Telomere length and telomere repeat-binding protein in children with sickle cell disease

This study aimed to assess the telomere length and plasma telomere repeat-binding factor 2 (TRF2) levels in addition to other inflammatory markers in children with sickle cell disease (SCD).

We enrolled 106 children (90 SCD and 26 controls) aged 1-15 years from the Hematology unit of King Fahad Medical City (KFMC), Saudi Arabia. Genomic DNA extracted from blood and leukocyte TL was determined using quantitative reverse transcription PCR, whereas TRF2, C-reactive protein, interleukin-6, and DNA oxidative damage were determined by using respective commercially available assays.

Leukocyte TL was inversely correlated with age in the SCD patients (r = -0.24, P = 0.02) and the controls (r = -0.68, P < 0.0001). In addition, SCD patients had significantly shorter TL (7.74 ± 0.81 kb) (P = 0.003) than controls (8.28 ± 0.73 kb). In contrast, no significant difference in TL among the SCD genotypes (HbSS and HbSβ0) has been observed. A modest, positive correlation was seen between TL and reticulocyte % (r = 0.21; P = 0.06). There were no significant differences in the TL and TRF2 concentrations between subjects with HbSS and HbSβ⁰ genotypes.

Short leukocyte TL was significantly associated with SCD. An inverse association was observed between TL and hemoglobin. Hydroxyurea treatment revealed no impact on TL.

This study explored the TL and plasma TRF2 in Saudi children with SCD. This is the first documentation that SCD children have shorter TL than their healthy counterparts, and no association between TL and TRF2 has been observed. Hydroxyurea treatment showed no impact on TL in children with SCD. This study is the first of its kind in children with SCD. It will pave the way for another study with a larger sample size in a diverse population to scrutinize these findings better.