Nucleic Acid Therapy for β-Thalassemia

Impact of Hemin on Interleukin-21 Levels and Plasma Cells in Transfusion-Dependent Thalassemia with Positive and Negative Allo-Autoantibody

Introduction

Antibody formation in transfusion-dependent thalassemia is associated with chronic hemolysis and repeated transfusions. Hemolysis produces heme, which mediates B-cell differentiation into plasma cells and produces antibodies influenced by interleukin-21 (IL-21).

Objective

This study aimed to compare IL-21 levels, plasma cell percentage, and red blood cell antibodies between positive and negative allo-autoantibody thalassemia before and after hemin administration.

Materials and Methods

This research employed a quasi-experimental nonequivalent control group pre-test and post-test design performed from April to November 2021 at Soetomo Academic Hospital in Surabaya, Indonesia. Heparinized blood samples of 5 mL and 4 mL and EDTA blood samples of 3 mL were taken from positive (29 patients) and negative (28 patients) allo-autoantibody thalassemia participants. Hemin 20 µM was added to 5 mL of heparinized blood, incubated for 2 hours, prepared into peripheral blood mononuclear cells (PBMCs), and cultured for 3 days. The percentage of plasma cells (CD38+CD184+) of cultured and uncultured PBMCs was measured by BD FACSCalibur Flow Cytometer. IL-21 levels of plasma and supernatants were measured with Sandwich Enzyme-Linked Immunosorbent Assay by Elabscience. Red blood cell antibodies were detected by QWALYS 3 E.M. Technology. Autoantibodies were determined by the Grifols gel tube method.

Results

IL-21 levels were significantly different in the positive and negative allo-autoantibody thalassemia groups after hemin administration. The percentage of plasma cells in the positive allo-autoantibody group increased significantly after the administration of hemin. The percentage of plasma cells between thalassemia groups was not significantly different before the hemin administration but increased significantly after it. Red blood cell antibodies after the administration of hemin were significantly different in the negative allo-autoantibody group but not significantly different in the positive allo-autoantibody group.

Conclusion

Hemin administration affected IL-21 levels, plasma cell percentage, and antibody formation in positive and negative allo-auto antibody thalassemia.

Molecular genetics of β-thalassemia: A narrative review

ABSTRACT

β-thalassemia is a hereditary hematological disease caused by over 350 mutations in the β-globin gene (HBB). Identifying the genetic variants affecting fetal hemoglobin (HbF) production combined with the α-globin genotype provides some prediction of disease severity for β-thalassemia. However, the generation of an additive composite genetic risk score predicts prognosis, and guide management requires a larger panel of genetic modifiers yet to be discovered.Presently, using data from prior clinical trials guides the design of further research and academic studies based on gene augmentation, while fundamental insights into globin switching and new technology developments have inspired the investigation of novel gene therapy approaches.Genetic studies have successfully characterized the causal variants and pathways involved in HbF regulation, providing novel therapeutic targets for HbF reactivation. In addition to these HBB mutation-independent strategies involving HbF synthesis de-repression, the expanding genome editing toolkit provides increased accuracy to HBB mutation-specific strategies encompassing adult hemoglobin restoration for personalized treatment of hemoglobinopathies. Allogeneic hematopoietic stem cell transplantation was, until very recently, the curative option available for patients with transfusion-dependent β-thalassemia. Gene therapy currently represents a novel therapeutic promise after many years of extensive preclinical research to optimize gene transfer protocols.We summarize the current state of developments in the molecular genetics of β-thalassemia over the last decade, including the mechanisms associated with ineffective erythropoiesis, which have also provided valid therapeutic targets, some of which have been shown as a proof-of-concept.

Role of Iron in the Molecular Pathogenesis of Diseases and Therapeutic Opportunities

Iron is an essential mineral that serves as a prosthetic group for a variety of proteins involved in vital cellular processes. The iron economy within humans is highly conserved in that there is no proper iron excretion pathway. Therefore, iron homeostasis is highly evolved to coordinate iron acquisition, storage, transport, and recycling efficiently. A disturbance in this state can result in excess iron burden in which an ensuing iron-mediated generation of reactive oxygen species imparts widespread oxidative damage to proteins, lipids, and DNA. On the contrary, problems in iron deficiency either due to genetic or nutritional causes can lead to a number of iron deficiency disorders. Iron chelation strategies have been in the works since the early 1900s, and they still remain the most viable therapeutic approach to mitigate the toxic side effects of excess iron. Intense investigations on improving the efficacy of chelation strategies while being well tolerated and accepted by patients have been a particular focus for many researchers over the past 30 years. Moreover, recent advances in our understanding on the role of iron in the pathogenesis of different diseases (both in iron overload and iron deficiency conditions) motivate the need to develop new therapeutics. We summarized recent investigations into the role of iron in health and disease conditions, iron chelation, and iron delivery strategies. Information regarding small molecule as well as macromolecular approaches and how they are employed within different disease pathogenesis such as primary and secondary iron overload diseases, cancer, diabetes, neurodegenerative diseases, infections, and in iron deficiency is provided.

Attitudes of Indonesian Medical Doctors and Medical Students Toward Genome Editing

Purpose

This study aimed to measure the attitudes of Indonesian medical doctors and students toward new technology in genome editing.

Materials and Methods

Online questionnaires regarding attitudes toward genome editing on health and non-health conditions, both in somatic cells and embryo, were distributed through researcher networks, email and social media specific to medical doctors and students. The data of 1055 valid questionnaires were processed; descriptive and association analyses between sociodemographic factors and attitudes toward genome editing were performed. Email in-depth interview was performed to explore the respondents’ answers.

Results

The results showed that Indonesian medical doctors’ and students’ knowledge of genome editing was limited and correlated with gender, place of residence, religion, education, marital status, childbearing and experience abroad. More than half of respondents supported genome editing for the treatment of fatal and debilitating diseases both in somatic cells and embryos, implying their consent to edited gene inheritance. However, this approval decreased when applied to non-health-related aspects, such as physical appearance, intelligence and strength. Factors affecting their attitudes toward genome editing included their status as medical doctors or students, gender, age, education, religion, economic status and place of residence.

Conclusion

Increasing knowledge and awareness of Indonesian medical doctors and students regarding genome editing is important. Even though its application in health-related matter was supported by a majority of the respondents, discussion from ethical and religious perspectives is necessary to ensure the acceptance.