Hydroxyurea and sickle cell anemia: effect on quality of life.

BACKGROUND: The Multicenter Study of Hydroxyurea (HU) in Sickle Cell Anemia (MSH) previously showed that daily oral HU reduces painful sickle cell (SS) crises by 50% in patients with moderate to severe disease. The morbidity associated with this disease is known to have serious negative impact on the overall quality of life(QOL) of affected individuals. METHODS: The data in this report were collected from the 299 patients enrolled in the MSH. Health quality of llife (HQOL) measures were assessed in the MSH as a secondary endpoint to determine if the clinical benefit of HU could translate into a measurable benefit perceptible to the patients. HQOL was assessed with the Profile of Mood States, the Health Status Short Form 36 (SF-36), including 4-week pain recall, and the Ladder of Life, self-administered twice 2-weeks apart pre-treatment and every 6 months during the two-year, randomized, double-blind, treatment phase. The effects of factors including randomized treatment, age, gender, pre-treatment crises frequency, Hb-F level mean, daily pain from 4-week pre-treatment diaries, and 2-year Hb-F response level (low or high) were investigated. RESULTS: Over two years of treatment, the benefit of HU treatment on QOL, other than pain scales, was limited to those patients taking HU who maintained a high HbF response, compared to those with low HbF response or on placebo. These restricted benefits occurred in social function, pain recall and general health perception. Stratification according to average daily pain prior to treatment showed that responders to HU whose average daily pain score was 5-9 (substantial pain) achieved significant reduction in the tension scale compared to the placebo group and to non-responders. HU had no apparent effect on other QOL measures. CONCLUSION: Treatment of SS with HU improves some aspects of QOL in adult patients who already suffer from moderate-to-severe SS.

Stroke and conversion to high risk in children screened with transcranial Doppler ultrasound during the STOP study.

The Stroke Prevention Trial in Sickle Cell Anemia (STOP) was a randomized multicenter controlled trial comparing prophylactic blood transfusion with standard care in sickle cell anemia (SCA) children aged 2 to 16 years selected for high stroke risk by transcranial Doppler (TCD). More than 2000 children were screened with TCD to identify the 130 high-risk children who entered the randomized trial. A total of 5613 TCD studies from 2324 children were evaluated. We also collected information on stroke. We describe the changes in TCD with repeated testing and report the outcome without transfusion in the STOP screened cohort. Risk of stroke was higher with abnormal TCD than with normal or conditional TCD (P <.001) or inadequate TCD (P =.002), and risk with conditional TCD was higher than with normal TCD (P <.001). Repeated TCD in 1215 children showed that the condition of 9.4% of children became abnormal during observation. Younger patients and those with higher initial flow velocities were most likely to convert to abnormal TCDs. Screening in STOP confirmed the predictive value of TCD for stroke. Substantial differences in the probability of conversion to abnormal TCD were observed, with younger children and those with higher velocity more likely to have an abnormal TCD with rescreening.

Invasive pneumococcal infections in children with sickle cell disease in the era of penicillin prophylaxis, antibiotic resistance, and 23-valent pneumococcal polysaccharide vaccination.

Rates and severity of pneumococcal infections in children with sickle cell disease were examined before licensure of pneumococcal-conjugated vaccine (PVC). Rates of peak invasive infection rates in 1-year-old children with hemoglobin SS and mortality in those 0 to 10 years of age were 36.5 to 63.4 and 1.4 to 2.8 per 1000 person-years, respectively (>10 and 100 times as frequent as in the general population). Overall, 71% of serotyped isolates (n=80) were PVC serotypes and 71% of nonvaccine serotype strains were penicillin-sensitive. Clinical presentation in children with hemoglobin SS (n=71; more with hypotension) and hemoglobin SC (n=18; more with acute chest syndrome, otitis media) differed. Penicillin nonsusceptibility (38% of isolates) varied between geographic study sites. Penicillin prophylaxis appeared less effective against intermediate and resistant strains. Of all infected children, meningitis developed in 20% and 15% died (hemoglobin SS, n=15 and 11; hemoglobin SC, n=1 each). Factors associated with death included age >4 years (58%), serotype 19F, and not being followed by a hematologist (42% each). The pneumococcal-polysaccharide vaccine was 80.4% effective within 3 years after vaccination (95% CI, 39.7, 93.6). Children with sickle cell disease of all ages may benefit from PVC boosted with polysaccharide vaccination.

Alpha Thalassemia is associated with decreased risk of abnormal transcranial Doppler ultrasonography in children with sickle cell anemia.

PURPOSE: Cerebrovascular complications of sickle cell disease (SCD) are common, but the risk factors remain unclear. The multicenter Stroke Prevention Trial in Sickle Cell Anemia (STOP) provided an opportunity to examine alpha thalassemia-2 as a modifying risk factor, using abnormal transcranial Doppler ultrasonography (TCD) as a surrogate marker for cerebrovascular disease. The authors hypothesized that children with abnormal TCD are less likely to have alpha thalassemia-2, and an increased hemoglobin level accounts for this protective effect. METHODS: A retrospective study was conducted of children with SCD who had both alpha gene and TCD data from STOP: 128 with TCD of at least 200 cm/s (abnormal TCD) and 172 with TCD less than 170 cm/s (normal TCD). RESULTS: Alpha thalassemia-2 was more frequent in the normal TCD group compared with the abnormal TCD group. The odds ratio for normal TCD and alpha thalassemia-2 was 4.1. Adjusting for either hemoglobin level or red cell size (mean corpuscular volume) reduced the odds ratio only slightly. Age, normal TCD, and alpha thalassemia-2 had significant statistical interaction, so that alpha thalassemia-2 was not related to TCD for age 10 years or older. CONCLUSIONS: The frequency of alpha thalassemia-2 was significantly higher in children with normal TCD. Speculation on mechanisms of effect includes improved erythrocyte deformability, reduced red cell adhesion, and reduced nitric oxide scavenging in alpha thalassemia-2. The association of alpha thalassemia-2 and normal TCD adds to the evidence on the protective effects of alpha thalassemia-2 in SCD and highlights the contribution of epistatic factors.

Effect of hydroxyurea on mortality and morbidity in adult sickle cell anemia: risks and benefits up to 9 years of treatment.

CONTEXT: Hydroxyurea increases levels of fetal hemoglobin (HbF) and decreases morbidity from vaso-occlusive complications in patients with sickle cell anemia (SCA). High HbF levels reduce morbidity and mortality. OBJECTIVE: To determine whether hydroxyurea attenuates mortality in patients with SCA. DESIGN: Long-term observational follow-up study of mortality in patients with SCA who originally participated in the randomized, double-blind, placebo-controlled Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH), conducted in 1992-1995, to determine if hydroxyurea reduces vaso-occlusive events. In the MSH Patients' Follow-up, conducted in 1996-2001, patients could continue, stop, or start hydroxyurea. Data were collected during the trial and in the follow-up period. SETTING: Inpatients and outpatients in 21 sickle cell referral centers in the United States and Canada. PATIENTS: Two-hundred ninety-nine adult patients with frequent painful episodes enrolled in the follow-up. Follow-up data through May 2001 were complete for 233 patients. INTERVENTION: In the MSH, patients were randomly assigned to receive hydroxyurea (n = 152) or placebo (n = 147). MAIN OUTCOME MEASURE: Mortality, HbF levels, painful episodes, acute chest syndrome, and blood cell counts. The randomized trial was not designed to detect specified differences in mortality. RESULTS: Seventy-five of the original 299 patients died, 28% from pulmonary disease. Patients with reticulocyte counts less than 250 000/mm3 and hemoglobin levels lower than 9 g/dL had increased mortality (P =.002). Cumulative mortality at 9 years was 28% when HbF levels were lower than 0.5 g/dL after the trial was completed compared with 15% when HbF levels were 0.5 g/dL or higher (P =.03 ). Individuals who had acute chest syndrome during the trial had 32% mortality compared with 18% of individuals without acute chest syndrome (P =.02). Patients with 3 or more painful episodes per year during the trial had 27% mortality compared with 17% of patients with less frequent episodes (P =.06). Taking hydroxyurea was associated with a 40% reduction in mortality (P =.04) in this observational follow-up with self-selected treatment. There were 3 cases of cancer, 1 fatal. CONCLUSIONS: Adult patients taking hydroxyurea for frequent painful sickle cell episodes appear to have reduced mortality after 9 of years follow-up. Survival was related to HbF levels and frequency of vaso-occlusive events. Whether indications for hydroxyurea treatment should be expanded is unknown.

A prospective study of the relationship over time of behavior problems, intellectual functioning, and family functioning in children with sickle cell disease: a report from the Cooperative Study of Sickle Cell Disease.

OBJECTIVE: To longitudinally assess the relationship of behavioral problems, intellectual functioning, and family functioning in children with sickle cell disease (SCD). METHOD: The study sample included 222 children enrolled in the Cooperative Study of Sickle Cell Disease (CSSCD). The study protocol included intellectual evaluation and brain magnetic resonance imaging (MRI) of the children, and mothers completed the Child Behavior Checklist and Family Environment Scale. At least two complete sets of measures were obtained across four assessment points over the study period of 9 years. RESULTS: Intellectual functioning declined, but family functioning and behavior problem scores did not change significantly. Consistent behavior problems were reported by mothers for 9% of the children. The risk of consistent behavior problems was not related to MRI classification, gender, education level of mother, or age of the child but significantly increased with higher baseline levels of family conflict and decreased with higher baseline full-scale IQ. An increase in behavior problems was associated with an increase in family conflict. CONCLUSIONS: Maternal appraisal of family conflict is a risk factor for the small subgroup of children with SCD with consistent mother-reported behavior problems and a salient intervention target for fostering adaptation.

Longitudinal changes in brain magnetic resonance imaging findings in children with sickle cell disease.

Children with sickle cell anemia (HbSS) are at high risk for neurologically overt cerebral infarcts associated with stroke and neurologically silent cerebral infarcts correlated with neuropsychometric deficit. We used complete magnetic resonance imaging (MRI) histories from 266 HbSS children, aged 6 through 19 years, who were enrolled in the Cooperative Study of Sickle Cell Disease (CSSCD) to examine silent infarct prevalence, localization, recurrence, and progression. We report a baseline prevalence of 21.8%, marginally higher than previously reported due to improved imaging technologies. Although we observed no overall sex difference in prevalence, most lesions in girls occurred before age 6, whereas boys remained at risk until age 10. Silent infarcts were significantly smaller and less likely to be found in the frontal or parietal cortex than were infarcts associated with stroke. Children with silent infarct had an increased incidence of new stroke (1.03/100 patient-years) and new or more extensive silent infarct (7.06/100 patient-years) relative to stroke incidence among all children in our cohort (0.54/100 patient-years). Both events were substantially less frequent than the risk of stroke recurrence among children not provided chronic transfusion therapy. Although chronic transfusion is known to decrease occurrence of new silent infarcts and strokes in children with elevated cerebral arterial blood flow velocity, further study is required to determine its risk-benefit ratio in children with silent infarct and normal velocities. Until safe and effective preventive strategies against infarct recurrence are discovered, MRI studies are best reserved for children with neurologic symptoms, neuropsychometric deficits, or elevated cerebral artery velocities.

Risk of recurrent stroke in children with sickle cell disease receiving blood transfusion therapy for at least five years after initial stroke.

OBJECTIVE: To test the hypothesis that children with sickle cell disease (SCD) who have an initial stroke temporally unrelated to another medical event are at higher risk for recurrent stroke than are children who had strokes temporally related to medical events. METHODS: A retrospective cohort study of children with SCD and stroke who received regularly scheduled blood transfusions for a minimum of 5 years was conducted. Medical records were examined for the documentation of antecedent or concurrent medical events (hypertension, acute chest syndrome, aplastic crisis, fever associated with infection, exchange transfusion) associated with physician contact within 14 days before the initial stroke. RESULTS: A total of 137 pediatric patients from 14 centers were studied. Mean age at first stroke was 6.3 years (1.4 to 14.0 years) with mean follow-up of 10.1 years (5 to 24 years). Thirty-one (22%) patients had a second stroke (2.2 per 100 patient years); 26 patients had an identified medical or concurrent event associated with their initial stroke. None of these patients had recurrent stroke 2 or more years after the initial event. The remaining 111 patients had an ongoing risk of recurrent stroke (1.9 per 100 patient-years) despite long-term transfusions (P =.038). CONCLUSIONS: The absence of an antecedent or concurrent medical event associated with an initial stroke is a major risk factor for subsequent stroke while receiving regular transfusions.