Recent improvement in the treatment and management of α-thalassaemia has enabled patients to live longer and have better quality of life, thus revealing other complications related to the disorder mainly due to the effects of chronic ineffective erythropoiesis and iron overload. We review the renal dysfunction seen in α-thalassaemia as it has been reported (published and personal communication) that the complications presented are more severe than those found in β-thalassaemia patients of similar severity clinically. This review aims to shed light on emerging com- plications that are currently faced by α-thalassaemia patients as they progress further in life.
Introduction: Iron deficiency anaemia (IDA) is the most common cause of anaemia worldwide. Determination of body iron status is necessary to diagnose IDA. This can be measured using a biochemistry assessment of the serum/ plasma. Plasma/serum iron quantitation is also important in diagnosing iron overload disorders. However, iron studies are limited due to high cost and lack of access to biochemical analysers. Therefore, a cost- and technical-ef- fective method is needed to measure human plasma iron concentration. Plasma iron is mainly transferrin-bound and an acidic plasmic condition is necessary to release the iron. This study investigated various candidate acid salts to achieve the acidic condition needed for plasma iron release. Method: Ten powdered or crystallised acid salts were studied for their water solubility as well as their pH reduction capability in revised simulated body fluid (r-SBF) and commercially available human plasma without any change in colour or form. Results: Six acid salts studied were discontinued from further investigation because they were insoluble in water. Another two candidates were unsuitable as they precipitated in r-SBF and human plasma. Maleic acid formed a jelly-like texture after a certain amount of time in human plasma. Only citric acid met all the criteria of a suitable acid salt to be investigated further as part of the reagent for a spontaneous plasma iron measurement. Conclusion: Citric acid, which is a colourless and odourless acid salt, was selected to lower the human plasma pH to an acidic condition for transferrin-bound iron release.
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).
Complete blood count (CBC) is used broadly to screen individual's general health status. Some inherited red blood cell (RBC) disorders influence the RBC parameters. Mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) are amongst the important RBC parameters used in thalassaemia-haemoglobinopathy screening [1-2]. Globin chain disorders and Southeast Asian Ovalocytosis (SAO) are common RBC disorders in Southeast Asian countries [3]. We evaluated the RBC parameters in patients with Hb E and those with SAO co-inheritance.
A total of 33 from 1500 Malay patient’s samples that were sent for thalassaemia-haemoglobinopathies screening in Hospital Kuala Lumpur (HKL) were identified and consented (30 cases with Hb E and 3 cases with co-inheritance of Hb E and SAO). The inclusion criteria were Malay patients with MCV and MCH levels less than 78 fL and 27 pg respectively with presence of oval and stomatocytic RBCs in the peripheral blood film. DNA extraction was performed in samples suspected of having co-inheritance of SAO and Hb E. Primers 198 and 199 (AIT biotech Pte Ltd. Singapore) were designed for SAO detection [4], [5]. Hb E mutation was detected using ARMS PCR [6].
SAO was characterised by presence of an in frame 27bp deletion in exon 11 of the band 3 gene. A band of 175bp was observed in normal subjects and two bands, 175bp and 148bp were observed in heterozygous SAO subjects (Fig. 1).
Globally, α-thalassaemia is a highly prevalent disease. In Malaysia, this disorder is a well-known public health problem [1]. The three most common deletional α-thalassaemia found in this region include --SEA deletion, -α3.7 and -α4.2 deletions [2]. The prevalence rate of triplication alpha cases such as αααanti3.7 and αααanti4.2 is unknown in Malaysia although it plays a pivotal role in exacerbating the clinical phenotypes in beta thalassaemia carriers [3]. Therefore, the purpose of this study was to design an assay for the detection of triplications and common deletional alpha thalassaemia using droplet digital PCR (ddPCR). Copy number changes were analysed using Quanta-SoftTM software version 1.6.6 after performing ddPCR. Sensitivity and validation analysis were also performed on the DNA samples. The changes in copy number changes (common deletions, duplications and triplications) in the alpha globin gene has been quantitatively detected using ddPCR. For the samples validation as determined by ddPCR, the mean copy number values for αα/αα are 2.0275±0.0177 (HS-40), 1.8175±0.0389 (HBA2), 2.0450±0.0848 (HB 3.7), 2.0050±0.0000 (HBA1). For -α3.7 /--SEA, the mean copy number values are 2.0225±0.2180 (HS-40), 0.9325±0.1213 (HBA2), 0 (HB 3.7), 0.9984±0.1333 (HBA1). As for –α4.2 /--SEA, the mean copy number values are 1.9350 (HS-40), 0 (HBA2), 0.7945 (HB 3.7), 0.8480 (HBA1). The mean copy number values for --SEA/αα samples are 1.9067±0.1327 (HS-40), 0.8164±0.0364 (HBA2), 0.8920±0.0434 (HB 3.7), 0.9148±0.0338 (HBA1) respectively. This study has found that the use of ddPCR is convenient as it allows direct quantification without the requirement of a calibration curve unlike qPCR [4]. Secondly, this study also showed that ddPCR is accurate and precise in the detection of alpha thalassaemia deletions and triplications based on the gene dosages using absolute quantification. In addition, the non-requirement of post-PCR work has minimised the risk of PCR carryover contamination. Thirdly, ddPCR saves time with less turnaround time and minimise the labour work required as compared to techniques such as MLPA which requires DNA denaturation and hybridisation reaction on day 1 while ligation and PCR reaction on day 2. Fourthly, this study found that the detection of α-thalassaemia using ddPCR is sensitive. DNA samples with low concentration as low as 1 ng were able to be detected for α-thalassaemia using ddPCR. The ability to detect minute amount of DNA concentration is crucial particularly in the diagnosing of the lethal HbH hydrops foetalis during the neonatal stage in α-thalassaemia. In conclusion, this is an alternative method (ddPCR) that can be employed for rapid detection of alpha thalassaemia variants in Malaysia.
Over the past 20 years, rapid technological advancement in the field of microfluidics has produced a wide array of microfluidic point-of-care (POC) diagnostic devices for the healthcare industry. However, potential microfluidic applications in the field of nutrition, specifically to diagnose iron deficiency anemia (IDA) detection, remain scarce. Iron deficiency anemia is the most common form of anemia, which affects billions of people globally, especially the elderly, women, and children. This review comprehensively analyzes the current diagnosis technologies that address anemia-related IDA-POC microfluidic devices in the future. This review briefly highlights various microfluidics devices that have the potential to detect IDA and discusses some commercially available devices for blood plasma separation mechanisms. Reagent deposition and integration into microfluidic devices are also explored. Finally, we discuss the challenges of insights into potential portable microfluidic systems, especially for remote IDA detection.
Pre-donation screening declarations and hemoglobin (Hb) testing are measures used to determine the quality of donated blood. The copper sulphate (CuSo4) method used to screen for blood abnormalities can give inaccurate results if strict quality control is not applied. Blood donors who are carriers of thalassemia and those with mild iron deficiency anemia (IDA) are usually asymptomatic and frequently missed at blood donation. The aim of this study was to evaluate the red blood cell (RBC) indices related disorders among blood donors who were deemed qualified to donate blood after screening with CuSo4 method. One hundred fifty-eight volunteer blood donors at the Universiti Putra Malaysia (UPM), who had passed the CuSo4 screening method, were recruited for this study. Their bloods specimens were examined with a complete blood count. Subjects with a low mean corpuscular hemoglobin (MCH) level were examined further by checking a serum ferritin level, Hb quantification, and molecular analysis to examine for common RBC disorders. Fourteen point six percent of subjects had a low Hb level, two (1.3%) had IDA and four (2.5%) had thalassemia or some other hemoglobinopathy. Using a MCH level < 27 pg as a cut-off point, 58 subjects (36.7%) had suspected IDA, thalassemia or some other hemoglobinopathy. Eight point nine percent of subjects with a normal Hb level had thalassemia, and 3.8% had IDA. Malaysia has a high prevalence of thalassemia and other hemoglobinopathies. Pre-donation accurate screening is crucial to protect the quality of blood transfusion products. Public education regarding RBC disorders especially among blood donors is important.