Prospective evaluation of chronic organ damage in adult sickle cell patients: A seven-year follow-up study

Organ damage in sickle cell disease (SCD) is a crucial determinant for disease severity and prognosis. In a previous study, we analyzed the prevalence of SCD-related organ damage and complications in adult sickle cell patients. We now describe a seven-year follow-up of this cohort. All patients from the primary analysis in 2006 (n = 104), were included for follow-up. Patients were screened for SCD-related organ damage and complications (microalbuminuria, renal failure, elevated tricuspid regurgitation flow velocity (TRV) (>= 2.5 m/seconds), retinopathy, iron overload, cholelithiasis, avascular osteonecrosis, leg ulcers, acute chest syndrome (ACS), stroke, priapism and admissions for vaso-occlusive crises (VOC) biannually. Upon 7 years of follow-up, progression in the prevalence of avascular osteonecrosis (from 12.5% to 20.4%), renal failure (from 6.7% to 23.4%), retinopathy (from 39.7% to 53.8%) was observed in the whole group. In HbSS/HbS beta(0)-thal patients also progression in microalbuminuria (from 34% to 45%) and elevated TRV (from 40% to 48%) was observed while hardly any progression in the prevalence of cholelithiasis, priapism, stroke or chronic ulcers was seen. The proportion of patients with at least one episode of ACS increased in the group of HbSS/HbS beta(0)-thal patients from 32% to 49.1%. In conclusion, 62% of the sickle cell patients in this prospective cohort study developed a new SCD-related complication in a comprehensive care setting within 7 years of follow-up. Although the hospital admission rate for VOC remained stable, multiple forms of organ damage increased substantially. These observations underline the need for continued screening for organ damage in all adult patients with SCD.