Prevalence and Risk Factors for Complications in Patients with Nontransfusion Dependent Alpha- and Beta-Thalassemia

Survival and causes of death in patients with alpha and beta-thalassemia in Northern Thailand

BACKGROUND

Thalassemia is the most prevalent hereditary anaemia worldwide. Severe forms of thalassemia can lead to reduced life expectancy due to disease-related complications.

OBJECTIVES

To investigate the survival of thalassemia patients across varying disease severity, causes of death and related clinical factors.

PATIENTS AND METHODS

We conducted a retrospective review of thalassemia patients who received medical care at Chiang Mai University Hospital. The analysis focused on survival outcomes, and potential associations between clinical factors and patient survival.

RESULTS

A total of 789 patients were included in our study cohort. Among them, 38.1% had Hb H disease, 35.4% had Hb E/beta-thalassemia and 26.5% had beta-thalassemia major. Half of the patients (50.1%) required regular transfusions. Sixty-five patients (8.2%) had deceased. The predominant causes of mortality were infection-related (36.9%) and cardiac complications (27.7%). Transfusion-dependent thalassemia (TDT) (adjusted HR 3.68, 95% CI 1.39-9.72, p = 0.008) and a mean serum ferritin level ≥3000 ng/mL (adjusted HR 4.18, 95% CI 2.20-7.92, p < 0.001) were independently associated with poorer survival.

CONCLUSIONS

Our study highlights the primary contributors to mortality in patients with thalassemia as infection-related issues and cardiac complications. It also underscores the significant impact of TDT and elevated serum ferritin levels on the survival of thalassemia patients.

Disease burden, management strategies, and unmet needs in α-thalassemia due to hemoglobin H disease

Alpha-thalassemia is an inherited blood disorder caused by impaired α-globin chain production, leading to anemia and other complications. Hemoglobin H (HbH) disease is caused by a combination of mutations generally affecting the expression of three of four α-globin alleles; disease severity is highly heterogeneous, largely driven by genotype. Notably, non-deletional mutations cause a greater degree of ineffective erythropoiesis and hemolysis, higher transfusion burden, and increased complication risks versus deletional mutations. There are limited treatment options for HbH disease, and effective therapies are needed. This review discusses the pathophysiology of HbH disease, current management strategies, unmet needs, and emerging treatment options.

Systematic review and evidence gap assessment of the clinical, quality of life, and economic burden of alpha-thalassemia

A recent evidence gaps assessment of the clinical, health-related quality of life, and economic burden associated with α-thalassemia is lacking. We conducted a systematic literature review (SLR) following the methodological and reporting requirements of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook for Systematic Reviews, using available literature over the past decade. This SLR identified a considerable evidence gap with regard to understanding the current burden of α-thalassemia as evident from paucity of studies published in the past 10 years. The limited data available still indicate that patients with α-thalassemia experience substantial morbidity and quality of life/economic burden that is generally comparable to patients with β-thalassemia.

Αlpha-thalassemia: A practical overview

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and β globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.

Justification of Universal Iron Supplementation for Infants 6-12 months in Regions with a High Prevalence of Thalassemia

Introduction

Many clinicians hesitate to adopt a universal infant iron supplementation program due to the risk of increased iron absorption for those with thalassemia. We aimed to determine thalassemia prevalence in 6- to 12-month-old infants, along with the iron status of those with and without thalassemia.

Methods

We performed a cross-sectional descriptive study of infants attending the Well Baby Clinic at Thammasat University Hospital for routine checkups. Complete blood count, hemoglobin electrophoresis, iron parameters, and molecular genetics for common α- and β-thalassemia were evaluated.

Results

Overall, 97 of 206 (47%) participants had thalassemia minor, the majority having Hb E traits. None had thalassemia intermedia or major. Familial history of anemia or thalassemia presented an increased risk of detecting thalassemia minor in offspring (OR 5.18; 95% CI 2.60-10.33, p=0.001). There were no statistical differences in transferrin saturation, serum ferritin and hepcidin between iron-replete infants with thalassemia minor and those without. However, one-third of infants with thalassemia minor (31/97) also had iron deficiency anemia (IDA), with a similar risk of having iron deficiency to infants without thalassemia. There was no hepcidin suppression in our infants with thalassemia minor as compared to controls.

Conclusions

Both thalassemia and IDA are endemic to Southeast Asia. Infants with thalassemia minor, particularly with Hb E and α-thalassemia traits, are at risk of IDA. Our short-term universal iron supplementation program for 6- to 12-month-old infants does not appear to increase the risk of those with thalassemia minor developing iron overload in the future.

Extramedullary haematopoiesis in patients with thalassemia: a cross-sectional description of its prevalence, clinical features and survival

INTRODUCTION

Despite knowledge advances on extramedullary haematopoiesis (EMH) in thalassemic patients, the real picture remains an open issue.

OBJECTIVES

To assess EMH prevalence in patients with thalassemia major (TM) and intermedia (TI), to describe magnetic resonance imaging (MRI) findings and to explore clinical risk factors.

METHODS

In this cross-sectional study, images and clinical records of 184 consecutive patients with thalassemia who underwent T2* MRI between 2004 and 2011 were reviewed. Association of EMH with survival was investigated for patients with available follow-up charts.

RESULTS

EMH was detected in 16/168 (9.5%) patients with TM (aged 19-49 years) and in 3/16 (18.8%) with TI (aged 36-41 years). Most (88%) had paravertebral thoracic and/or abdominal masses. Age was significantly associated with EMH risk (hazard ratio, [HR] 1.10/year; confidence interval [CI]: 1.03-1.18; p-value < 0.001), while lower pancreatic iron content by T2*MRI (HR: 0.94/ms; CI: 0.89-0.99; p-value = 0.049) was a protective factor. Estimated survival rate was superior for EMH-positive (n = 19) when compared to EMH-negative patients (n = 75) (p-value = 0.013).

CONCLUSIONS

The prevalence of EMH was 10.3% (19/184), presented mainly as tumoral masses of 3 to 10 cm. Age was a risk factor for EMH development, while lower pancreatic iron might be a protective factor in this cohort.

Genetic variant of endothelial protein C receptor genes and its serum level in B thalassemic children

BACKGROUND

Due to their chronic hypercoagulable status, thalassemic individuals are at an elevated risk of developing thromboembolic sequence consequences. The goal of the current study is to assesses the EPCR gene polymorphism and soluble EPCR in Egyptian thalassemic children and its role in hypercoagulable state.

RESEARCH DESIGN AND METHODS

Eighty children diagnosed as thalassemia major and 80 healthy youngsters as a control group. The EPCR gene was identified using a restriction fragment length polymerase chain reaction (RFLP PCR). Additionally, we assessed the soluble EPCR levels using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Frequency of 1651C-G EPCR, the GC genotype was strongly related with an increased risk of coagulation (OR = 1.83 (0.64-5.26), P = 0.0.016). In addition, soluble EPCR was considerably higher in patients with thalassemia than in controls, P value <0.001. Our study revealed significance difference between soluble EPCR and different genotypes.

CONCLUSION

Polymorphisms in the EPCR gene and an elevated soluble EPCR level in patients with β-thalassemia major may contribute to these patients' hemostatic derangement in thalassemic Egyptian children.

Prevalence and characteristics of inflammatory rheumatic diseases in patients with thalassemia

Reports of inflammatory rheumatic diseases (IRD) in thalassemia are limited. This study aimed to determine the prevalence and clinical characteristics of IRD in patients with thalassemia disease. Consecutive adult patients with thalassemia disease, confirmed by hemoglobin typing, attending the Hematology Clinic between June 2019 and May 2021 were invited to join this study. All of them had their history taken and a physical examination for IRD. Those with IRD had their medical records reviewed. Sixty-three patients (transfusion-dependent in 50) were included in this study. There was α-, β-, and co-inheritance of α- and β-thalassemia in 22.22%, 73.02%, and 4.76% of the patients, respectively, with β-thalassemia/Hb E disease in 53.97%. Twenty-three patients had IRD (rheumatoid arthritis in 9, gout in 6, systemic lupus erythematosus in 3, spondyloarthropathy in 2, and one patient each with dermatomyositis, overlap syndrome, and unclassified polyarthralgia). Clinical manifestations and laboratory findings were similar to IRD patients in general. In 40 patients without IRD, direct and indirect Coombs tests and antinuclear antibody (ANA) were positive in 51.72%, 27.59%, and 10.26%, respectively. When comparing among these 40 patients, between those with non-transfusion-dependent thalassemia (n = 10) and those with transfusion-dependent thalassemia (n = 30), the latter had non-significantly more positive direct Coombs (60.87% vs. 16.67%), indirect Coombs (30.43% vs. 16.67%), and ANA tests (13.33% vs. 0%). The prevalence of IRD in patients with thalassemia disease was rather high. Positive direct Coombs test and ANA were common in transfusion-dependent patients.

Thrombotic Events and Anticoagulants in Beta-thalassemia Patients with Focus on Anticoagulants for Atrial Fibrillation: A Brief Review

Despite many advances in the diagnosis and treatment of beta-thalassemia patients in recent years and their longevity and quality of life which has been greatly increased, many of these patients have other life-threatening risks. The prevalence of atrial fibrillation in beta-thalassemia patients and its related thromboembolism, stroke, and mortality have been increased in the last few years. Appropriate anticoagulant therapy may help to prevent the incidence or recurrence of thromboembolism. So far warfarin is the most widely used drug. Aspirin should use with caution in these patients because of its resistance to aspirin over time, which can increase the risk of thromboembolism. Direct oral anticoagulants (DOACs) are widely used to prevent embolism in coronary artery disease and venous thromboembolism, but their use in thalassemia patients is still very limited. More high-quality researches and clinical trials are needed to prove their effectiveness and safety for atrial fibrillation in beta-thalassemia patients.

The association between pre-transfusion hemoglobin levels and thalassemia complications

OBJECTIVES

To evaluate any association between pre-transfusion hemoglobin (Hb) levels and thalassemia complications and to identify the Hb cutoff values to predict thalassemia complications.

METHODS

We performed a cross-sectional study in thalassemia patients who attended the Adult Hematology Clinic of the tertiary care University Hospital from October 2017 to October 2018. A point-biserial correlation was used to identify any association between Hb levels and thalassemia complications. A receiver operating characteristic (ROC) curve was used to identify the diagnostic ability of Hb levels to predict thalassemia complications and identify Hb cutoff values.

RESULTS

Out of the 102 patients, there were 53 transfusion dependent thalassemia (TDT) patients and 49 non-transfusion dependent thalassemia (NTDT) patients. In theTDT group, Hb levels showed a negative correlation with severe hepatic iron overload and hypogonadism. The cutoff Hb levels to predict severe hepatic iron overload and hypogonadism were ≤7.01 and 6.81 g/dL, respectively, at which points the area under the ROC curve (AUC) were 0.721 and 0.708, respectively. In the NTDTgroup, Hb levels were negatively correlated with hepatic iron overload, osteoporosis, and pulmonary hypertension. The cutoff values of Hb levels to predict hepatic iron overload, osteoporosis, and pulmonary hypertension were ≤8.24, 7.16, and 7.16 g/dL, respectively, at which points the AUC were 0.923, 0.715, and 0.725, respectively.

CONCLUSIONS

Lower Hb level was associated with more frequent complications in both TDT and NTDT patients. The Hb cutoff levels to predict these complications were identified.

Epidemiology of thalassemia among the hill tribe population in Thailand

BACKGROUND

Thalassemia is a severe disease that occurs due to abnormalities in hemoglobin genes. Various genetic factors in different populations lead to different clinical manifestations of thalassemia disease, particularly among people who have a long history of migration and who have married among tribes, such as the hill tribe people in Thailand. This genetic epidemiological study aimed to estimate the prevalence of various forms of thalassemia among the six main hill tribe populations in Thailand.

METHODS

A cross-sectional study was conducted to obtain information and blood specimens from school children belonging to one of the six main hill tribes in Thailand: Akha, Lau, Hmong, Yao, Karen, and Lisu. Hill tribe children who were attending grades 4-6 in 13 selected schools in Chiang Rai Province, Thailand, were invited to participate in the study. A validated questionnaire and 3 mL blood specimens were collected after obtaining information consent forms from both the children and their parents on a voluntary basis. A complete blood count (CBC) was performed, followed by osmotic fragility (OF) and dichlorophenol indophenol precipitation (DCIP) tests to screen for thalassemia. High-performance liquid chromatography (HPLC) and real-time quantitative polymerase chain reaction (qPCR) were used to identify hemoglobin type and α-thalassemia, respectively. A t-test, chi-square and logistic regression were used to detect the associations between variables at the significance level of α = 0.05.

RESULTS

A total of 1,200 participants from 6 different tribes were recruited for the study; 50.0% were males, and 67.3% were aged 11-12 years. The overall prevalence of thalassemia carriers according to the screening tests was 9.8% (117 of 1,200). Among the cases, 83 were A2A (59 cases were α-thalassemia 1 carrier or α-thalassemia 2 carrier or homozygous α-thalassemia 2, and 24 cases were β-thalassemia trait with or without α-thalassemia); 1 case was EE (homozygous Hb E with or without α-thalassemia); 31 cases were EA (30 cases were the Hb E trait, and 1 case was Hb E trait with or without α-thalassemia); 1 case was A2A Bart's H (Hb H disease α-thalassemia 1/α-thalassemia 2); and 1 case was A2A with abnormal Hb. The prevalence of the α-thalassemia 1 trait among the hill tribe population was 2.5%. The greatest prevalence of the α-thalassemia 1 trait was found in the Karen (3.0%) and Hmong (3.0%) tribes.

CONCLUSIONS

The prevalence of some forms of thalassemia in the hill tribe population is higher than that in the Thai and other populations. Effective and available thalassemia screening tests, including essential information to protect the next generation through the specific counseling clinic, are crucial, particularly due to increasing marriages within these populations.

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.

Increased endothelial activation in α-thalassemia disease

One complication of thalassemia is thromboembolism (TE), which is caused by an abnormal red blood cell surface, as well as endothelial and platelet activation. These findings are commonly observed in severe β-thalassemia. However, limited information on α-thalassemia exists. This study enrolled subjects with deletional and non-deletional α-thalassemia and normal controls (NC). Plasma and serum of subjects were tested for endothelial activation markers including thrombomodulin (TM), vascular cell adhesion molecule-1 (VCAM-1), and von Willebrand factor antigen as well as platelet activation markers including thromboxane B2 and platelet factor 4. A total of 179 subjects were enrolled: 29 in the deletional group (mean age 13.3 ± 4.4 years), 31 in the non-deletional group (mean age 12.9 ± 4.8 years), and 119 in the NC group (mean age 13.6 ± 3.0 years). Twenty nine percent of subjects in the non-deletional group received regular red blood cell transfusion and iron chelator administration. Serum ferritin level was higher in the non-deletional group than that in the deletional group. Multivariate analysis demonstrated that VCAM-1 and TM levels were increased significantly in α-thalassemia compared with NC group (816.8 ± 131.0 vs 593.9 ± 49.0 ng/ml, and 4.9 ± 0.7 vs 4.0 ± 0.4 ng/ml, P < 0.001 respectively). VCAM-1 and TM levels in the non-deletional group were significantly higher than that in the deletional group. The present study demonstrated endothelial activation in children with α-thalassemia disease, especially those in the non-deletional group, which might be one risk factor for TE in α-thalassemia disease.

A prospective analysis for prevalence of complications in Thai nontransfusion-dependent Hb E/β-thalassemia and α-thalassemia (Hb H disease)

Recently, complications in patients with nontransfusion-dependent thalassemia (NTDT), in particular those with β-thalassemia intermedia (β-TI), were found to be significantly different from those in patients with transfusion dependent thalassemia (TDT), mainly β-thalassemia major (β-TM). However, this information is rather limited in other forms of NTDT. In this prospective study, adult Thai NTDT patients were interviewed and clinically evaluated for thalassemia related complications. Fifty-seven NTDT patients (age 18-74 years), 59.6% Hb E/β-thalassemia and 40.4% Hb H disease, were recruited; 26.4% were splenectomized. The most common complications were gallstones (68.4%), osteoporosis (26.3%), and pulmonary hypertension (15.8%). Splenectomy was associated with higher rate of gallstones and serious infection (P = .001 and .052, respectively), consistent with a multivariate analysis (RR = 9.5, P = .044, and RR = 15.1, P = .043, respectively). In addition, a higher hemoglobin level was inversely associated with gallstones in both univariate and multivariate analyses (P = .01 and .022, respectively). Serum ferritin was associated with abnormal liver function (P = .002). In contrast to the previous study, the prevalence of thrombosis was less common in our population (1.7%), probably due to differences in transfusion therapy, ethnicity, and underlying genotypes. For the first time, this prospective study provided the current prevalence of NTDT related complications in a Southeast Asian population with a different underlying genetic basis compared with previous studies. Although individual prevalence of each complication might differ from other studies, several important clinical factors such as splenectomy, degree of anemia, and iron overload seem to be determining risks of developing these complications consistently across different ethnicities.

Cholelithiasis in Thalassemia Major Patients: A Report from the South-East of Iran

Background: Cholelithiasis and its predisposing factors are less characterized in thalassemia syndromes. In the present study, we assessed the prevalence of gallstones and related-risk factors among thalassemia major (TM) patients in south-east of Iran. Materials and Methods: The patients were recruited form a single center in Zabol city, south-east of Iran. Demographic and clinical information were retrieved from medical histories. Abdominal ultrasonography was performed to scrutinize gallstones and organ dimensions of liver, spleen, gallbladder and kidney. Results: The study participants (n=127) consisted of 50 (39.4%) males and 77 (60.6%) females. The mean age of the patients was 15.2±7.9 years. Cholelithiasis was observed in 11 (8.7%) patients. Cholelithiasis was significantly associated with age (P=0.002) and splenectomy (P=0.001). The patients with cholelithiasis received a significantly higher blood volume than patients without cholelithiasis (546±108.7 ml and 425.1±134.7 ml, respectively, P=0.007). There were significant differences between cholelithiasis and non- cholelithiasis TM patients regarding the length of right and left liver lobes (P=0.001), as well as the length of gallbladder (P=0.006). Ferritin level was not associated with cholelithiasis in our patients. In multivariate analysis, age older than 15 (OR=10.4, 95% CI: 1.2-86.3, P=0.02) and 30 years old (OR=42.6, 95% CI: 2.9-613, P=0.006), and splenectomy (OR=8.7, 95% CI: 2.1-35.4, P=0.002) were significant risk factors for cholelithiasis. Conclusion: Cholelithiasis is a relatively common complication among TM patients in our region. The most prominent risk factors of cholelithiasis were advanced age, splenectomy and large-volume blood transfusion.