Biomedical subjects

Elliott P Vichinsky

Publications and source records attributed to Elliott P Vichinsky.

At least 19 recordsLinked to original sources

PubMed2006

Increased prevalence of iron-overload associated endocrinopathy in thalassaemia versus sickle-cell disease.

Iron-overload associated endocrinopathy is the most frequently reported complication of chronic transfusion therapy in patients with thalassaemia (Thal). This study compared iron-overloaded subjects with Thal (n = 142; 54%M; age 25.8 +/- 8.1 years) and transfused sickle-cell disease (Tx-SCD; n = 199; 43%M, 24.9 +/- 13.2 years) to non-transfused SCD subjects (non-Tx-SCD; n = 64, 50%M, 25.3 +/- 11.3 years), to explore whether the underlying haemoglobinopathy influences the development of endocrinopathy. Subjects were recruited from 31 centres in the USA, Canada and the UK. Subjects with Thal had more evidence of diabetes (13% vs. 2%, P < 0.001), hypogonadism (40% vs. 4%, P < 0.001), hypothyroidism (10% vs. 2%, P = <0.001) and growth failure (33% vs. 7%, P < 0.001), versus Tx-SCD. Fifty-six per cent of Thal had more than one endocrinopathy compared with only 13% of Tx-SCD (P < 0.001). In contrast, Tx-SCD was not different from non-Tx-SCD. Multivariate analysis indicated that endocrinopathy was more likely in Thal than SCD [Odds Ratio (OR) = 9.4, P < 0.001], with duration of chronic transfusion a significant predictor (OR = 1.4 per 10 years of transfusion, P = 0.04). Despite iron overload, endocrinopathy was not increased in Tx-SCD versus non-Tx-SCD, suggesting that the underlying disease may modulate iron-related endocrine injury. However, because transfusion duration remained a significant predictor of endocrinopathy, these data should be confirmed in SCD subjects that have been chronically transfused for longer periods of time.

Adult↗

PubMed2006

Pulmonary hypertension in thalassemia: association with platelet activation and hypercoagulable state.

The pathogenesis of pulmonary hypertension (PAH), a serious complication in thalassemia, is not well understood. Thromboembolism has been postulated as one of the causative factors; however, there are currently limited specific data on its role. To examine whether increased platelet activation and hypercoagulability are linked to PAH, 25 beta-thalassemia major and beta-thalassemia intermedia patients were evaluated with Doppler echocardiograms for estimation of pulmonary artery pressure and with laboratory assays for indications of a prothrombotic state. The association of clinical variables and abnormal coagulation assays with PAH was determined. PAH was identified in 17 (68%) patients; mean pulmonary artery systolic pressure was 39.8 +/- 5.4 mm Hg. PAH was significantly associated with prior splenectomy, older age, and evidence for chronic hemolysis, diagnosed in both transfused (n = 10) and nontransfused (n = 7) patients. Increased platelet activation, measured by P-selectin, was significantly associated with PAH (P = 0.001). Increased thrombin-antithrombin III level was more prevalent in the presence of PAH, but increased fibrinolysis or low protein C levels were not. This study underscores the role of platelet activation in the development of PAH and stresses its occurrence even among patients who are regularly transfused, especially those who are older and have had splenectomies.

Adolescent↗

PubMed2006

Bone mineral density in children with sickle cell anemia.

PURPOSE: We evaluated bone mineral density (BMD) and risk factors for poor bone mineralization in children with sickle cell anemia (SCA). PATIENTS AND METHODS: Twenty-five children with severe manifestations of SCA (frequent hospitalizations, growth delay, or need for chronic red cell transfusions) were enrolled. Bone density was assessed at lumbar spine and proximal femur with dual-energy X-ray absorptiometry (DXA), and Z-scores were calculated by comparison with age, sex, and ethnicity-specific reference data. RESULTS: The median age of the study population was 12.8 years (10.2-19.8 years). Calcium intake was inadequate in 60%, and serum 25-hydroxy vitamin D (25-OHD) level <50 nM in 74% of patients. Median Z-scores for lumbar spine (-2.3) and proximal femur (-1.7) were markedly reduced, and 64% (95% confidence interval, 43%-82%) of patients had low bone density. Z-scores were not related to age, growth delay, chronic transfusions, or ferritin level. CONCLUSION: Our results suggest that children with severe manifestations of SCA have low BMD, and possess significant deficits in dietary calcium and circulating vitamin D.

Adolescent↗

PubMed2006

Dose-escalation study of ICA-17043 in patients with sickle cell disease.

STUDY OBJECTIVE: To determine the dose tolerance, safety, and pharmacokinetics of a single oral dose of ICA-17043 in patients with sickle cell disease. DESIGN: Phase I, randomized, double-blind, placebo-controlled, single-dose, dose-escalation study. SETTING: Four university medical centers. PATIENTS: Twenty-eight patients with sickle cell disease, aged 18-60 years, who were otherwise healthy and in a noncrisis state. INTERVENTION: Patients in three separate dose cohorts--50 mg, 100 mg, and 150 mg--received single doses of ICA-17043 or placebo. MEASUREMENTS AND MAIN RESULTS: The mean area under the concentration-time curve from time zero extrapolated to infinity (AUC(0-infinity)) for ICA-17043 increased in a dose-related manner (11,827, 19,697, and 30,676 ng.hr/ml for 50, 100, and 150 mg, respectively). Overall mean half-life was 12.8 days. Mean peak plasma concentrations rose between the 50- and 100-mg dose levels but plateaued at 150 mg (59.1, 108.7, and 109.1 ng/ml, respectively). Weekly pharmacokinetic and safety assessments were conducted in each patient during the follow-up phase for 56 days. No dose-limiting adverse events were noted in any of the patients. CONCLUSION: Total systemic exposure of ICA-17043 after a single oral dose, as measured by AUC(0-infinity), increased nearly proportionally with the dose. The rate of absorption, however, appeared to be delayed at doses greater than 100 mg. With the long half-life of ICA-17043 demonstrated in this study, once-daily dosing is probably adequate to maintain steady-state plasma concentrations. In addition, single doses of ICA-17043 were well tolerated.

Acetamides↗

PubMed2006

Physical therapy alone compared with core decompression and physical therapy for femoral head osteonecrosis in sickle cell disease. Results of a multicenter study at a mean of three years after treatment.

BACKGROUND: Osteonecrosis of the femoral head is a common complication in patients with sickle cell disease, and collapse of the femoral head occurs in 90% of patients within five years after the diagnosis of the osteonecrosis. However, the efficacy of hip core decompression to prevent the progression of osteonecrosis in these patients is still controversial. METHODS: In a prospective multicenter study, we evaluated the safety of hip core decompression and compared the results of decompression and physical therapy with those of physical therapy alone for the treatment of osteonecrosis of the femoral head in patients with sickle cell disease. Forty-six patients (forty-six hips) with sickle cell disease and Steinberg Stage-I, II, or III osteonecrosis of the femoral head were randomized to one of two treatment arms: (1) hip core decompression followed by a physical therapy program or (2) a physical therapy program alone. Eight patients withdrew from the study, leaving thirty-eight who participated. RESULTS: Seventeen patients (seventeen hips) underwent decompression combined with physical therapy, and no intraoperative or immediate postoperative complications occurred. Twenty-one patients (twenty-one hips) were treated with physical therapy alone. After a mean of three years, the hip survival rate was 82% in the group treated with decompression and physical therapy and 86% in the group treated with physical therapy alone. According to a modification of the Harris hip score, the mean clinical improvement was 18.1 points for the patients treated with hip core decompression and physical therapy compared with 15.7 points for those treated with physical therapy alone. With the numbers studied, the differences were not significant. CONCLUSIONS: In this randomized prospective study, physical therapy alone appeared to be as effective as hip core decompression followed by physical therapy in improving hip function and postponing the need for additional surgical intervention at a mean of three years after treatment.

Adult↗

PubMed2005

Changes in the epidemiology of thalassemia in North America: a new minority disease.

OBJECTIVE: Changing patterns of immigration to North America, along with improved treatment, have altered the clinical spectrum of thalassemia, one of the world's most common genetic diseases. The new demography of the disease, with its widely variable phenotypes, has implications for its diagnosis, counseling, and management. Characterization of the new spectrum of this ancient disease, now predominated by minority groups, is essential for optimizing survival. METHODS: The National Institutes of Health-sponsored North American Thalassemia Clinical Research Network (TCRN) conducted a cross-sectional study of 721 patients with thalassemia syndromes. A detailed chart review was undertaken to define the relationships between ethnic origins, genotype, and phenotype. These results were compared with 3 previous surveys of similar regions. To determine if the TCRN patient epidemiology is representative of North American patients, 87 additional programs were reviewed, and hemoglobinopathy programs from the 2 largest thalassemia regions, Ontario and California, were analyzed. RESULTS: A total of 721 patients completed analysis in the TCRN study, including 389 (54%) patients with beta-thalassemia major, 105 (15%) patients with beta-thalassemia intermedia, 95 (13%) patients with hemoglobin E-beta-thalassemia, and 132 (18%) patients with alpha-thalassemia. beta-Thalassemia predominated in Eastern North America. Hemoglobin E-beta-thalassemia and alpha-thalassemia were common on the Western continent. Genotype broadly correlated with the clinical phenotype. However, there was marked heterogeneity in clinical phenotype among patients with similar globin mutations. In beta-thalassemia disorders, coinheritance of the alpha-thalassemia trait, triplication of alpha-thalassemia genes, and heterozygosity for the dominant beta-thalassemia allele affected the clinical phenotype. In alpha-thalassemia disorders, structural mutations such as hemoglobin H-Constant Spring resulted in a severe hemoglobin H phenotype. Sixty percent of patients received regular transfusions, and 86% received regular iron-chelation therapy. Increased survival and decreasing birth rates of Mediterranean patients resulted in an aging Greek/Italian population being replaced by a young Asian/Middle Eastern population. Now, Asian patients account for >50% of the thalassemia population. Evidence of increasing survival is reflected in an advancing mean age of white patients with thalassemia major (25 years, up from 11 years in 1974). The results of the non-TCRN thalassemia survey confirm these observations and describe a young multiethnic thalassemia population distributed throughout North America. Newborn-screening results suggest that thalassemia births in North America are increasing and reflect the change in genotype and phenotype observed in the TCRN populations. CONCLUSIONS: The epidemiology of thalassemia in North America reflects a heterogeneous group of diseases with new ethnicities, genotypes, and phenotypes. In these communities, physicians will need to provide education, prenatal diagnosis, counseling, and management of this newly diverse group of patients.

Adolescent↗

PubMed2005

Dysregulated arginine metabolism, hemolysis-associated pulmonary hypertension, and mortality in sickle cell disease.

CONTEXT: Sickle cell disease is characterized by a state of nitric oxide resistance and limited bioavailability of l-arginine, the substrate for nitric oxide synthesis. We hypothesized that increased arginase activity and dysregulated arginine metabolism contribute to endothelial dysfunction, pulmonary hypertension, and patient outcomes. OBJECTIVE: To explore the role of arginase in sickle cell disease pathogenesis, pulmonary hypertension, and mortality. DESIGN: Plasma amino acid levels, plasma and erythrocyte arginase activities, and pulmonary hypertension status as measured by Doppler echocardiogram were prospectively obtained in outpatients with sickle cell disease. Patients were followed up for survival up to 49 months. SETTING: Urban tertiary care center and community clinics in the United States between February 2001 and March 2005. PARTICIPANTS: Two hundred twenty-eight patients with sickle cell disease, aged 18 to 74 years, and 36 control participants. MAIN OUTCOME MEASURES: Plasma amino acid levels, plasma and erythrocyte arginase activities, diagnosis of pulmonary hypertension, and mortality. RESULTS: Plasma arginase activity was significantly elevated in patients with sickle cell disease, with highest activity found in patients with secondary pulmonary hypertension. Arginase activity correlated with the arginine-ornithine ratio, and lower ratios were associated with greater severity of pulmonary hypertension and with mortality in this population (risk ratio, 2.5; 95% confidence interval [CI], 1.2-5.2; P = .006). Global arginine bioavailability, characterized by the ratio of arginine to ornithine plus citrulline, was also strongly associated with mortality (risk ratio, 3.6; 95% CI, 1.5-8.3; P<.001). Increased plasma arginase activity was correlated with increased intravascular hemolytic rate and, to a lesser extent, with markers of inflammation and soluble adhesion molecule levels. CONCLUSIONS: These data support a novel mechanism of disease in which hemolysis contributes to reduced nitric oxide bioavailability and endothelial dysfunction via release of erythrocyte arginase, which limits arginine bioavailability, and release of erythrocyte hemoglobin, which scavenges nitric oxide. The ratios of arginine to ornithine and arginine to ornithine plus citrulline are independently associated with pulmonary hypertension and increased mortality in patients with sickle cell disease.

Adult↗

PubMed2005

Clinical evaluation of avascular necrosis in patients with sickle cell disease: Children's Hospital Oakland Hip Evaluation Scale--a modification of the Harris Hip Score.

OBJECTIVE: To establish the validity and reliability of the Children's Hospital Oakland Hip Evaluation Scale (CHOHES), a modification of the Harris Hip Score, for the evaluation of avascular necrosis (AVN) in sickle cell disease (SCD). DESIGN: Nonrandomized test-retest. SETTING: Outpatient clinic. PARTICIPANTS: Forty patients with SCD and 3 healthy controls participated. Twenty-six SCD patients (15 males, 11 females; mean age, 25 y) had been diagnosed with AVN. This group was compared with 14 SCD patients without AVN and 3 healthy controls (8 males, 9 females; mean age, 16 y). INTERVENTION: On average, subjects were assessed by 2 physical therapists by using the CHOHES on 3 separate outpatient visits within a 2-week period. MAIN OUTCOME MEASURES: A mixed model with random effects was constructed to compare patient scores on the CHOHES with disease severity as estimated by Ficat staging on plain radiographs. Correlations between and within physical therapists using the CHOHES were calculated to assess intra- and interrater reliability. RESULTS: From the random effects model, the CHOHES mean score was 88 for Ficat stage 0, 75 for Ficat stage I or II, and 61 for Ficat stages III or IV (P < .05). Intrarater reliability estimates for the total CHOHES score were very good (r > or = .87) as were interrater reliability estimates (r > or = .90) between therapists who measured hips with a wide range of CHOHES scores. CONCLUSIONS: The CHOHES appears to be an easy-to-use, valid, and reliable assessment tool and should be considered for use in the routine clinical evaluation of SCD patients with AVN.

Adolescent↗

PubMed2005

Fetal haemoglobin augmentation in E/beta(0) thalassaemia: clinical and haematological outcome.

Patients with E/beta(0) thalassaemia, the most common haemoglobinopathy in many Asian countries, might benefit from drugs that increase fetal and total haemoglobin and thereby decrease the need for transfusions. The long-term clinical efficacy and safety of such therapy is unknown, limiting its use in countries where resources for safe and regular transfusion are scarce. In this study, 45 patients were treated with hydroxyurea (18-20 mg/kg) for 24+/-9 months, hydroxyurea with sodium phenyl butyrate (n=8) and hydroxyurea with erythropoietin (n=9), each for approximately 6 months, and followed for 3 years from study exit. Hydroxyurea had minimal toxicity, resulted in a mean 1.3 g/dl steady-state increase in haemoglobin in 40% of patients, and a milder response (<OR=1 g/dl) in the others. Baseline haemoglobin F was significantly associated with an increase in haemoglobin (P<0.001). Combined treatment with erythropoietin benefited selected patients, but the addition of sodium phenyl butyrate had no effect. Of the 27/45 patients who discontinued regular transfusions before the study, 13 remained transfusion independent during long-term follow-up, 6/13 continued hydroxyurea. Hydroxyurea moderately increased steady-state haemoglobin in a sub-group of E/beta(0) thalassaemia patients and can be considered for patients with intermediate severity disease, thus delaying or avoiding the need for life-long transfusions. Continuous monitoring of toxicity and growth is required.

Adolescent↗

PubMed2005

Changing patterns of thalassemia worldwide.

Thalassemia is a growing global public health problem with an estimated 900,000 births of clinically significant thalassemia disorders expected to occur in the next 20 years. This growth will occur in disorders previously uncommon in many parts of the world. In particular, hemoglobin (Hb) E-beta-thalassemia and Hb H disease account for much of the projected increases in thalassemia. Worldwide, Hb E-beta-thalassemia is one of the most frequent hemoglobinopathies. The incidence of Hb E approaches 60% of the populations in many regions of Southeast Asia. In coastal regions of North America, its prevalence is rapidly growing. The severity of Hb E-beta-thalassemia ranges from a complete lack of symptoms to transfusion dependence. alpha-Thalassemia diseases, often considered benign, are now recognized to be more severe than originally reported. Hb H, Hb H-Constant Spring (CS), and homozygous alpha-thalassemia affect at least a million people worldwide. California considers Hb H disease a public health problem and has initiated a neonatal screening program for Hb H and particularly Hb H-CS. Homozygous alpha-thalassemia, usually fatal, is also being more commonly detected. Several regions have initiated universal prenatal screening programs to address homozygous alpha-thalassemia. In summary, the prognosis for thalassemia disorders is improving, but prenatal diagnosis and neonatal screenings are needed. Comprehensive services that address language and social barriers as well as access to Hb F-enhancing agents and transfusions are needed.

Adolescent↗

PubMed2005

Hemoglobin E-beta-thalassemia: Progress report from the International Study Group.

A long-term observational study of Hb E-beta-thalassemia in Sri Lanka is beginning to define some of the genetic and environmental factors that are responsible for its remarkable phenotypic variability. In this population there is a very small difference between the steady-state hemoglobin levels between the mild and severe phenotypes, and it has been possible to stop transfusion in many of those who have been on long-term treatment of this kind. These preliminary observations, made over the last 7 years, provide directions for future research into this increasingly important disease.

Adolescent↗

PubMed2005

Single and combination drug therapy for fetal hemoglobin augmentation in hemoglobin E-beta 0-thalassemia: Considerations for treatment.

Patients with hemoglobin E (Hb E)-beta 0-thalassemia, one of the most common hemoglobinopathies worldwide, could benefit from drugs that increase fetal and total hemoglobin levels and thereby decrease the need for transfusions. The long-term clinical outcome of such therapy, its hematologic effects, and which patients are likely to benefit from treatment are unknown. Consequently, the use of such drugs for Hb E-beta 0-thalassemia is limited, and countries where resources for safe and regular transfusion are scarce cannot benefit from them. In a multicenter trial of 42 patients treated with hydroxyurea for two years, almost half the patients demonstrated a significant increase in steady-state hemoglobin level. Drug toxicity was minimal. Combined treatment of hydroxyurea with erythropoietin benefited selected patients, but the addition of sodium phenyl butyrate was ineffective. After 5 years of follow-up, a subset of patients remained off transfusions. Hydroxyurea should be considered for a subset of Hb E-beta 0-thalassemia patients.

Blood Transfusion↗

PubMed2005

Treatment of hepatitis C virus infection in thalassemia.

Treatment of hepatitis C virus (HCV) in the general population has improved over the last decade. Patients treated with peginterferon alfa (PegIFN) and ribavirin (RBV) combination therapy demonstrate overall 50-55% sustained viral response (SVR) with rates as high as 80% in patients with genotypes 2 and 3. Because RBV induces hemolysis and subsequently increases blood transfusion requirements, combination therapy has been considered contraindicated for hemoglobinopathies. This report reviews the response to interferon alfa and RBV (IFN/RBV) and PegIFN/RBV combination therapies in patients treated in the Northern California Comprehensive Thalassemia Center. A total of six thalassemia major patients were treated with IFN/RBV (n = 5; age: 4-38 years) or with PegIFN/RBV (n = 1; age: 26 years). Quantitative HCV RNA polymerase chain reaction and liver iron level assessment were completed. Transfusion volumes were obtained from patients' medical records. On IFN/RBV combination, four of five patients demonstrated SVR. The one patient on PegIFN/RBV showed end-treatment viral response after 6 months of therapy (genotype 3), but subsequently relapsed. Liver iron pretreatment level ranged from 0.2 to 22 mg/g dry weight, with a mean +/- SD of 7.9 +/- 7.7. Transfusion requirement increased by a median of 43.5% (range: 32-137%). Five of the six patients had liver iron measurements within 1 year following completion of treatment, with quantitative liver iron increasing in two patients by 2.5 mg/g dry weight, decreasing in two patients by 3 and 14 mg/g dry weight, and remaining unchanged in one patient. All patients were able to complete combination therapy, although dose reductions were required. Patients with thalassemia and high iron overload can obtain SVR after combination therapy with rates similar to those in the general population and without significant complications. Although transfusion requirements increased in most patients, iron burden was not necessarily increased.

Adolescent↗

PubMed2005

Measuring chromosome breaks in patients with thalassemia.

Iron-mediated oxidative stress plays an important role in the pathophysiology of thalassemia. Oxidative stress can cause lesions in DNA, including double-strand breaks. DNA damage, which is a cause of cancer (although not the only one), is recognized as deleterious. Unlike cancer, DNA damage can be assayed easily and relatively inexpensively in humans. In this study, a sensitive micronucleus assay was used to measure the frequency of chromosomal breaks in patients with alpha- and beta-thalassemia. The micronucleus test is based on the observation that a secondary nucleus (micronucleus) is formed around a chromosomal fragment, outside the main nucleus of a dividing cell. Micronuclei are readily apparent in red blood cells (RBCs), which otherwise lack DNA. We combined an immunomagnetic separation technique with single-laser flow cytometry to isolate and analyze reticulocytes in peripheral blood for the presence of micronuclei before these cells are removed by the spleen. Blood samples were obtained from patients with thalassemia and healthy volunteers. After immunomagnetic enrichment of CD71-positive reticulocytes, the cells were stained for micronuclei using the DNA dye 7-aminoactinomycin D (7-AAD) and evaluated by flow cytometry. Our findings indicate that higher levels of micronuclei frequencies are present in thalassemic RBCs.

Cell Separation↗

PubMed2005

Hemolysis-associated pulmonary hypertension in thalassemia.

Accumulating evidence supports the existence of a condition involving hemolysis-associated pulmonary hypertension (PHT). Hemolysis-induced release of cell-free hemoglobin and red blood cell arginase, resulting in impaired nitric oxide bioavailability, endothelial dysfunction, and PHT, has been reported in sickle cell disease. Since thalassemia is also a condition of chronic hemolysis, these patients are at risk. The data demonstrate that hemolysis-induced dysregulation of arginine metabolism and PHT also occurs in thalassemia. Erythrocyte release of arginase during hemolysis contributes to the development of PHT. Therapies that maximize arginine and nitric oxide bioavailability may benefit patients with thalassemia.

Arginase↗

PubMed2005

Quality of life in patients with thalassemia intermedia compared to thalassemia major.

The impact of thalassemia major and thalassemia intermedia and their associated complications on quality of life (QOL) is largely unknown. Determining the degree of health impairment as perceived by the patient is essential information needed to recommend suitable therapy. The objective of this study was to evaluate QOL in transfusion-independent patients with thalassemia (non-Tx) compared with that in transfused patients (Tx) and to identify the factors that affect QOL in thalassemia. A convenient sample of 48 thalassemia patients (29 Tx and 19 non-Tx) with mean age of 14.6 years (SD = 7.5 years) were selected during a comprehensive visit to complete a Dartmouth Primary Care Cooperative Information Chart System (COOP) questionnaire. Patients rated QOL from excellent (1) to poor (5) on five dimensions of health status. Scores of 4 or 5 represent major limitations. These results were augmented by a brief medical history and chart review. Forty-one percent of Tx patients and 47% of non-Tx patients reported severe impairments in 1-6 and 1-2 domains, respectively. The most commonly reported affected domains were feelings such as anxiety, depression, and concern of overall health status or indications of recent deterioration in health. In contrast with previous beliefs, transfusion-independent thalassemia patients also suffer serious impairment in QOL. Presented data suggest that all patients with thalassemia undergo QOL assessment so that interventions focused on affected domains can be implemented.

Activities of Daily Living↗

PubMed2005

Outcomes of preimplantation genetic diagnosis therapy in treatment of beta-thalassemia: A retrospective analysis.

Thalassemia is one of the most common single-gene disorders that can be cured by hematopoietic stem cell transplantation (HCT) from a human leukocyte antigen (HLA)-identical sibling donor. In families that have an affected child, preimplantation genetic diagnosis (PGD) can be used to select an unaffected, HLA-identical embryo. In brief, this procedure requires in vitro fertilization, oocyte retrieval, fertilization, and blastomere biopsy for identification of unaffected HLA-identical embryos. After delivery, umbilical cord blood from the sibling donor is collected for HCT. The objective of this study was to determine the outcomes of families using PGD therapy for cure of beta-thalassemia and to review the limitations of PGD therapy. Families affected with beta-thalassemia who attempted PGD therapy were retrospectively identified and reviewed for indication, attempted cycles, successful pregnancy, and transplantation outcomes. Eight identified families affected by thalassemia underwent PGD. The diagnosis of their affected children included six cases of beta-thalassemia major and two cases of transfusion-dependent hemoglobin E-beta-thalassemia patients. A total of 14 cycles of PGD were attempted, ranging from one to four attempts per family. Following successful identification of HLA-identical cells, two pregnancies occurred, of which one resulted in engraftment of a beta-thalassemia child. PGD therapy offers the possibility of recruiting a suitable donor for HCT, yet is limited by financial cost due to labor-intensive techniques, low probability of obtaining an HLA-matched unaffected embryo, variable implantation capacity, and significant emotional impact. Improvements in PGD therapy's efficacy and cost will make this a more viable option for affected families.

Blastomeres↗

PubMed2005

Utility of Holter electrocardiogram in iron-overloaded hemoglobinopathies.

Cardiac arrhythmias are among the leading causes of morbidity and mortality of transfusion-dependent, iron-overloaded beta-thalassemia patients. Routine screening with Holter electrocardiogram has been recommended; however, infrequent electrocardiographic changes limit its clinical usefulness. The purpose of this study was to determine the diagnostic yield of Holter electrocardiogram monitoring and its correlation with patient symptoms and disease status. A retrospective analysis was performed on 27 transfusion-dependent thalassemia patients who underwent cardiac questionnaire and Holter screening yearly, in addition to echocardiogram and quantitative iron-level determination. Four patients had clinically significant arrhythmias detected on Holter screening, while 2 patients developed severe cardiac complications secondary to arrhythmias within 1 year of follow-up of normal Holter screening. Early detection of cardiac events among transfusion-dependent thalassemia patients with Holter electrocardiography is not clinically effective. Other screening modalities, including the transtelephonic event recorder, should be evaluated in arrhythmia surveillance.

Adolescent↗