Results
The mean age of the whole cohort was 8.11±5.71years (4 months-17 years). Thirty-five patients (50%) were male; of the 30 SARS-CoV-2 test positive patients, 15 (50%) were male. In the whole cohort (n=70), the most common presenting symptoms were fever (65.7%) and cough (60%). In the SARS-CoV-2 test positive and negative groups, 17 (56.7%) and 19 negative patients (47.5%) had pneumonia, respectively. None of the patients required treatment in the intensive care unit.
Complete blood count parameters of the SARS-CoV-2 test positive and negative groups were given in Table 1. Six patients (20%) with SARS-CoV-2 test positive and 11 patients (27.5%) with test negative were anemic according to age-specific intervals. Of note, a SARS-CoV-2 test positive 14-year-old Afghan patient with a diagnosis of aplastic anemia had pancytopenia before COVID-19.
The mean leukocyte counts of the SARS-CoV-2 test positive and negative groups were 7.0±3.7x109/L and 10.4±7.1x109/L, respectively (p<0.05). Within the SARS-CoV-2 test positive group, two patients (6.7%) had leukocytosis and four patients (13.3%) had leukopenia, according to age-specific intervals. The mean ALC of COVID-19 patients were 2.7±2.3x109/L; nine (30%) of them had lymphopenia, according to age-specific intervals. Twelve patients (30%) in the SARS-CoV-2 test negative group had also lymphopenia. The ALCs of COVID-19 patients with and without pneumonia were 2.1±0.9x109/L and 3.4±2.9x109/L, respectively (p<0.05). Reactive lymphocytes (Fig 1) were noted in 85.1% of the peripheral smears of the whole cohort; these figures were 77.8% and 90% in the SARS-CoV-2 test positive and negative groups. The mean absolute reactive lymphocyte (ARL) counts of SARS-CoV-2 test positive and negative groups were, 0.7±0.7x109/L, 1.2±1.3x109/L, respectively (p<0.05). The mean LUC counts of SARS-CoV-2 test positive and negative groups were 0.3±0.2x109/L and 0.2±0.23x109/L, respectively (p>0.05). No correlation between LUC count and ARL count was noted. The respective mean absolute neutrophil counts were 3.7±2.9 x109/L and 5.4±4.2 x109/L (p<0.05). Four patients (13.3%) with SARS-CoV-2 test positive and 10 patients (25%) with negative result groups had neutrophilia. Seven (23.3%) COVID-19 patients had mild neutropenia, whereas 3 (7.5%) patients with test negative had neutropenia. The mean neutrophil/lymphocyte ratios of SARS-CoV-2 positive and negative groups were 2.7±2.9 and 2.9±4.2, respectively (p>0.05). Immature myeloid cells (>2% in blood smear) were noted in 13 children (23%) in the COVID-19 group. All COVID-19 patients’ DNI were <0.4. The mean AMC was 0.4±0.3x109/L in the SARS-CoV-2 positive and 0.6±0.5x109/L in the SARS-CoV-2 negative patients (p<0.05). Leukoerythroblastic reaction was not noted in any children in the whole cohort.
The mean platelet count was 268±89x109/L in the SARS-CoV-2 positive and 339±178x109/L in the SARS-CoV-2 negative group (p<0.05) (Table 1). In the whole cohort, thrombocytopenia was detected in four patients; one of them was the patient with aplastic anemia and COVID-19; the remaining three were in the SARS-CoV-2 negative group. Thrombocytosis was noted in one patient only. The mean platelet volume (MPV) was comparable between the two groups; with no child noted to have increased MPV. The mean C-reactive protein level of the SARS-CoV-2 positive group was significantly lower when compared with that of SARS-CoV-2 negative group (p=0.006).
In the peripheral smears of a few children affected by COVID-19, vacuolated monocytes (n=3; 13.3%) and dysplastic changes such as hypergranulation/lobulation abnormalities in neutrophils (n=11; 36.7%) were noted (Figs. 2, and 3). The respective figures within the non-COVID-19 group were 4 (10.0%) and 9 (22.5%). Although the MPV values were within the normal range, 20% of the COVID-19 patients had giant platelets (Figure 4); however, giant platelets were also noted in 27.5% of the negative patients.