Sickle Cell Disease Related Vasculopathies and Early Evaluation in a Pediatric Population.

Abstract

Cardiovascular pathologies are ubiquitous in sickle cell disease (SCD). A targeted literature review was conducted to compare the overall epidemiology of selected vasculopathies seen in SCD (SCDVs) compared to the general population. Since many SCDV may originate in childhood, the study also focused on the retrospective investigation of SCDVs in a pediatric cohort at the Harbor-UCLA Medical Center. SCDVs were studied along patient age, β-globin genotypes, and fetal hemoglobin (HbF). Urine microalbumin/creatinine ratios (UM/Cr), trans-cranial doppler (TCD) and tricuspid regurgitant jet velocities (TRJV) were analyzed as well. Retinographies and overt vasculopathies were presented descriptively. Among 20 females and 20 males [average 8.3 years (2.3-19 years)], 70% had HbSS/Sβ0, 22.5% HbSC and 7.5%-HbSβ+. The mean(±SD) HbF% was 17.4±12.7% (30% higher in <10 vs. ≥10 y/o, and 3 times higher in SS/Sβ0). Twenty-six patients received hydroxyurea and 13/26, L-glutamine. Thirty-six patients had TCDs within 1.4±0.9 years and all laboratory values were obtained within the last 12 months. TCDs showed low-normal velocities, but 2 were higher for HbSS/Sβ0 vs. HbSC/Sβ+ (MCA-96 vs. 86 cm/s, p=0.03; and PCA-50 vs. 41, p<0.001). Nineteen of 28 patients with echocardiograms had measurable TRJV (2.46±0.19 m/s); 9 had TRJV ≥2.5-2.8 m/s, but BNP ≤80 pg/ml. SS/Sβ0 was associated with higher UM/Cr. There were 2 cases with silent infarcts, 1-Moyamoya, 2-persistent macroalbuminuria, and 1-hematuria/renal papillary necrosis. Most ≥9 y/o patients had retinographies without SCD-related changes. There was no correlation among TCD (MCA), TRJV, and UM/Cr (n=17); thus, in this subpopulation, pathologies of cerebral, cardiopulmonary, and renal vasculatures evolved independently. Patients with higher TRJV and/or overt vasculopathy (n=14) were older than ones without (12.5±4.7 vs. 6.1±3.1 y/o, p<0.001), and had lower HbF (11.4±7.6 vs. 20.6±13.8%, p=0.026). While overt SCDVs are less frequent in children, age-dependent trends/surrogate markers suggest their early origination in youth, justifying intense screening to prevent their progression with disease-modifying measures.