Impact of Red Cell Exchange Transfusion on Inflammatory Markers in Sickle Cell Disease.

Background: Red Blood Cell Exchange (RBCX) is a common treatment for pediatric sickle cell disease (SCD). Since inflammation with elevated proinflammatory cytokines plays a crucial role in SCD, this study hypothesized that RBCX might lower these cytokines and aimed to assess the impact of this technique on these markers.

Methods: Prospective and observational study of pediatric SCD patients (HbSS genotype) enrolled in a chronic RBCX program at a Portuguese Hospital from October 2022 to August 2024. Blood samples were collected before and after RBCX to assess hematological and inflammatory markers. Data were analyzed using SPSSv25 ^® (Significance level p < 0.05); Informed consents were obtained.

Results: Thirty-one children (median age 10 years) were studied: 14 were treatment-naïve, and 17 were previously in a chronic RBCX program. The primary indication for starting the program was cerebrovascular disease prevention (81%). Analysis of 286 RBCXs showed no major adverse events or disease-related hospitalizations. Hemoglobin levels increased by 1.5g/dL post-RBCX; HbS, leukocytes, IL-1, and CRP decreased by 69%, 20%, 21%, and 13%, respectively. Other markers showed no significant changes. IL-1, ferritin, and procalcitonin showed high levels before RBCX; IL-6 showed high levels post-RBCX. Considering only naïve patients, they had higher pre-RBCX IL-1 levels than those with prior RBCX (difference of 22.6 pg/mL); IL-6 increased by 17.3% and IL-1 decreased by 23.9% post-RBCX (p < 0.001).

Conclusions: RBCX safely reduces HbS, leukocytes, and IL-1 levels, suggesting a modulatory effect on inflammation in SCD patients. Further research is needed to explore cytokine mechanisms in SCD.