Background
In December 2019, the new coronavirus SARS-CoV-2 outbreak started in Wuhan, China and rapidly progressed into a pandemic1. Europe was its next stop and Spain (first case reported on January 31, 2020) was one of the first countries registering alarming increasing numbers of both confirmed cases and deaths. As of April 24, 2020, while our health care system was struggling to expand fully, mostly with adult wards and intensive care unit (ICU) beds, 202 990 cases had been tested positive and 22 524 deaths were reported in the country due to COVID-19.
As widely reported, the clinical presentation of COVID-19 is heterogeneous, ranging from asymptomatic or pauci-symptomatic cases to severe forms, with an overall small percentage of patients developing respiratory insufficiency and requiring admission in the ICU. The severe forms were observed more frequently in male adults older than 65 years with certain comorbidities like diabetes, hypertension, cardiac and pulmonary conditions, and obesity2. In contrast, a number of reported series show that pediatric patients rarely develop critical illness3,4. The reasons underlying this significant disparity in clinical presentation and outcome is still a matter of debate. In Spain, from all SARS-CoV-2 confirmed positive cases, the pediatric population (cases under the age of 19) represented only 0.9%. Furthermore, only 2.8% of these cases required pediatric intensive care unit (PICU) admission with a mortality rate of around 0.3%5. Children diagnosed with cancer receiving immunosuppressive chemotherapy and cellular therapies have typically significant abnormalities in immune function. Additionally, these abnormalities may persist for months or years and puts them at a higher risk for opportunistic viral –among other - infections. To this date, reports describing the clinical and epidemiological characteristics as well as outcomes in pediatric patients with cancer and/or under immunosuppression secondary to allogeneic-stem cell transplantation, or CART cell therapy acquiring the COVID-19 are scarce. A flash survey performed on March 16, 2020 on SARS secondary to SARS-CoV-2 infections in pediatric patients with anticancer treatment was recently published, identifying only 9 patients (among 10,000 patients at risk) from several countries in Europe who presented a mild or asymptomatic course6. Understandably, a reasonable fear exists that SARS-CoV-2, like other coronaviruses7, could cause more severe infections in immunocompromised children, as has been observed in adults8, especially in patients with hematological cancer were the highest severity index and death rate have been published9.
In this report, we present the initial Spanish experience with COVID-19 in pediatric patients affected with cancer, hematologic conditions, and post allogeneic stem cell transplantation since the beginning of this pandemic.