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.

How do we translate gaps and unmet needs of blood management for thalassemia into a collaborative implementation framework?

BACKGROUND AND OBJECTIVE: The mainstay of management for thalassemia is regular blood transfusions. However, gaps and unmet needs of blood services for thalassemia are still not clearly identified and addressed in Thailand, a country prevalent with thalassemia. What can be a collaborative implementation framework that helps advance practices and policies relating to blood management for thalassemia? METHODS: The first Blood & Beyond Roundtable Discussion was held in July 2022 to gather the current situation, gaps, and unmet needs of blood services for thalassemia from multidisciplinary experts and thalassemic patients. The Implementation Guide as suggested by the Centre for Effective Services was applied as a tool to consolidate information from the discussions and construct the collaborative implementation framework. RESULTS: The National Blood Center and hospitals in Thailand followed the missions specified in the National Blood Policy and the standard guidelines to ensure the best practice of blood management for thalassemia. However, there were six gaps and unmet needs identified from the discussions. After all discussion points were mapped onto the framework, an implementation plan comprised of five specific activities became clear and actionable. CONCLUSION: Without the complete information from both experts and patients, the implementation plan would not have been successfully constructed. The method that we employed to translate all information into the framework can be adapted by other countries to develop their own specific framework efficiently.

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.

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.

Diagnostic applications of newborn screening for α-thalassaemias, haemoglobins E and H disorders using isoelectric focusing on dry blood spots.

BACKGROUND: Neonatal screening for haemoglobin (Hb) disorders is a standard of care in several developed countries with the main objective to detect Hb S. Such practice has not been established in Thailand where α-thalassaemia and haemoglobin E (Hb E) are highly prevalent. Early identification of thalassaemias could be helpful and strengthen the programme for prevention and control for severe thalassaemias. METHODS: Data from isoelectric focusing (IEF) and Isoscan® for detecting types and amount (%) of each haemoglobin in 350 newborn's dried blood spots were analysed and compared with the comprehensive genotype analysis by DNA studies as a gold standard. RESULTS: Based on genetic profiles, there were 10 different categories: (1) normal (n = 227), (2) α(+)-thalassaemia trait (n = 14), (3) α(0)-thalassaemia trait (n = 13), (4) ß(0)-thalassaemia trait (n = 7), (5) Hb E trait (n = 72), (6) Hb E trait with α(0)-thalassaemia or homozygous α(+)-thalassaemia (n = 5), (7) Hb E trait with α(+)-thalassaemia trait (n = 5), (8) homozygous Hb E (n = 3), (9) homozygous Hb E with α(0)-thalassaemia trait (n = 1) and (10) Hb H disease (n = 3). The presence of Hb Bart's and Hb E were used to identify cases with α-thalassaemia and Hb E, respectively. We set 0.25% of Hb Bart's and 1.5% of Hb E as a cut-off level to detect α(+)-thalassaemia trait (sensitivity 92.86% and specificity 74.0%) and Hb E trait with 100% of both sensitivity and specificity for IEF diagnosis. CONCLUSION: Although molecular diagnosis seems to be better for definitive diagnosis of thalassaemia syndromes at birth, however, using our reference range described herein, IEF can be applied in a resource-limiting setting with acceptable reliability.

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 ß 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.

Outcome of Kasabach-Merritt phenomenon: the role of vincristine as monotherapy: report of a case.

Kasabach-Merrit phenomenon (KMP) is a rare disorder of pediatric hematological malignancies which is previously referred to Kasabach-Merrit syndrome (KMS). The disorder is characterized by prominent vascular mass resulting from abnormal proliferation of blood vessels, consumption coagulopathy and thrombocytopenia. The diagnosis is based upon three basic findings as above. The authors describe a 6-month-old girl with a huge ecchymotic mass at left buttock who is found to have thrombocytopenia and consumption coagulopathy. The clinical and imaging studies strongly suggested the diagnosis of KMP. Vincristine was administered after a trial of corticosteroids was failed to show clinical and laboratory improvement. After 2 weeks, the patient showed that the platelet count and fibrinogen level become to be normal without blood transfusion and gradually decreased in tumor size without any surgical procedure in 4 weeks and disappeared in 5 months without any complications. In the present report, the authors present the findings from successfully specific treatment with vincristine alone and supportive treatment for life-threatening hemorrhage with platelet concentrate and cryoprecipitate should be the best management in our situation.

Health-related quality of life in Thai thalassemic children treated with iron chelation.

Thalassemia is a chronic hereditary disease in which patients with severe disease present with anemia during their first year of life. In Thailand, stem cell transplantation is not an option for most patients. Supportive treatments, such as blood transfusions and iron chelation are used. Little data exists regarding the Health Related Quality of Life (HRQoL) of these patients. We conducted a study of the four dimensions of quality of life: physical, emotional, social, and role (school) functioning, using the PedsQL 4.0 Generic Core Scale to measure the HRQoL among thalassemic patients at the Hematology Unit, Department of Pediatrics, Phramongkutklao Hospital, during December 1, 2006 - November 30, 2007 to evaluate the quality of life in thalassemic patients treated with three iron-chelating agents. Forty-nine thalassemic patients were enrolled and treated with iron-chelating agents. The mean (SD) age of the patients was 10.61 years (4.33). Fifteen thalassemic patients were treated with desferrioxamine, 18 with deferiprone and 16 with deferasirox. The quality of life (QOL) results show the mean (SD) total summary score was 74.35 (12.42). For the psychosocial health summary, the social and school functioning scores were 85.40 (16.67) and 62.14 (15.84), respectively. The QOL scores of the patients who received desferrioxamine, deferiprone and deferasirox were 75.29 (9.09), 73.91 (15.25) and 73.98 (12.32), respectively (p = 0.94). The QOL had no significant differences by age, gender, type of thalassemia or serum ferritin level. Multivariate regression analysis showed no significant differences in clinical severity, age of onset or pre-transfusion hematocrit levels.

Factors affecting health-related quality of life in Thai children with thalassemia.

BACKGROUND: Knowledge of the factors associated with health-related quality of life (HRQOL) among patients with thalassemia is essential in developing more suitable clinical, counseling, and social support programs to improve treatment outcomes of these patients. In light of the limited research in this area, this study aims to examine factors associated with HRQOL among children and adolescents with thalassemia in Thailand. METHODS: A cross-sectional survey was conducted in three selected hospitals in Thailand during June to November 2006. PedsQL 4.0 Generic Core Scale (Thai version) was used to assess HRQOL in 315 thalassemia patients between 5 and 18 years of age. Other related clinical characteristics of the patients were collected via medical record review. RESULTS: The mean (SD) of the total summary score was 76.67 (11.40), while the means (SD) for the Physical Health Summary score and Psychosocial Health Summary score were 78.24 (14.77) and 75.54 (12.76), respectively. The school functioning subscale scored the lowest, with a mean of 67.89 (SD = 15.92). The following factors significantly affected the HRQOL of the patients: age; age at onset of anemia and age at first transfusion; pre-transfusion hemoglobin (Hb) level; receiving a blood transfusion during the previous three months; and disease severity. In addition, iron chelation therapy had a significant negative effect on HRQOL in the school functioning subscale. In contrast, serum ferritin level, frequency of blood transfusions per year, and gender were not significantly related to HRQOL among these patients. The results from multivariate analysis also confirmed these findings. CONCLUSIONS: To improve HRQOL of thalassemia patients, suitable programs aimed at providing psychosocial support and a link between the patient, school officials, the family and the physician are important, especially in terms of improving the school functioning score. The findings also confirmed the importance of maintaining a pre-transfusion Hb level of at least 9-10.5 g/dL. In addition, special care and attention should be given to patients with a severe condition, and those who are receiving subcutaneous iron chelation therapy.

Economic burden of beta-thalassemia/Hb E and beta-thalassemia major in Thai children.

BACKGROUND: Hemoglobin E beta-thalassemia (beta-thalassemia/Hb E) has a variable severity, and the cost of treatment has not been well studied. The aim of this study was to analyze the societal cost of caring for children with beta-thalassemias in Thailand. The study was designed as a prevalence-based cost-of-illness analysis in a societal perspective. Medical records from three public hospitals of children aged 2-18 years with beta-thalassemia/Hb E and homozygous beta-thalassemia were reviewed for direct medical cost determination. For direct non-medical cost and indirect cost, a family member was interviewed. FINDINGS: It was found that 201 patients with beta-thalassemia/Hb E (91%) and homozygous beta-thalassemia (9%) were recruited for this study. Ninety-two (46%) were severe thalassemia and 109 (54%) were mild to moderate severity. The annual average cost of treatment was US$950; 59% was direct medical cost, 17% direct non-medical cost, and 24% indirect cost. The costs were differentiated by some potential predictors. Significant predictor variables were: hospital, health insurance scheme, blood transfusion pattern, and iron chelation drug use. CONCLUSIONS: The average annual cost per patient was calculated, and the cost model was estimated. These would be applied for national planning, economic evaluation of treatment and prevention interventions, and budget impact analysis.

Effect of different transfusion regimens on craniofacial appearance and dentition in severe thalassemic children.

Thalassemia is a group of inherited diseases with a defect in the synthesis of hemoglobin. Severe thalassemic subjects suffer from craniofacial deformities and malocclusion due to bone marrow hyperplasia compensating for ineffective erythropoiesis. Blood transfusions are used to maintain life and reduce complications. The transfusions may have benefits in reducing craniofacial and dentition abnormalities. However, appropriate therapy is still controversial. This study evaluated the effect of different transfusion regimens on craniofacial appearance and dentition. Ninety-two severe thalassemic patients, aged 6 -13 years, were divided into 3 groups according to the frequency of transfusion: 1) high transfusion: more than 12 times/year. 2) low transfusion: 6-12 times/year. 3) occasional transfusion: less than 5 times/year. The appearance and dentition were evaluated and compared among groups. Most subjects in the high transfusion group had a normal appearance and a class I molar and incisor relationship with normal overjet and overbite. More than half of subjects in the low and occasional groups showed craniofacial abnormalities and malocclusion, particular in the occasional group. Frequency of transfusion has an effect on craniofacial appearance and dental occlusion; only high frequent transfusions were effective in preventing craniofacial and dental defects.

Use of the gel test to follow up chimerism in ABO mismatched bone marrow transplantation patient: a case report.

OBJECTIVE: The authors report here our experience using the gel test to follow up chimerism in a 5 year old girl with beta thalassemia/Hemoglobin E disease (beta thal/HbE), post allogeneic bone marrow transplantation with Hb E trait HLA identical sibling donor. They were ABO blood group major mismatched donor-recipient pairs (donor and recipient blood group are B and O, respectively). MATERIAL AND METHOD: Pre and post transplanted EDTA blood samples from the girl with beta thalassemia/ Hemoglobin E were tested for ABO, Rh and direct antiglobulin test (DAT) using the A-B-AB-D-ctl/ AHG card and the titer of anti-A and anti-B were tested by the conventional tube technique. The sex chromosome study and hemoglobin typing were also examined. RESULTS: In this technique, mixed field agglutination is clearly identified from positive and negative results. The authors detected peripheral recovery, mixed O/B population after transplantation on day +26 with positive DAT. The DAT was negative on day +67 after transplantation and the recipient blood group was completely changed to B on day +123. In addition, Hb typing was changed to Hb E trait with Hb F less than 5 % on day +37. The engraftment of neutrophils, more than 5x10(9)/L, was detected on day+14 and platelet count was more than 20x10(9)/L on day +28. On day +90, the patient was transfusion-independent with the mean Hb level at 11.4 g/dL (10.4-13.1). The sex chromosome and hemoglobin typing were changed to the donor on day +300. CONCLUSION: The gel test is an alternative method which is simple and helpful in detecting mixed red blood cell populations, particularly in the ABO or other blood group mismatched bone marrow transplantation.