Discussion
COVID-19 was declared by World Health Organization as a public health emergency of international concern (10) and despite the worldwide spread, clinical patterns of COVID-19 particularly among children remain largely unclear. (5) The clinical spectrum of COVID-19 could range from being asymptomatic to developing severe acute respiratory distress. (2) In the current study, despite of the immunocompromised status of the hospitalized patients with cancer, 66.7% were asymptomatic at admission and 33.3% had mild symptoms. This is in comparison to 4.4% and 50.9% respectively in large Chinese study in which 731 patients were confirmed positive by laboratory testing. (2)
While other coronaviruses can produce more severe disease in immunocompromised children with increased risk with coexisting pulmonary disease or concurrent lower respiratory tract infection (6,11), the severity of children’s COVID-19 cases was milder than adult. (2) A systemic review of 110 immunosuppressed patients, mostly presenting with cancer, along with transplantation and immunodeficiency, they seemed to have a favorable disease course, as compared to the general population, 72 (65.5%) recovered (discharged or inpatients) or did not require intensive care and 6 (5.5%) needed intensive care or invasive ventilation and 23 (20.9%) died. (12) In an Italian pediatric haemato‐oncology clinic, SARS‐CoV‐2 infection was detected in 4 out 170 patients at the molecular level; three of them were asymptomatic. (13)The clinical course and outcome of SARS‐CoV‐2 was reported to be more favorable in children than in adults (1) A possible explanation that children might have less severe disease was attributed to the lower expression of ACE2 receptor and present with a different inflammatory response, with higher numbers of B and T regulator cells, involved in immune tolerance and leading to a less inflammatory immune response. (14)
The detrimental impact of COVID-19 pandemic on childhood cancer may be delay in diagnosis (15), delay in starting treatment, the detrimental impact of infection on children with cancer, and the uncertainty about decision for chemotherapy in PCR-positive asymptomatic patients. Universal testing of asymptomatic cancer patients may help safe continuation of treatment. (16)
As regards the treatment, all the patients received supportive care in addition to antivirals or antibiotics guided by radiological findings and symptom progression (according to Children’s hospital and MOH guidelines). With the large diversity of therapeutic options, (17) whether a different treatment approaches in children with cancer on chemotherapy is not adopted. The important decision is the proper time to start anticoagulation, the main concern is that childhood cancer is predisposing for thrombosis (18). Whether early start of anticoagulation for COVID-19 or delay usage as that it might be an immune thrombosis related to neutrophil extracellular traps (19); yet it is acceptable that in both cancer (20) and COVID-19 (21), D-dimer level is the most important laboratory result in decision for anticoagulation.
As for total and differential leucocytic count, there was wide variability; lymphocytopenia was present in 50% of patients compared to 3.6% in a previous study that is evaluating children infected with SARS-CoV-2 and treated at the Wuhan Children’s Hospital. (11) Although lymphopenia was associated with severe disease (22) which was not consistent with the clinical manifestations of our patients group, yet the high frequency of lymphopenia might be attributed to the underlying cancer, chemotherapy and the wide variation could be due to the inclusion of three newly diagnosed patients with hematological malignancy.
The radiological findings in our patients were mainly ground glass opacities (GGO), not necessarily affecting the periphery, consolidation (lobar) and interstitial infiltrates. This finding is in agreement with Chen et al, 2020 who reported that initially, chest radiography findings can show signs of pneumonia, such as small irregular lung opacities and interstitial alterations, usually affecting peripheral areas. The authors also reported that chest computed tomography also exhibits GGO and segmental consolidation in both lungs while pleural effusion being uncommon. (23) However, correlation of radiological findings with COVID-19 severity in the current study may not be applicable due to small sample size.
Conclusion :
Pediatric oncology patients with SARS-COV-2 infection in this study were mainly asymptomatic or with mild symptoms. A high index of suspicion with mild symptoms and regular screening by NP swab in asymptomatic hospitalized cancer patients admitted for intensive chemotherapy and initiation of treatment, guided by laboratory data is recommended. More studies are required to report the incidence, outcomes and therapeutic decisions of SARS-COV-2 in pediatric patients with cancer.
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