful to improve their prognosis.

Multiple Organ Failure Associated with SARS-CoV-2 Infection in a Child with Down Syndrome: Is Trisomy 21 Associated with an Unfavourable Clinical Course?

INTRODUCTION: Down syndrome (DS) is one of the most frequent genomic disorders around the globe (∼1:700 births). During the COVID-19 pandemic, it has been recognized that children with DS are patients with a greater risk of presenting SARS-CoV-2 infection-related poor outcomes. Nonetheless, a few cases with DS and SARS-CoV-2 infection have been reported. Our aim is to describe the unfavorable clinical course of a child with DS infected with SARS-CoV-2 virus. CASE: Female, 2 years old, karyotype 47,XX,+21[30], previously diagnosed with a cyanotic congenital heart disease (tricuspid atresia and infundibular pulmonary stenosis, type Ib) who started with diarrhea, developed shortness of breath, and cyanosis and was admitted to the hospital presenting low-oxygen saturation (33%) requiring invasive mechanical ventilation support. The patient tested positive for SARS-CoV-2 infection. During hospitalization, the patient presented hypotension, anuria, retarded capillary filling, and metabolic acidosis; management with vasoactive drugs was needed. Nonetheless, the patient developed respiratory and cardiac failure, acute renal injury (AKIN-III), and septic shock. After 24 days of hospitalization, the patient died. CONCLUSIONS: Multiple organ failure observed in the patient presented could be related to the triple gene dose of four interferon receptors (IFNAR1, IFNAR2, IFNGR2, and IL10RB) located at 21q22.11. Additionally, overexpression of TMPRSS2 at the pulmonary level, located also at 21q22.3, could be related with an increased susceptibility for the development of SARS-CoV-2 infection in DS patients.