Thalassaemia-A global view.

The thalassaemias are a group of genetic disorders of haemoglobin which are endemic in the tropics but are now found worldwide due to migration. Basic standard of care therapy includes regular transfusions to maintain a haemoglobin level of around 10 g/dL, together with iron chelation therapy to prevent iron overload. Novel therapies, bone marrow transplantation, and gene therapy are treatment options that are unavailable in many countries with stressed economies. This Wider Perspectives article presents the strategies for management of an adolescent refugee patient with beta thalassaemia, as it would be performed by expert haematologists in six countries: Italy, Lebanon, Oman, the Sudan, Thailand and the United States. The experienced clinicians in each country have adapted their practice according to the resources available, which vary greatly. Even in the current modern era, providing adequate transfusions and chelation is problematic in many countries. On the other hand, ensuring adherence to therapy, particularly during adolescence, is a similar challenge seen in all countries. The concluding section highlights the disparities in available therapies and puts the role of novel therapies into a societal context.

Development of a Thalassemia International Prognostic Scoring System (TIPSS).

A prognostic scoring system that can differentiate ß-thalassemia patients based on mortality risk is lacking. We analysed data from 3145 ß-thalassemia patients followed through a retrospective cohort design for the outcome of death. An a priori list of prognostic variables was collected. ß Coefficients from a multivariate cox regression model were used from a development dataset (n = 2516) to construct a formula for a Thalassemia International Prognostic Scoring System (TIPSS) which was subsequently applied to a validation dataset (n = 629). The median duration of observation was 10.0 years. The TIPSS score formula was constructed as exp (1.4 × heart disease + 0.9 × liver disease + 0.9 × diabetes + 0.9 × sepsis + 0.6 × alanine aminotransferase ≥42 IU/L + 0.6 × hemoglobin ≤9 g/dL + 0.4 × serum ferritin ≥1850 ng/mL). TIPSS score thresholds of greatest differentiation were assigned as <2.0 (low-risk), 2.0 to <5.0 (intermediate-risk), and ≥5.0 (high-risk). The TIPSS score was a good predictor for the outcome of death in the validation dataset (AUC: 0.722, 95%CI: 0.641-0.804) and survival was significantly different between patients in the three risk categories (P < 0.001). Compared to low-risk patients, the hazard ratio for death was 2.778 (95%CI: 1.335-5.780) in patients with intermediate-risk and 6.431 (95%CI: 3.151-13.128) in patients with high-risk. This study provides a novel tool to support mortality risk categorization for patients with ß-thalassemia that could help management and research decisions.

Primary HBB gene mutation severity and long-term outcomes in a global cohort of ß-thalassaemia.

In ß-thalassaemia, the severity of inherited ß-globin gene mutations determines the severity of the clinical phenotype at presentation and subsequent transfusion requirements. However, data on associated long-term outcomes remain limited. We analysed data from 2109 ß-thalassaemia patients with available genotypes in a global database. Genotype severity was grouped as ß0 /ß0 , ß0 /ß+ , ß+ /ß+ , ß0 /ß++ , ß+ /ß++ , and ß++ /ß++ . Patients were followed from birth until death or loss to follow-up. The median follow-up time was 34·1 years. Mortality and multiple morbidity outcomes were analyzed through five different stratification models of genotype severity groups. Interestingly, ß0 and ß+ mutations showed similar risk profiles. Upon adjustment for demographics and receipt of conventional therapy, patients with ß0 /ß0 , ß0 /ß+ , or ß+ /ß+ had a 2·104-increased risk of death [95% confidence interval (CI): 1·176-3·763, P = 0·011] and 2·956-increased odds of multiple morbidity (95% CI: 2·310-3·784, P < 0·001) compared to patients in lower genotype severity groups. Cumulative survival estimates by age 65 years were 36·8% for this subgroup compared with 90·2% for patients in lower genotype severity groups (P < 0·001). Our study identified mortality and morbidity risk estimates across various genotype severity groups in patients with ß-thalassaemia and suggests inclusion of both ß+ and ß0 mutations in strata of greatest severity.

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.

Cardiac T2* MR in patients with thalassemia major: a 10-year long-term follow-up.

The consequence of regular blood transfusion in patients with thalassemia major (TM) is iron overload. Herein, we report the long-term impact of chelation on liver iron concentration (LIC) and cardiac T2* MR in patients with TM. This is a retrospective cohort study over 10 years of adolescents and adults with TM aged at least 10 years who had their first cardiac T2* MR between September 2006 and February 2007. One-year chelation therapy was considered the unit of analysis. A total of 99 patients were included in this study with a median age of 18 years. The median cardiac T2* MR and LIC at baseline were 19 ms and 11.6 mg/g dw, respectively. During follow-up, 18 patients died and six underwent successful bone marrow transplantation. Factors associated with decreased survival were older age (HR 1.12, p = 0.014) and high risk cardiac T2* (HR 8.04, p = 0.004). The median cardiac T2* and LIC significantly improved over the 10-year follow-up period (p = 0.000011 and 0.00072, respectively). In conclusion, this long-term "real-life" study confirms that low cardiac T2* adversely impacts the overall survival in patients with TM. Higher baseline LIC predicts a larger reduction in LIC, and lower baseline cardiac T2* predicts a larger improvement in T2*.

α-Globin Genotypes Associated with Hb H Disease: A Report from Oman and a Review of the Literature from the Eastern Mediterranean Region.

α-Thalassemia (α-thal) is the most common autosomal recessive hemoglobinopathy. There is a vast diversity and geographical variability in underlying genotypes in Hb H (ß4) patients. Herein, we describe the genotypes found in the largest report of Omani Hb H patients. Moreover, we reviewed and summarized the literature published from the Eastern Mediterranean region. A retrospective review of all genetically confirmed Hb H disease patients diagnosed between 2007 and 2017 at Sultan Qaboos University Hospital, Muscat, Oman, was performed. Hematological parameters and clinical presentations were assessed. Both α-globin genes were screened for deletional and nondeletional mutations using a stepwise diagnostic strategy as described before. A total of 52 patients (27 females and 25 males) with a mean age of 20.6 years (range 0.23-80.0) were molecularly confirmed to carry Hb H disease. The patients had a hemoglobin (Hb) level of 9.3 g/dL (range 5.7-13.0) and mean corpuscular volume (MCV) of 58.4 fL (range 48.2-82.1). A total of eight genotype combinations were identified, with α2 polyadenylation signal mutation (polyA1) (AATAAA>AATAAG (αPA1α/αPA1α), often cited as αT-Saudiα/αT-Saudiα, being the most common (53.8%) followed by -α3.7/- -MED I (28.8%). Our cohort also included patients with combinations of αPA1 with other Hb variants: αPA1α/αPA1α with Hb S (HBB: c.20A>T) trait (n = 2), -α3.7/αPA1α (n = 2) and αcodon 19α (HBA2: c.56delG)/αPA1α (n = 1). Nondeletional Hb H disease due to the αPA1 mutation is the most common in Omanis. Molecular diagnosis is necessary for accurate confirmation of the diagnosis of α-thal, determination of underlying genotypes, follow-up and counseling.

For Debate: Assessment of HbA1c in Transfusion Dependent Thalassemia Patients.

At present, assessment of haemoglobin A1c (HbA1c) is widely used for the diagnosis and monitoring of treatment in diabetes mellitus (DM). However, the HbA1c level is affected by many factors such as those influencing the lifespan of red blood cells and the structure, function and amount of normal HbA. Therefore, the clinical significance of HbA1c assessment in thalassemia patients needs careful consideration, especially in transfusion dependent thalassemia patients (TDT) in whom circulating Hb is that of blood donors. Preliminary reports have documented that HbA1c estimation in efficiently transfused patients seems valuable in diagnosis and monitoring of treatment in DM and other glucose disturbances in TDT patients. Herein, a short review of HbA1c measurement in anemias, blood transfusions and hemoglobinopathies, and the debate of the credibility of Hb A1c assessment in TDT patients is reported.

Red cell alloimmunization in transfusion-dependent and transfusion-independent beta thalassemia: A review from the Eastern Mediterranean Region (EMRO).

BACKGROUND: ß-Thalassemia is considered one of the common hemoglobin disorders in the Arabian Peninsula. Red blood cell (RBC) transfusion is a crucial component of the management of transfusion-dependent ß-Thalassemia patients. Patients with Thalassemia Intermedia (TI), also known as non-transfusion dependent ß-thalassemia, have a wide clinical presentation and variable transfusion dependence. Rates of RBC alloimmunization and its risk factors in transfusion-dependent ß-thalassemia patients varied between different reports. Risk of alloimmunization is higher in TI patients. MATERIAL AND METHODS: A literature review on existing reports on alloimmunization rates and risk factors in transfusion dependent and non-transfusion dependent ß-thalassemia in the Eastern Mediterranean region was performed. RESULTS: A total of 17 publications were found. Reported rates of alloimmunization among transfusion-dependent ß-Thalassemia patients ranged between 2.87 and 30 % and between 6.8 and 19.5 % among TI patients. Most centers utilize ABO and RhD matched RBCs. The most common antibodies described are anti-K and anti-E. The risk factors described included age at onset of transfusion, gender, history of splenectomy, duration of transfusion and number of units transfused. Rate of autoantibody formation ranged between 0.1 and 45 %. CONCLUSION: Our review showed variable alloimmunization rates and risk factors in thalassemia patients and scant data on TI patients. The commonest antibodies are anti-K and anti-E. Further studies are required in addressing the rate of alloimmunization, cross-match requirements and role of genotyping in this group of patients. Transfusion support of patients with thalassemia necessitates the availability of blood bank facilities and specialized expertise.

Risks of red blood cell alloimmunization in transfusion-dependent ß-thalassemia in Oman: a 25-year experience of a university tertiary care reference center and a literature review.

BACKGROUND: ß-Thalassemia is a common hemoglobinopathy in the Arabian Peninsula. Red blood cell (RBC) transfusion is a cornerstone for its management, but can create significant challenges including RBC alloimmunization. Herein, we examine alloimmunization risk factors in Omani patients with transfusion-dependent ß-thalassemia. Existing literature is summarized. STUDY DESIGN AND METHODS: A retrospective review of all patients attending our center over 25 years was performed. Clinical and transfusion records were examined. Chi-square test was used to assess the association between the categorical variables. Nonparametric Mann-Whitney test was used to assess the association between transfusion and risk of alloimmunization. RESULTS: A total of 268 patients were identified (168 adults and 100 pediatrics), of whom 226 are alive (84.3%). Males accounted for 53.4%. The cohort had a median age of 22 years (range, 2-43 years). The most common blood group was O+ (39%). The prevalence of alloimmunization was 9.3% with anti-E (24%) and anti-K (24%) being the commonest antibodies identified. There was a significant association between age and alloimmunization, with 68% of alloimmunized patients in the age group of 19 to 30 years (p < 0.01). Among adults, there was a significant association between alloimmunization and number of units transfused (p = 0.001). There was no association between alloimmunization and sex or history of splenectomy. CONCLUSION: Our study shows an association between alloimmunization and the age of the patients and number of units transfused. Transfusion support of this group of patients necessitates the availability of needed expertise and blood bank facilities.

Selected highlights of the VIII International Symposium of Clinicians for Endocrinopathies in Thalassemia and Adolescent Medicine (ICET-A) on Growth, Puberty and Endocrine Complications in Thalassaemia. Auditorium of the Sultan Qaboos University (SQU) Muscat (Sultanate of Oman), 20th of December 2014.

The VIII ICET-A International Symposium was held in Muscat (Sultanate of Oman) on the 20th of December, 2014. The symposium included four sessions on a wide range of topics covering growth disorders and endocrine complications in thalassaemia. Despite the fact that endocrine complications are very common in multi-transfused thalassaemia patients a recent survey conducted by the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescent Medicine (ICET-A) in 2014 in Acitrezza (Catania, Italy) showed that the major difficulties reported by hematologists or pediatricians experienced in thalassaemias or thalassaemia syndromes in following endocrine complications included: Lack of familiarity with medical treatment of endocrine complications, interpretation of endocrine tests, lack of collaboration and on-time consultation between thalassaemic centres supervised by haematologists and endocrinologists. Endocrine monitoring of growth, pubertal development, reproductive ability and endocrine function in general are essential to achieve a good quality of life as well as controlling the pain which results from the defects of bone structure, all of which increase with the age of patients. Such comprehensive care is best provided by coordinated, multidisciplinary teams working in expert centres. The multidisciplinary team must include an endocrinologist, preferably someone experienced in the management of hormonal deficiencies caused early in life by transfusion-induced iron overload.

Multicenter validation of spin-density projection-assisted R2-MRI for the noninvasive measurement of liver iron concentration.

PURPOSE: Magnetic resonance imaging (MRI)-based techniques for assessing liver iron concentration (LIC) have been limited by single scanner calibration against biopsy. Here, the calibration of spin-density projection-assisted (SDPA) R2-MRI (FerriScan®) in iron-overloaded ß-thalassemia patients treated with the iron chelator, deferasirox, for 12 months is validated. METHODS: SDPA R2-MRI measurements and percutaneous needle liver biopsy samples were obtained from a subgroup of patients (n = 233) from the ESCALATOR trial. Five different makes and models of scanner were used in the study. RESULTS: LIC, derived from mean of MRI- and biopsy-derived values, ranged from 0.7 to 50.1 mg Fe/g dry weight. Mean fractional differences between SDPA R2-MRI- and biopsy-measured LIC were not significantly different from zero. They were also not significantly different from zero when categorized for each of the Ishak stages of fibrosis and grades of necroinflammation, for subjects aged 3 to <8 versus ≥8 years, or for each scanner model. Upper and lower 95% limits of agreement between SDPA R2-MRI and biopsy LIC measurements were 74 and -71%. CONCLUSION: The calibration curve appears independent of scanner type, patient age, stage of liver fibrosis, grade of necroinflammation, and use of deferasirox chelation therapy, confirming the clinical usefulness of SDPA R2-MRI for monitoring iron overload.

Transfusion therapy and alloimmunization in Thalassemia Intermedia: a 10 year experience at a tertiary care university hospital.

BACKGROUND: Thalassemia Intermedia (TI) has a wide clinical profile with many patients requiring only occasional transfusions. To prevent alloimmunization, we adopted a policy of issuing phenotype matched red blood cells in 2009. We examined transfusion indications and alloimmunization rate in TI patients. STUDY DESIGN AND METHODS: Clinical and blood bank records of 37 TI patients were reviewed. RESULTS: 23 Patients required transfusion for pregnancy (26), splenectomy (8) and anemia (11). Since 2009, total of 335 units were transfused with only one antibody developing after transfusing a non-phenotype matched unit. CONCLUSION: The commonest indication for blood transfusion was pregnancy. Providing phenotype matched blood has successfully reduced the rate of alloimmunization.

Validation of a non-invasive pulse CO-oximetry based hemoglobin estimation in normal blood donors.

INTRODUCTION: Non-invasive hemoglobin estimation may increase the recruitment of blood donors. CO-oximetry hemoglobin estimation is a non-invasive method used to estimate the hemoglobin level. The primary objective of this study is to validate the pulse CO-oximetry based hemoglobin estimation in normal blood donors. METHODS: We conducted a prospective observational study on 106 in a tertiary care hospital blood bank over a period of 4 weeks. We performed a Spot Hemoglobin concentration (Sp Hb) using Masimo Pronto-7 Pulse CO-oximetry, and compared it to a venous sample Hb concentration (Reference Hemoglobin; Ref Hb) measured using Abbott CELL-DYN Sapphire hematology analyzer. Age, gender, weight, height, blood pressure and reference hemoglobin were used in the multivariable linear regression model of the difference in measurement. RESULTS: Total of 106 donors (98 males, 8 females) were enrolled with a mean age and Ref Hb of 27 years (SD 6.2; 18-49) and 14.2 g/dL (SD 1.2; 11.5-17) respectively. The mean Sp Hb was 14.4 g/dL (SD 1.2;11.3-16.7). The mean difference between the Sp Hb and Ref Hb was 0.2 g/dL (SD 1.2;-4.5 to 3) with a correlation coefficient of 0.46 (R(2)=21%). In the multivariable model, height (p=0.015) and Hb level (p<0.001) were statistically significant predictors. A strong correlation was found between the two CO-oximetry Hb measurements (coefficient 0.78, R(2)=60%). CONCLUSIONS: Our study validated the use of the CO-oximetry in blood donors. Larger prospective studies are needed to confirm our results.

Correlation of iron overload and glomerular filtration rate estimated by cystatin C in patients with ß-thalassemia major.

Historically, renal involvement has not been a commonly recognized complication in patients with ß-thalassemia major (ß-TM). Herein, we studied the impact of iron overload on glomerular filtration rate (GFR) estimated by cystatin C based GFR (Cyst C eGFR). We enrolled 149 patients with ß-TM in a cross sectional study in a single center in Oman. We investigated the correlation between measurement of serum ferritin and Cyst C eGFR. We used univariable linear regression to study the impact of serum ferritin on Cyst C eGFR and backwards stepwise regression to adjust for potential confounders. We included 78 males and 71 females with a mean age of 17.3 ± 9 years (range 2.5-38.5). Seventeen patients had diabetes mellitus. Patients were taking deferiprone (DFP) and deferoxamine (DFO) (26 patients), DFP (58 patients), deferasirox (DFX) (62 patients) and one patient was taking only DFO. There was a very weak negative linear relationship between serum ferritin and Cyst C eGFR (correlation coefficient -0.25). In the univariable analyses, serum ferritin (p = 0.004), diabetes status (p < 0.001) and chelation therapy (p < 0.001) were statistically significant. In the multivariable model, age (p = 0.033), chelation with DFX (p = 0.05) and diabetes status (p < 0.001) were statistically significant. We found a very weak inverse linear correlation between serum ferritin and Cyst C eGFR. However, when concomitant use of chelation therapy was considered, serum ferritin did not associate with glomerular function. Prospective and larger studies are needed to confirm these findings.

Can we Predict Incipient Diabetes Mellitus in Patients with Transfusion Dependent ß-Thalassemia (ß-TDT) Referred with a History of Prediabetes?

Background: Prediabetes and diabetes mellitus (DM) are complications in adult patients with transfusion-dependent ß-thalassemia (ß-TDT), with their incidence increasing with age. Objective: This retrospective observational study describes the glycemic trajectories and evaluates predictive indices of ß-cell function and insulin sensitivity/resistance in ß-TDT patients with prediabetes, both in a steady state and during 3-h oral glucose tolerance test (OGTT), in order to identify patients at high risk for incipient diabetes. Setting: The study was mainly conducted at the Pediatric and Adolescent Outpatient Clinic, Quisisana Hospital, Ferrara (Italy), in collaboration with thalassemia referring centers across Italy. Patients: The study included 11 ß-TDT (aged 15.11-31.10 years) with prediabetes. Methods: The ADA criteria for the diagnosis of glucose dysregulation were adopted. Investigations included evaluating plasma glucose levels and insulin secretion, analyzing glycemic trajectories and indices of ß-cell function, and insulin sensitivity/resistance assessed in steady state and during OGTT. Results: The duration of progression from prediabetes to DM, expressed in years, showed a positive direct correlation with corrected insulin response (CIR-30 = r: 0.7606, P: 0.0065), insulinogenic index (IGI 0-120 = r: 0.6121, P:0.045), oral disposition index (oDI = r: 0.7119, P:0.013), insulin growth factor-1 (IGF-1= r: 0.6246, P: 0.039) and an inverse linear correlation with serum ferritin (SF = r: -0.7197, P: 0.012). The number of patients with 1-hour post-load PG value ≥ 155 mg/dL ( ≥ 8.6 mmol/L) was at -4 years: 4/9 (44.4%); -3 years: 8/9 (88.8%); - 2 years: 7/10 (70 %) and at -1 year: 11/11 (100%) (PG range:162-217 mg/dL). Conclusions: A progressive increase in 1-hour PG in response to OGTT is associated with progressive ß-cell failure, peripheral resistance to insulin action, and reduced oDI and may be considered a relevant marker for incipient DM in ß-TDT patients with prediabetes.

A stepwise α-thalassemia screening strategy in high-prevalence areas.

INTRODUCTION: Coinheritance of α-thalassemia influences the clinical and hematological phenotypes of ß-hemoglobinopathies (ß-thalassemia and sickle cell disease) and when present together in significant frequency within a population, a spectrum of clinical forms is observed. Precise molecular characterization of α-thalassemia is important in understanding their disease-modifying role in ß-hemoglobinopathies and for diagnostic purposes. PATIENTS AND METHODS: Because currently used approaches are labor/cost-intensive, time-consuming, error-prone in certain genotype combinations and not applicable for large epidemiological screening, we developed a systematic stepwise strategy to overcome these difficulties. We successfully applied this to characterize the α-globin gene status in 150 Omani cord blood samples with Hb Barts and 32 patients with HbH disease. RESULTS: We observed a good correlation between α-globin genotypes and level of Hb Bart's with the Hb Bart's levels significantly higher in both deletional and non-deletional α-globin genotypes. The most common α-globin genotype in HbH cases was α(TSaudi) α/α(TSaudi) α (n = 16; 50%) followed by -α(3.7) /-(MED) (n = 10; 31%). This approach detects also the α-globin gene triplication as exemplified by the study of a family where the ß-globin gene defect failed to explain the ß-thalassemia intermedia phenotype. CONCLUSION: Molecular characterization of α-thalassemia is complex due to high sequence homology between the duplicated α-globin genes and to the existence of a variety of gene rearrangements (small and large deletions of various sizes) and punctual substitutions (non-deletional alleles). The novelty of our strategy resides, not in the individual technical steps per se but in the reasoned sequential order of their use taking into consideration the hematological phenotype as well.