Resolution of chronic hepatic sequestration in a patient with homozygous sickle cell disease receiving hydroxyurea

Hepatic sequestration is an uncommon complication in patients with homozygous sickle cell disease. Although transfusion therapy has been effective for the acute condition, no definitive treatment of chronic hepatic sequestration has been identified. We describe a 17-year-old male patient with hemoglobin SS and chronic hepatic sequestration who was treated with long-term (60 months) hydroxyurea. After 36 months of HU therapy, the patient had both an excellent hematologic response and a resolution of hepatic sequestration, as evidenced by disappearance of clinical hepatomegaly, normalization of liver volume on serial computed tomography scans, as well as decreased sinusoidal dilatation and congestion and red blood cell sickling on liver biopsy. The findings in this case suggest that hydroxyurea may benefit patients who have unusual complications of sickle cell disease, such as chronic erythrocyte sickling in the liver.     

Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia.

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.     

Haploidentical bone marrow transplantation in a patient with sickle cell disease and acute myeloid leukemia

Myeloid neoplasms in children with sickle cell disease have been rarely reported, and the exact underlying connection between these two conditions is not clearly understood. Whether the acute myeloid leukemia in hydroxyurea‐treated sickle cell patients is co‐incidental or related to therapy remains an unanswered question. Herein, we report a 14‐year‐old girl of Haitian descent with sickle beta zero thalassemia on chronic hydroxyurea therapy who developed FMS‐like tyrosine kinase 3 (FLT3)‐mutated acute myeloid leukemia and underwent a complete disease remission following a combination chemotherapy with sorafenib and was subsequently treated using a T cell replete unmanipulated haploidentical bone marrow transplantation followed by post‐transplant cyclophosphamide.     

Beneficial effect of blood transfusion in children with sickle cell chest syndrome

Reports in the 1970s suggested that acute chest syndrome (ACS) in children with sickle cell disease is usually due to bacterial infection. Studies in adults and more recently in children, however, showed that proved bacterial infection occurs in a minority of these patients and that vascular occlusion is the main pathologic process. In a retrospective study of 32 episodes of ACS in children, a definite bacterial infection was found in 3% (one patient), possible bacterial infection in 11% (four patients), and a possible mycoplasma in 13% (five patients). With the intent to dilute sickle cells, 23 patients received blood transfusion within 24 hours after hospital admission; all showed a dramatic clinical and roentgenographic improvement. Of the nine patients who did not receive a transfusion after hospital admission, the conditions of five patients deteriorated but improved after "late" transfusion; three patients showed slow improvement, and only one patient improved within 48 hours. From this we conclude that vascular occlusion might be the main process in ACS and that early blood transfusion may be valuable in shortening the course and decreasing mortality. The low hemoglobin value at presentation in our patients makes dilution of sickle cells possible by packed red blood cell transfusion rather than exchange transfusion.     

Use of hydroxyurea in children ages 2 to 5 years with sickle cell disease

The efficacy and side effects of hydroxyurea in young children with sickle cell disease are unknown. The authors followed-up eight young children (mean age 3.7 years) during therapy with hydroxyurea for an average of 137 weeks. Total and fetal hemoglobin levels rose with hydroxyurea therapy. Hospital admission rates and total hospital days decreased during hydroxyurea therapy. No unexpected toxicity occurred, and growth and development were unaffected. This pilot study suggests that hydroxyurea is safe and effective in young children with sickle cell disease.     

Effect of hydroxyurea therapy on resting energy expenditure in children with sickle cell disease

Effects of hydroxyurea therapy on resting energy expenditure (REE) in children with sickle cell disease have not been evaluated. Eight children with sickle cell disease were examined before hydroxyurea therapy and again 6.9 +/- 3.5 months after hydroxyurea initiation. Resting energy expenditure, dietary intake, and growth were assessed. In six children, baseline REE was elevated, and REE decreased an average of 17% with hydroxyurea. This was associated with a significant increase in fetal hemoglobin. These pilot data suggest that hydroxyurea may curtail the hypermetabolic state observed in children with sickle cell disease and may offer a clinically important secondary benefit.     

Sickle cell anemia from central India: A retrospective analysis

Although sickle cell anemia in India is believed to have a mild clinical presentation, few studies report severe disease in many patients from central India. Hence, we have retrospectively studied 316 children with SCA who were followed up for a period of 5.8±5.7 years. There were 55.4 blood transfusions, 43.3 episodes of vaso-occlusive crises requiring hospitalization, and 108.9 hospitalizations per 100 person years. Ninety six (30%) patients had severe disease whereas 74 patients also fulfilled the criteria for hydroxyurea therapy. Significant proportion of children with sickle cell anemia from central India present with severe clinical presentation and require regular medical attention.     

Enalapril and hydroxyurea therapy for children with sickle nephropathy

Proteinuria in children with sickle cell anemia (SCA) is an early sign of sickle nephropathy, and portends the development of nephrotic syndrome and chronic renal failure. Enalapril has been shown to reduce proteinuria in adult patients with SCA, but the potential benefits of hydroxyurea in this clinical setting have not been reported. A single institution retrospective analysis was performed. Children with sickle nephropathy were identified, and the laboratory effects of enalapril and hydroxyurea therapy were evaluated in children with substantial proteinuria. Three children developed proteinuria at 8 +/- 1 years of age. Pre-treatment laboratory studies included a low serum albumin (2.8 +/- 0.8 g/dl) and a highly elevated urine protein/creatinine ratio (6.9 +/- 3.7, normal <0.2). Enalapril treatment for 3.0 +/- 1.3 years normalized serum albumin (3.9 +/- 0.3 g/dl) without significant changes in serum potassium, serum creatinine, or systolic blood pressure. However, urine protein/creatinine remained elevated in the nephrotic range (1.6 +/- 0.7). The addition of hydroxyurea therapy for 3.5 +/- 1.2 years increased fetal hemoglobin levels (7.0 +/- 3.6% to 21.0 +/- 3.2%) and was associated with a near-normal urine protein/creatinine ratio (0.5 +/- 0.1). Enalapril therapy for children with sickle nephropathy reduces urinary protein excretion and normalizes serum albumin. Hydroxyurea therapy may further normalize the urine protein/creatinine ratio. Combination therapy should be tested prospectively in children with sickle nephropathy.     

Resolution of chronic hypoxemia in pediatric sickle cell patients after treatment with hydroxyurea

Chronic hypoxemia is a common manifestation among patients with sickle cell anemia (SCA) who develop chronic lung disease. We report the beneficial effect of hydroxyurea on chronic hypoxemia in three pediatric patients with SCA and recurrent episodes of acute chest syndrome (ACS). All three patients improved rapidly after they were treated with hydroxyurea despite having additional risk factors for hypoxemia. A prospective trial is warranted to assess whether there is a therapeutic effect from the use of hydroxyurea in pediatric SCA patients with chronic hypoxemia.     

Massive accidental overdose of hydroxyurea in a young child with sickle cell anemia

The Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG) confirmed safety and efficacy of hydroxyurea therapy for infants with sickle cell anemia. Treatment was associated with reduction in rates of pain, acute chest syndrome, hospitalizations, and blood transfusions; improved hematologic values; and, perhaps, preservation of organ function. During the study, a 2-year-old ingested at one time an entire 35-day supply of hydroxyurea (612 mg/kg body weight). Despite a serum level of 7,756 μM 4 hours post-ingestion, the only toxicity was transient mild myelosuppression. With wider usage of hydroxyurea anticipated, conservative management of future overdoses seems reasonable (ClinicalTrials.gov NCT00006400).     

Impact of hydroxyurea on perioperative management and outcomes in children with sickle cell anemia

Hydroxyurea has enhanced the treatment for children with sickle cell anemia. The objectives of this study were to compare perioperative transfusions and outcomes for children taking hydroxyurea versus those not taking hydroxyurea. We retrospectively reviewed perioperative management and outcomes for 51 children with sickle cell anemia (HbSS genotype) who underwent surgery in our center between January 2003 and April 2008. Of the 51 patients, 30 (59%) were taking hydroxyurea and 21 (41%) were not taking hydroxyurea. Eight of 30 (27%) in the hydroxyurea group were not transfused preoperatively, 12 of 30 (40%) received a single transfusion and 10 of 30 (33%) received serial transfusions, compared with 1 of 21 (5%) children in the nonhydroxyurea group who was not transfused, 2 of 21 (10%) who received a single transfusion and 18 of 21 (85%) who received serial transfusions or pheresis (P=0.004; for comparison across groups). One patient not taking hydroxyurea developed a delayed hyperhemolytic transfusion reaction, and 2 children taking hydroxyurea developed acute chest syndrome. Overall, children taking hydroxyurea had substantially fewer transfusions compared with children not taking hydroxyurea. Both groups of children had a low complication rate. Further research should be done to optimize perioperative management of children taking hydroxyurea.     

Hydroxyurea for children with sickle cell disease

Hydroxyurea therapy offers promise for ameliorating the clinical course of children with sickle cell disease (SCD). Hydroxyurea is a prototypic therapeutic option; it can be administered with minimal side effects, has a relatively wide therapeutic window, and has mechanisms of action that address pathophysiologic pathways of sickling, vaso-occlusion, hemolysis, and organ damage. There are limited data regarding hydroxyurea's ability to prevent or diminish organ dysfunction, and the long-term risks of hydroxyurea therapy remain incompletely defined. Although clinical trials are underway to address long-term issues, hydroxyurea remains an effective but underutilized therapy for SCD.     

Differences in health-related quality of life in children with sickle cell disease receiving hydroxyurea

Hydroxyurea is a safe and efficacious medication for children with sickle cell disease (SCD). Our objective was to compare health-related quality of life (HRQL) between children taking hydroxyurea and those not taking hydroxyurea. We conducted a retrospective cohort study of children with SCD who had completed the PedsQL 4.0 at Duke University Medical Center or the Midwest Sickle Cell Center. Our primary outcome was HRQL in children receiving hydroxyurea therapy compared with those not receiving hydroxyurea. One hundred and ninety-one children with SCD were included in the study. Children in the hydroxyurea group had higher self-reported Total PedsQL median scores than children in the no hydroxyurea group (P=0.04). Child self-reported physical functioning scores were significantly higher for children in the hydroxyurea group (P=0.01). In conclusion, children with SCD who received hydroxyurea therapy reported better overall HRQL and better physical HRQL than children who did not receive this therapy despite disease severity. Further research assessing the impact of hydroxyurea therapy on HRQL, such as prospective assessment over time, would aid in our understanding of the effectiveness of hydroxyurea for individual children. Ultimately, this may aid in decreasing the barriers to the use of hydroxyurea.     

Prevalence, prevention, and treatment of microalbuminuria and proteinuria in children with sickle cell disease

Microalbuminuria (MA) and proteinuria (P) are believed to be precursors of sickle cell nephropathy. We analyzed our longitudinal data on MA/P in children with sickle cell disease (SS) to define the age of onset, association with age, sex, and hemoglobin, and to explore the safety and efficacy of hydroxyurea and angiotensin converting enzyme inhibitor (ACEI) therapy. Data on 191 patients with SS (ages 3 to 20 y) with a mean follow up of 2.19 years+/-2.05 were available. Urine MA was measured yearly with follow-up testing if abnormal. Prevalence of MA/P was 19.4%. Increasing age and lower hemoglobin levels were related to MA/P but sex was not. Microalbumin excretion normalized in 44% of patients treated with hydroxyurea and 56% of patients treated with ACEI. Hyperkalemia developed in 4 ACEI patients resulting in discontinuation of treatment in 3 children. In summary, MA/P often develops in childhood and preventive and treatment strategies for sickle cell nephropathy should be a focus of pediatric programs. Our preliminary data suggest that although both hydroxyurea and ACEI therapy may be beneficial for MA/P, hyperkalemia may limit the utility of ACEI.     

Variability in rates of alloimmunization in different groups of children with sickle cell disease: effect of ethnic background

We evaluated the incidence of red blood cell alloimmunization in children with sickle cell disease from different backgrounds using standard blood banking techniques. Transfusion number, sequence of antibody formation, and antigen phenotyping were analyzed. Children with non-American ethnic origins had a 42.9% incidence of alloimmunization compared to 17.6% in American patients. Antigen frequencies were similar in the two groups. Fewer transfusions resulted in more antibodies in the non-American children. We recommend that all sickle cell patients be fully phenotyped prior to initiation of transfusion therapy. Phenotypically matched units do not appear to be indicated for the majority of sickle cell patients receiving either simple or hypertransfusion, but should be considered for patients of non-American ethnic origin once such patients become immunized.     

Transfusion therapy for cerebrovascular abnormalities in sickle cell disease.

Cerebral angiograms were performed in patients with sickle cell disease and symptoms of stroke to evaluate transfusion therapy for cerebrovascular accidents. Three patients who were transfused repeatedly for one year to maintain less than 30% hemoglobin S were compared to two patients who were not transfused. All patients had abnormal angiograms initially. After one year the angiographic abnormalities resolved in two and improved in one transfused child. The two children who were not transfused showed progressive vascular disease. For all arteriograms, the patients were prepared by transfusion with normal red cells and careful hydration.     

Prevention of secondary stroke and resolution of transfusional iron overload in children with sickle cell anemia using hydroxyurea and phlebotomy

OBJECTIVE: Transfusions prevent secondary stroke in children with sickle cell anemia (SCA) but also cause iron overload. Alternatives for stroke prophylaxis with effective therapy to reduce iron burden are needed. STUDY DESIGN: For 35 children with SCA and stroke, transfusions were prospectively discontinued. Hydroxyurea was prescribed for stroke prophylaxis, and phlebotomy removed excess iron. Initial patients discontinued transfusions before hydroxyurea therapy, but later patients overlapped transfusions with hydroxyurea until tolerating full-dose therapy. RESULTS: Children received hydroxyurea for 42 +/- 30 months (range, 3-104 months). Hydroxyurea (26.7 +/- 4.8 mg/kg per day) led to mild neutropenia (3.9 +/- 2.3 x 10(9)/L) with significant increases in hemoglobin concentration, mean corpuscular volume, and fetal hemoglobin. Stroke recurrence rate was 5.7 events per 100 patient-years, but children receiving overlapping hydroxyurea therapy had only 3.6 events per 100 patient-years. For 26 children with >6 months of phlebotomy, 14,311 +/- 12,459 mL blood (315 +/- 214 mL/kg) was removed, with serum ferritin decreasing from a median of 2722 to 298 ng/mL. Among patients completing phlebotomy, liver biopsy documented normal histology and no excess iron deposition. CONCLUSIONS: For children with SCA and stroke, hydroxyurea effectively prevents secondary stroke and serial phlebotomy leads to complete resolution of transfusional iron overload.     

Anaplastic Ependymoma in a Child With Sickle Cell Anemia: A Case Report Highlighting Treatment Challenges for Young Children With Central Nervous System Tumors and Underlying Vasculopathy

A 3‐year‐old boy with sickle cell anemia (SCA) presented with progressive daily emesis and was found to have an anaplastic ependymoma. Radiation therapy and chemotherapy are usually employed after subtotal resections of anaplastic ependymomas, although the benefits from chemotherapy are unclear. To mitigate the risks of adjuvant treatment in this patient at risk for SCA‐associated vasculopathy, renal impairment, and other end‐organ damage, proton beam irradiation without chemotherapy was chosen. Scheduled packed red blood cell transfusions were instituted to maintain sickle hemoglobin levels less than 30%. This case highlights treatment complexities for malignant brain tumors in patients predisposed to treatment‐related adverse effects.     

Preliminary report of a toxicity study of hydroxyurea in sickle cell disease. French Study Group on Sickle Cell Disease.

AIM: To evaluate the tolerance of hydroxyurea in children affected with sickle cell disease. DESIGN: Questionnaire study of French physicians likely to treat patients with sickle cell disease. Data were collected on 101 children with sickle cell disease, treated for a median of 22 months, 36 of whom were treated for more than three years. 13 children were younger than 5 years of age at inclusion. RESULTS: Hydroxyurea was stopped for medical reasons in 11 patients: 6 failures, 1 pregnancy, 1 cutaneous rash, 1 leg ulcer, 1 lupus. Acute lymphoblastic leukaemia occurred in a girl treated for 1.5 months with hydroxyurea, this short interval arguing against a causative association. One 17 year old boy had paraparesis after 8 years of treatment. CONCLUSIONS: No major short or medium term toxicity was related to hydroxyurea in this cohort of 101 children. However, the number of children treated for more than 3 years is too few to make firm conclusions on the long term tolerance of this drug.     

Red blood cell folate and serum vitamin B12 status in children with sickle cell disease

PURPOSE: To determine red blood cell (RBC) folate and serum vitamin B12 levels in children with sickle cell disease, SS-type, and to evaluate the associations of these nutrient levels with growth and hematologic parameters. PATIENTS AND METHODS: Subjects enrolled in this prospective, cross-sectional study were recruited from one tertiary care setting. Complete blood counts, measurement of red blood cell (RBC) folate and serum vitamin B12, anthropometric measures (height, weight, skinfold measurements), pubertal status, and 24-hour dietary recalls were obtained from 70 patients ages 1 to 19 years. RESULTS: Low RBC folate levels were found in 15% of the children. Fifty-seven percent of the sample had inadequate dietary folate intake. Three percent of the children had low serum vitamin B12 levels. All children and adolescents sampled had adequate dietary intake of vitamin B12. Both RBC folate (P = 0.01) and serum vitamin B12 levels (P < 0.01) decreased with increasing age. CONCLUSIONS: More than half of the subjects had inadequate intake of folate from food, and despite daily folate supplementation, 15% had low RBC folate levels. Low serum vitamin B12 levels were rare, and dietary vitamin B12 intake was adequate. Additional research is needed to explore the effects of improved folate status, the need for folate supplementation, and the relationship of folate, vitamin B12, and homocysteine levels and the risk for vascular damage and stroke in children with sickle cell disease.