Clinical and hematological phenotype of homozygous hemoglobin E: revisit of a benign condition with hidden reproductive risk.

Hemoglobin E (HbE) is one of the most prevalent beta-globin variant, which is widely distributed in Southeast Asia especially in Thailand. Homozygosity for this variant is common and may occur with iron deficiency. In order to study clinical and hematological phenotypes without the confounding effect of iron deficiency, investigations were carried out before and after iron supplementation for 2 months. The effect of G6PD deficiency and coinheritance of alpha-thalassemia in homozygous HbE were also studied. HbE homozygotes were clinically benign, never had been transfused and had no hepatosplenomegaly. Out of 76 HbE homozygotes, hematological parameters of 7 individuals with iron deficiency improved after iron supplementation. Hemoglobin analysis revealed that HbE was the main hemoglobin detected, but 12 subjects were found to have a substantial percentage of HbF, which might lead to misdiagnosis as HbE/beta-thalassemia. Both clinical and hematological phenotypes of simple homozygous HbE did not differ from those who also inherited alpha-thalassemia and/or G6PD deficiency. It is necessary to perform a comprehensive DNA analysis for alpha-thalassemia in cases of homozygous HbE when their partner is suspected of having alpha-thalassemia 1 gene.

Development of a comprehensive red blood cell enzymopathy laboratory in Thailand: the study of normal activity in eight erythroenzymes in Thais.

In order to provide a reference range for normal red blood cell enzyme activities in Thai, we analyzed data from 113 healthy non-anemic Thai people (55 males and 58 females) age 1-42 years, who all had a normal pattern of hemoglobin typing (HbA and HbA2 less than 3.5%). Hematological analysis was performed using an automated cell counter and the hemoglobin studies were carried out by low pressure liquid chromatography. Owing to a high frequency of alpha-thalassemia in Thailand, cases with an MCV < 75 fl were excluded from the study since these cases were likely to be heterozygotes for alpha0-thalassemia. Cases with reticulocytes > 2.5% were excluded from the study since reticulocytes have a higher enzyme activity than mature erythrocytes. Cases with abnormal red blood cell morphology, such as spherocytes and ovalocytes, were also excluded. These criteria were applied to select "normal" controls for our analysis. We assayed eight red blood cell enzyme activities in normal subjects: glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), pyruvate kinase (PK), hexokinase (HK), glucose phosphate isomerase (GPI), phosphofructokinase (PFK), aldolase (ALD) and phosphoglycerate kinase (PGK). The mean normal ranges (+/- SD) for G6PD, 6PGD, PK, HK, GPI, PFK, ALD and PGK were 12.7 (+/-2.2), 10.7 (+/-1.3), 18.5 (+/-4.0), 1.5 (+/-0.4), 80.5 (+/-11.8), 11.8 (+/-2.1), 4.5 (+/-1.6) and 370 (+/-43) IU/gHb, respectively. Age-dependent differences for the reference values for these enzyme activities were summarized. All red blood cell enzyme activities were highest during the early childhood period and slightly lower in the adult period. These values will be of clinically useful for future reference.

Validation of osmotic fragility test and dichlorophenol indophenol precipitation test for screening of thalassemia and Hb E.

The strategy for screening of thalassemia and Hb E by a combination of osmotic fragility (OF) test and dichlorophenol indophenol precipitation (DCIP) test was validated with 436 unrelated Thai subjects. Hemoglobin (Hb) typing, Hb A2 quantitation, PCR and DNA sequence analysis were used as confirmatory methods for diagnosis of thalassemia and hemoglobinopathy. The sensitivity and specificity of this strategy was 100% and 79.7%, respectively. The results assessed by two medical scientists were exactly the same with 93.3% accuracy in comparison with the confirmatory methods. A combination of OF and DCIP has been shown to be a reliable, rapid, simple and sensitive strategy for screening thalassemia and Hb E in the Thai population.

The validation of an automated liquid chromatography system for the diagnosis of thalassemias and hemoglobinopathies.

Accurate and precise hemoglobin separation and the quantitation of Hb A2 and Hb F are essential for the diagnosis of the thalassemias and hemoglobinopathies. Presented in this study is the validation of the the Hb A2 assay of the HbGold analyzer, a fully automated liquid chromatography system for hemoglobin separation and quantitation. Variability of Hb A2 quantitation was quite low; the CV's of within-run, between-run and interlaboratory studies were 1.8-3.1%, 3.4-6.0% and 6.8-8.8% respectively. The results of the %Hb A2 quantitated by HbGold analyzer correlated well with those given by the Bio-Rad Variant Hb testing system (r=0.98). The application of the HbGold analyzer for the diagnosis of the thalassemia phenotypes frequently observed in Thailand is considered. In conclusion, the Hb A2 assay of the HbGold analyzer could be used for the quantitation of Hb A2 and Hb F and the presumptive identification of abnormal hemoglobins.

Malignancies in HIV-infected children at Siriraj Hospital.

BACKGROUND: Some malignancies such as Kaposi's sarcoma, non-Hodgkin's lymphoma (NHL) are one of the acquired immunodeficiency syndrome (AIDS)-defining illnesses. With the improving survival of patients with AIDS due to better prevention and treatment of infectious complications, there may well be an increase in AIDS-related malignancies. OBJECTIVE: To study malignancies in human immunodeficiency virus (HIV)-infected children in view of demographic data, HIV disease status, characters of malignancies, and treatment outcome. METHOD: Retrospective study was performed in HIV-infected children with malignancies at Siriraj Hospital from January 1995 to October 2001. RESULTS: During the 6 year and 10 month period, there were 7 HIV-infected children (2 boys, 5 girls) with malignancies. Mean age at diagnosis of malignancies was 3 years 7 months (2 years 6 months-5 years). Hepatomegaly and lymphadenopathy were the most common presenting symptoms. All patients had NHL stage III or IV. Burkitt's lymphoma was the predominant type. Six patients were treated with appropriate chemotherapy and one patient also received antiretroviral therapy. Only one patient with large cell lymphoma stage IV who received both antiretroviral and chemotherapy has survived to date. Five patients died during chemotherapy treatment and one patient died before receiving chemotherapy. Causes of death of these patients were infections. One of them with Burkitt's lymphoma stage III also had central nervous system (CNS) relapse at the time of death. Mean survival time after diagnosis with malignancies was 11 months (15 days-3 years 1 month). CONCLUSION: NHL is the most common malignancy in HIV-infected children at Siriraj Hospital. Age at presentation of NHL in these children is younger than their non-HIV counterpart. Outcome of treatment is poor. Adjustment protocol for treatment of malignancy in HIV-infected children combined with antiretroviral therapy for controlling HIV infection should be studied further.

Effect of red blood cell glucose-6-phosphate dehydrogenase deficiency on patients with dengue hemorrhagic fever.

Eighty nine males aged 1-13 years diagnosed with dengue haemorrhagic fever (DHF) and admitted to the Department of Pediatrics Siriraj Hospital from March 1998 to April 2000 were included in this study. 17 cases (19.1%) had red blood cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and 72 cases (80.9%) had normal G-6-PD enzyme activities. Most of the patients were classified as DHF grade II in severity. 3 of 17 G-6-PD deficient cases had serious complications and all of them had acute intravascular hemolysis requiring blood transfusions. One of these also had hematemesis, one had azothemia and the other one had renal failure and severe liver failure with hepatic encephalopathy. In the cases without obvious hemolytic or hepatic complications, G-6-PD deficient cases had mildly but significantly higher total birirubin and indirect bilirubin, as well as a lower hematocrit than those who had normal G-6-PD. Reticulocyte count was low during the acute phase, however, during recovery, the levels were significantly increased in both groups. In the non G-6-PD deficient group, G-6-PD enzyme levels were significantly decreased during the acute phase compared to the normal controls but rose significantly to normal levels during the recovery phase. There were no statistically significant differences in other laboratory data. All patients recovered fully from DHF. The prevalence of G-6-PD deficiency in male patients who had DHF in this study was 19.1 per cent which was higher than the prevalence in a previous study of 12 per cent in Bangkok. This may imply that G-6-PD deficient males suffer more from DHF compared to normal G-6-PD subjects.

Allele related mutation specific-polymerase chain reaction for rapid diagnosis of Hb New York (beta 113 (G15) Val-->Glu, beta(CD113 GTG-->GAG)).

Hemoglobin New York (beta 113 (G15) Val-->Glu), a beta-globin variant, was first reported in a Chinese family living in New York. Subsequently, this abnormal hemoglobin was reported in many Chinese descendants from several groups and it was also known as Hb Kaohsiung. The subtle change in alpha1beta1 contact region apart from the heme group connecting area by Val-->Glu substitution has minor changes in both the electrophoretic mobility and stability making this hemoglobin variant difficult to distinguish from Hb A using routine hemoglobin analysis. The authors described a case of heterozygosity of Hb New York diagnosed by a molecular technique and revealed a mutation in beta(CD113 GTG-->GAG). A novel Allele Related Mutation Specific-Polymerase Chain Reaction (ARMS-PCR) for rapid diagnosis of this mutation has been proposed.

Early detection of cardiac involvement in beta-thalassemia children.

BACKGROUND: Beta-thalassemia major and beta-thalassemia/HbE are the important causes of chronic hemolytic anemia in Thailand. The objectives of the study were to determine variables associated with cardiac involvement in asymptomatic beta-thalassemia patients. PATIENTS AND METHOD: The authors studied beta-thalassemia major and beta-thalassemia/HbE patients who came to the clinic between July 1st 1999 and July 31st 2000. There were 211 asymptomatic patients included in study. Their ages ranged from 2.6 to 18.2 years. Previous clinical history including blood transfusion and iron chelation were recorded. All patients received a thorough physical examination, chest X-ray, electrocardiogram and echocardiogram. Patients who had abnormal systolic or diastolic function detected by echocardiogram were identified as having cardiac involvement. RESULTS: Cardiac involvement was found in 26 patients (12.3%). There was no difference in physical examination between patients who had and did not have cardiac involvement. Abnormal chest X-Ray defined as cardiothoracic (CT) ratio>0.55 and electrocardiogram (ECG) findings of left or right ventricular hypertrophy were associated with cardiac involvement. Other associated findings were older age and lower average pretransfusion hematocrit (23 +/- 6.6%). CONCLUSIONS: In asymptomatic beta-thalassemia children, chest X-ray and ECG should be used for screening patients for the detection of cardiac involvement.

Secondary hemophagocytic lymphohistiocytosis in children: an analysis of etiology and outcome.

Fifty-two pediatric patients were diagnosed with secondary hemophagocytic lymphohistiocytosis (HLH) at the Department of Pediatrics, Siriraj Hospital between 1989 and 1998. Of these, 15 were infection-associated (IAHS), 25 were malignancy-associated (MAHS) and 12 were idiopathic HLH. Causative organisms for IAHS were Salmonella (3), Staphylococcus (2), enterobactor (2), dengue virus (3), malaria (2) and one each of Ebstein Barr virus (EBV), Serratia marcesens and Penicillium maneffei. Unlike those reported in adults and in the Western literature, 47 of 52 children in the present series were immunocompetent hosts. In addition, the proportion of MAHS was higher than expected (48.1%). Twenty-two of 25 MAHS presented with hemophagocytic syndrome and were subsequently found to have malignant diseases. Sixty per cent of MAHS (15 cases) were associated with non-Hodgkin's lymphoma (NHL), mainly T-cell. Other malignancies included acute leukemias (7) MDS (1), Langerhans cell histiocytosis (1) and histiocytic sarcoma (1). Treatment approaches were specific therapy for individuals with known causes. Supportive treatment with blood components transfusions, steroid, intravenous immunoglobulins (IVIG), and chemotherapeutic agents, mainly vinblastine and etoposides, were used in indicated cases. Of the 52 cases, 15 (28.8%) had a fatal outcome during the acute phase, and other 4 died of their subsequent malignant diseases. There was a statistically significant association between poorer prognosis and patients' age < 3 years (p= 0.004) or MAHS (p=0.005). Conclusion: Secondary HLH is not uncommon in Thai children who are immunocompetent. Malignancies, particulary NHL, are highly suspicious especially for cases not responsive to conventional therapy. Poor prognostic factors are age less than 3 years and MAHS.

Thrombotic complications during induction chemotherapy of acute childhood lymphoblastic leukemia.

The incidence of thrombosis during induction chemotherapy of acute childhood lymphoblastic leukemia (ALL) patients was 6 found to be in 105 (5.7%). There were 4 cerebral infarctions, 1 superior vena cava (SVC) obstruction and 1 deep vein thrombosis. Among these, 2 of them died. A prospective study was further conducted of the change in coagulation and anticoagulation factors during 6 weeks of induction chemotherapy. It was found that the activated partial thromboplastin time (aPTT) was within normal range in all cases throughout 6 weeks, while prothrombin time (PT) and thrombin time (TT) were slightly prolonged, especially during the first 3 weeks of this phase. The natural anticoagulant panels which included protein C (PC), protein S (PS) and antithrombin III (AT III) and also fibrinogen level, were lower during the first 3 weeks and reached its nadir during the second and third week. The lower level of natural anticoagulants might be an important predisposing factor for the occurrence of thrombosis in these patients.

Nutritional support for children underwent bone marrow transplantation.

Nutritional support for children underwent bone marrow transplantation was studied by comparing parenteral nutritional support and oral intakes. During 1988-1991 a total of 15 recipients, 10 boys and 5 girls, ages ranging 1-12 years from the Department of Pediatrics, Faculty of Medicine, Siriraj Hospital were studied. The patients were classified according to underlying diseases into 3 groups; Group I (thalassemia), Group II (aplastic anemia) and Group III (malignancy). The results indicate that Group I required less parenteral support than the other groups. Group III required the most parenteral support. Complications from bone marrow transplantation support among the 3 groups were similar. Therefore the requirement for nutritional support depend on the type of hematologic disease from which the patient is suffering.