Asymmetric dimethylarginine levels in children with sickle cell disease and its correlation to tricuspid regurgitant jet velocity.

BACKGROUND: Pulmonary hypertension (PH) is an increasingly recognized life-threatening complication in sickle cell disease (SCD), with associated high mortality in adults. The prevalence of PH in children with SCD is still unknown. The etiology and pathophysiologic mechanisms are still not well understood.

AIM OF THE STUDY: To assess the plasma levels of asymmetric dimethylarginine (ADMA) in children with SCD and its correlation with elevated tricuspid regurgitant jet velocity and other hemolytic markers.

SUBJECTS & METHODS: This study was carried out on a cohort of patients (30) with SCD and 30 healthy children as a control group. Certain investigations were carried out for all subjects: CBC, lactate dehydrogenase (LDH), ferritin, reticulocytic count, bilirubin, AST, ALT, and plasma levels of ADMA. Doppler echocardiography was carried out for all subjects.

RESULTS: The prevalence of high tricuspid regurgitant velocity (TRV) was 30% in SCD patients. ADMA mean plasma level was significantly higher in patients than in controls (0.79 ± 0.15 μmol/L and 0.46 ± 0.11 μmol/L, respectively, P < 0.001). ADMA was significantly higher in patients with high TRV than those with normal TRV (1.10 ± 0.11 μmol/L, 0.80 ± 0.06 μmol/L, respectively, P < 0.001). There was a significant positive correlation between ADMA plasma levels and TRV ≥2.5 m/s (r = 0.475).

CONCLUSION: High plasma ADMA levels may be implicated in the pathogenesis of increased tricuspid regurgitant jet velocity in children with SCD.