Table 3Predictors of Benefit from Hydroxyurea in Studies of Sickle Cell Disease

Author, yearPredictors of Benefit from Hydroxyurea TreatmentOutcome
Trials
Steinberg, 199740Lower baseline crisis rates, baseline reticulocyte count (>300,000/ul), women, absence of CAR haplotype, F reticulocytes > 12%, absolute neutrophil count >7500/μl, Hb>7.5%, >80% adherence, and >2 hematological toxicity episodes during treatmentHb F%
Ferster, 199644Not associated with the initial Hb F level, white blood cell count, or platelet countHb F%
Ballas, 200642Higher Hb F%, higher baseline quality of life, lower baseline daily pain, baseline crisis rate <6/yearQuality of life
Hackney, 199741Men compared to womenAerobic power
Charache, 199521Prior crisis rate, lower absolute neutrophil count, higher reticulocyte count, and MCVPainful episodes
Observational Studies
Charache, 299246Last plasma HU level, higher initial Hb F%, and higher white blood countHb F%
Hankins, 200572Dose increaseHb F%
Loukopoulous, 199869FemalesHb F%
Loukopoulous, 200074Low Hb F at baseline; great similarity in response between siblingsHb F%
Maier-Redelsperger, 199875Increase in MCV and higher initial F reticulocytes; not age, gender, haplotypes; Hb F% at 6 months did not predict maximumHb F%
Vicari, 200580Not age, not sexHb F%
Ware, 200273Positively associated with Hb F% at baseline, Hb at baseline, and MTD achieved. Negatively associated with # of pills returned. Not age, not sex, not hematologic toxicities. Other predictors: change in Hb from baseline to MTD, MCV change from baseline to MTD, decline in reticulocytes from baseline and number at MTD, white count decline from baseline and white count at MTDHb F%
Ferguson, 200252Duration and completeness of therapyHospital admissions
Ferster, 200158Not predicted by hematological valuesHospital admissions
Zimmerman, 200763Higher TCD velocity at baseline predicted responseCerebral blood flow velocity
Ware, 200467Lower recurrence for those who initiated HU therapy before discontinuation of transfusion therapyRecurrent stroke
Kratovil, 200662Dose of HUCerebral blood flow velocity

CAR = Central African Republic; Hb F%=fetal hemoglobin percentage; MCV = mean corpuscular volume; HU = hydroxyurea; MTD = maximum tolerated dose; TCD=transcranial Doppler

From: 3, Results

Cover of Hydroxyurea for the Treatment of Sickle Cell Disease
Hydroxyurea for the Treatment of Sickle Cell Disease.
Evidence Reports/Technology Assessments, No. 165.
Segal JB, Strouse JJ, Beach MC, et al.

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