The predictive value of eosinophils in children with febrile seizures
Authors: Xiao Yao , Fu Rong , Ou Yuan-xiang 
Published: June 2023

Objective
To evaluate the predictive value of eosinophil count (EOS) in children with febrile seizures (FS).
Methods
a total of 92 children with FS who visited the Third Hospital of Changsha from May 2017 to May 2022 were selected as the observation group, another 61 children with only fever but no seizures (n-FS) who received respiratory infection from the outpatient clinic of our hospital were selected as the control group, and 35 children with health examination were selected as the healthy group. Differences between the groups in the levels of routine blood indicators, serum electrolyte levels, and blood gas analysis values were retrospectively analyzed to explore the predictive value of EOS and the neutrophil to eosinophil ratio (N/EOS) for FS in children using logistic regression and ROC curves.
Results
1. Children in the FS had lower serum Na + levels (135.20 (3.24) mmol / L) than those in the n-FS group (136.90 (2.84) mmol / L) and the healthy group (138.00 (3.17) mmol / L) (P < 0.05); Serum K + levels (4.09 (0.59) mmol / L vs 4.23 (0.90) mmol / L), Cl − levels (100.40 (4.15) mmol / L vs 103.39 (2.77) mmol / L) and Ca2 + levels (2.22 (1.19) mmol / L vs 2.40 (0.25) mmol / L) in the FS group were also significantly lower than those in the healthy group (P < 0.05). 2. PH level in FS group (7.43 (0.05)) was higher than that in healthy group (7.38 (0.05)) (P < 0.05), while PCO2 value (95.10 (54.00) mmHg) was lower than that in healthy group (86.90 (43.90) mmHg) (P < 0.05). 3. EOS in the FS group was lower than that in the n-FS group, which was again lower than that in the healthy group (0.03 (0.10) vs 0.22 (0.30) vs 0.05 (0.18)) (P < 0.05). After treatment, children in the FS group had significantly higher EOS (0.06 (0.07) vs 0.17 (0.20)) (P < 0.05), which remained lower than those in the healthy and n-FS groups (0.17 (0.20) vs 0.25 (0.32) vs 0.23 (0.28)), (P < 0.05). 4. Multiple logistic regression suggested that blood K +, Ca2 +, EOS and PCO2 were significant for the diagnosis of FS, that is, for every 1 mmol / L increase in blood K +, the probability of FS decreased 2.38-fold (95% CI: 0.36–3.08), for every 1 mmol / L increase in blood Ca2 +, the probability of FS decreased 2.1-fold (95% CI: 1.75–13.29), for every 0.01 increase in EOS, the probability of FS decreased 0.68-fold (95% CI: 0.026–17.88), and for every 1 mmHg increase in PCO2, 1.1-fold (95% CI: 1.01–1.15) decrease in the probability of developing FS. 5. When the N/EOS value was 68.80, the area under the ROC curve was the largest at 0.70, the diagnostic sensitivity at this point was 76.3% and the specificity was 55.4%, and when this value was exceeded, the possibility of FS was considered.
Conclusions
Children with FS have significant hyponatremia, hypokalemia, and hypocalcemia, and EOS is also lower than in healthy children and n-FS children. After the children in FS group were treated, the EOS value was still lower than that in n-FS children, and the N / EOS value equal to 68.80 could be used clinically as an indicator to discriminate between them.