Enhancing thalassemia gene carrier identification in non-anemic populations using artificial intelligence erythrocyte morphology analysis and machine learning

BACKGROUND

Non-anemic thalassemia trait (TT) accounted for a high proportion of TT cases in South China.

OBJECTIVE

To use artificial intelligence (AI) analysis of erythrocyte morphology and machine learning (ML) to identify TT gene carriers in a non-anemic population.

METHODS

Digital morphological data from 76 TT gene carriers and 97 controls were collected. The AI technology-based Mindray MC-100i was used to quantitatively analyze the percentage of abnormal erythrocytes. Further, ML was used to construct a prediction model.

RESULTS

Non-anemic TT carriers accounted for over 60% of the TT cases. Random Forest was selected as the prediction model and named TT@Normal. The TT@Normal algorithm showed outstanding performance in the training, validation, and external validation sets and could efficiently identify TT carriers in the non-anemic population. The top three weights in the TT@Normal model were the target cells, microcytes, and teardrop cells. Elevated percentages of abnormal erythrocytes should raise a strong suspicion of being a TT gene carrier. TT@Normal could be promoted and used as a visualization and sharing tool. It is accessible through a URL link and can be used by medical staff online to predict the possibility of TT gene carriage in a non-anemic population.

CONCLUSIONS

The ML-based model TT@Normal could efficiently identify TT carriers in non-anemic people. Elevated percentages of target cells, microcytes, and teardrop cells should raise a strong suspicion of being a TT gene carrier.

[Progress in the Genetic Detection of Thalassemia Based on Third-Generation Gene Sequencing --Review]

Thalassemia is most widely distributed single gene autosome recessive genetic disease in the world, whose clinical manifestation was changed from asymptomatic anemia to severe anemia requiring continous blood transfusion to maintain life, thus resulting in a serious economic burden to society and families. Therefore, it is necessary to carry out the corresponding prentatal screening and diagnosis. Most of the conventional detection methods can only detect the common thalassemia genotype, it can easy to cause misdiagnosis or missed diagnosis for those rate genetic variantions. The third-generation sequecing (TGS) has been applied to the detection of thalassemia genes, which is more accurate, reliable and superior to the converntional detection methods. This article reviews the latest research progress of the TGS technology in genetic testing of thalassemia.

Comparison of Third-Generation Sequencing and Routine Polymerase Chain Reaction in Genetic Analysis of Thalassemia

CONTEXT.—

Thalassemia is the most widely distributed monogenic autosomal recessive disorder in the world. Accurate genetic analysis of thalassemia is crucial for thalassemia prevention.

OBJECTIVE.—

To compare the clinical utility of a third-generation sequencing-based approach termed comprehensive analysis of thalassemia alleles with routine polymerase chain reaction (PCR) in genetic analysis of thalassemia and explore the molecular spectrum of thalassemia in Hunan Province.

DESIGN.—

Subjects in Hunan Province were recruited, and hematologic testing was performed. Five hundred four subjects positive on hemoglobin testing were then used as the cohort, and third-generation sequencing and routine PCR were used for genetic analysis.

RESULTS.—

Of the 504 subjects, 462 (91.67%) had the same results, whereas 42 (8.33%) exhibited discordant results between the 2 methods. Sanger sequencing and PCR testing confirmed the results of third-generation sequencing. In total, third-generation sequencing correctly detected 247 subjects with variants, whereas PCR identified 205, which showed an increase in detection of 20.49%. Moreover, α triplications were identified in 1.98% (10 of 504) hemoglobin testing-positive subjects in Hunan Province. Seven hemoglobin variants with potential pathogenicity were detected in 9 hemoglobin testing-positive subjects.

CONCLUSIONS.—

Third-generation sequencing is a more comprehensive, reliable, and efficient approach for genetic analysis of thalassemia than PCR, and allowed for a characterization of the thalassemia spectrum in Hunan Province.

[Research progress on differential diagnosis of thalassemia trait and iron deficiency anemia by blood erythrocyte parameters]

Thalassemia trait is an autosomal recessive genetic disease, which is a hemolytic anemia caused by disturbance of erythrocyte hemoglobin production caused by gene mutation or deletion. Iron deficiency anemia is caused by a lack of iron in the body due to an imbalance between the demand and supply of iron. The laboratory manifestations of both are microcytic hypochromic anemia, but the treatment schemes are completely different, and it is difficult to distinguish them from the results of blood count. Erythrocyte parameters can be used to establish a formula or model to differentiate them, which can achieve the purpose of early screening, early diagnosis and early treatment,preventing the occurrence of severe anemia and providing a scientific basis for the thalassemia and iron deficiency anemia prevention. This article will review the research progress of using erythrocyte parameters to distinguish thalassemia trait with iron deficiency anemia.

A proposed methodology of health education for inherited genetic disorders: Bag and Ball technique

The life-threatening genetic blood disorder, thalassaemia, which causes decreased haemoglobin production, is preventable. Sociocultural determinants and the level of public health awareness must be used to adopt control measures of prevention. Identifying information gaps and educating the community about screening should be a priority, especially in areas with high disease burdens. A relevant health education technique, with which the audience can identify, can effectively bring understanding necessary effectively to sensitise the community. We propose the 'Bag and Ball' method, which includes role-play for health education specifically concerning inherited genetic disorders.

Detecting rare thalassemia in children with anemia using third-generation sequencing

BACKGROUND

In China, conventional genetic testing methods can only detect common thalassemia variants. Accurate detection of rare thalassemia is crucial for clinical diagnosis, especially for children that need long-term blood transfusion. This study aims to explore the application value of third-generation sequencing (TGS) in the diagnosis of rare thalassemia in children with anemia.

METHODS

We enrolled 20 children with anemia, excluding from iron deficiency anemia (IDA). TGS was employed to identify both known and novel thalassemia genotypes, while sanger sequencing was used to confirm the novel mutation detected.

RESULTS

Among the 20 samples, we identified 5 cases of rare thalassemia. These included β-4.9 (hg38,Chr11:5226187-5231089) at HBB gene, α-91(HBA2:c.*91delT), αCD30(HBA2:c.91-93delGAG), Chinese Gγ+(Aγδβ)0(NG_000007.3: g .48795-127698 del 78904) and delta - 77(T > C)(HBD:c.-127T>C). Notably, the -SEA/α-91α genotype associated with severe non-deletional hemoglobin H disease (HbH disease) has not been previously reported. Patients with genotypes β654/β-4.9 and -SEA/α-91α necessitate long-term blood transfusions, and those with the -SEA/αCD30α, Chinese Gγ+(Aγδβ)0 and delta thalassemia demonstrate mild anemia.

CONCLUSIONS

TGS demonstrates promising potential as a diagnostic tool for suspected cases of rare thalassemia in children, especially those suspected to have transfusion-dependent thalassemia (TDT).

Diagnostic Performance of 10 Mathematical Formulae for Identifying Blood Donors with Thalassemia Trait

OBJECTIVE

To compare the diagnostic performance of 10 mathematical formulae for identifying thalassemia trait in blood donors.

METHODS

Compete blood counts were conducted on peripheral blood specimens using the UniCel DxH 800 hematology analyzer. Receiver operating characteristic curves were used to evaluate the diagnostic performance of each mathematical formula.

RESULTS

In the 66 donors with thalassemia and 288 subjects with no thalassemia analyzed, donors with thalassemia trait had lower values for mean corpuscular volume and mean corpuscular hemoglobin than subjects without thalassemia donors (77 fL vs 86 fL [P < .001]; 25 pg vs 28 pg [P < .001]). The formula developed by Shine and Lal in 1977 showed the highest area under the curve value, namely, 0.9. At the cutoff value of <1812, this formula had maximum specificity of 82.35% and sensitivity of 89.58%.

CONCLUSIONS

Our data indicate that the Shine and Lal formula has remarkable diagnostic performance in identifying donors with underlying thalassemia trait.

Comparison Of Knowledge Among Millennials Studying In Non-Medical Universities Regarding Premarital And Prenatal Thalassemia Screening Policies In Pakistan

Thalassemia awareness among the youth is vital for policy- making to reduce the disease burden in our country. A descriptive cross-sectional study was conducted via simple random sampling technique for which data was collected from May 2020 to May 2021 through Google forms. Results showed that out of a total of 394 non-medical university students, the majority, i.e. 265 (67.3%), were not aware of prenatal screening. Majority, i.e. 117 (29.7%), agreed that the couple should be screened before marriage, and 190 (48.2%) strongly agreed, while 46 (11.7%) had no knowledge. Students, however, believed premarital screening was either unavailable, not possible, or expensive. Other reasons included custom and culture of arranged marriages and religious reasons. The query that if both the parents are carriers and the foetus has thalassemia major should they have an abortion, showed mixed results. The key to controlling thalassemia is awareness of future parents.

The comprehensive analysis of thalassemia alleles (CATSA) based on single-molecule real-time technology (SMRT) is a more powerful strategy in the diagnosis of thalassemia caused by rare variants

Thalassemia is one of the most widely distributed monogenic disorders in the world and affects the largest number of people. It can manifest a wide spectrum of phenotypes from asymptomatic to fatal, which is associated with the degree of imbalance between α- and β-globin chains. Therefore, individuals with different genotypes could present with a similar phenotype. Genetic analysis is always needed to make a correct diagnosis. However, routine genetic analysis of thalassemia used in the Chinese population identifies only 23 common variants, resulting in many cases undiagnosed or being misdiagnosed. In this study, we applied a long-read sequencing-based approach termed comprehensive analysis of thalassemia alleles (CATSA) to 30 subjects whose hematologic screening results could not be explained by the routine genetic test results. The identification of additional variants and the correction of genotypes allowed the interpretation of the clinical phenotype in 24 subjects, which have been confirmed to be correct by independent experiments. Moreover, we identified a novel 8.4-kb deletion containing the entire HBB and HBD genes as well as part of the HBBP1 gene, expanding the genotype spectrum of β-thalassemia. CATSA showed a great advantage over other genetic tests in the diagnosis of thalassemia caused by rare variants.

Early screening of thalassemia in pregnant women in northern China by capillary electrophoresis for the determination of hemoglobin electrophoresis

The objective of this study was to analyze the effectiveness of capillary electrophoresis detection of hemoglobin electrophoresis (HE) for the early screening of thalassemia. In the first choice, 974 pregnant women were selected for capillary electrophoresis to detect HE, which showed that 46 of them were abnormal (4.72%), including 16 cases with HbA2<2.5% and 28 cases with HbA2>3.5% and/or HbF≥2.0%. In one case each of HbH and HbBart's abnormal bands was found. The genotype test results showed the presence of thalassemia in 34 cases, using the genotype test results as the gold standard, after calculation it was seen that capillary electrophoresis for HE diagnosis of the occurrence of thalassemia had a sensitivity and specificity of 54.34% and 70.97% (P<0.05). These results suggest that in the screening of thalassemia in northern China, capillary electrophoresis for HE has good application and can be used as one of the routine screening tools, but further confirmation by genotype testing is still needed.

A highly sensitive self-powered sensing method designed on DNA circuit strategy and MoS2 hollow nanorods for detection of thalassemia

Thalassemia is one of the most common monogenic diseases, which seriously affects human growth and development, cardiovascular system, liver, etc. There is currently no effective cure for this disease, making screening for thalassemia particularly important. Herein, a self-powered portable device with high sensitivity and specificity for efficiently screening of low-level thalassemia is developed which is enabled with AuNPs/MoS2@C hollow nanorods and triple nucleic acid amplification technologies. It is noteworthy that AuNPs/MoS2@C electrode shows the advantages of high electrocatalytic activity, fast carrier migration rate and large specific surface area, which can significantly improve the stability and output signal of the platform. Using high-efficiency tetrahedral DNA as the probe, the target CD122 gene associated with thalassemia triggers a catalytic hairpin assembly reaction to achieve CD122 recycling while providing binding sites for subsequent hybridization chain reaction, greatly improving the detection accuracy and sensitivity of the device. A reliable electrochemical/colorimetric dual-mode assay for CD122 is then established, with a linear response range of 0.0001-100 pM for target concentration and open circuit voltage, and the detection limit is 78.7 aM (S/N = 3); a linear range of 0.0001-10000 pM for CD122 level and RGB Blue value, with a detection limit as low as 58.5 aM (S/N = 3). This method achieves ultra-sensitive and accurate detection of CD122, providing a new method for the rapid and accurate screening of thalassemia.

Challenges of having a child with thalassemia in Pakistan: A phenomenological study

BACKGROUND

Thalassemia is a persistent hemolytic disease and has debilitating effects on patients and their parents. Parents of these children experience pain and suffer from additional emotional strain as they provide daily and lifetime care and are mostly concerned about the health and future of their children.

AIM

The study aimed to understand the experiences of parents of children with thalassemia related to their family, financial, social, treatment, and psychological issues in Pakistan.

METHODS

This descriptive phenomenological study recruited 21 parents of children with thalassemia through purposive sampling until data saturation was achieved. Analysis of transcribed interviews was performed through Colaizzi's method and themes and subthemes revolving around diagnosis, challenges, and treatment issues were extracted.

FINDINGS

A total of 21 Pakistani parents participated in this study. Most of the participants were females (n = 16, 76.19%), housewives/stay-at-home moms (n = 13 (61.90%), and were uneducated (n = 6, 28.57%). Regarding genetic traits, only three (14.28%) parents declared that they had genetic traits of thalassemia. The findings of our study revealed that thalassemia is enormously influenced by psychosocial and economic problems because of this disease in their families.

CONCLUSION

Our findings indicated that parents of these children face multi-faceted challenges, such as physical, socio-emotional, financial, and familial. These findings may lead to an adequate understanding of their individual needs and efficient utilization of supportive and care programs.

PRACTICE IMPLICATIONS

An understanding of such experiences, involving those distinctive to Pakistani culture, is especially vital to inform the care of these children and enhance their quality of life.

Thalassaemia in China

Because of successful thalassaemia prevention programmes in resource-rich countries and it's huge population China now has the greatest number of new cases of thalassaemia globally as well as more people with thalassaemia than any other country. 30 million Chinese have thalassaemia-associated mutations and about 300,000 have thalassaemia major or intermedia requiring medical intervention. Over the past 2 decades there has been tremendous economic growth in China including per capita spending on health care. There is now nation-wide availability and partial or full insurance for prenatal genetic testing, RBC-transfusions, iron-chelating drugs and haematopoietic cell transplants. Prenatal screening and educational programmes have reduced the incidence of new cases. However, substantial challenges remain. For example, regional differences in access to medical care and unequal economic development require innovations to reduce the medical, financial and psychological burdens of Chinese with thalassaemia and their families. In this review we discuss success in preventing and treating thalassaemia in China highlighting remaining challenges. Our discussion has important implications for resource-poor geospaces challenged with preventing and treating thalassaemia.

Predicting thalassemia using deep neural network based on red blood cell indices

BACKGROUND AND OBJECTIVE

The traditional statistical screening method for thalassemia based on red blood cell (RBC) indices is being replaced by machine learning. Here, we developed deep neural networks (DNNs) that outperformed the traditional method for predicting thalassemia.

METHOD

Using a dataset of 8693 records comprising genetic tests and other 11 features we constructed 11 DNN models and 4 traditional statistical models and then compared their performances and analysed feature importance for interpreting DNN models.

RESULTS

The area under the receiver operating characteristic curve, accuracy, Youden's index, F1 score, sensitivity, specificity, positive predictive value and negative predictive value, were 0.960, 0.897, 0.794, 0.897, 0.883, 0.911, 0.914, and 0.882, respectively, for our best model, and compared with the traditional statistical model based on the mean corpuscular volume, these values were increased by 10.22%, 10.09%, 26.55%, 8.92%, 4.13%, 16.90%, 13.86% and 6.07%, respectively, and by 15.38%, 11.70%, 31.70%, 9.89%, 3.05%, 22.13%, 17.11% and 5.94%, respectively, for the mean cellular haemoglobin model. The DNN model performance will reduce without age, RBC distribution width (RDW), sex, or both WBC and PLT.

CONCLUSIONS

Our DNN model outperformed the current screening model. In 8 features, RDW and age were the most useful, followed by sex and the combination of WBC and PLT, the remaining nearly useless.

Specific refraction-index increments of oxygenated hemoglobin from thalassemia-minor patients are not significantly different than those from healthy individuals

The mass and concentration of hemoglobin per erythrocyte are important hematological parameters. Measuring these parameters from intact erythrocytes requires the value of specific refraction-index increment (RII) of oxygenated hemoglobin, which diverges in the literature. Refractive indices of hemoglobin solutions are measured directly by digital holographic microscopy on a microfluidic channel filled with hemoglobin solutions prepared by hemolysis of fresh human erythrocytes and refractive-index standards sequentially. Hemoglobin extracted from thalassemic patients shows 3-4% higher RII than that from healthy volunteers, but the difference is not significant in comparison to inter-subject variations within each group. The quantified RIIs are applied to quantify mean corpuscular hemoglobin mass of blood from 37 human subjects, and results are in accord with standard clinical test results.

Non-Transfusion-Dependent Thalassemia: A Panoramic Review

Non-transfusion-dependent thalassemia (NTDT) has been considered less severe than its transfusion-dependent variants. The most common forms of NTDT include β-thalassemia intermedia, hemoglobin E/beta thalassemia, and hemoglobin H disease. Patients with NTDT develop several clinical complications, despite their regular transfusion independence. Ineffective erythropoiesis, iron overload, and hypercoagulability are pathophysiological factors that lead to morbidities in these patients. Therefore, an early and accurate diagnosis of NTDT is essential to ascertaining early interventions. Currently, several conventional management options are available, with guidelines suggested by the Thalassemia International Federation, and novel therapies are being developed in light of the advancement of the understanding of this disease. This review aimed to increase clinicians’ awareness of NTDT, from its basic medical definition and genetics to its pathophysiology. Specific complications to NTDT were reviewed, along with the risk factors for its development. The indications of different therapeutic options were outlined, and recent advancements were reviewed.

Cell count-based parameters and algorithms for thalassaemia trait screening in the southern Chinese population

INTRODUCTION

Thalassaemia trait (TT) is potential to be missed clinically, especially normocytic thalassaemia. We aimed to establish discriminant functions (DFs) and an algorithm for detecting microcytic or normocytic TT in epidemiological screening.

METHODS

The receiver operating characteristics (ROC) curve analysis was used to determine the diagnostic performance of the proposed formulas in differentiating TT and nonthalassaemia (non-TT). DFs combined the two blood count parameters with the highest performance, based on the area under the curve (AUC) value, into mathematical formulas, using logistic regression. The diagnostic efficacy of DFs was subsequently evaluated in 761 participants, and reliability (including adjusted agreement [AA] and Kappa values) and validity (including sensitivity, specificity, likelihood ratio and Youden's Index) were calculated.

RESULTS

Among microcytic participants, the proposed DFs showed good diagnostic performance (in females: AUC = 0.892 [DF1 = 0.015 × RDW-CV/RBC - 0.096 × RDW-SD/RBC + 1.29], in males: AUC = 0.861 [DF2=-0.025 × RDW-SD/RBC - 0.035 × MCV/RBC + 1.415]). Youden's Index, AA and Kappa values for microcytic TT detection were 0.72, 0.86, and 0.72 and 0.63, 0.81 and 0.63 for females and males, respectively. In normocytic participants with RDW-CV/RBC ≤ 3.54, DF3=-0.38 × MCH-0.02 × MCHC+17.37 achieved AUC = 0.857 in females, whereas DF4 = 0.007 × MCV-0.113 × MCH+2.829 achieved AUC = 0.969 in males. The Youden's Index, AA and Kappa values for the proposed DFs for thalassaemia detection were 0.69, 0.84 and 0.67 in females, 0.76, 0.91 and 0.71 in males, respectively.

CONCLUSION

The proposed DFs performed well in the detection of TT among participants with microcytic and normocytic parameters and could be utilized in epidemiological study for TT.

The parental perspective of thalassaemia in Bangladesh: lack of knowledge, regret, and barriers

BACKGROUND

Thalassaemia, a hereditary haemoglobin disorder, is a major public health concern in some parts of the world. Although Bangladesh is in the world's thalassaemia belt, the information on this disease is scarce. Additionally, the awareness of this life threatening, but potentially preventable disease is surprisingly poor. However, mass awareness is pivotal for the development of an effective preventive strategy. In this context, the understanding of parental perspectives is essential to grasp the magnitude of the problem. Therefore, this study aimed to investigate the parental knowledge gaps and perceptions regarding thalassemia, the barriers confronted by the parents for caring for their thalassaemic children and their attitude to prenatal screening and prenatal diagnosis.

METHODS

This cross-sectional study was conducted between January 2018 and December 2018 at a dedicated thalassemia hospital located in Dhaka. A structured questionnaire was used for face-to-face interviews with parents of thalassaemic children. Descriptive statistics were used to analyse data.

RESULTS

Of 365 respondents, nearly all respondents (97%) had not heard about the term, 'thalassemia' before the disease was diagnosed in their children; all (100%) were unscreened for carrier status prior to marriage. Mean knowledge scores were significantly higher in respondents with higher income and education. Most respondents (~ 91%) had a guilty feeling for not undergoing premarital screening. Only around 36% of them had heard about prenatal diagnosis. Approximately 25% participants would consider prenatal diagnosis in a future pregnancy, while 70% of them were unsure and only ~ 5% would decline prenatal diagnosis. Only 9.3% mothers had prenatal diagnosis in a previous pregnancy. Nearly 80% of the parents faced difficulty for obtaining blood donors regularly and a similar proportion (~ 81%) of them did not receive support from any organized blood clubs. More than 40% of the parents reported they felt socially stigmatized.

CONCLUSION

This study suggests poor parental knowledge regarding thalassaemia including prenatal diagnosis and the challenges faced while caring for their children. These findings would be of paramount importance in planning and devising effective prevention and intervention strategies in Bangladesh as well as other countries with similar sociocultural setting.

A complication risk score to evaluate clinical severity of thalassaemia syndromes

The thalassaemia syndromes (TS) show different phenotype severity. Developing a reliable, practical and global tool to determine disease severity and tailor treatment would be of great value. Overall, 7910 patients were analysed with the aim of constructing a complication risk score (CoRS) to evaluate the probability of developing one or more complications. Nine independent variables were included in the investigation as predictors. Logistic regression models were used for Group A [transfusion-dependent thalassaemia (TDT)], Group B [transfused non-TDT (NTDT)] and Group C (non-transfused NTDT). Statistically significant predictors included age (years), haemoglobin levels, hepatic transaminases [alanine aminotransferase (ALT) and aspartate aminotransferase] and left-ventricular ejection fraction (LVEF) for Group A; age (years), age at first chelation (months), ALT and LVEF for Group B; and age (years), mean serum ferritin (SF) levels and LVEF for Group C. The area under the receiver operating characteristic curve was 84·5%, 82·1% and 80·0% for Groups A, Group B and Group C respectively, suggesting the models had good discrimination. Finally, the CoRS for each group was categorised into four risk classes (low, intermediate, high, and very high) using the centiles of its distribution. In conclusion, we have developed a CoRS for TS that can assist physicians in prospectively tailoring patients' treatment.

Microcytic to hypochromic ratio as a discriminant index of thalassaemia trait in subjects with hypochromic anaemia

INTRODUCTION

Differentiating between thalassaemia and iron deficiency anaemia (IDA) in hypochromic anaemia is a challenge to pathologists as it influences the choice of subsequent specialized confirmatory tests. In this study, we aimed to evaluate the performance of microcytic to hypochromic ratio (MicroR/ Hypo-He, M/H ratio) as a discriminant index in hypochromic anaemia.

MATERIALS AND METHODS

A retrospective study was carried out on 318 subjects with hypochromic anaemia, which comprised 162 IDA and 156 thalassaemia trait subjects with α-thalassemia, β-thalassemia and HbE trait. Optimal cut-off value, sensitivity and specificity of M/H ratio for thalassaemia trait discrimination was determined using Receiver Operating Characteristic (ROC) analysis.

RESULTS

Subjects with thalassaemia trait showed higher MicroR compared to IDA ( p< 0.001) while subjects with IDA demonstrated higher Hypo-He than thalassaemia trait (p < 0.001). M/H ratio was significantly higher in thalassaemia trait compared to IDA, with medians of 3.77 (interquartile range: 2.57 - 6.52) and 1.73 (interquartile range: 1.27 - 2.38), respectively (p < 0.001). M/H ratio ≥ 2.25 was the optimal cut-off value for discriminating thalassaemia trait from IDA in hypochromic anaemia, with the area under ROC curve (AUC) of 0.83, sensitivity of 80.8% and specificity of 71.6%.

CONCLUSIONS

M/H ratio is a useful discriminant index to distinguish thalassaemia trait from IDA in hypochromic anaemia prior to diagnostic analysis for thalassaemia confirmation. High M/H ratio is suggestive of thalassaemia trait than of IDA. However, more studies are required to establish the role of M/H ratio as a screening tool for thalassaemia discrimination in hypochromic anaemia.

Spectroscopic Evaluation of Red Blood Cells of Thalassemia Patients with Confocal Microscopy: A Pilot Study

Hemoglobinopathies represent the most common single-gene defects in the world and pose a major public health problem, particularly in tropical countries, where they occur with high frequency. Diagnosing hemoglobinopathies can sometimes be difficult due to the coexistence of different causes of anemia, such as thalassemia and iron deficiency, and blood transfusions, among other factors, and requires expensive and complex molecular tests. This work explores the possibility of using spectral confocal microscopy as a diagnostic tool for thalassemia in pediatric patients, a disease caused by mutations in the globin genes that result in changes of the globin chains that form hemoglobin-in pediatric patients. Red blood cells (RBCs) from patients with different syndromes of alpha-thalassemia and iron deficiency (including anemia) as well as healthy (control) subjects were analyzed under a Leica TCS SP8 confocal microscope following different image acquisition protocols. We found that diseased RBCs exhibited autofluorescence when excited at 405 nm and their emission was collected in the spectral range from 425 nm to 790 nm. Three experimental descriptors calculated from the mean emission intensities at 502 nm, 579 nm, 628 nm, and 649 nm allowed us to discriminate between diseased and healthy cells. According to the results obtained, spectral confocal microscopy could serve as a tool in the diagnosis of thalassemia.

A stable version of capillary electrophoresis for determining human hemoglobin chains aiming at the screening and diagnosis of thalassemia

As a fast, high-performance and cost-effective separation technique, capillary electrophoresis (CE) is applicable to the screening and diagnosis of diseases such as thalassemia. However, it is often not preferred due to its unrepeatable and/or irreproducible migration times. Herein, we propose a stable version of CE that uses migration charge density instead of the migration time to plot the electropherogram. The peak position is now independent of the applied voltage or current and the capillary geometry and is also insensitive to temperature. Its applicability was demonstrated in the quantitative analysis of human hemoglobin. On a laboratory-built device, with a running buffer simply consisting of 3.0 M acetic acid and 0.1% (w/v) hydroxyethyl cellulose, it allows a direct injection of whole blood samples and all the concerned globin chains, α, β, Aγ and Gγ can be well separated in 15 minutes. The resolution of α/β, β/Aγ, and Aγ/Gγ reached 4.4, 3.1 and 5.3, respectively. The intra- and inter-day precisions for the peak position based on the migration charge densities were below 0.6%. Its diagnostic applicability was validated in the analysis of several real blood samples from newborns, children and adults, and its capacity was demonstrated to screen and define the type of thalassemia.

The First Asian, Single-Center Experience of Blastocyst Preimplantation Genetic Diagnosis with HLA Matching in Thailand for the Prevention of Thalassemia and Subsequent Curative Hematopoietic Stem Cell Transplantation of Twelve Affected Siblings

RESULTS

In 221 cycles from 138 patients (104 cycles requiring HLA matching), 90.5% had embryo(s) biopsied for genetic testing. There were 119 embryo transfers for thalassemia (76) and thalassemia-HLA cases (43), respectively, resulting in overall clinical pregnancy rates of 54.6%, implantation rates of 45.7%, and live birth rates of 44.1%. Our dataset included fifteen PGD-HLA live births with successful HSCT in twelve affected siblings, 67% using umbilical cord blood stem cells (UCBSC) as the only SC source.

CONCLUSIONS

We report favorable thalassemia PGD and PGD-HLA laboratory and clinical outcomes from a single center. The ultimate success in PGD-HLA is of course the cure of a thalassemia-affected sibling by HSCT. Our PGD-HLA HSCT series is the first and largest performed entirely in Asia with twelve successful and two pending cures and predominant UCBSC use.

Establishing and evaluating an auto-verification system of thalassemia gene detection results

The manual verification of gene tests is time-consuming and error prone. In this study, we try to explore a high-efficiency, clinically useful auto-verification system for gene detection of thalassemia. A series of verification elements were rooted in the auto-verification system. Consistency check was applied initially as one of the essential elements in our study. One hundred twenty-four archived cases were used to choose the consistency-check rules' indices from routine blood examination and hemoglobin electrophoresis by the receiver operating characteristic curves. Rule 1 and rule 2 established by the chosen indices were compared by their passing rate, consistency with manual validation, and error rate. Finally, 748 cases were used for verifying the system's feasibility by evaluating the passing rate, turn-around time (TAT), and error rate. The rule 2 had a higher passing rate (67.7% vs. 50.8%) and consistency (0.623 vs. 0.364) than the rule 1 with an error rate of zero. In a "live" valuation, the auto-verification system can reduce the TAT and error rate of verification by 51.5% and 0.13%, respectively, with a high passing rate of 82.8%. The auto-verification system for gene detection of thalassemia in this study can shorten the validation time, reduce errors, and enhance efficiency.

"I didn't take it too seriously because I'd just never heard of it": Experiential knowledge and genetic screening for thalassaemia in the UK

Members of the public face particular challenges when undergoing reproductive genetic screening. Lack of family history with genetic disease has been identified as a key barrier affecting screening uptake and responses to genetic risk. This study explores this obstacle using beta thalassaemia as a case study. Fifteen in-depth qualitative interviews were conducted exploring the reproductive views and decisions of people at risk of transmitting thalassaemia. Eleven participants had thalassaemia themselves and/or were members of an affected family. Four participants were identified as thalassaemia carriers through genetic screening programmes with no family history. Notable differences were observed between these two groups. For thalassaemic individuals and families, past experience clarified and facilitated their sense of reproductive responsibility, however carriers struggled to relate to, and incorporate the information into their lives. It was witnessing their child becoming symptomatic-rather than receiving a diagnosis or genetic risk information per se that had the most substantial influence on carriers' subsequent views and decisions. Educational resources used to support genetic screening programmes would benefit from an engagement with the experiential accounts of life with genetic disease in order to more effectively bridge the chasm in knowledge and understanding between affected families and the general public, towards whom expansive genetic screening is aimed.

Effectiveness and Safety of Deferasirox in Thalassemia with Iron Overload: A Meta-Analysis

Deferasirox (DFX) has recently been used to treat thalassemia with iron overload; however, its long-term effectiveness and safety await multi-year studies. In this study, a systematic meta-analysis was performed to assess the effectiveness and safety of DFX in the treatment of thalassemia with iron overload. We performed a systematic electronic literature search for randomized controlled studies of DFX in the Embase, Medline, Cochrane, and Chinese Biomedical Literature (CBM) databases from January 1990 to May 2018. Particular attention was paid to mortality, serum ferritin (SF), liver iron concentration (LIC), myocardial iron concentration, and adverse events (AEs). Six studies comparing DFX with deferoxamine (DFO) and placebo were enrolled. DFX was not better than DFO in lowering SF and LIC, with an exception that high DFX dose (> 30 mg/kg/day) was superior to DFO in LIC. Otherwise, AEs such as gastrointestinal problems appeared to be more common with DFX. DFX does not seem to be superior to DFO at low dose. Similar efficacy seems to be achievable depending on dose. However, the convenient oral administration of DFX has a higher compliance rate.

Feasibility and Safety of Chorionic Villus Sampling (CVS) for Prenatal Diagnosis of Thalassemia in Bangladesh

Thalassaemia is one of the commonest inherited disorders in Bangladesh. Since population is rapidly increasing in Bangladesh, therefore birth of large number of new cases is expected every year. Chorionic villus sampling (CVS) is an invasive diagnostic procedure done in early pregnancy to obtain fetal cells for the prenatal diagnosis of chromosomal and genetic disorders like thalassemia. To investigate the feasibility, safety, and outcome of transabdominal Chorionic Villus Sampling (CVS) for prenatal diagnosis of Beta Thalassemia, this retrospective analytical study was carried out on women who had undergone transabdominal CVS for prenatal diagnosis of Beta thalassemia. All CVS are done at Fetal Medicine Centre, Family Foundation, Green Road, Dhaka, Bangladesh from June 2013 to December 2016. A total of 236 couples who were referred for prenatal diagnosis of thalassemia (Beta thalassemia & Hb-E beta thalassemia) were studied. Transabdominal CVS was done under local anesthesia and real-time ultrasound guidance. A 18G/88mm Spinal Needle (B Braun, Germany) was used. Most procedures were done between 11 and 13 weeks (range 11-14 weeks). All CVS were performed with the "2 operators" technique. The samples were sent for prenatal diagnosis by genetic analysis. Results were recorded and analyzed for descriptive statistics. Out of 236, 123 (52.1%) fetuses were diagnosed as trait (Beta trait or HbE trait), 64 (27.1%) as healthy fetuses and 49 (20.7%) as affected fetuses. A total of 236 CVSs were performed as outdoor basis. Most aspirations (95.1%) were easy; however, in 4.8% cases the aspiration was difficult due to a variety of factors. The overall success rate was 100%. Minor complications like placental hematoma and pervaginal (P/V) bleeding occurred in 2% & 1.3% respectively which were subsided by conservative management. The procedure related miscarriage within three weeks not occurred in any cases. Transabdominal CVS under real-time sonography is a useful outdoor procedure for prenatal diagnosis of beta thalassaemia in early pregnancy without significant risk to the mother and the fetus.

Molecular Basis and Genetic Modifiers of Thalassemia

Thalassemia is a disorder of hemoglobin characterized by reduced or absent production of one of the globin chains in human red blood cells with relative excess of the other. Impaired synthesis of β-globin results in β-thalassemia, whereas defective synthesis of α-globin leads to α-thalassemia. Despite being a monogenic disorder, thalassemia exhibits remarkable clinical heterogeneity that is directly related to the intracellular imbalance between α- and β-like globin chains. Novel insights into the genetic modifiers have contributed to the understanding of the correlation between genotype and phenotype and are being explored as therapeutic pathways to cure this life-limiting disease.

Thalassaemia

Inherited haemoglobin disorders, including thalassaemia and sickle-cell disease, are the most common monogenic diseases worldwide. Several clinical forms of α-thalassaemia and β-thalassaemia, including the co-inheritance of β-thalassaemia with haemoglobin E resulting in haemoglobin E/β-thalassaemia, have been described. The disease hallmarks include imbalance in the α/β-globin chain ratio, ineffective erythropoiesis, chronic haemolytic anaemia, compensatory haemopoietic expansion, hypercoagulability, and increased intestinal iron absorption. The complications of iron overload, arising from transfusions that represent the basis of disease management in most patients with severe thalassaemia, might further complicate the clinical phenotype. These pathophysiological mechanisms lead to an array of clinical manifestations involving numerous organ systems. Conventional management primarily relies on transfusion and iron-chelation therapy, as well as splenectomy in specific cases. An increased understanding of the molecular and pathogenic factors that govern the disease process have suggested routes for the development of new therapeutic approaches that address the underlying chain imbalance, ineffective erythropoiesis, and iron dysregulation, with several agents being evaluated in preclinical models and clinical trials.

Geographic Hematology: Some Observations in Mexico

In 1963 Jean Bernard introduced the concept of "geographic hematology" and distinguished 2 branches, i.e., "ethnic hematology," which deals with differences between populations, and "environmental hematology," which considers factors such as food habits, infections, and others. Both of these branches have implications in the distribution of hematological diseases worldwide. In comparison with Caucasian populations, in Mexico a significantly higher prevalence of acute lymphoblastic, acute promyelocytic, and acute megakaryoblastic leukemias has been described. The rate of chronic myeloid leukemia seems to be as high as that reported in Caucasian populations, while other myeloproliferative neoplasias are significantly less frequent in Mexico. Significantly lower prevalences of hairy cell leukemia, chronic lymphocytic leukemia, multiple myeloma, and Waldenström's macroglobulinemia have been reported from Mexico. Regrettably, the influence of drug companies interested in selling their new and expensive drugs has resulted in both overdiagnosis of some diseases and overidentification of the refractory forms of some of these conditions to justify the use of unnecessary drugs.

Frequency of carrier screening and preventive orientation among first degree relatives of Thalassaemia patients

OBJECTIVE

To get preliminary data regarding the prevention of thalassaemia major in future generations.

METHODS

This Knowledge Attitude Practices study was conducted at Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from January to June 2016, using non-probability purposive sampling. Parents of children undergoing transfusion were interviewed. Questionnaires were used to collect demographics and data about awareness, attitude and frequency of screening among the first degree relatives of a thalassaemia major patient. SPSS 20 was used for data analysis.

RESULTS

Of the 270 respondents 240(88.9%) had utilised screening services for their asymptomatic children and had a positive attitude towards prevention, but 30(11.1%) families did not screen asymptomatic children for thalassaemia minor. Besides, 49(18.1%) families had more than one thalassaemia major child in their nuclear family, while, 3(1.1%) were unwilling to let their children undergo tests. Nine (3.3%) respondents said they will not ask a prospective daughter/son-in-law to get tested for thalassaemia minor, while 194(71.9%) respondents had had cousin marriages.

CONCLUSIONS

There were significant gaps in awareness among affected families.

Iron overload in thalassemia: different organs at different rates

Thalassemic disorders lie on a phenotypic spectrum of clinical severity that depends on the severity of the globin gene mutation and coinheritance of other genetic determinants. Iron overload is associated with increased morbidity in both patients with transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT). The predominant mechanisms driving the process of iron loading include increased iron burden secondary to transfusion therapy in TDT and enhanced intestinal absorption secondary to ineffective erythropoiesis and hepcidin suppression in NTDT. Different organs are affected differently by iron overload in TDT and NTDT owing to the underlying iron loading mechanism and rate of iron accumulation. Serum ferritin measurement and noninvasive imaging techniques are available to diagnose iron overload, quantify its extent in different organs, and monitor clinical response to therapy. This chapter discusses the general approach to iron chelation therapy based on organ involvement using the available iron chelators: deferoxamine, deferiprone, and deferasirox. Other novel experimental options for treatment and prevention of complications associated with iron overload in thalassemia are briefly discussed.

Molecular Diagnosis of Thalassemias and Hemoglobinopathies: An ACLPS Critical Review

OBJECTIVES

To describe the use of molecular diagnostic techniques for patients with hemoglobin disorders.

METHODS

A clinical scenario is presented in which molecular diagnosis is important for genetic counseling. Globin disorders, techniques for their diagnosis, and the role of molecular genetic testing in managing patients with these disorders are described in detail.

RESULTS

Hemoglobin disorders, including thalassemias and hemoglobinopathies, are among the commonest genetic diseases, and the clinical laboratory is essential for the diagnosis of patients with these abnormalities. Most disorders can be diagnosed with protein-based techniques such as electrophoresis and chromatography. Since severe syndromes can result due to inheritance of combinations of globin genetic disorders, genetic counseling is important to prevent adverse outcomes. Protein-based methods cannot always detect potentially serious thalassemia disorders; in particular, α-thalassemia may be masked in the presence of β-thalassemia. Deletional forms of β-thalassemia are also sometimes difficult to diagnose definitively with standard methods.

CONCLUSIONS

Molecular genetic testing serves an important role in identifying individuals carrying thalassemia traits that can cause adverse outcomes in offspring. Furthermore, prenatal genetic testing can identify fetuses with severe globin phenotypes.

[Thalassaemia and pregnancy]

Global migration has resulted in a larger geographical spread of people with risk of hereditary anaemias. This leads to an increased incidence of pregnant women with rare diseases, including thalassaemia also in Scandinavia. Thalassaemia can cause severe anaemia and other complications during pregnancy, like risk of miscarriage, intrauterine fetal death, abruptio, intrauterine growth retardation, hypertension, gestational diabetes and pre-eclampsia. In this article, we focus on the aetiology, assessment, antenatal care and treatment of pregnant women with thalassaemia.

Thalassemia in the United Arab Emirates: Why it can be prevented but not eradicated

Thalassemia is a genetic blood disorder that causes abnormal hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen and is made of two proteins from four α-globin genes and two β-globin genes. A defect in one or more of these genes causes thalassemia. The treatment of thalassemia mostly depends on life-long blood transfusions and removal of excessive iron from the blood stream. Such tremendous blood consumption puts pressure on the national blood stock in many countries. In particular, in the United Arab Emirates (UAE), various forms of thalassemia prevention have been used and hence, the substantial reduction of the thalassemia major population has been achieved. However, the thalassemia carrier population still remains high, which leads to the potential increase in the thalassemia major population through carrier-carrier marriages. In this work, we investigate the long-term impact and efficacy of thalassemia prevention measures via mathematical modeling at a population level. To our best knowledge, this type of assessment has not been done before and there is no mathematical model that has investigated such a problem for thalassemia or any blood disorders at a population level. By using UAE data, we perform numerical simulations of our model and conduct sensitivity analysis of parameter values to see which parameter values affect most the dynamics of our model. We discover that the prevention measures can contribute to reduce the prevalence of the disease only in the short term but not eradicate the disease in the long term.

PILOT SCREENING PROGRAM FOR THALASSEMIA IN A COUNTRY WITH LIMITED RESOURCES: A COLLABORATION MODEL BETWEEN CLOSE NEIGHBORING COUNTRIES

Screening for thalassemia carriers should not only be conducted in middle-income countries but also can be possible in low-middle income countries, through cooperation of experienced professionals from middle income countries. We describe a collaborating model between two close neighboring countries in establishing such a screening program for thalassemia. After training and setting up of facilities, a total of 152 out of 187 hospital staff were screened as a pilot activity to encourage community participation. Referring system for sending blood samples to a reference center in Thailand was also established. Among 152 health staff, 12.5% α0-thal, 2% β-thal and 13% Hb E carriers were found. Applying thalassemia screening to 411 pregnant women and 71 spouses, 5 couples at risk of bearing a child of thalassemia disease were identified. The thalassemia screening program has a sensitivity of 99.5%, specificity of 77%, positive predictive value of 73%, and negative predictive value of 99.5%. Thus, it is possible to operate a thalassemia screening program with acceptable performance in a low-middle income country (Lao People’s Democratic Republic) with the cooperation of a referral center located within close proximity in a middle income country (Thailand).

Pulmonary hypertension associated with thalassemia syndromes

Chronic hemolytic anemia has increasingly been identified as an important risk factor for the development of pulmonary hypertension (PH). Within the thalassemia syndromes, there are multiple mechanisms, both distinct and overlapping, by which PH develops and that differ among β-thalassemia major or intermedia patients. PH in β-thalassemia major correlates with the severity of hemolysis, yet in patients whose disease is well treated with chronic transfusion therapy, the development of PH can be related to cardiac dysfunction and the subsequent toxic effects of iron overload rather than hemolysis. β-Thalassemia intermedia, on the other hand, has a higher incidence of PH owing to the low level of hemolysis that exists over years without the requirement for frequent transfusions, while splenectomy is shown to play an important role in both types. Standard therapies such as chronic transfusion have been shown to mitigate PH, and appropriate chelation therapy can avoid the toxic effects of iron overload, yet is not indicated in many patients. Limited evidence exists for the use of pulmonary vasodilators or other therapies, such as l-carnitine, to treat PH associated with thalassemia. Here, we review the most recent findings regarding the pathogenic mechanisms, epidemiology, presentation, diagnosis, and treatment of PH in thalassemia syndromes.

Mean reticulocyte volume: a specific parameter to screen for hereditary spherocytosis

This study assessed the value of mean reticulocyte volume (MRV) for differential diagnosis of hereditary spherocytosis (HS) so as to develop conventional and new specific screen indexes. Subjects in this study were divided into three groups: 53 cases in HS group, 217 cases in hemolytic anemia control group (109 cases of thalassemia (THAL), 56 cases of glucose-6-phosphate dehydrogenase G6PD deficiency anemia, and 52 cases of autoimmune hemolytic anemia (AIHA)), and 100 cases in healthy control group. We analyzed erythrocyte and reticulocyte parameters including MRV, mean sphered corpuscular volume, mean corpuscular hemoglobin concentration, and immature reticulocyte fraction. Results demonstrated that MRV was significantly lower in the HS group but significantly higher in the AIHA and G6PD deficiency anemia groups than that in the healthy control group (P = 0.000). MRV was not significantly different between the AIHA and G6PD deficiency anemia groups (P = 0.977) and between the healthy control and THAL groups (P = 0.168). The area under the ROC curve of MRV for diagnosis of HS was 0.942, with a standard error of 0.019, 95% confidence interval of 0.905-0.979, and optimal critical diagnosis point of 95.77 fL. When the MRV was ≤95.77 fL, the sensitivity and specificity for diagnosis of HS were 86.80% and 91.20%, respectively. Therefore, MRV is a general and specific new index for screening HS and important for differential diagnosis of different types of hemolytic anemia.

Non-transfusion-dependent thalassemia and thalassemia intermedia: epidemiology, complications, and management

OBJECTIVE

The non-transfusion-dependent thalassemias (NTDTs), including thalassemia intermedia (TI), hemoglobin E beta thalassemia, and hemoglobin H disease, have sometimes been regarded as less severe than their transfusion-dependent variants; however, these disorders carry a substantial disease burden (e.g., splenomegaly, iron overload, skeletal effects, and cardiopulmonary disease). The aim of this review is to increase clinician awareness of the growing global problem of NTDT and TI, and discuss the current management strategies for these conditions.

METHODS

Recent peer-reviewed articles (publication years 2000 through 2015) addressing the epidemiology, complications, management, and monitoring of NTDT were identified in the PubMed database and reviewed.

RESULTS

The changing epidemiology of thalassemia constitutes a growing health problem. Increased clinician awareness is necessary for the appropriate diagnosis and management of patients with NTDT.

CONCLUSIONS

Management of NTDT requires a comprehensive approach, beginning with screening and prenatal diagnosis, monitoring for iron overload and associated complications, and iron chelation therapy. Several novel strategies are in the early stages of investigation and may help increase treatment options in patients with NTDT. Importantly, ethnic or cultural barriers may exist within the affected populations and need to be considered in the management approach.

Evaluation of a Flow-Cytometric Osmotic Fragility Test for Hereditary Spherocytosis in Chinese Patients

BACKGROUND

Osmotic fragility testing based on flow cytometry was recently introduced for the screening of hereditary spherocytosis (HS). This study was undertaken to evaluate the clinical diagnostic value of a flow-cytometric osmotic fragility test for HS.

METHODS

Peripheral blood was collected from 237 subjects at the First Affiliated Hospital of Guangxi Medical University, including 56 HS patients, 86 thalassemia patients and 95 healthy controls. The samples were examined by flow-cytometric osmotic fragility test and the percentage of residual red blood cells was used to determine HS. Peripheral blood smears were performed to examine the red blood cell morphology.

RESULTS

With clinical diagnosis of HS as the gold standard and the percentage of residual red blood cells <23.6% as the diagnostic threshold in the flow-cytometric osmotic fragility test, the sensitivity of the flow-cytometric osmotic fragility test for HS was 85.71% and the specificity was 97.24%.

CONCLUSION

The flow-cytometric osmotic fragility test combined with a red blood cell morphology test by peripheral blood smear could be a simple, practical and accurate laboratory screening method for HS.

Screening for Thalassemia Carrier Status in Pregnancy and Pre-Natal Diagnosis

This hospital-based study reports the results of antenatal screening for thalassemia in pregnant women visiting a hospital in Jodhpur, Rajasthan, India. Eighty-eight (5.9%) of 1500 women screened for thalassemia had thalassemia trait. Twenty at-risk couples were identified and two fetuses were detected to be having thalassemia major.

Pulmonary hypertension in non-transfusion-dependent thalassemia: Correlation with clinical parameters, liver iron concentration, and non-transferrin-bound iron

BACKGROUND

Pulmonary hypertension is a major cardiac complication in non-transfusion-dependent thalassemia (NTDT). Several clinical and laboratory parameters, including iron overload, have been shown to have a positive correlation with the incidence of pulmonary hypertension. Non-transferrin-bound iron (NTBI) is a form of free-plasma iron that is a good indicator of iron overload.

OBJECTIVES

The aim of this study was to determine the prevalence of pulmonary hypertension in patients with NTDT and to investigate its correlation with the clinical parameters, liver iron concentration (LIC) and NTBI.

METHODS

Patients with NTDT were evaluated using echocardiography, and magnetic resonance imaging for cardiac T2* and LIC. Pulmonary hypertension was defined as peak tricuspid regurgitation velocity ≥2.9 m/s measured using trans-thoracic echocardiography. Clinical parameters and the status of iron overload as determined by LIC, serum ferritin, and NTBI level were evaluated for their association with pulmonary hypertension.

RESULTS

Of 76 NTDT patients, mean age 23.7 ± 8.5 years, seven patients (9.2%) had pulmonary hypertension. Previous splenectomy (71.4 vs. 24.6%, P-value 0.019), higher cumulative red blood cell (RBC) transfusions (received ≥10 RBC transfusions 85.7 vs. 33.3%, P-value 0.011), higher nucleated RBCs (353 ± 287 vs. 63 ± 160/100 white blood cells, P-value <0.001), and a high NTBI level (5.7 ± 3.0 vs. 3.3 ± 2.8 µmol/l, P-value 0.034) were associated with pulmonary hypertension. There was no significant correlation between LIC or serum ferritin and pulmonary hypertension.

CONCLUSION

Pulmonary hypertension in NTDT is common, and is associated with splenectomy and its related factors. NTBI level shows a significant correlation with pulmonary hypertension.

When to consider transfusion therapy for patients with non-transfusion-dependent thalassaemia

Non-transfusion-dependent thalassaemia (NTDT) refers to all thalassaemia disease phenotypes that do not require regular blood transfusions for survival. Thalassaemia disorders were traditionally concentrated along the tropical belt stretching from sub-Saharan Africa through the Mediterranean region and the Middle East to South and South-East Asia, but global migration has led to increased incidence in North America and Northern Europe. Transfusionists may be familiar with β-thalassaemia major because of the lifelong transfusions needed by these patients. Although patients with NTDT do not require regular transfusions for survival, they may require transfusions in some instances such as pregnancy, infection or growth failure. The complications associated with NTDT can be severe if not properly managed, and many are directly related to chronic anaemia. Awareness of NTDT is important, and this review will outline the factors that should be taken into consideration when deciding whether to initiate and properly plan for transfusion therapy in these patients in terms of transfusion interval and duration of treatment.