Molecular characteristics of hereditary red blood cell membrane disorders in Thailand: a multi-center registry

Red blood cell (RBC) membrane disorders represent a significant category of hereditary hemolytic anemia; however, information from Southeast Asia is limited. We established a national registry aiming to characterize RBC membrane disorders and their molecular features in Thailand. A total of 100 patients (99 kindreds) diagnosed with RBC membrane disorders between 2011 and 2020 from seven university hospitals were enrolled. The most prevalent disorders observed were hereditary elliptocytosis (HE; n=33), hereditary pyropoikilocytosis (HPP; n=28), hereditary spherocytosis (HS; n=19), Southeast Asian ovalocytosis (SAO; n=10 of 9 kindreds), and two cases of homozygous SAO. The remaining cases were grouped as unclassified membrane disorder. Seventy-six patients (76%) were molecularly confirmed by PCR, direct DNA sequencing, or hi-throughput sequencing. The primary causative gene for HE and HPP was SPTB, accounting for 28 out of 29 studied alleles for HE and 56 of 56 studied alleles for HPP. In the case of HS, dominant sporadic mutations in the ANK1 gene (n=4) and SPTB gene (n=3) were identified as the underlying cause. Notably, the four most common variants causing HE and HPP were SPTB Providence (c.6055 T>C), SPTB Buffalo (c.6074 T>G), SPTB Chiang Mai (c.6224 A>G), and SPTB c.6171__82delins TGCCCAGCT. These recurrent SPTB mutations accounted for 79 out of 84 mutated SPTB alleles (94%). In summary, HE and hereditary HPP associated with recurrent SPTB mutations are the predominant types of RBC membrane disorders observed in Thailand. These findings have significant implications for the clinical management and future research of RBC membrane disorders in the region.

Thalassemia-related complications in pediatric, adolescent, and young adult patients with transfusion-dependent thalassemia: A multicenter study in Thailand

INTRODUCTION

Management of transfusion-dependent thalassemia (TDT) can be challenging due to numerous potential disease-related complications and comorbidities in particular age groups. The objective of this study was to report thalassemia-related complications and risk factors in pediatric, adolescent, and young adult patients with TDT.

METHODS

A multicenter web-based registry was conducted in patients with TDT aged 25 years and younger from eight university hospitals covering all parts of Thailand. Factors significantly associated with each complication were analyzed by logistic regression methods.

RESULTS

Of 605 patients, 267 thalassemia-related complications were reported from 231 pediatric, adolescent, and young adult patients with TDT patients (38.2%). The most common complications were infections, followed by cholelithiasis and growth failure. Splenectomy and elevated pre-transfusion hemoglobin were statistically significant risk factors for infections (adjusted odds ratio [AOR] = 2.3, 95% confidence interval [CI]: 1.2-4.5, p-value = .01 and AOR = 1.5, 95% CI: 1.2-1.7, p-value < .005, respectively). There were two statistically significant risk factors conferred endocrinopathies, including older age (AOR = 1.06, 95% CI: 1.01-1.1, p-value = .01) and being male (AOR = 2.4, 95% CI: 1.4-4.0, p-value = .002).

CONCLUSION

Nearly 40% of the patients in this cohort had thalassemia-related complications. Periodic surveillance and optimal care for respective complications may minimize comorbidities in pediatric, adolescent, and young adult patients with TDT.

National strategic advocacy to manage patients with inherited bleeding disorders in low and lower-middle income countries

INTRODUCTION

Inherited bleeding disorders (IBDs) including hemophilia, von Willebrand disease, platelet disorders, mucocutaneous bleeding disorders and coagulation factor deficiencies are rarely found and under-recognized in low and lower-middle-income countries. Some patients succumbed to serious bleeding without diagnosis and treatment during childhood.

AREA COVERED

Diagnosis, management, and prevention should be integrated into the existing health care system. Although some countries have not implemented appropriate health care infrastructure, an initiative plan should be set up by cooperation of experienced experts and health care providers. Identification of patients with IBDs should be started in the antenatal setting to search for females at risk of carrier state. The investigations include bleeding assessment, mixing venous clotting time, coagulogram, coagulation factor assay and mutation detection. Genotypic analysis is helpful for confirming the definite diagnosis, carrier detection as well as prenatal diagnosis for females at risk of bearing an offspring with severe bleeding manifestations. Management involves replacement therapy ranging from blood component to virus-inactivated factor concentrate. Appropriate research is an essential backbone for improving patients' care.

EXPERT OPINION

Effective national strategic advocacy to manage patients with IBDs requires intensive collaboration among policy makers, health care providers, patients, and family members.

Practices and challenges for hemophilia management under resource constraints in Thailand

Hemophilia is an inherited bleeding disorder caused by deficiency of a specific coagulation factor. Factor VIII deficiency is responsible for hemophilia A while factor IX deficiency is responsible for hemophilia B. As per the 2020 annual global survey by the World Federation of Hemophilia, only 1828 Thai hemophiliacs have been registered to the national healthcare system. The reason for the low number is the underdiagnosis which is a major concern in the real-world practice among Asian countries. In Thailand, most hemophiliacs are diagnosed by general practitioners, pediatricians or internists at rural hospitals and are referred to hemophilia specialists at the Hemophilia Treatment Centers (HTCs). Despite the challenges pertaining to infrastructure and cost of treatment, Thailand has progressed substantially in providing the required hemophilia care, as evidenced by an evolution in acquiring and sharing knowledge as well as collaborative efforts among multiple stakeholders over the past three decades. In this letter-to-the-editor, the authors have summarized the practices for and challenges faced with hemophilia management in Thailand.

Red blood cell alloimmunization and other transfusion-related complications in patients with transfusion-dependent thalassemia: A multi-center study in Thailand

BACKGROUND

Thalassemia is a common genetic disease in Southeast Asia. Red blood cell (RBC) transfusion is an essential treatment for severe forms of thalassemia. We performed a study to demonstrate RBC alloimmunization and other transfusion-related complications in patients with transfusion-dependent thalassemia (TDT).

STUDY DESIGN AND METHODS

A multi-center web-based registry of TDT was conducted in eight medical centers across Thailand. Thalassemia information, transfusion therapy, and transfusion-related complications were collected. Factors associated with each complication were demonstrated using the logistic regression analysis.

RESULTS

Of 1000 patients recruited for the study, 449 were males (44.9%). The mean age was 23.9 ± 15.4 years. The majority of patients, 738 (73.8%) had hemoglobin E/beta-thalassemia. In the study, 421 transfusion-related complications were reported from 357 patients (35.7%). Alloimmunization was the most common complication which was found in 156 patients (15.6%) with 284 positive antibody tests. The most frequent antibodies against RBC were anti-E (80/284, 28.2%) followed by anti-Mia (45/284, 15.8%) and anti-c (32/284, 11.3%). Age ≥3 years at initial blood transfusion, splenomegaly, higher frequencies, and volumes of transfusion were significant factors associated with alloimmunization. None of the patients had to terminate blood transfusion due to multiple alloantibodies. Other commonly seen complications were allergic reactions (130, 13.0%), autoimmune hemolytic anemia (70, 7.0%) and febrile non-hemolytic transfusion reaction (54, 5.4%).

CONCLUSIONS

Transfusion-related complications, especially alloimmunization, were common among Thai patients with TDT. Extended RBC antigen-matching for the Rh system and Mia should be implemented to prevent the development of alloantibodies in multi-transfused patients.

Clinical Outcomes of Extracranial Germ Cell Tumors: A Single Institute’s Experience

Objective: To determine the clinical features and treatment outcomes of pediatric extracranial germ cell tumor (EGCT) in Thailand.Materials and methods: A retrospective chart review of children under 15 years old with newly diagnosed EGCT who were treated at Faculty of Medicine Siriraj Hospital from January, 2004 to December, 2013 was conducted.Results: Forty-four patients were included in the study. The median age at diagnosis was 1.74 years (1 day-14.7 years) with the median follow up time of 6.9 years (14 days-15.2 years). Twenty-eight patients (64%) had extragonadal tumor. The most common primary tumor location was the sacrococcygeal area. Majority of the patients (61%) had malignant EGCT; yolk sac tumor was the most common diagnosis. Six patients (14%) had stage IV disease. Forty patients (91%) underwent surgery; 27 patients (61%) received chemotherapy. Thirty-eight patients (86%) achieved remission; 3 patients (7%) subsequently relapsed at a median time of 1 year. Eight patients (18%) died, mostly from tumor progression. The 5-year event-free survival (EFS) and overall survival (OS) rate were 78.3% and 81.1%, respectively. Patients achieving total tumor removal had significantly better 5-year EFS and OS. Cox regression analysis revealed that the adequacy of surgery was the only prognostic factor for survival. Conclusion: The survival rate of pediatric EGCT in our study was relatively favorable, but still inferior to that of developed countries. Novel therapy may be warranted for those patients who are unresponsive to the current treatment.

Antifungal Prophylaxis with Posaconazole versus Fluconazole in Children with Neutropenia Following Allogeneic Hematopoietic Stem Cell Transplantation: Single Center Experience

Background

Invasive fungal diseases (IFDs) are common and contribute to mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). The relative efficacies of posaconazole (POS) and fluconazole (FLU) as primary antifungal prophylaxes are uncertain.

Methods

A retrospective study was performed on children treated with allogeneic HSCT who received POS or FLU during the early neutropenic period. The efficacies, safety, and tolerabilities of the prophylaxes were compared.

Results

Data on 78 HSCT recipients were analyzed. Most had thalassemia (58%). Pre-engraftment, POS and FLU were administered to 41 and 37 cases, respectively. There were no proven cases of IFD. However, 2 POS cases and 1 FLU case had probable IFDs. The IFD incidences of the POS (5%) and FLU (3%) groups demonstrated no statistical difference (p = 0.620). Of the 75 surviving cases receiving FLU post-engraftment (including 39 cases previously given POS), 3 had proven IFDs whereas 3 had probable IFDs (total, 6 [8%]) within 1 year post-HSCT. No cases discontinued the prophylaxes due to drug intolerance. The common adverse events with POS and FLU were not significantly different. Only 19% of the patients achieved the therapeutic POS level, with a starting dose of 4 mg/kg thrice daily.

Conclusion

POS and FLU demonstrate comparable levels of effectiveness, safety, and tolerability as IFD prophylaxes for neutropenic children treated with allogeneic HSCT. Determination of the optimum POS dose and duration requires larger studies.

MYH9 disorder: Identification and a novel mutation in patients with macrothrombocytopenia

The diagnosis of MYH9 disorder is guided by recognizing granulocyte Döhle body-like inclusion bodies and large/giant platelets in the peripheral blood smear. Immunofluorescence study of nonmuscle myosin heavy chain IIA is a sensitive screening method for diagnosis of MYH9 disorder. The diagnosis can then be confirmed by genetic analysis. A total of 67 patients with macrothrombocytopenia were included, of which 11 patients (16%), aged 4 months to 22 years, were ultimately diagnosed with MYH9 disorder. One novel mutation in exon 30 at c.4338T>C (p.F1446A) was detected. This mutation was associated with nonhematologic manifestations presenting in late adolescence with cataracts, hearing loss, and hematuria.

Clinical outcomes and prognosis of Thai retinoblastoma patients

BACKGROUND

Retinoblastoma (RB) outcomes in Thailand are unfavorable compared to those of developed countries. This study aims to determine whether the clinical outcomes of patients with RB significantly improved after the implementation of new therapeutic approaches and which clinical factors affect survival and globe-saving outcomes.

METHODS

The medical records of patients newly diagnosed with RB and treated at Siriraj Hospital between January 2005 and December 2018 were reviewed retrospectively. Clinical data, treatments, and outcomes were collected and analyzed.

RESULTS

In 194 eyes (144 patients), leukocoria was the most common presenting feature (76.8%); 129 (66.5%) eyes were staged in group E of the International Classification of Intraocular Retinoblastoma. Of the 149 enucleated eyes, 35 had high-risk histopathological features, mostly choroidal invasion; 45 eyes (23.2%) could be salvaged. The 5-year overall survival rate was 90.3%, an improvement compared to the previous study. The 5-year enucleation-free survival rates of Groups A and B, C, D and E were 100%, 83.1%, 36.7% and 16.6% respectively. Factors associated with a lower survival rate were interval from symptom onset to diagnosis >3 months (hazard ratio (HR): 5.8: 95% confidence interval (CI): 1.637, 20.579) and buphthalmos (HR: 12.57: 95% CI: 3.936, 40.153). Factors associated with high-risk features were secondary glaucoma (HR: 11.016: 95% CI: 1.24, 98.10) and pseudohypopyon (HR: 14.110: 95% CI: 2.16, 92.05).

CONCLUSIONS

Survival rates and globe-saving rates appear to have improved; however, advanced-stage presentation remains the major hindrance. Further studies with a larger cohort and longer follow-up are warranted.

Using of deferasirox and deferoxamine in refractory iron overload thalassemia

BACKGROUND

Iron overload is a major complication of transfusion-dependent thalassemia (TDT) and requires iron chelation (IC) therapy. However, a combination therapy may be required for patients responding poorly to monotherapy.

METHODS

Nine TDT patients previously treated with IC were enrolled; five patients were previously treated with deferasirox (DFX) twice daily. The dose of DFX was 20-40 mg/kg/day, while the dose of deferoxamine (DFO) was 18-40 mg/kg/day for 3-6 days/week.

RESULTS

At the 6- and 12-month time points, six and eight patients demonstrated decreased serum ferritin levels, with median reductions of 707 ng/mL (range, 1,653-5,444 ng/mL) and 1,129 ng/mL (range, 1,781-7,725 ng/mL) compared to the baseline, respectively. Eight patients also had a reduced liver iron concentration (LIC), with a median reduction of 3.9 mg/g dry wt (range, 8.3-11.1 mg/g dry wt). Of the five patients treated with DFX twice daily, four responded to combination therapy. All responsive patients could finally stop DFO after the decline in LIC. Moreover, there were no treatment-related complications.

CONCLUSION

The combination of DFX and DFO proved to be effective and without significant toxicities for TDT patients who had been unresponsive to standard IC therapy. Further studies with a larger cohort size and long-term follow-up are warranted to elucidate the efficacy of the combination.

Impact of splenectomy on outcomes of hematopoietic stem cell transplantation in pediatric patients with transfusion-dependent thalassemia

BACKGROUND

The role of splenectomy prior to hematopoietic stem cell transplantation (HSCT) is controversial. Only few studies compared the outcomes of splenectomized and nonsplenectomized children with transfusion-dependent thalassemia (TDT) undergoing allogeneic HSCTs.

METHODS

A retrospective analysis was undertaken on a transplantation cohort of TDT patients; August 1987-December 2014 to compare transplant outcomes between splenectomized and nonsplenectomized groups.

RESULTS

Ninety-six transplants in 86 TDT patients were analyzed. Sixteen patients were splenectomized before HSCTs. The splenectomized patients were significantly older (8.0 ± 1.9 vs 4.7 ± 0.6 years; P = 0.001), had larger livers and spleens (P = 0.001), and had a significantly shorter neutrophil engraftment time (absolute neutrophil count > 500/mm³ ; 15.0 ± 2.3 vs 19.2 ± 1.3 days; P = 0.004). Graft rejection occurred in 13.8% of the nonsplenectomized group, but not among the splenectomized patients. Though the splenectomized group's mortality rate was higher (25.0% vs 8.8%), this was not statistically significant (P = 0.491). The main causes of death in both groups were severe infections. The five-year overall survival (OS) rate was better for the nonsplenectomized group (91.78% vs 75.00%; P = 0.06).

CONCLUSIONS

Although splenectomies prior to HSCT for the TDT patients in our cohort were associated with faster neutrophil engraftments and lower rejection rates, they did not produce significantly better OS or affect the mortality. As the splenectomies did not provide any distinct advantages, this procedure should not be routinely performed as a pre-HSCT regimen for TDT patients with splenomegaly. Better pre-HSCT preparation for TDT patients, including early and adequate blood transfusions to avoid splenomegaly, is recommended.

Effect of NUDT15 on incidence of neutropenia in children with acute lymphoblastic leukemia

BACKGROUND

6-Mercaptopurine (6-MP) is considered the backbone of therapy in the maintenance phase of acute lymphoblastic leukemia (ALL). Gene polymorphisms involved in thiopurine degradation are predictors of toxicity in patients treated with 6-MP. We investigated the effects of nucleoside diphosphate linked moiety X (nudix) type motif 15 (NUDT15) polymorphism NUDT15c.415C>T on neutropenia incidence, dose adjustment for 6-MP, and survival rates in Thai children with ALL.

METHODS

Children diagnosed with ALL who received 6-MP in the maintenance phase of treatment, in 2005-2016, were retrospectively enrolled.

RESULTS

The subjects consisted of 102 patients (median age, 5.2 years; 58 boys). On genetic testing 78, 22, and two patients were normal (CC), heterozygous (CT), and homozygous (TT), respectively. The incidence of neutropenia at 3 months was significantly higher in the CT/TT than CC polymorphism groups (OR, 12; 95%CI: 3.781-38.085, P < 0.001). The mean dose of 6-MP at 3, 6, and 12 months was significantly lower in the CT/TT versus the CC group (P < 0.001). The 5 year overall survival (OS) rate for CC was 80.4%, and for CT/TT, 95.5% (P = 0.34). The 5 year event-free survival (EFS) for CC and CT/TT was 75.1% and 85.7%, respectively (P = 0.17). After adjusted risk classification, no significant differences were observed for OS or EFS between the CC and CT/TT groups.

CONCLUSION

Patients harboring the CT/TT polymorphism of NUDT15 had a significantly higher incidence of neutropenia during the first 3 months of maintenance, resulting in significantly lower doses of 6-MP.

Outcomes of pediatric retinoblastoma treated with ICEV regimen: A single-center study

Retinoblastoma is the most common intraocular malignancy in children. The aim of this study was to investigate the efficacy and toxicity of combination ifosfamide, carboplatin, etoposide, and vincristine (ICEV) in advanced-stage pediatric retinoblastoma [International Classification of Retinoblastoma (ICRB) group D or E], and in ICRB group C in the second eye in simultaneously treated bilateral retinoblastoma. The medical records of retinoblastoma patients treated with concurrent ICEV regimen and focal therapy were retrospectively reviewed. The ICEV treatment protocol was, as follows: ifosfamide 1800 mg/m² on Days 1-3; MESNA 600 mg/m² on Days 1-3; carboplatin 560 mg/m² on Day 1; etoposide 150 mg/m² on Days 1-3; and vincristine 1.5 mg/m² on Day 1. Of 16 retinoblastoma patients, 13 had bilateral disease. Seven first eyes in bilateral disease that were enucleated prior to ICEV therapy were excluded. Twenty-two eyes were finally included (six group C, six group D, and ten group E). Median follow-up was 3.4 years, and the median number of ICEV courses was 7. Fifteen globes could be salvaged, 12 responded to ICEV (six group C, five group D, and one group E), and three unresponsive eyes could be salvaged with external beam radiation therapy (EBRT). Enucleation-free and relapse-free survival was 68.2 and 54.5%, respectively. The results of this study suggest ICEV as an alternative therapeutic approach for globe salvage in pediatric retinoblastoma, especially in ICRB groups C and D with manageable acute toxicity. Further study in larger cohort is needed to confirm the effectiveness of treatment.

Eltrombopag for children with chronic immune thrombocytopenia (PETIT2): a randomised, multicentre, placebo-controlled trial

BACKGROUND

The thrombopoietin receptor agonist eltrombopag has been shown to be safe, tolerable, and effective for adults with chronic immune thrombocytopenia. We aimed to investigate the safety and efficacy of eltrombopag for children with chronic immune thrombocytopenia.

METHODS

PETIT2 was a two part, randomised, multicentre, placebo-controlled study done at 38 centres in 12 countries (Argentina, Czech Republic, Germany, Hong Kong, Israel, Italy, Russia, Spain, Taiwan, Thailand, UK, and USA). Paediatric patients aged 1-17 years who had chronic immune thrombocytopenia and platelet counts less than 30 × 10(9) per L were randomly assigned (2:1) to receive eltrombopag or placebo. We stratified patients by age into three cohorts (patients aged 12-17 years, 6-11 years, and 1-5 years) before randomly entering them into a 13 week, double-blind period. Randomisation was done by the GlaxoSmithKline Registration and Medication Ordering System and both patients and study personnel were masked to treatment assignments. Patients who were allocated eltrombopag received tablets (except for those aged 1-5 years who received an oral suspension formulation) once per day for 13 weeks. Starting doses for patients aged 6-17 were based on bodyweight, and ethnic origin and ranged between 50 mg/day and 25 mg/day (starting dose for patients aged 1-5 years was 1·2 mg/kg/day or 0·8 mg/kg/day for east Asian patients). Patients who completed the double-blind period entered a 24 week open-label treatment period in which all patients received eltrombopag at either the starting dose (if they were formerly on placebo) or their established dose. The primary outcome was the proportion of patients achieving platelet counts of at least 50 × 10(9) per L in the absence of rescue therapy for 6 or more weeks from weeks 5 to 12 of the double-blind period. The intention-to-treat population included in the efficacy assessment consisted of all patients who were randomly assigned to one of the treatment groups, and the safety population included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01520909.

FINDINGS

Beginning in March 15, 2012, 92 patients were enrolled, and the trial was completed on Jan 2, 2014. 63 patients were assigned to receive eltrombopag and 29 were assigned to receive placebo. In the double-blind period, three patients discontinued treatment because of adverse events: two patients in the eltrombopag group withdrew because of increased liver aminotransferases and one in the placebo group withdrew because of abdominal haemorrhage. 25 (40%) patients who received eltrombopag compared with one (3%) patient who received placebo achieved the primary outcome of platelet counts of at least 50 × 10(9) per L for 6 of the last 8 weeks of the double-blind period (odds ratio 18·0, 95% CI, 2·3-140·9; p=0·0004). Responses were similar in all cohorts (eltrombopag vs placebo: 39% vs 10% for patients aged 12-17 years, 42% vs 0% for patients aged 6-11 years, and 36% vs 0% for patients aged 1-5 years). Proportionately fewer patients who received eltrombopag (23 [37%] of 63 patients) had WHO grades 1-4 bleeding at the end of the double-blind period than did those who received placebo (16 [55%] of 29 patients); grades 2-4 bleeding were similar (three [5%] patients who received eltrombopag vs two [7%] patients who received placebo). During the 24-week open-label treatment period, 70 [80%] of 87 patients achieved platelet counts of 50 × 10(9) per L or more at least once. Adverse events that occurred more frequently with eltrombopag than with placebo included nasopharyngitis (11 [17%] patients), rhinitis (10 [16%] patients), upper respiratory tract infection (7 [11%] patients), and cough (7 [11%] patients). Serious adverse events occurred in five (8%) patients who received eltrombopag and four (14%) who received placebo. Safety was consistent between the open-label and double-blind periods. No deaths, malignancies, or thromboses occurred during the trial.

INTERPRETATION

Eltrombopag, which produced a sustained platelet response in 40% of patients with chronic immune thrombocytopenia, is a suitable therapeutic option for children with chronic symptomatic immune thrombocytopenia. We identified no new safety concerns and few patients discontinued treatment because of adverse events.

FUNDING

GlaxoSmithKline.

Asthma-like symptoms as a presentation of antiphospholipid syndrome

We herein report a case of antiphospholipid syndrome (APS) primarily presenting with asthma-like symptoms that had been misdiagnosed as severe asthma. Patients presenting with severe asthma symptoms along with systemic thrombosis should be systematically evaluated for APS.

Outcomes of thalassemia patients undergoing hematopoietic stem cell transplantation by using a standard myeloablative versus a novel reduced-toxicity conditioning regimen according to a new risk stratification

Improving outcomes among class 3 thalassemia patients receiving allogeneic hematopoietic stem cell transplantations (HSCT) remains a challenge. Before HSCT, patients who were ≥ 7 years old and had a liver size ≥ 5 cm constitute what the Center for International Blood and Marrow Transplant Research defined as a very high-risk subset of a conventional high-risk class 3 group (here referred to as class 3 HR). We performed HSCT in 98 patients with related and unrelated donor stem cells. Seventy-six of the patients with age < 10 years received the more conventional myeloablative conditioning (MAC) regimen (cyclophosphamide, busulfan, ± fludarabine); the remaining 22 patients with age ≥ 10 years and hepatomegaly (class 3 HR), and in several instances additional comorbidity problems, underwent HSCT with a novel reduced-toxicity conditioning (RTC) regimen (fludarabine and busulfan). We then compared the outcomes between these 2 groups (MAC versus RTC). Event-free survival (86% versus 90%) and overall survival (95% versus 90%) were not significantly different between the respective groups; however, there was a higher incidence of serious treatment-related complications in the MAC group, and although we experienced 6 graft failures in the MAC group (8%), there were none in the RTC group. Based on these results, we suggest that (1) class 3 HR thalassemia patients can safely receive HSCT with our novel RTC regimen and achieve the same excellent outcome as low/standard-risk thalassemia patients who received the standard MAC regimen, and further, (2) that this novel RTC approach should be tested in the low/standard-risk patient population.

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.

Deferiprone (GPO-L-ONE(®) ) monotherapy reduces iron overload in transfusion-dependent thalassemias: 1-year results from a multicenter prospective, single arm, open label, dose escalating phase III pediatric study (GPO-L-ONE; A001) from Thailand

Accessibility to iron chelators including deferoxamine and deferasirox remains obscured in many developing countries. To provide an alternative, the government pharmaceutical organization of Thailand (GPO) manufactured deferiprone which has similar bioequivalent to the standard product. Seventy-three pediatric patients with severe β thalassemias, age range 3.2-19 years, were recruited to a 1-year multicenter prospective, single arm, open label, dose escalating Phase III study of deferiprone to determine its clinical efficacy and safety. Sixty-four patients (87.6%) completed the study with good compliance (>94%). Average deferiprone dose was 79.1±4.3 mg/kg/day. Overall, mean serum ferritin (SF) levels at 1 year were not significantly changed from baseline. However, 45% of patients (response group) had SF reduced >15% from baseline at 1 year with a median reduction of 1,065 ng ml(-1) . Baseline SF was the major factor that predicts clinical efficacy; patients with baseline SF>3,500 ng ml(-1) had the most significant fall of SF at 1 year. A subgroup analysis by MRI-T2* confirmed that the response group had higher baseline liver iron and deferiprone could significantly reduce liver iron overload and normalize levels of ALT at 1 year. Although, gastrointestinal irritation (20.5%) was the most common drug-related adverse events (AEs) followed by transaminitis (16.4%) and neutropenia (6.8%), all patients were well tolerated. There was no mortality and agranulocytosis found in this trial. Monotherapy of deferiprone with appropriate dose adjustment and monitoring for adverse events appeared to be an effective chelation therapy in some patients with good compliance and acceptable safety profiles.

A 13-year-old female with Xp11.2 translocation renal cell carcinoma; the first case diagnosed at Siriraj Hospital

Xp11.2 translocation renal cell carcinomas are rare tumors characterized by translocations involving chromosome Xp11.2. These tumors are predominantly reported in pediatric patients. The authors report Xp11.2 translocation renal cell carcinoma in a 13-year-old girl who presented with asymptomatic palpable right renal mass. Right radical nephrectomy was performed and revealed a well-defined solid mass at the lower pole of the kidney. Microscopically, the tumor was composed of sheets and nests of clear to pale eosinophilic cells with some alveolar growth pattern. Psammoma bodies were detected. Immunohistochemically, the tumor cells marked with TFE3, focally marked with smooth muscle actin, HMB-45, CD68, progesterone receptor (PR) and CD10 but did not mark with epithelial markers (AE1/AE3, EMA and CAM5.2), vimentin, S-100 and p53. The presence of psammoma bodies is an important diagnostic clue for these tumors. Cytogenetic study and/or immunohistochemistry for TFE3 protein are needed for confirming the diagnosis. Currently, surgery seems to be the most effective therapy Pediatric patients with these tumors are believed to have a favorable prognosis.

Inter-site validations of the Pixel-Wise method for cardiac T2* analysis in transfusion-dependent Thai thalassemia patients

OBJECTIVE

To compare inter-site observer variability of the Pixel- Wise (PW) method for cardiac T2* analysis in thalassemia patients using the mono-exponential with a constant fitting (offset) model and to compare the cross-model variability of the offset model to the mono-exponential (typical) model.

MATERIAL AND METHOD

Eighty-eight cardiac T2* measurements were performed on 72 Thalassemia major patients. Both bright- and black-blood techniques were acquired and analyzed at both the reference (REF) and local (LOC) sites using the PW method by defined region of interest on the whole (at the REF site) and partial (at the LOC site) septum. The offset model was analyzed at the reference site while both the offset and typical models were performed at the local site. The inter-site variability of the T2* values were analyzed by independent observers blinded to the results.

RESULTS

The T2* values from the REF-offset, LOC-offset and LOC-typical methods were statistically comparable on both scanning techniques. The inter-site variations of the offset model were about 5.2% and 4.4% on the bright- and black-blood techniques, respectively, which was about 1.7% higher than from the intra-site, but was still in a reasonable range compared to the conventional method of around 5.4%. The cross-model comparisons presented with 0.4 ms of bias and variation of about 6.9% and 4.7%, respectively, which is about 1.4% higher than from the intra-site.

CONCLUSION

The observer variability on the PW method using the offset or typical model provided equivalent coefficient of variation on both scanning techniques, which was also comparable to the previous reports. The inter-site variability of the offset and cross models was also in a reasonable range, being less than 2% higher than the intra-site with bias of about 0.4 ms.

Outcome of children with aplastic anemia treated with immunosuppressive therapy

BACKGROUND

Immunosuppressive therapy (IST) is the alternative treatment in children with aplastic anemia (AA) who do not have an HLA-matched sibling. The aim of this study is to evaluate the outcome of children with AA treated with IST.

METHODS

We retrospectively reviewed the hospital records of children with AA from 1984 to 2004, treated at our institution with antithymocyte globulin (ATG), cyclosporine (CS), and short course of prednisone.

RESULT

Forty-two patients were treated with IST (24 boys, 18 girls); of whom 26% received G-CSF. The median age at diagnosis was 8.5 years. Sixty-nine, 19, and 12% were diagnosed with severe, very severe, and moderate AA, respectively. Twenty-one percent had hepatitis-associated AA. Median follow-up time was 53.3 months. Sixty-two percent had complete response; 19% had partial response. Two patients relapsed and received a second course of ATG; both had a partial response. The actuarial 5 years survival rate was 67.5%. Two patients developed myelodysplastic syndrome (MDS); both received long-term G-CSF and had partial response after two courses of IST. Fifteen percent of survivors had significant hypertension which persisted after CS was discontinued.

CONCLUSIONS

This study shows promising response in children with AA treated with IST; however, the outcome was inferior to our institutional results with hematopoietic stem cell transplantation from a sibling donor. Hypertension and MDS are late complications. Longer follow-up, larger cohorts, and prospective studies are warranted to evaluate late complications and risk factors.

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.

Recombinant activated factor VII combined with local measures in preventing bleeding from invasive dental procedures in patients with Glanzmann thrombasthenia

Recombinant activated factor VII (rFVIIa), combined with local measures of fibrin glue and a celluloid splint, preventing bleeding from four invasive dental procedures is reported. A single dose of 180-200 micro g/kg was successfully used in three surgical removals of impacted teeth. Four doses of rFVIIa were required in another full mouth treatment of extraction, pulpotomy, filling and the stainless steel crowning of 13 teeth. The repeated dose of rFVIIa was given whenever the bleeding complication was visualized. It is cost-effective for preventing external bleeding. Additionally, an oral rinsing solution of tranexamic acid (25 mg/kg) was given three times a day for 7 days. In conclusion, rFVIIa has been shown to be an effective alternative to platelet concentrate in patients with Glanzmann thrombasthenia.