Prevalence of iron deficiency in children with Down syndrome.

Objectives: To determine the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) in a sample of children with Down syndrome (DS) and to evaluate the effect of macrocytosis on the diagnosis of ID/IDA in these children.

Study Design: Children with DS ≥ 12 months of age who were followed at the Duke University Medical Center Comprehensive DS Clinic from December 2004 to March 2007 were screened for ID/IDA with a complete blood count, reticulocyte count, iron panel, and erythrocytic protoporphyrins.

Results: A total of 114 children were enrolled, with a median age of 4.

A pilot study of hydroxyurea to prevent chronic organ damage in young children with sickle cell anemia.

Background: Hydroxyurea improves laboratory parameters and prevents acute clinical complications of sickle cell anemia (SCA) in children and adults, but its effects on organ function remain incompletely defined.

Methods: To assess the safety and efficacy of hydroxyurea in young children with SCA and to prospectively assess kidney and brain function, 14 young children (mean age 35 months) received hydroxyurea at a mean maximum tolerated dose (MTD) of 28 mg/kg/day.

Results: After a mean of 25 months, expected laboratory effects included significant increases in hemoglobin, MCV and %HbF along with significant decreases in reticulocytes, absolute neutrophil count, and bilirubin.

Partial splenectomy for children with congenital hemolytic anemia and massive splenomegaly.

Partial splenectomy is an alternative to total splenectomy for the treatment of congenital hemolytic anemias (CHAs) in children, although the feasibility of this technique in the setting of massive splenomegaly is unknown. This study was designed to evaluate the safety and efficacy of partial splenectomy in children with CHAs and massive splenomegaly. This retrospective study examined 29 children with CHAs who underwent partial splenectomy.

Hydroxyurea therapy for management of secondary erythrocytosis in cyanotic congenital heart disease.

Secondary erythrocytosis in cyanotic congenital heart disease (CCHD) causes substantial morbidity because of complications of hyperviscosity, including stroke and chronic end organ damage. Phlebotomy provides temporary improvement but leads to iron deficiency and can actually increase blood viscosity. We describe the successful use of hydroxyurea (hydroxycarbamide) in four patients with uncorrected CCHD and symptomatic secondary erythrocytosis.

Hydroxyurea therapy lowers transcranial Doppler flow velocities in children with sickle cell anemia.

Hydroxyurea has hematologic and clinical efficacy in sickle cell anemia (SCA), but its effects on transcranial Doppler (TCD) flow velocities remain undefined. Fifty-nine children initiating hydroxyurea therapy for clinical severity had pretreatment baseline TCD measurements; 37 with increased flow velocities (> or = 140 cm/s) were then enrolled in an institutional review board (IRB)-approved prospective phase 2 trial with TCD velocities measured at maximum tolerated dose (MTD) and one year later. At hydroxyurea MTD (mean +/- 1 SD = 27.

Quantitative analysis of Howell-Jolly bodies in children with sickle cell disease.

Objectives: Although functional asplenia in sickle cell disease (SCD) begins early in life and has important clinical consequences, quantitative measurement of splenic function is not readily available. A novel high-throughput flow cytometric method for quantitating Howell-Jolly bodies (HJB) has been developed which isolates HJB-containing CD71(+) and CD71(-) erythrocytes. Analysis of these cell populations allows quantitative measurement of splenic filtrative function and possible chromosomal damage.

Pelger-Huët anomaly in a child with 1q42.3-44 deletion.

Congenital Pelger-Huët anomaly (PHA) is an autosomal dominant disorder characterized by hypolobulated neutrophils with coarse clumping of the nuclear chromatin. PHA has been recently linked to the gene encoding the lamin B receptor, located at chromosome 1q41-43. The authors report a case of PHA in a child with interstitial deletion of the 1q subtelomeric region (1q42.

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.

Acute parvovirus B19 infection mimicking congenital dyserythropoietic anemia.

Infection with human parvovirus B19 is known to cause transient erythroid aplasia in children with hemolytic anemia but has also been associated with bone marrow necrosis and morphologic changes suggesting myelodysplasia. The authors describe a previously healthy child who presented with severe hypoplastic anemia. Initial bone marrow aspiration revealed erythroid hyperplasia, dyserythropoiesis, and multinucleated erythroid cells with nuclear budding and bridging, consistent with the diagnosis of congenital dyserythropoietic anemia.

Sustained long-term hematologic efficacy of hydroxyurea at maximum tolerated dose in children with sickle cell disease.

Hydroxyurea improves hematologic parameters for children with sickle cell disease (SCD), but its long-term efficacy at maximum tolerated dose (MTD) has not been determined. Between 1995 and 2002, hydroxyurea therapy was initiated for 122 pediatric patients with SCD including 106 with homozygous sickle cell anemia (HbSS), 7 with sickle hemoglobin C (HbSC), 7 with sickle/beta-thalassemia (HbS/ beta-thalassemia [6 HbS/beta0, 1 HbS/beta+]), and 2 with sickle hemoglobin OArab (HbS/OArab). Median age at initiation of therapy was 11.

Childhood autoimmune cytopenia secondary to unsuspected common variable immunodeficiency.

Immune thrombocytopenic purpura and autoimmune hemolytic anemia are typically idiopathic processes without underlying systemic illness. Four children with autoimmune cytopenia had low immunoglobulin levels that led to the diagnosis of common variable immunodeficiency. Routine screening of immunoglobulins is suggested for children with chronic or recurrent immune thrombocytopenic purpura and autoimmune hemolytic anemia.

Subclinical parvovirus B19 infection in children with sickle cell anemia.

Purpose: To investigate the prevalence and clinical consequences of previous parvovirus B19 exposure in a large cohort of pediatric patients with sickle cell anemia (SCA).

Methods: Prospective serologic testing for previous parvovirus B19 exposure was performed in steady-state pediatric patients with SCA, either prior to starting hydroxyurea therapy or in preparation for transition to the adult service. A retrospective chart review was performed to ascertain whether patients had a documented history of a transient aplastic crisis.

UGT1A promoter polymorphisms influence bilirubin response to hydroxyurea therapy in sickle cell anemia.

Hydroxyurea therapy reduces hemolysis and decreases serum bilirubin levels in children and adults with sickle cell anemia (SCA) and may therefore help prevent the development of cholelithiasis in this patient population. We recently reported that a promoter polymorphism in the uridine diphosphoglucuronate glucuronosyltransferase 1A (UGT1A) gene affects steady-state bilirubin levels and the incidence of gallstones in children with SCA. We have now analyzed the influence of the UGT1A genotype on the therapeutic response to hydroxyurea.