The CYB5R3c .350C>G and G6PD A alleles modify severity of anemia in malaria and sickle cell disease.

Genetic modifiers of anemia in Plasmodium falciparum infection and sickle cell disease (SCD) are not fully known. Both conditions are associated with oxidative stress, hemolysis and anemia. The CYB5R3 gene encodes cytochrome b5 reductase 3, which converts methemoglobin to hemoglobin through oxidation of NADH. CYB5R3c.350C > G encoding CYB5R3T117S , the most frequent recognized African-specific polymorphism, does not have known functional significance, but its high allele frequency (23% in African Americans) suggests a selection advantage. Glucose-6-phosphate dehydrogenase (G6PD) is essential for protection from oxidants; its African-polymorphic X-linked A+ and A- alleles, and other variants with reduced activity, coincide with endemic malaria distribution, suggesting protection from lethal infection. We examined the association of CYB5R3c.350C > G with severe anemia (hemoglobin <5 g/dL) in the context of G6PD A+ and A- status among 165 Zambian children with malaria. CYB5R3c.350C > G offered protection against severe malarial anemia in children without G6PD deficiency (G6PD wild type or A+/A- heterozygotes) (odds ratio 0.29, P = .022) but not in G6PD A+ or A- hemizygotes/homozygotes. We also examined the relationship of CYB5R3c.350C > G with hemoglobin concentration among 267 children and 321 adults and adolescents with SCD in the US and UK and found higher hemoglobin in SCD patients without G6PD deficiency (ß = 0.29, P = .022 children; ß = 0.33, P = .004 adults). Functional studies in SCD erythrocytes revealed mildly lower activity of native CYB5R3T117S compared to wildtype CYB5R3 and higher NADH/NAD+ ratios. In conclusion, CYB5R3c.350C > G appears to ameliorate anemia severity in malaria and SCD patients without G6PD deficiency, possibly accounting for CYB5R3c.350C > G selection and its high prevalence.

A randomized clinical trial of adolescents with HIV/AIDS: pediatric advance care planning.

The objective of this study is to determine if pediatric advance care planning (pACP) increases adolescent/family congruence in end-of-life (EOL) treatment preferences longitudinally. Adolescents aged 14-21 years with HIV/AIDS and their families were randomized (N = 105 dyads) to three-60-minute sessions scheduled one week apart: either the pACP intervention (survey administered independently, facilitated conversation with adolescent and family present, completion of legal advance directive document with adolescent and family present) or an active control (developmental history, safety tips, nutrition and exercise education). This longitudinal, single-blinded, multi-site, randomized controlled trial was conducted in six pediatric hospital-based HIV-clinics, located in high HIV mortality cities. The Statement of Treatment Preferences measured adolescent/family congruence in EOL treatment preferences at immediately following the facilitated pACP conversation (Session 2), and at 3-month post-intervention. The mean age of adolescent participants was 18 years (range 14-21 years); 54% were male; and 93% were African-American. One-third had an AIDS diagnosis. Immediately post-intervention the Prevalence Adjusted Bias Adjusted Kappa showed substantial treatment preference agreement for pACP dyads compared to controls (High burden/low chance of survival, PABAK = 0.688 vs. 0.335; Functional impairment, PABAK = 0.687 vs. PABAK= 0.34; Mental impairment, PABKA = 0.717 vs. 0.341). Agreement to limit treatments was greater among intervention dyads than controls (High burden: 14.6% vs. 0%; Functional impairment = 22.9% vs. 4.4%; and Mental impairment: 12.5% vs. 4.4%). Overall treatment preference agreement among pACP dyads was high immediately post-intervention, but decreased over time. In contrast, treatment agreement among control dyads was low and remained low over time. As goals of care change over time with real experiences, additional pACP conversations are needed.

Prasugrel in children with sickle cell disease: pharmacokinetic and pharmacodynamic data from an open-label, adaptive-design, dose-ranging study.

INTRODUCTION: This phase 2 study was designed to characterize the relationship among prasugrel dose, prasugrel's active metabolite (Pras-AM), and platelet inhibition while evaluating safety in children with sickle cell disease. It was open-label, multicenter, adaptive design, dose ranging, and conducted in 2 parts. Part A: Patients received escalating single doses leading to corresponding increases in Pras-AM exposure and VerifyNow®P2Y12 (VN) platelet inhibition and decreases in VNP2Y12 reaction units and vasodilator-stimulated phosphoprotein platelet reactivity index. Part B: Patients were assigned daily doses (0.06, 0.08, and 0.12 mg/kg) based on VN pharmacodynamic measurements at the start of 2 dosing periods, each 14±4 days. Platelet inhibition was significantly higher at 0.12 mg/kg (56.3%±7.4%; least squares mean±SE) compared with 0.06 mg/kg (33.8%±7.4%) or 0.08 mg/kg (37.9%±5.6%). Patients receiving 0.12 mg/kg achieved ≥30% platelet inhibition; only 1 patient receiving 0.06 mg/kg exceeded 60% platelet inhibition. High interpatient variability in response to prasugrel and the small range of exposures precluded rigorous characterization of the relationship among dose, Pras-AM, and platelet inhibition. SAFETY: No hemorrhagic events occurred in Part A; 3 occurred in Part B, all mild and self-limited. CONCLUSIONS: Most children with sickle cell disease may achieve clinically relevant platelet inhibition with titration of daily-dose prasugrel.

Differences in the clinical and genotypic presentation of sickle cell disease around the world.

Sickle cell disease (SCD), caused by a mutation in the ß-globin gene HBB, is widely distributed in malaria endemic regions. Cardiopulmonary complications are major causes of morbidity and mortality. Hemoglobin SS (Hb SS) represents a large proportion of SCD in the Americas, United Kingdom, and certain regions of Africa while higher proportions of hemoglobin SC are observed in Burkina Faso and hemoglobin Sß-thalassemia in Greece and India. Coinheritance of α-thalassemia and persistence of hemoglobin F production are observed in highest frequency in certain regions of India and the Middle East. As confirmed in the PUSH and Walk-PHaSST studies, Hb SS, absence of co-inheriting alpha-thalassemia, and low hemoglobin F levels tend to be associated with more hemolysis, lower hemoglobin oxygen saturations, greater proportions of elevated tricuspid regurgitant jet velocity and brain natriuretic peptide, and increased left ventricular mass index. Identification of additional genetic modifiers will improve prediction of cardiopulmonary complications in SCD.

Effect of hydroxyurea treatment on renal function parameters: results from the multi-center placebo-controlled BABY HUG clinical trial for infants with sickle cell anemia.

BACKGROUND: Children with sickle cell anemia (SCA) often develop hyposthenuria and renal hyperfiltration at an early age, possibly contributing to the glomerular injury and renal insufficiency commonly seen later in life. The Phase III randomized double-blinded Clinical Trial of Hydroxyurea in Infants with SCA (BABY HUG) tested the hypothesis that hydroxyurea can prevent kidney dysfunction by reducing hyperfiltration. PROCEDURE: 193 infants with SCA (mean age 13.8 months) received hydroxyurea 20 mg/kg/day or placebo for 24 months. (99m) Tc diethylenetriaminepentaacetic acid (DTPA) clearance, serum creatinine, serum cystatin C, urinalysis, serum and urine osmolality after parent-supervised fluid deprivation, and renal ultrasonography were obtained at baseline and at exit to measure treatment effects on renal function. RESULTS: At exit children treated with hydroxyurea had significantly higher urine osmolality (mean 495 mOsm/kg H(2) O compared to 452 in the placebo group, P = 0.007) and a larger percentage of subjects taking hydroxyurea achieved urine osmolality >500 mOsm/kg H(2) O. Moreover, children treated with hydroxyurea had smaller renal volumes (P = 0.007). DTPA-derived glomerular filtration rate (GFR) was not significantly different between the two treatment groups, but was significantly higher than published norms. GFR estimated by the Chronic Kidney Disease in Children (CKiD) Schwartz formula was the best non-invasive method to estimate GFR in these children, as it was the closest to the DTPA-derived GFR. CONCLUSION: Treatment with hydroxyurea for 24 months did not influence GFR in young children with SCA. However, hydroxyurea was associated with better urine concentrating ability and less renal enlargement, suggesting some benefit to renal function.

Elevated tricuspid regurgitation velocity and decline in exercise capacity over 22 months of follow up in children and adolescents with sickle cell anemia.

BACKGROUND: While in adults with sickle cell disease an elevation of tricuspid regurgitation velocity is associated with increased mortality, the importance of this finding in children has not been established. The role of intravascular hemolysis in the development of this complication is controversial. DESIGN AND METHODS: We conducted a prospective, longitudinal, multi-center study of 160 individuals aged 3-20 years with hemoglobin SS, performing baseline and follow-up determinations of clinical markers, six-minute walk distance less than tricuspid regurgitation velocity and E/Etdi ratio by echocardiography. RESULTS: At baseline, 14.1% had tricuspid regurgitation velocity of 2.60 m/sec or over, which suggests elevated systolic pulmonary artery pressure, and 7.7% had increased E/Etdi, which suggests elevated left ventricular filling pressure. Over a median of 22 months, baseline elevation in tricuspid regurgitation velocity was associated with an estimated 4.4-fold increase in the odds of a 10% or more decline in age-standardized six-minute-walk distance (P = 0.015). During this interval, baseline values above the median for a hemolytic component derived from four markers of hemolysis were associated with a 9.0-fold increase in the odds of the new onset of elevated tricuspid regurgitation velocity (P = 0.008) and baseline E/Etdi elevation was associated with an estimated 6.1-fold increase in the odds (P = 0.039). In pathway analysis, higher baseline hemolytic component and E/Etdi predicted elevated tricuspid regurgitation velocity at both baseline and follow up, and these elevations in turn predicted decline in six-minute-walk distance. CONCLUSIONS: Further studies should define the long-term risks of elevated tricuspid regurgitation velocity in childhood and identify potential interventions to prevent increased pulmonary artery pressure and preserve function.

Association of G6PD with lower haemoglobin concentration but not increased haemolysis in patients with sickle cell anaemia.

The genetic bases of the highly variable degrees of anaemia and haemolysis in persons with Hb SS are not fully known, but several studies have indicated that G6PD deficiency is not a factor. The G6PD(202A) and G6PD(376G) alleles and alpha-thalassaemia were determined by molecular genetic testing in 261 children and adolescents with Hb SS in a multicentre study. G6PD(202A,376G) (G6PD A-) was defined as hemizygosity for both alleles in males and homozygosity in females. Among the participants 41% were receiving hydroxycarbamide. The prevalence of G6PD(202A,376G) was 13.6% in males and 3.3% in females with an overall prevalence of 8.7%. G6PD(202A,376G) was associated with a 10 g/l decrease in haemoglobin concentration (P = 0.008) but not with increased haemolysis as measured by lactate dehydrogenase, bilirubin, aspartate-aminotransferase, reticulocyte count or a haemolytic component derived from these markers (P > 0.09). Similar results were found within a sub-group of children who were not receiving hydroxycarbamide. By comparison, single and double alpha-globin deletions were associated with progressively higher haemoglobin concentrations (P = 0.005 for trend), progressively lower values for haemolytic component (P = 0.007), and increased severe pain episodes (P < 0.001). In conclusion, G6PD(202A,376G) may be associated with lower haemoglobin concentration in sickle cell anaemia by a mechanism other than increased haemolysis.

Adherence to study medication and visits: data from the BABY HUG trial.

BACKGROUND: Subject retention and adherence are essential to maintain the power and validity of the Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG). We designed a study to assess adherence with study medication administration and study visits and to evaluate socioeconomic factors (SES) that may influence these measurements of adherence. These data are important for assessing impact of adherence on BABY HUG trial outcome and defining impact of SES on adherence. METHODS: Each subject's median study medication (MedAd) and mean visit adherence (VAd) were evaluated. We examined associations of adherence with SES of participating families. RESULTS: MedAd data were available on 153 of the 191 subjects who started randomized study medication. MedAd was 101.7% of volume prescribed, with 88.9% of subjects taking at least 80% of doses. VAd data were available on 185 of the 191 subjects who started randomized study medication. VAd was 97.3%, with 82.2% of subjects having no missed visits. During dose titration, subjects had on average 12.9% higher medication adherence than subjects who were on a stable dose and had less frequent study visits. MedAd and VAd were not significantly associated with SES. CONCLUSION: Subjects in the BABY HUG trial have had excellent adherence. SES was not associated with adherence, suggesting that SES should not be used as a criterion for enrolment in clinical trials. Additional efforts are needed to maintain medication adherence, particularly when the interval between scheduled visits increases. (ClinicalTrials.gov number, NCT00006400).

Lemierre's syndrome resulting from streptococcal induced otitis media and mastoiditis: a case report.

INTRODUCTION: Lemierre's syndrome is an extremely rare and almost universally fatal disease characterized as thrombophlebitis of the internal jugular venous system with subsequent metastatic infection. Fusobacterium necrophorum is the most common organism implicated in causation of Lemierre's syndrome. Group A Streptococcus has mainly been observed as a polymicrobial organism in the syndrome. We report a rare finding of a rare disease where Group A Streptococcus was the sole organism triggering Lemierre's syndrome. To our knowledge, this is only the third recorded patient with such an occurrence. CASE PRESENTATION: We describe a 9-year-old African American boy, who presented with otitis media and mastoiditis that culminated in Lemierre's syndrome. Isolates bore only Group A Streptococcus. The patient was appropriately treated and responded with full recovery from the syndrome. CONCLUSION: Since Lemierre's syndrome is classically detected by clinical diagnosis, these findings should prompt clinicians to consider Group A Streptococcus as an alternative catalyst. It should be pondered that patients who present with typical Group A streptococcal infections have the possibility for developing Lemierre's syndrome. Though this complication appears to be rare, early diagnosis and prompt intervention have proven critical in survival outcome. Indeed, what would seem to be a routine case of strep throat or otitis media easily treated with antibiotics could end up being an unalterable progression to death unless Lemierre's syndrome is immediately diagnosed and treated.

Growth hormone deficiency in patients with sickle cell disease and growth failure.

BACKGROUND: Growth disorders are common in children with sickle cell disease (SCD). The etiology for growth disturbances in this population appears to be multifactorial. Recent evidence suggests abnormalities in the growth hormone (GH)/insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) axis may play a role. OBJECTIVE: To measure GH levels through provocative stimulation in a group of patients with SCD with growth failure, and to evaluate response to treatment. PATIENTS AND METHODS: Growth records were reviewed of 79 children with sickle cell hemoglobinopathies to identify children with growth failure. GH levels were measured in patients with SCD with and without growth failure using arginine and L-Dopa as provocative stimulation tests. Treatment with GH was offered to GH-deficient children with SCD and these patients were followed longitudinally over 5 years. RESULTS: Of the 79 patients, 13 (16.5%, all SS) had heights less than -2 SD below the mean or a growth velocity < -2 SD below the mean for age. Seven of the 13 children with growth failure participated in this study. Five patients received GH for 3 or more years and demonstrated significant improvement in their height SDS. One of the two who declined treatment was lost to follow-up and the other had significant worsening of height SDS score. CONCLUSION: GH deficiency may be associated with growth failure in some patients with SCD. These patients may benefit from treatment with GH.

Frequent and prolonged hospitalizations: a risk factor for early mortality in sickle cell disease patients.

A subset of patients with sickle cell disease (SCD) has frequent and prolonged hospitalizations. Clinical outcomes for this subset of patients are not known. We analyzed mortality data in 71 such patients enrolled in a case management study. Adult patients (mean age 32 years) with SCD and > or = 50 hospitalization days/year or > or = 6 admissions/year were enrolled. Clinical and psychosocial data were obtained. During a mean 24-month follow up, 11 of 71 patients died (15.5%). Patients who died had a higher mean number of hospitalization days in the year before study entry (116 vs. 40, P < 0.000008) and were also more depressed than those who survived (mean score 17.8 vs. 11.9, P = 0.031). Frequent and prolonged hospitalizations are a risk factor for early mortality in patients with SCD.