Biomedical subjects

Michael R Jeng

Publications and source records attributed to Michael R Jeng.

9 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↗

PubMed2005

Granulocyte-macrophage colony stimulating factor and immunosuppression in the treatment of pediatric acquired severe aplastic anemia.

BACKGROUND: Immunosuppressive therapy (IS) is effective in the treatment of patients with acquired severe aplastic anemia (SAA). An enhanced myeloid response and decreased infection risk may be possible with the addition of a hematopoietic cytokine. Published data on the combination of cytokines and IS in patients with SAA are limited. The addition of G-CSF to IS shortens the time to neutrophil count recovery, but may not improve overall survival. Because GM-CSF acts differently than G-CSF, its use in combination with IS may be different. PROCEDURE: A retrospective chart review was performed on patients diagnosed with SAA and treated with IS and GM-CSF at St. Jude Children's Research Hospital. Hematologic recovery, prognostic factors, and infection data were collected. RESULTS: Eighteen patients were included in this study. The median age at diagnosis was 7.2 years (range 1.8-17.0). Ten patients (56%) had a complete response, four (22%) a partial response, and four (22%) no response. Median time to erythrocyte and platelet transfusion independence were 90 (18,243) and 64 days (18-243), and to discontinuation of treatment 287 days (90-730). Median time to partial (ANC > 500) and full (ANC > 1,500) neutrophil recovery were 41 and 51 days, respectively. Seventeen documented discrete infections occurred in six patients over 36 patient years. CONCLUSIONS: GM-CSF, in addition to IS, may shorten time to neutrophil count recovery, may be beneficial in decreasing infection rates, and may improve platelet response in patients with SAA. However, consistent with studies utilizing G-CSF, GM-CSF probably does not affect overall response rate. To fully answer whether or not cytokine therapy is of added value to IS in pediatric patients, a multi-institutional randomized trial is needed.

Adolescent↗

PubMed2004

Natural history of moderate aplastic anemia in children.

BACKGROUND: Moderate aplastic anemia (MAA) in children is a rare, idiopathic condition of bone marrow insufficiency that can resolve spontaneously, persist for months or years, or progress to severe aplastic anemia (SAA). We evaluated the rate of progression to SAA. METHODS: We reviewed the records of 136 children referred for evaluation of bone marrow failure from 1978 to 2002 at St. Jude Children's Research Hospital. MAA was defined by a hypocellular bone marrow (<50%) and 2 or 3 cytopenias (absolute neutrophil count <1,500/mm(3), absolute reticulocyte count <40,000/mm(3), platelet count <100,000/mm(3)) lasting at least 6 weeks. RESULTS: Twenty-four patients met the criteria for MAA. At a median follow-up of 66 months (range, 10-293), 16 patients (67%) progressed to SAA, 5 (21%) had persistent MAA, and 3 (12%) had complete resolution of MAA. No risk factors for progression could be identified. CONCLUSIONS: When childhood MAA is treated with supportive care alone, 2/3 of patients progress to SAA.

Adolescent↗

PubMed2004

Hematologic problems in immigrants from Southeast Asia.

An increasing number of Southeast Asian immigrants have come to North America. Physicians who care for this population should be aware of the high prevalence of hematologic disorders and develop an approach to their diagnosis and management. Malaria and the hematologic sequelae, glucose-6-phophate dehydrogenase deficiency, the thalassemia syndromes, Southeast Asian ovalocytosis, visceral leishmaniasis, HIV infection, and iron-deficiency anemia, all of which may pertain to these patients, are reviewed in this article.

Asia, Southeastern↗

PubMed2003

Identification of hemochromatosis gene polymorphisms in chronically transfused patients with sickle cell disease.

Three polymorphic gene mutations in the human hemochromatosis (HFE) gene (C282Y, H63D, S65C) are associated with non-transfusion-related iron overload in Caucasians. More recently, these mutations have also been identified in African-Americans. However, the prevalence of HFE gene mutations in African-Americans with sickle cell disease (SCD) has not been described. The presence of these mutations in this population is particularly important, because patients with SCD may be placed on chronic red cell transfusion therapy and are thus at further risk for iron overload. Thus, we attempted to establish the gene mutation prevalence in African-Americans with SCD, to compare this frequency with published gene frequencies in African-Americans, and to evaluate their significance with regard to transfusion-related iron overload. Eighty-nine African-American patients with SCD, all of whom were receiving chronic red cell transfusion therapy, were screened by DNA analysis for the three HFE gene mutations. Two patients were heterozygous for the C282Y HFE mutation (2.3%), six were heterozygous for the H63D mutation (6.8%), none carried the S65C mutation (0.0%), and no homozygous or compound heterozygous subjects were identified. The prevalence of C282Y and H63D in the SCD population was similar to that observed in the general African-American population. In addition, there was no increased mutation prevalence when comparing those SCD patients on chronic transfusion therapy who had ferritin levels greater than 2,500 ng/mL and those less than 2,500 ng/mL. This study represents the first identification of the known HFE gene mutations by DNA analysis in the SCD population. We conclude that the presence of recognized HFE coding region mutations do not seem to have an impact on the degree of iron overload in patients with SCD receiving chronic transfusion therapy.

Adolescent↗

PubMed2003

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.

Adolescent↗

PubMed2002

Central venous catheter complications in sickle cell disease.

A review of patients with sickle cell disease (SCD) and central venous catheters (CVCs) was performed to evaluate the frequency of catheter complications (infections, thrombotic events, and premature CVC removal. Fifteen evaluable patients were identified during our review of a 7.5-year period. The median age was 18 years (range, 1.5-30 years); 14 were African American, and 1 was Latino; 5 were male, and 10 were female. Forty-one CVCs were placed (36 Mediport and 5 Broviac catheters) for a total of 12,120 CVC days. We observed a median of 2 CVCs per patient (range, 1-8 CVCs per patient) with 67 discrete episodes of CVC-associated infection (range, 0-18 per patient) involving 10 patients. The rate of CVC-associated infection for patients with SCD at our institution was 5.5 infections per 1,000 CVC days; this rate was significantly higher than the rate of CVC-associated infection in our patients with cancer (P < 0.001). We also determined that the rate of CVC-associated thrombosis was 0.99 events per 1,000 CVC days and involved 33% of the patients with SCD; the rate of premature CVC removal was 3.15 per 1,000 CVC days, and 78% of CVCs were removed prematurely. We conclude that patients with SCD are at high risk for CVC-related complications, and improved care and close monitoring of CVCs should be encouraged to decrease morbidity in these chronically ill patients.

Adolescent↗

PubMed2002

Pseudotumor cerebri in two adolescents with acquired aplastic anemia.

A 13-year-old boy and a 16-year-old girl both presented with headaches and nausea after they were diagnosed with severe acquired aplastic anemia. Both patients had symptoms and signs consistent with the clinical syndrome of pseudotumor cerebri including headaches, nausea, papilledema, and elevated intracranial pressure. Both patients were treated with therapeutic lumbar puncture and acetazolamide, which relieved their symptoms. Acetazolamide dosage was given while the patients underwent an immunosuppressive regimen. We hypothesize that the pseudotumor cerebri in these two pediatric patients was the result of an increased production of cerebrospinal fluid in response to anemia and that the removal of fluid and treatment with acetazolamide appear to be helpful in such cases.

Acetazolamide↗

PubMedDate not supplied

Darbepoetin alfa and ferric gluconate ameliorate the anemia associated with recessive dystrophic epidermolysis bullosa.

Our objective was to describe the efficacy of darbepoetin alfa and ferric gluconate complex in the treatment of the anemia associated with recessive dystrophic epidermolysis bullosa. To accomplish this aim, we retrospectively reviewed a series of patients with this disease treated in a single institution with darbepoetin alfa and parenteral iron for anemia. Four patients with recessive dystrophic epidermolysis bullosa were treated for a mean length of treatment of 14.5 months (4-18 months). Three patients received parenteral iron in the form of ferric gluconate complex and one received iron dextran. The mean pretreatment hemoglobin was 6.8 g/dL (4.9-9.6 g/dL). All four had improvements in their hemoglobin levels and energy levels with a mean increase in hemoglobin level of 2.8 g/dL (p = 0.003). We found darbepoetin alfa and ferric gluconate complex to be effective in the treatment of anemia associated with recessive dystrophic epidermolysis bullosa and to have distinct advantages over previously described formulations, and we concluded that they should be considered in the supportive care of this disease. We recommend the development of a standardized protocol for the evaluation and management of recessive dystrophic epidermolysis bullosa-associated anemia.

Adolescent↗