Compound Heterozygosity for One Novel and One Recurrent Mutation in a Thai Patient with Severe Protein S Deficiency

Homozygous or compound heterozygous protein S (PS) deficiency is a very rare disorder in the anticoagulant system, that can lead to life-threatening thrombotic complications shortly after birth. This report describes the results of the genetic analysis of the PROS1 genes in a Thai girl patient. She was reported in 1990 as the first case with homozygous PS deficiency and neonatal purpura fulminans. In the present report, we identified the mutations in this patient by direct sequencing of PCR products representing all 15 exons of the PROS1 gene and their flanking intronic regions. The patient turned out to be compound heterozygous for two null mutations. One allele contained a novel sequence variation, an A-insertion in an A5-tract covering codon 146 and 147, that results in a frameshift and a stop codon (TAA) at position 155. The other allele contained a nonsense mutation in exon 12 by a transition at codon 410 CGA (Arg) to TGA (stop). Cosegregation of PS deficiency with these two genetic defects was observed in her family.

Outcome of Childhood Acute Lymphoblastic Leukemia Treated Using the Thai National Protocols

BACKGROUND

In recent decades, the prognosis for childhood leukemia has improved, especially for acute lymphoblastic leukemia (ALL). In Thailand, though, the survival rate for ALL is unimpressive. In 2006, standard national protocols for childhood leukemia treatment were implemented. We herein report the outcome of the ALL national protocols and explanations behind discrepancies in outcomes between institutions.

MATERIALS AND METHODS

Between March 2006 and February 2008, 486 children with ALL from 12 institutions were enrolled in the Thai national protocols. There were 3 different protocols based on specific criteria: one each for standard risk, high risk and Burkitt's ALL. We classified participating centers into 4 groups of institutions, namely: medical schools in Bangkok, provincial medical schools, hospitals in Bangkok and provincial hospitals. We also evaluated supportive care, laboratory facilities in participating centers, socioeconomics, and patient compliance. Overall and event-free survival were determined for each group using the Kaplan Meier method. Statistical differences were determined using the log-rank test. Previous outcomes of Thai childhood ALL treatment between 2003 and 2005 served as the historic control.

RESULTS

Five-year overall survival of ALL treated using the Thai national protocol was 67.2%; an improvement from the 63.7% of the 12-institute historical control (p-value=0.06). There were discrepancies in event-free survival of ALL between centers in Bangkok and up-country provinces (69.9% vs 51.2%, p-value <0.01). Socioeconomics and patient compliance were key elements in determining the outcome (65.5% vs 47.5%, 59.4% vs 42.9%) (p-value < 0.02).

CONCLUSIONS

Implementation of standard national protocols for childhood leukemia in Thailand did not significantly improve the outcome of ALL. Factors leading to better outcomes included (a) improvement of treatment compliance (b) prevention of treatment abandonment and

Acute haemolytic crisis in a Thai patient with homozygous haemoglobin Constant Spring (Hb CS/CS): a case report

Acute haemolysis associated with mild upper respiratory tract infection was observed in a Thai boy who presented with a rapid decline in haemoglobin (Hb) levels, haemoglobinuria and evidence of intravascular haemolysis. Several possible causes giving rise to such a condition were excluded including G6PD deficiency, which is extremely common in Thailand. Subsequent haematological and molecular analyses demonstrated that the patient was homozygous for Hb Constant Spring (Hb CS/CS), an a globin haemoglobinopathy. It has been shown previously that patients with homozygous Hb CS had mild haemolytic anaemia secondary to an accumulation of alpha(CS) chains, which are toxic to red blood cell membrane cytoskeletons. Increased body temperature might induce more precipitation of this a globin variant. This report highlights the importance of Hb CS/CS as a potential predisposing cause of acute haemolysis in children that might be aggravated by acute bacterial or viral infections. This is particularly relevant for patients of Southeast Asian descent where this abnormal haemoglobin is highly prevalent.

Childhood cancer incidence and survival 2003-2005, Thailand: study from the Thai Pediatric Oncology Group

BACKGROUND

Previous population-based incidences of childhood cancer in Thailand were achieved by extrapolating from data limited to a small number of cancer registries, not from the whole country. In addition, survival of childhood cancer patients is often described in specialized hospitals and/or institutions, but not in the general population.

METHODS

All children aged 0-15 years who were newly diagnosed as having cancer were registered from 18 treatment centers during 2003-5 and classified into 12 diagnostic groups according to the International Classification of Childhood Cancer. Incidences were calculated by a standard method and survival was investigated using the ThaiPOG (Thai Pediatric Oncology Group) population-based registration data. Overall survival was calculated by the Kaplan Meier method.

RESULTS

In the study period (2003-5) 2,792 newly diagnosed cases of childhood cancer were registered, with mean and median ages of 6.5 (SD=0.13) and 5.0 (0-14) years, respectively. The age-peak was between 1 and 4 years and the age-standardized rate (ASR) was 74.9 per million. Leukemia was the most common cancer (N=1421, ASR 38.1) followed by lymphoma (N=266, ASR 6.4) and neoplasms of the central nervous system (CNS, N=246, ASR 6.3). The follow-up duration totaled 101,250 months. The death rate was 1.11 per 100 person-months (95%CI: 1.02 -1.20). The 5-year overall survival was 54.9% (95%CI: 53.0%-56.9%) for all cancers. The respective, 5-year overall survival for (1) acute lymphoblastic leukemia (ALL), (2) acute non-lymphoblastic leukemia (ANLL), (3) lymphoma, (4) retinoblastoma, (5) renal tumors, (6) liver tumors, (7) germ cell tumors, (8) CNS tumors, (9) neuroblastoma, (10) soft tissue tumors and (11) bone tumors were (1) 64.5%, (2) 35.1%, (3) 59.5%, (4) 73.1%, (5) 70.4%, (6) 44.5%, (7) 70.6%, (8) 41.7%, (9) 33.6%, (10) 50.1%, and (11) 33.7%.

CONCLUSIONS

The incidence of childhood cancer is lower than in western countries. Respective overall survival for ALL, lymphoma, renal tumors, liver tumors, retinoblastoma, soft tissue tumors is lower than those reported in developed countries while for CNS tumors, neuroblastoma and germ cell tumors the figures are comparable.

N-terminal pro brain natriuretic peptide and cardiac function in doxorubicin administered pediatric patients

OBJECTIVE

Assess the use of N terminal pro brain natriuretic peptide (NT-pro BNP) to early diagnose ventricular dysfunction in doxorubicin-administered children.

MATERIAL AND METHOD

Fifty-five cancer patients who received accumulative dose of doxorubicin <300 mg/m2 (group 1), 49 cases with accumulative dose > or = 300 mg/m2 (group 2) and 52 cases as a control group (group 3) were included in the study. Electrocardiogram, chest roentgenogram, echocardiogram, and serum NT-pro BNP were studied.

RESULTS

At age 1-10 years, there were significantly higher NT-pro BNP in group 2 than group 1 (384 +/- 291 vs. 92.2 +/- 89 pg/ml; p = 0.001), and than group 3 (79 +/- 92 pg/ml; p = 0.001). Patients with NT-pro BNP level > 1 SD of the control group were more likely to have abnormal > or = 2 echocardiographic parameters of left ventricular diastolic dysfunction than patients with NT-pro BNP < or = 1 SD (OR = 3.8, 95% CI 1.18-12.5). Patients in group 2 were more likely to have abnormal > or = 2 parameters of left ventricular diastolic dysfunction than patients in group 1 (OR = 2.8, 95% CI 1.07-7.7) and more likely to have NT-pro BNP >1 SD than group 1 (OR = 8, 95% CI 1.96-38.4). There were association of NT-pro BNP > 1 SD, accumulative dose of doxorubicin > or = 300 mg/m2, and early left ventricular diastolic dysfunction by echocardiogram.

CONCLUSION

Serum NT-pro BNP > 1 SD has a high probability to diagnose early doxorubicin-induced cardiomyopathy in patient 1-10 years old.

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.

Secondary acute myelogenous leukemia in patients with retinoblastoma: is chemotherapy a factor?

PURPOSE

To describe a series of patients with secondary acute myelogenous leukemia (sAML) and retinoblastoma (RB).

DESIGN

Retrospective observational cases series.

PARTICIPANTS

Ocular and pediatric oncologists at referral centers in Europe and the Americas and the RB databases at the National Institutes of Health and the Ophthalmic Oncology Service at Memorial Sloan-Kettering Cancer Center.

METHODS

Physician survey, retrospective database review, and literature search.

MAIN OUTCOME MEASURES

History of RB and development of sAML, management of RB (surgery, radiotherapy, chemotherapy), age at diagnosis of RB and leukemia, French-American-British (FAB) subtype, and current status of patient (alive or dead).

RESULTS

Fifteen patients with sAML were identified; 13 occurred in childhood. Mean latent period from RB to AML diagnosis was 9.8 years (median, 42 months). Nine cases were of the M2 or M5 FAB subtypes. Twelve patients (79 %) had received chemotherapy with a topoisomerase II inhibitor, 8 (43%) had received chemotherapy with an epipodophyllotoxin. Ten children died of their leukemia.

CONCLUSIONS

Acute myelogenous leukemia is a rare secondary malignancy among retinoblastoma patients, many of whom were treated with primary or adjuvant chemotherapy. Additional studies are needed to assess potential risk factors contributing to sAML development in this cohort.

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.

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.

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.

Hospital-based epidemiologic survey of malignancies in children infected with human immunodeficiency virus in Thailand

To determine the incidence and spectrum of malignancies in human immunodeficiency virus-infected children, we surveyed 48 hospitals in Thailand between 1996 and 2000. There were 23 children (14 boys and 9 girls; average age at diagnosis of malignancy, 4.2 years), and the incidence rate was 0.6 per 1000 person-years. The most common malignancy was lymphoma (87.0%). The prognosis was poor.

Co-inheritance of Hb Pak Num Po, a novel alpha1 gene mutation, and alpha0 thalassemia associated with transfusion-dependent Hb H disease

Hb H disease is generally associated with moderate to severe anemia but rarely requires regular blood transfusion. We recently studied two apparently unrelated patients with transfusion-dependent Hb H disease. Hemoglobin studies demonstrated Hb H and Hb Bart's without other detectable abnormal globin species. Extensive molecular analyses of the alpha globin genes and their regulatory sequence (HS-40) revealed that both patients are compound heterozygotes for alpha0 thalassemia (--(SEA)) and a novel point mutation, a thymidine insertion after codon 131 of the alpha1 gene. The resulting frameshift gives rise to a highly unstable alpha globin chain, which we refer to as "Hb Pak Num Po," containing an additional 34 amino acids. This unusual alpha1 globin variant clearly causes alpha thalassemia, but the unexpectedly severe phenotype suggests that this mutation may have additional effects on red cell physiology. A PCR-based (ARMS) assay was developed for rapid detection of this novel mutation, and this might be useful to study the prevalence of this novel mutation which poses potentially significant clinical consequences in populations of Southeast Asia. Detecting carriers of this mutation using the molecular diagnostic procedures described will provide the means to screen and prevent a potentially severe form of alpha thalassemia in Thailand.

Genotype and phenotype of haemophilia A in Thai patients

To study genotype and phenotype correlation of haemophilia A in Thai patients, molecular defects of the factor VIII (FVIII) gene were examined and their correlation with clinical phenotypes were evaluated. The molecular pathologies of FVIII in Thai patients were found to be heterogeneous. The most common mutation was FVIII intron 22 inversion accounting for about 30% of the severe cases while gene deletion was rare. Sixteen point mutations were identified, comprising two nonsense mutations (R-5X and R1966X), five missense mutations (T233I, D542Y, G1850V, W2229S and G2325C), five nucleotide deletions (1145delT, 1187-8delACAC, 1191-4delA, 1458delGA and 1534delA), three nucleotide insertions (1439-41insA, 1934insTA and 2245insACTA) and one splicing defect (IVS15+1G>T). Nine mutations (T233I, D542Y, 1145delT, 1458delGA, 1534delA, 1934insTA, W2229S, 2245insACTA and G2325C) were novel, firstly identified in Thai patients. The genotypes were found to correlate with clinical phenotypes in a majority of cases. However, in five patients the molecular defects did not correlate with clinical severity and FVIII:C level. Cellular and molecular mechanisms were proposed to be responsible in amelioration of clinical severity caused by deleterious mutations. Carrier detection by direct mutation analysis was also demonstrated.

Homozygous hemoglobin Tak causes symptomatic secondary polycythemia in a Thai boy

Secondary polycythemia caused by high-oxygen-affinity hemoglobin is rare in children. Most patients with this condition have asymptomatic erythrocytosis. In this article the authors describe a young boy from Thailand with plethora, hypoxemia, and aggravated respiratory distress following a chest infection. Hematological and molecular studies revealed that the boy is homozygous for Hb Tak, an extended beta-globin variant with high oxygen affinity. This report of a patient who is homozygous for high-oxygen-affinity hemoglobin highlights the clinical significance of this hemoglobin disorder, which has been previously reported in several unrelated families from Southeast Asia.

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.

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.

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.

Gaucher's disease;thirty-two years experience at Siriraj Hospital

Gaucher's disease, a lysosomal disorder, is not a common disease in Thailand. During the period 1966-1998 we saw 20 patients with Gaucher's disease at the Department of Pediatrics. Siriraj Hospital. The patients came from different regions of the country but mostly from the central part of Thailand. There were 8 males and 12 females from 13 families of Thai, Thai-Chinese, Thai-Laos and Chinese-Chinese in origin. A history of consanguinity was present in 2 families. The age of onset was 2 months-4 years and the age when they were diagnosed was 4 months-15 years. The most common clinical features included splenomegaly, hepatomegaly, growth retardation, pallor, bleeding disorders and neurological abnormalities. The diagnosis was made by the clinical manifestations, hematologic complications and demonstration of Gaucher cells in the bone marrow and/or other tissues. In one family, the diagnosis was confirmed by evaluation of glucocerebrosidase activities in skin fibroblasts. The management of these patients was symptomatic ie packed red cell and platelet transfusion, splenectomy and other supportive measures. Most patients died of bleeding or infection at an early age.

Linear growth in homozygous beta-thalassemia and beta-thalassemia/hemoglobin E patients under different treatment regimens

The effects on linear growth and development among thalassemic patients under different treatment regimens were compared. Twelve homozygous beta-thalassemia (homozygous beta-thal) and 36 beta-thalassemia/Hb E (beta-thal/Hb E) were studied longitudinally between 1977 and 1998. Eighteen cases (10 homozygous beta-thal and 8 beta-thal/Hb E) received hypertransfusion with iron chelation by desferrioxamine. Another 30 cases (2 homozygous beta-thal and 28 beta-thal/Hb E) were given a low transfusion (depending on their clinical requirement). Their heights were measured serially and are presented as a standard deviation score (SDS). There was no significant difference in initial basic hematological data and ferritin levels between either group. However, the hypertransfused group, seemed to be clinically more severely affected than the other group as evidenced by early age at initial transfusion, the early onset of anemia and diagnosis and also their large acquired iron load after a period of transfusion. The average height SDS of the hypertransfused patients was within the 50th percentile +/- 1 SD during the first decade of life in both sexes and both genotypes. Whereas, in patients who were transfused infrequently, the SDS was always below the -1 SD and decreased gradually. In severe beta-thal/Hb E cases, their growth SDS showed no difference from those with homozygous beta-thal. Normal linear growth in those with homozygous beta thal and severe beta-thal/Hb E was only seen in the group that underwent hypertransfusion and this regimen contributed to normal growth during the first ten years of life. However, adequate iron chelation and hormonal treatment in these patients were also required in order to achieve normal adult height.

Mutation causing exon 15 skipping and partial exon 16 deletion in factor VIII transcript, and a method for direct mutation detection

A splicing defect with 201 nucleotide deletion in the factor VIII transcript due to IVS15 + 1G > T mutation inactivating this donor splice site and activating a cryptic acceptor splice site in exon 16 was identified in a severe haemophilia A patient. Allele specific amplification (ASA) method was successfully developed for direct detection of this mutation.

Penicilliosis-associated hemophagocytic syndrome in a human immunodeficiency virus-infected child: the first case report in children

Infection-associated hemophagocytic syndrome (IAHS) has been found in many systemic infectious conditions with a high mortality rate. Disseminated Penicillium marneffei infection is a common opportunistic condition among HIV-infected patients in many regions in Southeast Asia. We report the first case of IAHS caused by penicilliosis in an HIV-infected child who presented with cytopenias and recovered promptly after antifungal and intravenous immunoglobulin therapy.

Neonatal alloimmune thrombocytopenia due to anti-Nak(a)

BACKGROUND

The accurate diagnosis of neonatal alloimmune thrombocytopenia is essential in the effective treatment of potentially serious bleeding in neonates.

CASE REPORT

Reported here is a case of a full-term female baby who was delivered by vacuum extraction from a gravida 1 para 1 healthy mother. She presented with generalized petechiae and bilateral cephalhematoma, which she had had since birth. At 7 hours of life, she had an upper gastrointestinal hemorrhage and was found to have severe anemia and marked thrombo-cytopenia. Coagulation screening tests were normal. The diagnosis of neonatal alloimmune thrombocytopenia was suspected, and maternal serum was collected for further study. The baby was treated with a single dose of hydrocortisone (10 mg/kg) and IVIG (400 mg/kg) while waiting for irradiated platelets from her mother. After 30 mL of a transfusion of maternal platelets, the baby's platelet count rose dramatically, from 15,000 to 162,000 per microL, and it remained stable at that level. She was discharged on the 10th hospital day in good condition. During the follow-up period of 8 months, her growth and development were satisfactorily normal, as well as her platelet count. A high-titered platelet antibody was detected in the maternal serum by use of a solid phase platelet adherence technique.

RESULTS

The specificity of the platelet antibody was identified as anti-Nak(a) by the mixed passive hemagglutination test method.

CONCLUSION

These findings suggested a diagnosis of NAIT caused by anti-Nak(a).

Determination of haemophilia A carrier status by mutation analysis

A reliable method for determination of carrier status and genetic counselling is required for effective control of haemophilia. Linkage analysis is currently the most widely used method for this purpose; however, in cases where there is no prior family history and/or unavailability of informative polymorphic markers it is less applicable. Detection of a mutation characterized in each family may be an alternative method for determination of the carrier status. In this study, linkage analysis using four polymorphic DNA markers, and direct mutation analysis were compared to determine the carrier status in six unrelated Thai haemophilia A families, two with a family history and four without. In the two families with a family history of haemophilia A, the carrier and noncarrier statuses could readily be determined in eight females by either linkage or direct mutation analysis. In the four families without a family history, the polymorphic DNA markers for linkage analysis were informative in two families and uninformative in the other two. The carrier status could be excluded in all four female siblings of the patients in the former. However, the specific FVIII gene mutation was not observed in the mother of one patient, who should have carried the mutation. In the remaining two families with uninformative polymorphic DNA markers, the carrier and noncarrier statuses of four female members could only be determined by direct mutation analysis. Therefore, direct mutation analysis could circumvent the limitations of linkage analysis in the determination of haemophilia A carrier status in families without a previous history or informative polymorphic markers.

Successful prophylaxis of intracranial hemorrhage in infants with severe congenital factor VII deficiency

During the period 1984-1992, 2 severe cases (1 male, 1 female) of congenital F VII deficiency with intracranial hemorrhage (ICH) were referred to the Department of Pediatrics, Siriraj Hospital Bangkok, Thailand at the ages of 1 and 3 months old. They both responded very well to fresh frozen plasma (FFP) transfusion therapy. Subsequently, both had repeated episodes of ICH (repeated ICH) 5 and 6 times, despite the 10-14 days of replacement therapy for each episode and eventually died at the ages of 11 and 13 months. Since September 1996, another 2 severe cases (2 females) of congenital F VII deficiency who had ICH within their first month of life were referred to us. In order to prevent repeated ICH, we started a prophylactic regime after the second episode of ICH, by giving FFP 10 ml/kg twice a week. The average duration of follow up was 21 months (at 8 and 34 months). All of them (aged 14, and 38 months old) are doing well at this time and free from repeated ICH. From this observation, if there is FFP available, this regime is an effective way to prevent repeated ICH in infants with severe congenital Factor VII deficiency.

Frameshift mutations with severe and moderate clinical phenotypes in Thai hemophilia A patients

Six frameshift mutations in exon 14 of the factor VIII gene were identified in Thai hemophilia A patients. Although all these mutations created premature stop codons and expected to cause severe disease, the molecular defects and clinical severity were in discrepancy in some patients. Four mutations (delT3490, delACAC3618-21, delGA4429-30, and delA4658) were found in the patients with the severe clinical phenotype while two (delA3629-37 and insA4372-9) were observed in the patients who had moderate severity, with FVIII:C of 4.2 and 2.8%. The frameshift mutations in these two patients were due to deletion and insertion of an 'A' nucleotide in the stretches of 9As and 8As in codons 1191-4 and 1439-41, respectively. This indicates that deletion or insertion in the stretches of poly A nucleotides in exon 14 of the factor VIII gene is a likely cause of the moderate clinical severity in some cases of Thai hemophilia A patients.

Successful bone marrow transplantation in a child with red blood cell pyruvate kinase deficiency

We report the first successful use of BMT for the treatment of RBC pyruvate kinase (PK) deficiency in a boy who developed neonatal jaundice and severe transfusion-dependent hemolytic anemia a few months after birth. He received a BMT at the age of 5 from an HLA-identical sister who has normal PK activity after conditioning with busulfan and cyclophosphamide. The post-transplant course was uneventful. At present, 3 years after transplant, he is 8 years old and has a normal hemoglobin level and normal RBC PK activity without evidence of hemolysis. DNA analysis has confirmed full engraftment.

What is the sudden death syndrome in Southeast Asian males?

Sudden unexplained death syndrome describes the death of apparently healthy individuals--usually young men--in whom postmortem examination does not reveal the cause of death. The victims are in apparently good health and usually die at night while sleeping. They die within minutes after the onset of agonal respiration. Patients who have been resuscitated were found to have ventricular fibrillation and inducible polymorphic ventricular tachycardia in the electrophysiologic laboratory. This syndrome has been most frequently described in young Southeast Asian men. In this review, the epidemiology, clinical and electrophysiologic manifestations, pathology and risk factors, prognosis, and treatments for sudden unexplained death syndrome are described.

Mutations of the factor VIII gene in thai hemophilia A patients

Hemophilia A is a common X-linked bleeding disorder caused by mutations in the coagulation factor VIII gene. The entire coding and essential sequences of the factor VIII gene were generated by a combination of genomic DNA amplification and long reverse transcription-polymerase chain reaction (long RT-PCR) using factor VIII transcripts prepared from lymphocytes. Mutations were then screened by non-radioactive single strand conformation polymorphism (SSCP) analysis and characterized by DNA sequencing. We have identified six potentially pathogenic mutations in the factor VIII gene in Thai hemophilia A patients, including two nonsense mutations (R-5X and R1966X), three missense mutations (D542Y, G1850V, and G2325C), and a 4-bp insertion (ACTA) at codon 2245. Three of these mutations (D542Y, G2325C, and 4-bp insertion) have never been previously reported, and the ins2245 is the first example of such insertion probably causing factor VIII elongation. R1966X, D542Y, G1850V, and 4-bp insertion were associated with a severe hemophiliac phenotype whereas R-5X and G2325C were observed in moderately affected patients. Mutations in the factor VIII gene in Thai hemophilia A patients are likely to be heterogeneous. This study represents the first attempt to further the understanding of the molecular basis of hemophilia A in Thai.

Compound heterozygosity for one novel and one recurrent mutation in a Thai patient with severe protein S deficiency

Homozygous or compound heterozygous protein S (PS) deficiency is a very rare disorder in the anticoagulant system, that can lead to life-threatening thrombotic complications shortly after birth. This report describes the results of the genetic analysis of the PROS 1 genes in a Thai girl patient. She was reported in 1990 as the first case with homozygous PS deficiency and neonatal purpura fulminans. In the present report, we identified the mutations in this patient by direct sequencing of PCR products representing all 15 exons of the PROS 1 gene and their flanking intronic regions. The patient turned out to be compound heterozygous for two null mutations. One allele contained a novel sequence variation, an A-insertion in an A5-tract covering codon 146 and 147, that results in a frameshift and a stop codon (TAA) at position 155. The other allele contained a nonsense mutation in exon 12 by a transition at codon 410 CGA (Arg) to TGA (stop). Cosegregation of PS deficiency with these two genetic defects was observed in her family.

Novel AE1 mutations in recessive distal renal tubular acidosis. Loss-of-function is rescued by glycophorin A

The AE1 gene encodes band 3 Cl-/HCO3- exchangers that are expressed both in the erythrocyte and in the acid-secreting, type A intercalated cells of the kidney. Kidney AE1 contributes to urinary acidification by providing the major exit route for HCO3- across the basolateral membrane. Several AE1 mutations cosegregate with dominantly transmitted nonsyndromic renal tubular acidosis (dRTA). However, the modest degree of in vitro hypofunction exhibited by these dRTA-associated mutations fails to explain the disease phenotype in light of the normal urinary acidification associated with the complete loss-of-function exhibited by AE1 mutations linked to dominant spherocytosis. We report here novel AE1 mutations linked to a recessive syndrome of dRTA and hemolytic anemia in which red cell anion transport is normal. Both affected individuals were triply homozygous for two benign mutations M31T and K56E and for the loss-of-function mutation, G701D. AE1 G701D loss-of-function was accompanied by impaired trafficking to the Xenopus oocyte surface. Coexpression with AE1 G701D of the erythroid AE1 chaperonin, glycophorin A, rescued both AE1-mediated Cl- transport and AE1 surface expression in oocytes. The genetic and functional data both suggest that the homozygous AE1 G701D mutation causes recessively transmitted dRTA in this kindred with apparently normal erythroid anion transport.

Bone marrow, peripheral blood and cord blood stem cell transplantation in children: ten years' experience at Siriraj Hospital

Stem cell transplantations were performed in 69 children at Siriraj Hospital over a ten year period. The source of stem cells was bone marrow (60), peripheral blood (3), or cord blood (6). The diseases treated included 35 thalassemias, 11 Burkitt's lymphoma, five non-Hodgkin's lymphoma, five aplastic anemia, eight acute leukemia, and one each of neuroblastoma, severe combined immunodeficiency, Wiskott-Aldrich syndrome, myelodysplastic syndrome, and pyruvate kinase deficiency. The success rate of stem cell transplantation in Thai children varied according to the underlying diseases of the patients, ranging from 50% in acute leukemia to 100% in aplastic anemia. The outcome of stem cell transplantation in 35 thalassemic children revealed 23 (79.4%) were cured, whereas three (10.3%) remain alive with disease and the other three (10.3%) died. The incidence of graft-versus-host disease was low hen compared with that of Western countries. It is concluded that bone marrow, peripheral blood and cord blood stem cell transplantation will be the treatment of choice and will be widely used in the future to cure many hematologic and malignant disorders in children.

Malignant lymphoma in Thailand: changes in the frequency of malignant lymphoma determined from a histopathologic and immunophenotypic analysis of 425 cases at Siriraj Hospital

BACKGROUND

Analysis of malignant lymphoma in a single institution at different periods of time can determine the changing status of the disease in the region.

METHODS

To compare with the large series of 1095 lymphoma cases reported between 1957-1971 at Siriraj Hospital, the largest hospital in Thailand, a similar study was performed through histopathologic evaluation of 425 lymphoma cases diagnosed consecutively at the same institution between August 1993 and October 1995. Phenotypic analysis was performed by paraffin section-immunoperoxidase studies.

RESULTS

A striking increase in lymphoma cases was noted from 73 cases/year in the first series to 189 cases/year in the second series (an increase of 158.9%). Lymphoma occurred in all age groups, with a peak incidence at the seventh decade of life. The male to female ratio decreased from 2:1 in 1957-1971 to 1.3:1 in the more recent series. The incidence of Hodgkin's disease (HD) was found to have decreased from 28.9% to 8.5%. There were 36 cases (8.5%) of HD and 389 cases (91.5%) of non-Hodgkin's lymphoma (NHL) reported in the second series. The subtypes of HD included 16 cases of mixed cellularity, 13 cases of nodular sclerosis, 6 cases of lymphocyte depletion, and 1 case of lymphocyte predominance. According to the Working Formulation, the 389 NHL cases included low grade (14.1%), intermediate grade (57.3%), high grade (11.3%), and miscellaneous groups (17.2%). They were classified as small lymphocytic (9.5%), follicular (11.1%), diffuse (50.9%), immunoblastic (4.1%), small noncleaved (4.4%), lymphoblastic (2.8%), anaplastic large cell (9.0%), mycosis fungoides (1.8%), hairy cell leukemia (0.3%), true histiocytic (0.5%), and extramedullary plasmacytoma (1.0%). The immunophenotypes of the 359 NHL cases available for paraffin section-immunoperoxidase studies were B-cell (71.0%), T-cell (24.5%), histiocyte (0.6%), and undetermined phenotypes (3.9%).

CONCLUSIONS

The incidence of malignant lymphoma is increasing in Thailand, with a high frequency of intermediate to high grade NHL of B-cell phenotype reported.

Pyruvate kinase deficiency in an alpha-thalassemia family: first case report in Thailand

In Thailand, the most common cause of chronic hemolytic anemia is thalassemia hemoglobinopathy. We report here a 10-year-old girl with pyruvate kinase (PK) deficiency who was initially diagnosed to have Hb H disease, like her sister. The patient had a history of neonatal jaundice which required blood exchange transfusion twice and phototherapy. She became anemic and regular blood transfusion was required since the age of 2 1/2 months. She was very anemic compared to her sister and was transfusion dependent. Besides, she never had red cell inclusion bodies, thus re-evaluation was performed. The diagnosis of red cell pyruvate kinase deficiency and the exclusion of Hb H disease was achieved after cessation of blood transfusion for 3 months. The family study also confirmed the diagnosis. The patient is now on high transfusion and iron chelation. She is doing well with mild splenomegaly.

Arrhythmogenic marker for the sudden unexplained death syndrome in Thai men

BACKGROUND

Between 1981 and 1988, the Centers for Disease Control and Prevention reported a very high incidence of sudden death among young male Southeast Asians who died unexpectedly during sleep. The pattern of death has long been prevalent in Southeast Asia. We carried out a study to identify the clinical markers for patients at high risk of developing sudden unexplained death syndrome (SUDS) and long-term outcomes.

METHODS AND RESULTS

We studied 27 Thai men (mean age, 39.7+/-11 years) referred because they had cardiac arrest due to ventricular fibrillation, usually occurring at night while asleep (n=17), or were suspected to have had symptoms similar to the clinical presentation of SUDS (n=10). We performed cardiac testing, including EPS and cardiac catheterization. The patients were then followed at approximately 3-month intervals; our primary end points were death, ventricular fibrillation, or cardiac arrest. A distinct ECG abnormality divided our patients who had no structural heart disease (except 3 patients with mild left ventricular hypertrophy) into two groups: group 1 (n=16) patients had right bundle-branch block and ST-segment elevation in V1 through V3, and group 2 (n=11) had a normal ECG. Group 1 patients had well-defined electrophysiological abnormalities: group 1 had an abnormally prolonged His-Purkinje conduction time (HV interval, 63+/-11 versus 49+/-6 ms; P=.007). Group 1 had a higher incidence of inducible ventricular fibrillation (93% for group 1 versus 11% for group 2; P=.0002) and a positive signal-averaged ECG (92% for group 1 versus 11% for group 2; P=.002), which was associated with a higher incidence of ventricular fibrillation or death (P=.047). The life-table analysis showed that the group 1 patients had a much greater risk of dying suddenly (P=.05).

CONCLUSIONS

Right bundle-branch block and precordial injury pattern in V1 through V3 is common in SUDS patients and represents an arrhythmogenic marker that identifies patients who face an inordinate risk of ventricular fibrillation or sudden death.

Itraconazole for treatment of oral candidosis in pediatric cancer patients

Oral candidosis commonly occurs in malignancy children undergoing antineoplastic chemotherapy. Inadequate response to antifungal treatment leads to a risk of disseminated infection. The aim of this study is to evaluate the efficacy and side effects of itraconazole on treatment of oral candidosis. Fourteen children with malignancy undergoing chemotherapy received itraconazole 100-200 mg/day for 10 days to treat oral candidosis. The severity of disease was defined as mild and moderate depending on the number of lesions and symptoms. Oropharyngeal lesions and symptoms were recorded initially and daily. Blood chemistries were done on day 0, day 10 and day 16. The overall response rate was 87.5 per cent. The mild group (4 cases) had a response rate of 100 per cent which had lesions and symptoms resolved on day 2 and day 1.5 +/- 0.7 respectively. The moderate group (10 cases) had 8 responders (80%) whose lesions and symptoms resolved on day 6 +/- 2.5 and day 4.1 +/- 2.3 respectively. Side effects and abnormal blood chemistry values. were not seen.

Percutaneous transluminal angioplasty of saphenous vein grafts for medically refractory unstable angina

OBJECTIVES

We attempted to answer the question, Is balloon angioplasty a reasonable alternative to repeat coronary artery bypass graft surgery in patients with previous coronary bypass graft surgery, medically refractory unstable angina and vein graft lesions?

BACKGROUND

Patients with medically refractory unstable angina need revascularization. Patients with previous coronary artery bypass graft surgery and medically refractory angina are at "high risk" for adverse outcomes with repeat coronary bypass graft surgery. Conversely, patients with angioplasty of old vein grafts are also at "high risk" for adverse outcomes.

METHODS

Balloon angioplasty of 89 lesions in saphenous vein grafts was performed in 75 consecutive patients with medically refractory unstable angina. Of these 75 patients, 24 (32%) had myocardial infarct within 30 days, 23 (31%) had left ventricular ejection fraction < 0.35, and 50 (67%) had major comorbidity. Patients underwent standard balloon angioplasty with aggressive use of intravenous and intracoronary heparin, urokinase, nitroglycerin, oral aspirin, calcium channel blocking agents and coumadin.

RESULTS

Angiographic success (reduction of stenosis < or = 50% without major complication) was seen in 84 of 89 lesions. Clinical success (angiographic success plus hospital discharge without major complication) was seen in 70 of 75 patients. During index hospitalization, two patients (3%) died, two (3%) had nonfatal infarcts, and one (1%) had emergency reoperation (coronary bypass graft surgery). In late follow up (3 to 66 months), 14 (20%) patients were lost to follow-up, 17 (23%) had repeat percutaneous transluminal coronary angioplasty, 2 (3%) had late bypass graft reoperation, 18 (25%) had late death, and 1 (< 1%) had a heart transplant. Of the 41 patients alive after one or more angioplasties, 25 have little or no angina, and 16 have occasional or more angina. We compared long-term survival rate in these 75 patients with a cohort of patients with high risk, unstable angina from the Veterans Affairs Surgical Registry (2,570 patients). The 30-day survival rate was better in patients with coronary angioplasty (97% vs. 92%, p < 0.05), but by 6 months there was no difference, and by 5 years a trend toward a higher survival rate with coronary artery bypass graft surgery was seen.

CONCLUSIONS

Balloon angioplasty of saphenous vein grafts with aggressive adjunctive pharmacotherapy is a reasonable alternative to repeat coronary bypass graft surgery in patients with medically refractory unstable angina, previous coronary bypass graft surgery and saphenous vein narrowing.

Intravascular ultrasonography for the diagnosis of traumatic aortic disruption: a case report

Thoracic aortic disruptions after blunt trauma are highly lethal injuries. Diagnosis of these injuries has traditionally been based on clinical suspicion, chest radiographs, and aortography. The roles of dynamic computed tomography and transesophageal echocardiography are currently under investigation. Intravascular ultrasonography is a new technology with potential as a diagnostic adjunct in the evaluation of these injuries. We present a case of traumatic aortic disruption identified by intravascular ultrasonography after nondiagnostic aortography and dynamic computed tomography studies.