Blood transfusion in beta thalassaemia major

Red cell alloantibodies in beta-thalassaemia major patients' blood referring to the regional blood transfusion center of Tehran, Iran

Introduction: Thalassemia is associated with a genetic decline in the rate of synthesis of one or more types of natural hemoglobin polypeptide chains. One of the major complications in thalassemia patients is alloimmunization, which is antibody production by the patient against transfused red blood cells (RBCs). These RBCs are unknown by the recipient and the formed antibodies against them are called alloantibodies. This study aimed to evaluate the frequency of alloantibodies against RBCs in beta-thalassemia patients referred to Tehran Regional Blood Transfusion Center.

Methods: In this study, antibody screening tests (Dia-cell I, II, and III) were performed on 184 thalassemia patients. An identification test by the Dia panel consisting of 11 different O RBCs groups to examine sera with Dia cells (I, II, or III) was performed.

Results: In our study, males and females patients comprised 66 (35.87%) and 118 (64.13%), respectively, of whom 116 (63%) had alloimmunization. In addition, 68 thalassemia subjects (37%) lacked alloantibodies. Among 184 patients with beta-thalassemia major, anti-K (Kell system), anti-D, and anti-E (Rhesus system) had the most abundant alloantibody variants with an incidence of 24 (13%), 11 (5.98%), and 10 (5.4%), respectively.

Conclusion: Before RBC transfusion, regular RBC antigen phenotypes, as well as problem-solving of alloantibody production by receiving compatible blood for Kell and RH subgroups, are suggested for all cases of transfusion-derived thalassemia.

Anti-Thyroid Peroxidase Antibodies and Male Gender Are Associated with Diabetes Occurrence in Patients with Beta-Thalassemia Major

BACKGROUND

Intensive transfusion schedule and iron-chelating therapy prolonged and improved quality of life in patients with β-thalassemia (β-T) major. However, this led to an increased risk of developing impaired glucose tolerance or diabetes. In this study we analyzed variables associated with the occurrence of impaired glucose tolerance or diabetes in patients with β-T major.

METHODS

388 Sardinian patients were included. Age, gender, duration of chelation therapy, body mass index, and markers of pancreatic and extrapancreatic autoimmunity were analyzed.

RESULTS

Multiple logistic regression analysis showed that anti-thyroid peroxidase (TPO) antibodies (Ab) (OR = 3.36; p = 0.008) and male gender (OR = 1.98; p = 0.025) were significantly associated with glucose impairment, while the other variables were not. Ferritin levels were significantly higher in TPOAb positive compared to TPOAb negative patients (4870 ± 1665 μg/L versus 2922 ± 2773 μg/L; p < 0.0001).

CONCLUSIONS

In patients with β-T major a progressive damage of insulin-producing cells due to secondary hemosiderosis appears to be the most reasonable mechanism associated with glucose metabolism disorders. The findings need to be confirmed with additional well designed studies to address the question of whether TPOAb may have a role in the management of these patients.

Model-Based Optimisation of Deferoxamine Chelation Therapy

Purpose

Here we show how a model-based approach may be used to provide further insight into the role of clinical and demographic covariates on the progression of iron overload. The therapeutic effect of deferoxamine is used to illustrate the application of disease modelling as a means to characterising treatment response in individual patients.

Methods

Serum ferritin, demographic characteristics and individual treatment data from clinical routine practice on 27 patients affected by β-thalassaemia major were used for the purposes of this analysis. The time course of serum ferritin was described by a hierarchical nonlinear mixed effects model, in which compliance was parameterised as a covariate factor. Modelling and simulation procedures were implemented in NONMEM (7.2.0).

Results

A turnover model best described serum ferritin changes over time, with the effect of blood transfusions introduced on the ferritin conversion rate and the effect of deferoxamine on the elimination parameter (Kout) in a proportional manner. The results of the simulations showed that poor quality of execution is preferable over drug holidays; and that independently of the compliance pattern, the therapeutic intervention is not effective if >60% of the doses are missed.

Conclusions

Modelling of ferritin response enables characterisation of the dynamics of iron overload due to chronic transfusion. The approach can be used to support decision making in clinical practice, including personalisation of the dose for existing and novel chelating agents.

Electronic supplementary material

The online version of this article (doi:10.1007/s11095-015-1805-0) contains supplementary material, which is available to authorised users.

Increasing prevalence of thalassemia in America: Implications for primary care

Thalassemia, once a rarity in the United States, is increasingly encountered in clinical practice due to shifts in immigration. Early carrier screening in at-risk populations can help clinicians implement genetic counseling and prevent new cases. Chronic transfusions are the mainstay of therapy for patients with severe thalassemia (beta thalassemia major), and are used intermittently in individuals with milder forms of thalassemia (Hb H/H Constant Spring disease and beta thalassemia intermedia). Iron overload is a major source of morbidity and mortality in individuals with transfusion and non-transfusion-dependent thalassemia, necessitating iron chelation therapy. Iron overload contributes to increased risk of cirrhosis, heart failure, and endocrinopathies, while ineffective erythropoiesis and hemolysis contribute to multiple complications, including splenomegaly, extramedullary hematopoiesis, pulmonary hypertension, and thrombosis. An understanding of the importance of carrier screening, complications, monitoring, and management strategies, coupled with collaboration with a hematologist with thalassemia expertise, is essential to reduce the morbidity and mortality in patients with thalassemia.

Donor cycle and donor segmentation: new tools for improving blood donor management

BACKGROUND AND OBJECTIVES

An adequate donor population is of key importance for the entire blood transfusion chain. For good donor management, a detailed overview of the donor database is therefore imperative. This study offers a new description of the donor cycle related to the donor management process. It also presents the outcomes of a European Project, Donor Management IN Europe (DOMAINE), regarding the segmentation of the donor population into donor types.

MATERIALS AND METHODS

Blood establishments (BEs) from 18 European countries, the Thalassaemia International Federation and a representative from the South-Eastern Europe Health Network joined forces in DOMAINE. A questionnaire assessed blood donor management practices and the composition of the donor population using the newly proposed DOMAINE donor segmentation. 48 BEs in 34 European countries were invited to participate.

RESULTS

The response rate was high (88%). However, only 14 BEs could deliver data on the composition of their donor population. The data showed large variations and major imbalances in the donor population. In 79% of the countries, inactive donors formed the dominant donor type. Only in 21%, regular donors were the largest subgroup, and in 29%, the proportion of first-time donors was higher than the proportion of regular donors.

CONCLUSION

Good donor management depends on a thorough insight into the flow of donors through their donor career. Segmentation of the donor database is an essential tool to understand the influx and efflux of donors. The DOMAINE donor segmentation helps BEs in understanding their donor database and to adapt their donor recruitment and retention practices accordingly. Ways to use this new tool are proposed.

Blood transfusion and alloimmunization in patients with thalassemia: multicenter study

One of transfusion's side effects is alloimmunization against red blood cell (RBC) antigens. Early diagnosis by antibody screening is an important step in the detection of these alloantibodies. The authors studied the frequency of alloimmunization in thalassemic patients of 4 centers (2 adult and 2 pediatric centers) and compared the rates in children (up to 15 years) and adults. Antibody screening tests were performed by gel method according to its standard pattern and respective program. In positive cases, antibody identification test by gel method was performed. Eight hundred thirty-five patients were studied; 548 (65.6%) were adults (mean age = 24.5), and 287 (34.4%) cases were pediatrics (mean age = 10.05). Of these patients, 74.1% had no history of transfusion reaction, whereas 21 (2.5%) had hemolytic complications. Seventy-eight (9.3%) exhibited allergic symptoms, and 117 (14%) cases experienced febrile reactions during transfusion. Antibody screening showed positive results in 22 pediatric cases (7.7%) and 79 adults (14.4%); 72 (71.3%), 19 (18.8%), 3 (3%), and 1 (1%) cases exhibited single, double, triple, and autoantibodies, respectively. Anti-Kell antibody was seen in 34 (33.7%) cases, anti-D was seen in 11 (10.9%) cases, and anti-E in was seen in 10 (9.9%) cases. The authors observed 8 anti-D+C (7.9%) cases, 1 anti-D+E (1%), 3 anti-Kell+E, 3 anti-Kell+Kpa (3%), and 1 anti-Kell+D double antibodies. These antibodies were also a combination of Rh subgroups or Rh and Kell subgroups. The authors observed meaningful relations between history of transfusion reactions and age with antibody screening results (P = .005). Based on alloantibodies types, more than two thirds of them were Rh subgroups and Kell groups. Phenotype determination of RBCs before beginning chronic blood transfusion and careful cross-matching with Kell and Rh subgroups in addition to ABO may help reduce alloimmunization in chronic transfusion patients.

Thalassemia: an overview of 50 years of clinical research

The thalassemias are attributable to the defective production of the α- and β-globin polypeptides of hemoglobin. Significant discoveries have illuminated the pathophysiology and enhanced the prevention and treatment of the thalassemias, and this article reviews many of the advances that have occurred in the past 50 years. However, the application of new approaches to the treatment of these disorders has been slow, particularly in the developing world where the diseases are common, but there is definite progress. This article emphasizes how the increasing knowledge of cellular and molecular biology are facilitating the development of more effective therapies for these patients.

Comparison of subcutaneous infusion needles for transfusion-dependent thalassemia patients by the intrapersonal cross-over assessment model

Needle-induced trauma is one of the major contributing factors for poor compliance in patients with thalassaemia major on iron chelation therapy. A new generation of needles is currently available on the market, but their theoretical advantages have not been tested clinically. We performed a study to compare the pros and cons of the representative prototypes from each of the new (Thalaset needle) and old (butterfly scalp vein needle) generations of needles. Patients with thalassemia major who had been receiving subcutaneous iron chelation therapy for at least 2 years were recruited. Patients using butterfly needles were instructed to switch to the newer form of needle (Thalaset) for 2.5 months and then to change back to butterfly needles for another 2.5 months. Comparison was done by the intrapersonal cross-over model using three identical sets of questionnaires collected at the beginning of the study and after the use of Thalaset and butterfly needles, respectively. Fifty-four (22 females; 32 males) patients were included in the statistical analysis. The median age was 24.1 years (range = 7.6-47.2 years). Local reactions such as pain, itchiness, tenderness, and swelling were significantly different among the three evaluation periods and were all in favor of the Thalaset needle (all with P < 0.001), even after adjusting for the intention-to-treat calculation. The Thalaset needle is significantly better than the butterfly needle in reducing needle-related trauma. It induced fewer local skin reactions such as pain, itchiness, tenderness, and swelling. However, recommendations for its routine clinical use require further cost-effectiveness analysis.