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Fulltext Genetic variants in HBS1L-MYB rs9399137 and rs11759553 associated with elevated HbF levels among Filipino β°-deletion carriers

Lai, Kuan Teh, Koh, Sam Yu, Shi, Min Chua, George, Elizabeth, Mei, I Lai, Wong, Lily

Journal of Biomedical and Clinical Sciences, 2017;2(202):28-29.
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In Malaysia, Sabah population constitutes the most number of β-thalassaemia cases ranging from asymptomatic to transfusion dependent. Filipino β°-deletion has been reported as the predominant mutation in Sabah [1]. Despite having the same primary mutation, co-inheritance of genetic variants at HbF quantitative trait loci of HBS1L-MYB intergenic region may cause variability in clinical features by affecting the haemoglobin (Hb) subtypes level, especially HbF. Study suggested that MYB would activate γ-globin repressor gene directly and subsequently initiate the molecular HbF repression mechanisms. Polymorphisms within HBS1L-MYB intergenic region would inhibit binding of transcription factor on MYB and leading to elevation of HbF levels [2]. This can act as an ameliorating factor in the clinical presentation of β-thalassaemia patients [3]. This study aimed to elucidate the association of Hb subtypes levels with three HBS1L-MYB variants among 134 Filipino β°-deletion carriers. PCR-RFLP analysis was done for HBSIL-MYB rs4895441 (A→G) while tetra-primers ARMS PCR analysis was done for HBSIL-MYB rs9399137 (T→C) and rs11759553 (A→T) (Fig.1).
HbA2 levels in β-thalassaemia carriers with the Filipino β0-deletion: are the levels higher than what is found with non-deletional forms of β0-thalassaemia?

George E, Teh LK, Tan J, Lai MI, Wong L

Pathology, 2013 01;45(1):62-5.
PMID: 23222244 DOI: 10.1097/PAT.0b013e32835af7c1

AIMS: Classical carriers of β-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino β-deletion has high raised HbA2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser is a common instrument used to quantify HbA2 levels in thalassaemia screening. This study aimed to determine HbA2 levels in carriers of Filipino β-mutation using the BioRad Variant II Hb analyser.
METHODS: The Filipino β-deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β-thalassaemia patients who were homozygous for the Filipino β-deletion in the indigenous population of Sabah, Malaysia. Hb subtypes were quantified on the BioRad Variant II Hb analyser. Concurrent α-thalassaemia was identified by multiplex gap-PCR for deletions and amplification refractory mutation system (ARMS)-PCR for non-deletional mutations.
RESULTS: The mean HbA2 level for Filipino β-thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α heterozygous) and 6.7 ± 0.36 (-α homozygous). The HbA2 levels were all >4% in keeping with the findings of classical β-thalassaemia trait and significantly higher than levels seen in non-deletional forms of β-thalassaemia.
CONCLUSION: The HbA2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β-thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α) is associated with significantly higher HbA2 level.
Molecular basis of transfusion dependent beta-thalassemia major patients in Sabah

Teh LK, George E, Lai MI, Tan JA, Wong L, Ismail P

J Hum Genet, 2014 Mar;59(3):119-23.
PMID: 24369358 DOI: 10.1038/jhg.2013.131

Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of β-thalassemia major patients. Accurate population frequency data of the molecular basis of β-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of β-globin gene defects was done in 252 transfusion dependent β-thalassemia patients incorporating few PCR techniques. The study demonstrates that β-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent β-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino β(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of β-thalassemia major in Sabah.
Susceptibility to aplastic anemia is associated with HLA-DRB1*1501 in an aboriginal population in Sabah, Malaysia

Dhaliwal JS, Wong L, Kamaluddin MA, Yin LY, Murad S

Hum Immunol, 2011 Oct;72(10):889-92.
PMID: 21762745 DOI: 10.1016/j.humimm.2011.06.013

The incidence of aplastic anemia is reported to be higher in Asia than elsewhere. We studied the frequency of human leukocyte antigen (HLA) DRB1 alleles in aplastic anemia patients from 2 genetically similar aboriginal groups, the Kadazan and the Dusun, and compared them with genetically matched community and hospital controls. HLA-DRB1*15 was significantly higher in the patients compared with controls (p = 0.005), confirming similar findings in Japanese and Caucasian studies. Further testing indicated a significantly higher frequency of HLA-DRB1*1501 in patients compared with controls (p = 0.0004) but no significant difference in the frequency of HLA-DRB1*1502. The high frequency of HLA-DRB1*15 in the Kadazan and Dusun population combined with the wide variety of environmental factors associated with aplastic anemia could be the reason for the elevated incidence of aplastic anemia in the Kadazan and Dusun in Sabah.
Fulltext Iptacopan monotherapy in patients with paroxysmal nocturnal hemoglobinuria: a 2-cohort open-label proof-of-concept study

Jang JH, Wong L, Ko BS, Yoon SS, Li K, Baltcheva I, et al.

Blood Adv, 2022 08 09;6(15):4450-4460.
PMID: 35561315 DOI: 10.1182/bloodadvances.2022006960

Iptacopan (LNP023) is a novel, oral selective inhibitor of complement factor B under clinical development for paroxysmal nocturnal hemoglobinuria (PNH). In this ongoing open-label phase 2 study, PNH patients with active hemolysis were randomized to receive single-agent iptacopan twice daily at a dose of either 25 mg for 4 weeks followed by 100 mg for up to 2 years (cohort 1) or 50 mg for 4 weeks followed by 200 mg for up to 2 years (cohort 2). At the time of interim analysis, of 13 PNH patients enrolled, all 12 evaluable for efficacy achieved the primary endpoint of reduction in serum lactate dehydrogenase (LDH) levels by ≥60% by week 12 compared with baseline; mean LDH levels dropped rapidly and durably, namely by 77% and 85% at week 2 and by 86% and 86% at week 12 in cohorts 1 and 2, respectively. Most patients achieved a clinically meaningful improvement in hemoglobin (Hb) levels, and all but 1 patient remained transfusion-free up to week 12. Other markers of hemolysis, including bilirubin, reticulocytes, and haptoglobin, showed consistent improvements. No thromboembolic events were reported, and iptacopan was well tolerated, with no severe or serious adverse events reported until the data cutoff. In addition to the previously reported beneficial effect of iptacopan add-on therapy to eculizumab, this study showed that iptacopan monotherapy in treatment-naïve PNH patients resulted in normalization of hemolytic markers and rapid transfusion-free improvement of Hb levels in most patients. This trial was registered at www.clinicaltrials.gov as #NCT03896152.
Fulltext A phase III, randomised, double-blind, multi-national clinical trial comparing SB12 (proposed eculizumab biosimilar) and reference eculizumab in patients with paroxysmal nocturnal haemoglobinuria

Jang JH, Gomez RD, Bumbea H, Nogaieva L, Wong LLL, Lim SM, et al.

EJHaem, 2023 Feb;4(1):26-36.
PMID: 36819188 DOI: 10.1002/jha2.632

Treatment of paroxysmal nocturnal haemoglobinuria (PNH) includes the monoclonal antibody eculizumab. This randomised, double-blind, multi-national cross-over Phase III study in PNH patients aimed to demonstrate the equivalence of the proposed eculizumab biosimilar SB12 and reference eculizumab (Soliris, ECU). PNH patients with lactate dehydrogenase (LDH) ≥1·5× upper limit of normal were randomised into treatment sequences SB12-ECU or ECU-SB12. Four weekly infusions of 600 mg eculizumab were followed by fortnightly infusions of 900 mg until week 50 (ECU/SB12 cross-over at week 26). Primary endpoints were LDH at week 26 and the time-adjusted area under the effect curve (AUEC) of LDH over weeks 14‒26 and 40‒52. Among 46 patients (92%) who completed the study, the least squares mean (LSM) difference in LDH at week 26 (34·48; 95% confidence interval [CI] -47·66‒116·62 U/l) and geometric LSM ratio of time-adjusted AUEC of LDH (1·08; 90% CI 0·95‒1·23) were within pre-defined equivalence margins. Mean numbers of transfused red blood cell units, other secondary endpoints, pharmacokinetics, and pharmacodynamics were comparable. No patients developed anti-drug antibodies. Treatment-emergent adverse events were reported in 72% and 68% of patients in the SB12 and ECU treatment groups, respectively. The results demonstrate equivalence of SB12 to ECU and support SB12-use in PNH patients.
MRI for the diagnosis of cardiac and liver iron overload in patients with transfusion-dependent thalassemia: An algorithm to guide clinical use when availability is limited

Viprakasit V, Ajlan A, Aydinok Y, Al Ebadi BAA, Dewedar H, Ibrahim AS, et al.

Am J Hematol, 2018 06;93(6):E135-E137.
PMID: 29473204 DOI: 10.1002/ajh.25075
Fulltext Clinical Significance of BCL2, C-MYC, and BCL6 Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients

Ting CY, Chang KM, Kuan JW, Sathar J, Chew LP, Wong OJ, et al.

Int J Med Sci, 2019;16(4):556-566.
PMID: 31171907 DOI: 10.7150/ijms.27610

Background: Clinical significance of germinal center B-cell (GCB) and non-GCB sub-categorization, expression of MYC, BCL2, BCL6, CD5 proteins and Epstein Barr virus encoded RNA (EBER) positivity in diffuse large B-cell lymphoma (DLBCL) remain controversial. Could these biomarkers accurately identify high risk DLBCL patients? Are MYC, BCL2 and BCL6 proteins expression feasible as baseline testing to predict c-Myc, BCL2 or BCL6 gene rearrangements? Aims: To investigate prognostic values of GCB/non-GCB sub-categorization, Double Protein Expression Lymphoma (DPL), Triple Protein Expression Lymphoma (TPL), positivity of CD5 protein and EBER in patients with DLBCL disease. To evaluate correlation between BCL2 , c-Myc and BCL6 gene rearrangements with BCL2, MYC and BCL6 proteins expression. Methods: Diagnostic tissue samples of 120 DLBCL patients between January 2012 to December 2013 from four major hospitals in Malaysia were selected. Samples were subjected to immunohistochemical staining, fluorescent in-situ hybridization (FISH) testing, and central pathological review. Pathological data were correlated with clinical characteristics and treatment outcome. Results: A total of 120 cases were analysed. Mean age of diagnosis was 54.1 years ± 14.6, 64 were males, 56 were females, mean follow up period was 25 months (ranged from 1 to 36 months). Of the 120 cases, 74.2% were non-GCB whereas 25.8% were GCB, 6.7% were EBER positive, 6.7% expressed CD5 protein, 13.3% were DPL and 40% were TPL. The prevalence of c-Myc, BCL2, BCL6 gene rearrangements were 5.8%, 5.8%, and 14.2%, respectively; and 1.6% were Double Hit Lymphoma (DHL). EBER positivity, DPL, TPL, c-Myc gene rearrangement, BCL2 gene rearrangement, extra copies of BCL2 gene and BCL6 gene rearrangement were associated with shorter median overall survival (P<0.05). IPI score was the significant determinants of median overall survival in DPL and TPL (P<0.05). CD5 protein expression and GCB/non-GCB sub-categorization did not affect treatment outcome (P>0.05). Overall, c-Myc, BCL2 and BCL6 gene rearrangements showed weak correlation with expression of MYC, BCL2 and BCL6 proteins (P>0.05). Fluorescent in situ hybridization is the preferred technique for prediction of treatment outcome in DLBCL patients. Conclusion:c-Myc, BCL2, and BCL6 gene rearrangements, EBER expression, DHL, TPL and IPI score are reliable risk stratification tools. MYC, BCL2 and BCL6 proteins expression are not applicable as baseline biomarkers to predict c-Myc, BCL2, and BCL6 gene rearrangements.
The epidemiology and clinical characteristics of myeloproliferative neoplasms in Malaysia

Yap YY, Law KB, Sathar J, Lau NS, Goh AS, Chew TK, et al.

Exp Hematol Oncol, 2018;7:31.
PMID: 30564475 DOI: 10.1186/s40164-018-0124-7

Background: The evolution of molecular studies in myeloproliferative neoplasms (MPN) has enlightened us the understanding of this complex disease consisting of polycythaemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The epidemiology is well described in the western world but not in Asian countries like Malaysia.
Materials and methods: This retrospective national registry of MPN was conducted from year 2009 to 2015 in Malaysia.
Results: A total of 1010 patients were registered over a period of 5 years. The mean age was 54 years with male predominance. The ethnic distribution revealed that Chinese had a relatively high weighted incidence proportion (43.2%), followed by Indian (23.8%), Malay (15.8%) and other ethnic groups (17.2%). The types of MPN reported were 40.4% of ET (n = 408), 38.1% of PV (n = 385), 9.2% of PMF (n = 93), 3.1% of hypereosinophilic syndrome (HES) (n = 31) and 7.9% of unclassifiable MPN (MPN-U) (n = 80). Splenomegaly was only palpable clinically in 32.2% of patients. The positive JAK2 V617F mutation was present in 644 patients with 46.6% in PV, 36.0% in ET, 9.0% in PMF, and 7.4% in MPN-U, and had significantly lower haemoglobin (p
Fulltext Asian-Pacific perspective on the psychological well-being of healthcare workers during the evolution of the COVID-19 pandemic

Chew NWS, Ngiam JN, Tan BY, Tham SM, Tan CY, Jing M, et al.

BJPsych Open, 2020 Oct 08;6(6):e116.
PMID: 33028449 DOI: 10.1192/bjo.2020.98

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to significant strain on front-line healthcare workers.
AIMS: In this multicentre study, we compared the psychological outcomes during the COVID-19 pandemic in various countries in the Asia-Pacific region and identified factors associated with adverse psychological outcomes.
METHOD: From 29 April to 4 June 2020, the study recruited healthcare workers from major healthcare institutions in five countries in the Asia-Pacific region. A self-administrated survey that collected information on prior medical conditions, presence of symptoms, and scores on the Depression Anxiety Stress Scales and the Impact of Events Scale-Revised were used. The prevalence of depression, anxiety, stress and post-traumatic stress disorder (PTSD) relating to COVID-19 was compared, and multivariable logistic regression identified independent factors associated with adverse psychological outcomes within each country.
RESULTS: A total of 1146 participants from India, Indonesia, Singapore, Malaysia and Vietnam were studied. Despite having the lowest volume of cases, Vietnam displayed the highest prevalence of PTSD. In contrast, Singapore reported the highest case volume, but had a lower prevalence of depression and anxiety. In the multivariable analysis, we found that non-medically trained personnel, the presence of physical symptoms and presence of prior medical conditions were independent predictors across the participating countries.
CONCLUSIONS: This study highlights that the varied prevalence of psychological adversity among healthcare workers is independent of the burden of COVID-19 cases within each country. Early psychological interventions may be beneficial for the vulnerable groups of healthcare workers with presence of physical symptoms, prior medical conditions and those who are not medically trained.