Whole-blood transcriptome profile in children with sickle cell anemia before and after exercise

Patients with sickle cell anemia (SCA) show higher levels of circulating pro-inflammatory cytokines and endothelial activation markers compared to healthy peers and altered blood transcriptome profiles. However, the characterization of the whole-blood transcriptome profile in response to exercise has not been evaluated in children with SCA. Twenty-three children/adolescents with SCA (10-19 years old) and 17 healthy controls (10-22 years old) performed eight 2-min bouts of cycle ergometry interspersed with 1-min rest intervals (50% or 70% of the peak workload achieved during the cardiopulmonary exercise test). Whole-blood transcriptome profile (RNA-seq) was performed before and after the exercise protocol. Following exercise, gene pathways associated with innate immunity were altered in both children with SCA and controls. Our results shed light on the common and different immune responses to acute exercise at the molecular level in children with SCA and healthy controls. The exercise protocol consisted of 8 bouts (2 minutes duration each with 1-minute rest between bouts) of cycling at a constant workload (randomized to 50% or 70% of the peak workload achieved during the CPET). This type of interval exercise challenge mimics the movement patterns of children during play. Blood samples were collected before (baseline) and immediately after completing the exercise protocol using PAXgene blood RNA tubes (PreAnalytiX; PN 762165). The storage of the PAXgene tubes after blood collection was as recommended by the manufacturer. The RNA was extracted using the PAXgene blood RNA kit (PreAnalytiX; PN 762174) and automated on the QIACube (Qiagen).