Systematic Evaluation Of Chronic Organ Damage In Adult Sickle Cell Patients. A Seven-Year Follow-Up Study

The occurrence of organ damage in sickle cell disease (SCD) is a crucial determinant for both medical treatment and prognosis. In a previous study, we systematically analyzed the prevalence of SCD related organ damage and complications in adult sickle cell patients in a tertiary teaching hospital in the Netherlands. We now describe a seven-year follow-up of this patient cohort, to provide an insight into the course of the various forms of organ damage and SCD related complications.

At baseline in 2006, 110 adult patients visiting the outpatient clinic of our hospital were enrolled. All enrolled patients from the primary analysis were included for follow-up. Patients were screened for sickle cell related manifestations during visits to the outpatient clinic biannually. Various forms of sickle cell related organ damage and complications (presence of microalbuminuria, renal failure, pulmonary hypertension retinopathy, iron overload, cholelithiasis, avascular osteonecrosis, leg ulcers, acute chest syndrome, stroke, priapism and admissions for painful crises) were routinely screened according to international guidelines. Patients with genotype HbSS/HbSβ⁰ and HbSC/HbSβ⁺were grouped for further analysis.

Of all originally included patients (N=110), nine were lost to follow-up (N=9). The mean age of the current study cohort is 37 years (IQR 27-46). Overall, 59 patients (58%) developed a new form of organ damage or new complication since baseline analysis, including eight patients who deceased (7 due to a sickle cell disease related death). In the HbSS/HbSβ⁰ genotype group (N=60) we found an increase in the percentage of patients who have had an Acute Chest Syndrome (29% to 47%) or have been diagnosed with avascular osteonecrosis (15% to 24%), retinopathy (23% to 34%) or pulmonary hypertension (31% to 48%). In the HbSC/HbSβ⁺ (N=35) group we found an increase in the occurrence of avascular osteonecrosis (9% to 14%), retinopathy (59 % to 70%) and pulmonary hypertension (9% to 19%). Furthermore, the use of hydroxycarbamide increased in both genotype groups and the frequency of admissions for painful crises remained stable for both genotype groups.

In the past period of seven years 58% of the patients in a previously well descript cohort of adult SCD patients developed a new sickle cell related complication. For some forms of organ damage or complications a substantial increase occurred dependent of a patient’s genotype.

No relevant conflicts of interest to declare.