Introduction
Coronavirus Disease 2019 (COVID-19) is an infectious disease with a
rapid increase in cases and deaths since its first identification in
Wuhan, China, in December 2019. The virus that causes COVID-19 is
designated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Sore throat, high fever, shortness of breath, dry cough, headache,
confusion, nausea, vomiting, diarrhea or loss of taste/smell are the
most common manifestations of the disease (1, 2). COVID-19 testing
includes either the detection of the virus itself by real-time reverse
transcription polymerase chain reaction or those antibodies produced in
response to infection (3). COVID-19 is predominantly prevalent among
adults; patients under 18 years only account for 2% of the severely
affected patients (4, 5).
Quantitative changes in blood cells, including leukocytes, lymphocytes,
neutrophils, monocytes and platelets, have been reported in adults
patients with COVID-19 (2, 6-8); moreover, the extent of such
quantitative changes has been correlated with the severity of the
disease in adults (6, 9). Normal (10), decreased (11) and increased (8)
leukocyte counts have been reported. In general, decreased lymphocyte
(11, 12) and increased neutrophil (2, 9, 13), counts have been noted in
various studies. However, there is paucity of data on the hematologic
parameters of children with COVID-19 (4). In a review article on
COVID-19 in children, a Chinese article was quoted reporting that “the
most routine blood examinations were normal” (4). In another study
reporting 10 pediatric patients affected with the disease, “a few
cases” were reported to have leukopenia and lymphopenia (14). Moreover,
although the morphological changes in peripheral blood cells have been
reported in adults with COVID-19 (15), such changes, to our knowledge,
have not been reported in children affected with the disease .
The aim of this retrospective study is to report the quantitative and
qualitative changes of peripheral blood cells in children with COVID-19
and compare them with those of symptomatic children suspected but then
confirmed to be negative for SARS-CoV-2.