Discussion
This case highlights the relationship between likely SARS-CoV-2 associated MIS-C and thrombotic complications, particularly pulmonary embolism. Although this patient’s SARS-CoV-2 PCR was negative multiple times, the SARS-CoV-2 IgM antibody was positive during hospitalization. Her positive antibody test coupled with fever, age less than 21 years, hospitalization, laboratory evidence of inflammation and evidence of multisystem involvement fit reported criteria for MIS-C2. The negative PCR is not unusual in MIS-C cases; recent evidence has demonstrated only 70% of patients have PCR or antibody evidence of SARS-CoV-2 infection and up to 44% of reported pediatric patients with MIS-C have a negative or unknown SARS-CoV-2 PCR test during hospitalization2.
Thrombotic complications have been described in adults in both previous case reports and more recently in large case series and prospective studies1,3,4. A case series in a French hospital reported rates of pulmonary embolism of 20.6% of COVID-19 patients, rates twice as high compared to a similar time period in 2019 in their institution. A multicenter study also in France reported significantly higher rates of pulmonary embolism of 16.7% in COVID-19 ARDS patients vs. 1.3% in non-COVID-19 ARDS patients, and this association persisted after matching
between groups4. The high incidence of thrombotic complications amongst COVID-19 has led to much discussion regarding appropriate prevention of deep vein thrombosis, with pharmacologic VTE prophylaxis recommended in hospitalized patients without other risk factors5,6.
Thrombotic complications in children with COVID-19 are not as well described as in adults, perhaps due to the less severe nature of the disease in younger patients. To our knowledge, the youngest patient described in a case report prior to this case is a 17 year old pregnant female7. Thrombotic complications with MIS-C are relatively uncommon, but increase with age, with the incidence highest in the 13-20 year age group at a rate of 7%2. The patient in this case had a particular set of known risk factors that likely contributed to her thrombotic complications, particularly obesity and recent surgery.
Given the increased incidence of pulmonary embolism in COVID-19 in older teenagers, pediatric providers taking care of these patients may be confronted with treatment decisions regarding pulmonary embolism. In this patient, catheter directed thrombolysis for twenty-four hours provided resolution of bilateral pulmonary emboli on CT angiography within three days. Catheter directed thrombolysis has previously been described as safe and effective in pediatric patients, and has recently been described in a case report for an adult patient with COVID-19 and pulmonary embolus8,9. In pediatric patients with massive pulmonary embolus and COVID-19, it should also be considered as definitive therapy. Despite the successful treatment of the pulmonary emboli in this patient, unfortunately, due to her associated cardiac arrest, her overall neurologic outcome remains poor.