“…Sickle cell-specific criteria included homozygous SCD, compound heterozygous hemoglobin S and C disease or hemoglobin S and b 0 -thalassemia disease, stroke, sickle cell-related renal insufficiency (defined by creatinine $1.5 times the upper limit of normal and kidney biopsy consistent with sickle cell nephropathy, or nephrotic syndrome or creatinine clearance ,50 mL/minute or requiring dialysis), [19][20][21] tricuspid regurgitant jet velocity $2.5 m/s, 22,23 sickle hepatopathy (defined as either ferritin $1000 mg/L or direct bilirubin .0.4 mg/dL and platelet count ,250 000/mL at baseline), 24 .1 hospitalization per year for vaso-occulsive crises or any acute chest syndrome while receiving a maximum tolerated dose of hydroxyurea for at least 6 months.…”