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.

Hematological parameters and red blood cell indices in healthy Thai children: a revision for 2005.

In order to provide a reference range for hematological parameters and red blood cells indices in Thai children, we analyzed data from 395 healthy non-anemic Thai children age from 1-16 years old, who all had normal pattern of hemoglobin typing (Hb A and Hb A2 less than 3.5%). Hematological analysis was performed using an automated cell counter and the hemoglobin studies were carried out by electrophoresis and liquid chromatography. Owing to a high frequency of a thalassemia in Thailand, cases with MCV < 75 fL has been excluded from the study since these cases were likely to be heterozygotes for alpha0 thalassemia. These criterions were applied to select so-called 'normal' controls for our analysis. Relatively mild microcytosis and hypochromia were observed, in particular in the first three years of age, suggesting an intrinsic immature nature of erythropiesis in the children. Age-dependent differences in the reference values for white blood cell (WBC) count and differential and platelet count were observed. Herein the hematological data and red blood cell indices were summarized according to ages and these will be of clinically useful for the future reference.

Clinical phenotypes and molecular diagnosis in a hitherto interaction of Hb E/beta thalassemia syndrome (beta(E)/beta(-31), (A -->G)).

Molecular identification of affected alleles in the index family with rare mutation(s) and/or interaction(s) is an important prerequisite toward a proper genetic counseling. In Thailand, where more than 30% of the populations are heterozygotes for either alpha or beta thalassemia mutation(s). More than 60 different thalassemia syndromes resulting from the interactions of these heterogeneous alleles have been observed. The majority of patients in the hospital based-study are compound heterozygotes for beta thalassemia alleles and another hemoglobinopathy namely Hb E, highly prevalent in Thailand, gave rise to Hb E/beta thalassemia syndrome. The phenotypes of these syndromes vary from asymptomatic individual to a very severe phenotype mimic that of beta thalassemia major. In this report, we describe a three-year-old Thai girl presenting with mild hypochromic microcytic anemia since birth. She was born prematurely and developed anemia within the first week of life. The cause of anemia was suspected to result from prematurity and low intrauterine iron storage, however hypochromic anemia did not resolve after a three-month of iron supplement therapy. Subsequent studies indicated that the patient had Hb E/beta thalassemia disease and the molecular study revealed that the patient was a compound heterozygote for Hb E and a rare beta thalassemia mutation (beta(-31), A --> G). This hitherto genotype results in a relatively mild clinical symptom since the patient's baseline Hb values were around 9-10 g/dL with normal weight and height development during the follow-up period.

Evaluation of guideline for treatment of febrile neutropenia in pediatric cancer at Siriraj Hospital.

BACKGROUND: Febrile neutropenia (FN) is a common and important clinical problem in pediatric cancer. Our Institution has developed a clinical practice guideline (CPG) for treatment of FN to assist the clinicians taking care of these patients.OBJECTIVE: To evaluate characteristics of FN, sources and causative agents of infection, applicability and effectiveness of the CPG, and factors that associated with response to treatment. MATERIALS AND METHODS: The medical records of patients with FN that had completed data from September, 2003 to May, 2005 were reviewed and analysed. RESULTS: A total of 148 FN episodes in 90 patients were analysed. The predominant underlying malignancy was acute leukemia. About 50% had absolute neutrophil count (ANC) less than 100 cells/mm3 at the beginning and at reassesment on day 3 of treatment. The causes of infection with microbiological confirmation was 25%. Urinary tract infection was the predominant source of infection and gram negative bacteria was the predominant causative agent. Sixty-two percents responded to initial treatment without changing of antibiotics. Of all episodes, 91.2% were able to complete treatment according to the CPG. The mortality rate was 1.4%. ANC of less than 100 cell/mm3 on day 3 of treatment was the significant risk factor for prolonged duration of fever and unresponsiveness to low risk regimen of antibiotics. ANC of less than 100 cell/mm3 on day 3, having hematologic malignancies, and recurrent fever were associated risks for the need for antifungal agent or referral to infectious diseases specialist or death. The pretreatment ANC more than 100 cells/mm3 was a significant predictor for the responsiveness to low risk regimen without recurrent fever. CONCLUSION: Our CPG could practically be applied in FN patients and resulted in low mortality rate.

Dengue hemorrhagic fever in patients with thalassemia.

Dengue hemorrhagic fever (DHF) causing by dengue viral infection is endemic in Thailand and Southeast Asian countries where thalassemias are prevalent. Thalassemic patients are also at risk to acquire dengue viral infections and to develop DHF. However, they can have different clinical manifestations and complications as well as more severity than general population requiring special awareness for proper diagnosis and management. We reported 20 thalassemic patients (10 boys and 10 girls) with DHF admitted to Department of Pediatrics, Siriraj Hospital during 1977 to 2001. Their ages ranged from 2-16 years (average 9.5 years). These cases included 5 cases of Hb H disease, 5 cases of Hb H with Hb Constant Spring (CS), 9 cases of beta-thalassemia/Hb E disease and 1 case of beta-thalassemia major. Two cases were in Grade I, 10 cases in grade II, 7 cases in Grade III and one case in grade IV severity of DHF. Though there were evidences of plasma leakage, instead of hemoconcentration, eighteen patients (90 percent) had hematocrit dropped at the range of 11-66% of the initial level. Fifteen patients (75 percent) required at least one packed red cell transfusion. Nine patients (45 percent) had mild bleeding symptoms, one of them had upper gastrointestinal hemorrhage requiring platelet concentrate transfusion. Two patients (10 percent) had serious complications including one with infection-associated hemophagocytic syndrome (IAHS) requiring intravenous immunoglobulin (IVIG) and packed red cell transfusion and the other had generalized seizure due to hyponatremia and hypotension. No mortality was observed among this group of patients. Early recognition of the DHF in thalassemic patients and appropriate packed red cell transfusion in patients with anemic symptoms is warranted to reduce morbidity and mortality in these patients.

A man with chronic recurrent ulcers at the axillac and groins.

Langerhans cell histiocytosis is an uncommon disease. There are various skin manifestations of this disorder. We report a 15 year-old patient with Langerhams cell histiocytosis, who first presented with polyuria, polydipsia and right elbow pain. A few years later, he developed chronic recurrent ulcers at his axillae and groins, simulating hidradenitis suppurativa. Histopathology and ultramicroscopic study showed Langerhans cells infiltrating the lesions. He also had fingernail changes without any evidence of fungal infection. Hidradenitis suppurative-like lesions with nail changes are rare manifestations of this disorder.

Carrier detection by DNA linkage analysis in eighty Thai hemophilia A families.

DNA linkage analysis was performed in Thai hemophilia A families to evaluate its value for carrier detection. Both intragenic and extragenic polymorphic DNA regions of the factor VIII gene, including Bcl I-RFLP in intron 18, microsatellites (CA repeats) in introns 13 and 22, and extragenic Stl4 (DXS 52) VNTR, were amplified by polymerase chain reaction (PCR) before analyses by appropriate electrophoretic procedures. A total of 80 Thai hemophilia A families (48 with a family history and 32 with a sporadic case), containing 349 DNA samples from 90 hemophilia A patients, 143 parents, and 116 relatives, were analyzed. Heterozygosities in the patients' mothers from both families with a family history and with a sporadic case were observed in 71 out of 80 families (88.75%) for all polymorphic DNA markers analyzed. The carrier status could be identified in 36 females and excluded in 44 females. This result indicates that the DNA linkage analysis can be used for carrier detection or exclusion in the majority of Thai hemophilia A families. It should also be useful for prenatal diagnosis in families at risk of hemophilia A, which is part of the prevention and control of this disease.

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.

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.

Treatments of severe aplastic anemia in children.

We carried out a retrospective analysis of the outcome of treatment in patients with severe aplastic anemia who attended the Department of Pediatrics, Siriraj Hospital, during 1972- 1998. There were 31 patients, 17 boys and 14 girls, by Camitta’s criteria for severe aplastic anemia. All of them were idiopathic. Twenty patients were treated conventionally with steroid and androgen compounds, 5 with immunosuppressive therapy and 6 with bone marrow transplantation. In the conventional treatment group, after 1 year to 19 years of follow up, 64.7% achieved complete response, 11.8% achieved partial response and 23.5% died. The response rate in the immunosuppressive therapy group was only 40% after 3 months to 2 years of follow up. In the bone marrow transplantation group, bone marrow engraftment was achieved in all cases (means 29.8, range 19 - 42 days), and the patients yielded the highest complete response rate (100%). However, 1 case relapsed after complete response for 1 year, but he was successfully cured after second transplantation. The overall survival rate and cure rate were also 100% after 1 year and a half to 10 years of follow up. Bone marrow transplantation, when compared to other treatments, resulted in the highest response or cure rate with the shortest treatment duration. The only disadvantages of bone marrow transplantation are the high cost and the limited availability of HLA compatible donors.

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.