Hematological Changes from Baseline in Children with Sickle Cell Disease Admitted for Acute Chest Syndrome Compared to Acute Pain Crisis
Authors: Klouda Timothy , Apollonsky Nataly , Raybagkar Deepti , Bernstein Bruce 
Published: October 2019

Abstract
Title: Hematological Changes from Baseline in Children with Sickle Cell Disease Admitted for Acute Chest Syndrome Compared to Acute Pain Crisis
Authors: Timothy Klouda1, Deepti. Raybagkar2, Bruce Bernstein1, Nataly Apollonsky2,
Institutes:1Pediatrics, St Christopher's Hospital for Children, Philadelphia, PA, United States, 2Hematology, St Christopher's Hospital for Children, Philadelphia, PA, United States,
Introduction: Children with Sickle Cell Disease suffer from multiple complications including acute pain crisis (VOC) and acute chest syndrome (ACS). Nearly 30% of children with SCD have had one episode of ACS, with the incidence higher in early childhood. The proposed pathophysiology of ACS is thought to be multi-factorial, with pulmonary fat embolism or infectious etiology being identified in a large number of patients. Increased sickling due to hypoxemia or pain has been shown to place patients at risk for ACS development., Studies have shown an increase in inflammatory markers including leukocytes and neutrophils, along with a decreased hemoglobin in SCD children who developed ACS, but no studies to date have compared laboratory changes during the acute illness to their baseline values. We hypothesized that children with SCD who are admitted for ACS will have a larger decrease in hemoglobin from baseline and a higher increase in white blood cell count from baseline when compared to those admitted for an acute pain crisis.
Methods: Through retrospective chart review of patients with SCD admitted to St.Christopher's Hospital for Children we identified 45 patients with ACS. Laboratory data collected on admission from chart review included SCD genotype, age, BMI, hemoglobin, white blood cell count, absolute neutrophil count, absolute eosinophil count, platelets, reticulocyte count, hemoglobin F, vital signs and medication history. All 45 children had laboratory data collected from an acute pain crisis that occurred during a different admission for comparison. Collected data was compared to baseline laboratory data, collected during routine visit at sickle cell clinic within 1 year of admission. Changes in laboratory data from baseline during admission for ACS were compared to changes during admission for uncomplicated VOC.
Results: Children with SCD who were admitted or developed ACS during admission had a larger increase in leukocyte count (6.99 vs 4.18, p=0.027) and neutrophil count (6.3 vs 3.74, p=0.04) from baseline compared to those admitted for VOC alone. Patients with ACS development also had a larger decrease in platelets (-124.74 vs -56.21, p=.047) from baseline when compared to VOC admissions. There was no statistically significant change from baseline labs when comparing hemoglobin (p=0.10), eosinophil count (p=.382), reticulocyte count (p=0.754), AST (p=0.061) and ALT (p=0.082) in the ACS and VOC groups. Children with a history of 2 or more lifetime ACS were more likely to have OSA (p=0.021), 3 or more VOCs in the past year (p=0.002), and a history of splenectomy, but it was not found to be statistically significant (p=0.155)
Conclusion: Children with SCD who developed or were admitted with ACS had a significant increase in leukocyte and neutrophil count from baseline, and a decrease in platelets when compared to VOC admissions. There was no significant change from baseline in hemoglobin, reticulocyte and eosinophils detected. Future larger and multi-center prospective studies need to be performed to confirm the various changes identified in hematological markers seen in ACS vs VOC.

Disclosures
No relevant conflicts of interest to declare.