Arporn Sriphrapradang

Bone mineral density, biochemical and hormonal profiles in suboptimally treated children and adolescents with β‐thalassaemia disease

objective Thalassaemia/haemoglobinopathy is a hereditary disease causing increased erythropoiesis and expansion of the bone marrow cavity. As a consequence, there is a reduction in trabecular bone tissue resulting in osteopenia/osteoporosis. The present study was performed to assess bone mineral density (BMD) in children and adolescents with β‐thalassaemia disease and to determine biochemical and hormonal changes that may affect BMD.

Association between bone mineral density and erythropoiesis in Thai children and adolescents with thalassemia syndromes

Increased marrow erythropoiesis in patients with thalassemia syndromes results in the expansion of bone marrow cavities and consequently decreases bone tissues, leading to osteoporosis. Whether the soluble transferrin receptor (sTfR), a marker of erythropoietic activity, correlates with the bone mineral density (BMD) in thalassemic patients has not previously been addressed. Forty-six children and adolescents with thalassemia syndromes, who were either not transfused or suboptimally transfused, were studied. BMD was determined by dual-energy X-ray absorptiometry. Blood samples were obtained in order to determine sTfR and hemoglobin. The patients were categorized into four groups: 1, β-thalassemia/hemoglobin E (β-thal/E) with transfusion-dependency (TD) (n = 18); 2, β-thal/E with transfusion-independency (TI) (n = 15); 3, β-thalassemia major (β-major) (n = 6); 4, hemoglobin H (HbH) (n = 7). All patients had normal serum free thyroxine (FT4) and thyroid-stimulating hormone (TSH), and intact parathyroid hormone (PTH), serum calcium (Ca), phosphate (P), and 25-OH-vitamin D levels. The BMD of patients in the β-major and β-thal/E with TD groups were not significantly different. In comparison with the β-major and β-thal/E with TD groups, the β-thal/E with TI and HbH groups had significantly higher BMD of the total body (TB), femoral neck (FN), and lumbar spine (LS), as well as higher levels of hemoglobin. In contrast, the sTfR levels of the β-major, β-thal/E with TI, and HbH groups were significantly lower than those of the β-thal/E with TD group. The BMD of TB, FN, and LS was negatively correlated with the sTfR level, but positively correlated with the hemoglobin level. In conclusion, increased marrow erythropoiesis is one of the major determinants of reduced bone mass in thalassemic patients with either no transfusion or suboptimal transfusion.

Electrophysiological and immunological study in myasthenia gravis: Diagnostic sensitivity and correlation

OBJECTIVE To determine the diagnostic sensitivity of repetitive nerve stimulation (RNS), single fiber electromyography (SFEMG) and acetylcholine receptor antibody (AChRAb) in myasthenia gravis (MG), and to compare the degree of SFEMG abnormality between ocular and generalized MG and between seronegative and seropositive patients. METHODS The sensitivities of RNS, SFEMG and AChRAb were estimated. SFEMG abnormality was compared between ocular and generalized MG and between seronegative and seropositive patients. RESULTS Abnormal RNS, abnormal SFEMG and AChRAb were detected in 62%, 93% and 38% of 42 ocular, and 80%, 99% and 73% of 70 generalized cases, respectively. The degree of SFEMG abnormality was significantly greater in the generalized than ocular patients and was significantly greater in the seropositive than seronegative patients in both extensor digitorum communis and orbicularis oculi muscles. CONCLUSION SFEMG is a very sensitive and useful test for MG. A correlation between SFEMG abnormality and clinical phenotype or severity and between SFEMG abnormality and AChRAb seropositivity was demonstrated. SIGNIFICANCE The sensitivities of RNS, SFEMG and AChRAb in the diagnosis of MG were documented. The differences in severity between the ocular and generalized MG and between the seronegative and seropositive MG were confirmed and quantitatively determined by SFEMG.

Short-term cyproheptadine therapy in underweight children: effects on growth and serum insulin-like growth factor-I.

BACKGROUND Cyproheptadine, an appetite stimulant, has been used in poor-appetite underweight children. Its beneficial effects on enhancing growth rate have been demonstrated. In contrast, an adverse effect on blunting growth hormone (GH) secretion has also been reported. To date, however, its effect on insulinlike growth factor-I (IGF-I), a GH-mediated growth factor, has not been documented. AIM To examine the effect of cyproheptadine therapy on growth and serum IGF-I in underweight children. METHODS Twenty-one underweight, otherwise healthy children were recruited. They were randomly assigned into cyproheptadine administration (n = 10) and placebo (n = 11) groups. The former received cyproheptadine for 4 months. Serum IGF-I levels were measured in both groups. RESULTS Weight and height velocities and IGF-I z-scores during cyproheptadine therapy were significantly greater in the intervention group than those of the placebo group. CONCLUSION Cyproheptadine therapy in underweight children increased caloric intake and serum IGF-I concentration and consequently enhanced growth velocity.

Bone mineral density in children and young adults with beta-thalassemia trait.

BACKGROUND Homozygous beta-thalassemia is a hereditary hematological disease due to defective beta-globin synthesis. Consequently, there is ineffective erythropoiesis and increased peripheral hemolysis. Increased erythropoiesis in bone marrow results in expansion of marrow cavity and reduced bone mass. Patients with heterozygous beta-thalassemia or beta-thalassemia trait may have mild anemia, and consequently mildly increased erythropoiesis. Whether modestly increased erythropoiesis might decrease bone mass is not well established. OBJECTIVE To evaluate bone mineral density (BMD) in children and young adults with beta-thalassemia trait. METHODS Thirty-one healthy young adults aged 20-45 yr and 26 healthy children aged 8-15 yr with beta-thalassemia trait were enrolled in the study. BMD was determined by dual X-ray absorptiometry (DEXA). Determinations of intact parathormone (PTH), 25-hydroxyvitamin D (25-OHD), and bone markers were performed. RESULTS In adults, all had z-scores of BMD more than -2 above the mean. The mean z-scores of BMD of lumbar spine, radius and femoral neck were 0.11, -0.10 and 0.41, respectively. In children, only two of 26 had z-scores of lumbar spine BMD more than -2 below the mean. The mean z-scores of BMD of total body, lumbar spine, radius and femoral neck were 0.12, -0.28, 0.30 and -0.14, respectively. All subjects had normal PTH, 25-OHD and bone markers levels. CONCLUSION beta-Thalassemia trait is not a contributing factor for osteopenia/osteoporosis in children and young adults.

Final Height after Long-Term Growth Hormone Treatment in Thai Children with Turner Syndrome

This article is also accessible online at: http://BioMedNet.com/karger We presented 12 Thai girls with Turner syndrome treated with recombinant human growth hormone (rhGH) in an effort to augment the rate of growth and improve final height. The girls ranged in age from 6.1 to 14.8 years. The range of their bone ages was from 4.1 to 10 years. All were prepubertal at the time of study. The standard deviations (SD) in their heights and weights, as based upon normal Thai standards, were –3.72 B 1.88 and –1.39 B 2.89 (mean B SD) respectively. The mean pretreatment height velocity (HV) was 2.83 B 0.56 (mean B SD) cm/year (table 1). The girls were treated for a period of 1–5 years with rhGH. The dosage of 0.1–0.125 IU/kg/day was administered by daily subcutaneous injection. The mean HV increased significantly over the treatment period, to 8.78 B 1.49 cm/year in the first year of treatment, 6.57 B 1.69 cm/year in the second year, and 5.38 B 2.03 cm/year in the third year. In addition, the mean height SDS and weight SDS increased to –2.59 B 1.54 and –0.88 B 2.50 respectively. Six patients reached final adult height. This final height ranged from 136.8 to 147.9 cm with mean B SD of 142.4 B 5.03 cm which is significantly improved in comparison with 136.2 B 1.47 cm in that of untreated Turner syndrome in the Thai population. All patients had normal glycosylated hemoglobin and normal thyroid function tests before and during treatTable 1. Chromosome karyotypes

P34-18 Electrophysiological and immunological tests in myasthenia gravis: Their diagnostic sensitivities and correlation

Objectives: To describe the clinical features of patients with myasthenia gravis (MG) in a Malaysian population. Methods: A retrospective study of patients with MG presenting to University Malaya Medical Centre (UMMC), Kuala Lumpur was performed. Following review of patients medical records, we describe the demographics, MG classification, treatment response and the presence of other autoimmune diseases in this group of patients. Results: 92 patients were identified. Of this, 60% were female; 59% Chinese, 24% Malays and 17% Indians. The mean age of onset was 50.17 years old (male 52.75 years and female 48.25 years). There were 2 age peaks seen: 20 29 years (predominantly females) and 50 59 years (predominantly males). 40% had ocular MG and 53% generalized MG. In 52 patients, the presence of acetylcholine receptor antibodies was assessed and found positive in 71%. 13% of patients had an associated autoimmune disease. Thymectomy was done in 30 patients and thymic histology showed thymoma in 40% and thymic hyperplasia in 20% Conclusions: In our patient population, the clinical features of MG were similar to that of the Western population in terms of gender and age distribution. However, there appears to be a higher proportion of ocular MG and also a higher incidence of MG in the Chinese population.

P01.4 Electrophysiological and immunological studies in patients with myasthenia gravis

Background: Many patients with MuSK antibody positive MG (MMG) have weakness and atrophy of facial and oropharyngeal muscles. Dysphagia is a common symptom in these patients but the results of esophageal motility studies have not been reported. Objective: To report a patient with MMG with esophageal adynamia. Case report: This woman had onset of fluctuating dysarthria at age 26. Two years later she had transient double vision. At age 46, after onset of facial weakness and recurrent diplopia, she sought evaluation for these symptoms. Examination demonstrated slurred, nasal speech; minimal diplopia on extreme lateral gaze; marked weakness of eyelid closure and lower facial function; and marked frontalis muscle atrophy. Edrophonium produced no improvement. Repetitive nerve stimulation studies were normal in the hypothenar and trapezius muscles but there was a decrementing response in the nasalis. Jitter was normal in the forearm but markedly increased in the orbicularis oris. AChR-abs were not elevated. Pyridostigmine made her symptoms worse and produced profuse fasciculations in facial and limb muscles. Plasma exchange produced immediate and dramatic improvement, which persisted after treatment with prednisone. Thymectomy was performed, with removal of an enlarged gland, containing 15% lymphoid tissue and 85% fibro-adipose tissue. Low dose prednisone was continued, with persistent mild facial weakness and dysarthria. At age 57, she began having recurrent episodes of bronchitis and MuSK antibodies were found. Manometric studies of esophageal function demonstrated absence of active muscle contraction of the upper esophagus. Discussion: Dysphagia is a common symptom in MG and abnormal cricopharyngeal muscle function has been reported in MG patients with this symptom. Adynamia of upper esophageal function, as in this patient, has not previously been reported in MG and may be another manifestation of the severe oropharyngeal weakness seen in many MMG patients.