Correlation of RBC survival to measurable hematologic parameters in participants with HbSS pre- vs posttransplant. Hematologic parameters were measured with each sample throughout the study and correlated to the final RBC survival (days). AST, aspartate transaminase; Hb, hemoglobin; Hct, hematocrit; HbA, adult hemoglobin; HbS, sickle hemoglobin; MCV, mean corpuscular volume; TB, total bilirubin; WBC, white blood cell count. Black, HbSS pretransplant; Red, HbSS posttransplant (mixed chimerism; full-donor chimerism).