P0483 - Varying Illness Severity in Patients with MyD88 Deficiency Infected with Coronavirus SARS-CoV-2

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for coronavirus disease 2019 (COVID-19) started in December 2019 in Wuhan, Hubei Province of China. In multiple countries affected by COVID-19, children are a small proportion of those affected by the disease. In children who are affected, symptoms often range from absent to mild or moderate. The exact mechanism by which children are affected less severely is not yet understood, but adults may have more severe presentations secondary to immune dysregulation. There remains limited data regarding COVID-19 infections in pediatric patients with underlying medical conditions, including immunodeficiency syndromes. Myeloid differentiation factor 88 (MyD88) deficiency is a rare immunodeficiency characterized by increased susceptibility to infections caused by pyogenic bacteria with only 24 cases discussed in medical literature.

We present a case series of three siblings with MyD88 deficiency with COVID-19 who had various presentations and courses. The patients had close contact with a family member who recently traveled and developed fever and cough. SARS-CoV-2 PCR testing of nasopharyngeal specimens from all three patients was positive.

In case 1 and 2, the two females (16 y.o. and 15 y.o.) presented with fevers, labs significant for lymphocytopenia and elevated inflammatory markers and chest x-rays (CXR) with lobar pneumonia. They had persistent fevers and tachypnea with worsening hypoxia. With worsening clinical condition and progression of radiologic evidence to multifocal pneumonia, they were transferred to the ICU. They were initially started on NIV but rapidly progressed to moderate ARDS requiring invasive mechanical ventilation. The 16 y.o. remained on mechanical ventilation for 9 days and transitioned to high-flow nasal cannula (HFNC) for 3 days. The 15 y.o. progressed to severe ARDS and started on veno-venous extracorporeal membrane oxygenation (VV-ECMO), which she remained on for 7 days. She was subsequently extubated within 1 day to HFNC. In case 3, the 13 y.o. male presented with cough without fevers, labs significant for mildly elevated inflammatory markers and CXR without consolidation. With worsening clinical condition and progression of radiologic evidence to multifocal pneumonia he was transferred to the ICU for close monitoring. He had no hypoxia and required no supplemental oxygen or ventilatory support. During hospitalization in the ICU, all three patients received hydroxychloroquine. The two patients on mechanical ventilation received tocilizumab and a 10-day course of remdesivir. All three patients recovered from their respiratory illness.

COVID-19 in the pediatric population remains an area to be studied. Patients with immunodeficiency may be at increased risk for infection not just secondary to the underlying disease pathology, but also from increased susceptibility to immune dysregulation. This case series describes the variability in illness severity in the context of the same underlying medical condition.