Understanding Thalassemia: A comprehensive overview
Vinitha. M*
Group Clinical Pharmacist, Kauvery Hospital, Trichy
*Correspondence: Clinicalcst@kauveryhopitla.com
Definition
Thalassemia is a group of inherited blood disorders characterized by reduced hemoglobin production. Hemoglobin is the protein in red blood cells that carries oxygen throughout the body. Thalassemia results in anemia, which can vary in severity.
Thalassemia is an inherited blood disorder that affects hemoglobin production. This condition results in anemia, which can range from mild to severe. Understanding thalassemia, its types, symptoms, diagnosis, and treatment options is crucial for managing the condition effectively and improving the quality of life for those affected.
Types of Thalassemia
Alpha Thalassemia
It is caused by mutations in the HBA1 and HBA2 genes, which encode the alpha-globin subunits of hemoglobin. There are four types, depending on how many of the four alpha-globin genes are affected:
- Silent Carrier State: One gene is affected. Individuals are typically asymptomatic.
- Alpha Thalassemia Trait: Two genes are affected. Individuals may have mild anemia.
- Hemoglobin H Disease: Three genes are affected. Symptoms include moderate to severe anemia, splenomegaly, and bone deformities.
- Hydrops Fetalis: All four genes are affected. This condition is usually fatal before or shortly after birth.
Beta Thalassemia
It is Caused by mutations in the HBB gene, which encodes the beta-globin subunits of hemoglobin. There are three types based on the severity of the mutations:
- Beta Thalassemia Minor (Trait): One gene is affected. Individuals are typically asymptomatic or have mild anemia.
- Beta Thalassemia Intermedia: Both genes are affected, but the mutations allow for some beta-globin production. Symptoms range from moderate to severe anemia.
- Beta Thalassemia Major (Cooley’s Anemia): Both genes are affected, leading to little or no beta-globin production. Symptoms are severe and include severe anemia, growth retardation, and skeletal abnormalities.
Flowchart: Types of Thalassemia
Medical history and physical examination
- Family history of anemia or known thalassemia.
- Symptoms such as fatigue, weakness, pallor, jaundice, and growth issues.
- Physical examination may reveal pallor, jaundice, splenomegaly, and skeletal deformities.
Laboratory Tests
- Complete Blood Count (CBC): Shows anemia, reduced mean corpuscular volume (MCV), and red blood cell (RBC) count abnormalities.
- Hemoglobin Electrophoresis: Identifies abnormal hemoglobin types and quantifies hemoglobin A2 and F.
- Genetic Testing: Confirms mutations in the HBA or HBB genes.
Imaging and Other Tests
- Ultrasound: Assesses spleen and liver size.
- Bone Marrow Examination: In some cases, to evaluate erythropoiesis.
Treatment
Mild Thalassemia
- Often requires no treatment.
- Regular monitoring and supportive care, such as folic acid supplements.
Moderate to Severe Thalassemia
- Regular Blood Transfusions: To maintain adequate hemoglobin levels and manage anemia.
- Iron Chelation Therapy: To prevent iron overload due to frequent transfusions. Excess iron can be toxic and lead to organ damage. There are several types of iron chelation therapy, which involve different chelating agents that bind to iron and help remove it from the body. Medications include Deferoxamine, Deferasirox, and Deferiprone.
- Folic Acid Supplements: To support red blood cell production.
- Splenectomy: May be considered in cases of severe splenomegaly.
- Bone Marrow or Stem Cell Transplant: The only potential cure, usually recommended for severe cases, especially in children.
Experimental and Future Treatments
- Gene Therapy: Research is ongoing to correct the genetic mutations causing Thalassemia.
- New Medications: Such as Luspatercept, which is designed to improve hemoglobin levels.
The latest advancements in thalassemia treatment
Gene Therapy
- Gene therapy approaches using lentiviral vectors, gene editing techniques like CRISPR-Cas9, and induced pluripotent stem cells are showing promising results for treating beta-thalassemia . These therapies aim to correct the genetic defect causing thalassemia.
- One gene therapy product, betibeglogene autotemcel (beti-cel), has reached phase 3 clinical trials with promising results in reducing transfusion requirements for patients with transfusion-dependent beta-thalassemia.
Other Emerging Treatments
- Drugs like Luspatercept and Roxadustat can help stimulate red blood cell production and reduce transfusion needs in beta-thalassemia patients.
- Hematopoietic stem cell transplantation, though limited by donor availability and complications, remains a potential curative option for Thalassemia.
- Approaches to reactivate fetal hemoglobin production, such as with hydroxyurea, can also help ameliorate symptoms in some Thalassemia patients.
Clinical Data on Thalassemia in Kauvery hospital, Cantonment
Table 1. Age wise Distribution of patients diagnosed as Thalassemia
| Age range | Number of patients | Percentage of patients |
|---|---|---|
| <1 Year | 8 | 3% |
| 1 - 5 Year | 99 | 42% |
| 6 - 10 Year | 63 | 27% |
| 11 - 15 Year | 48 | 21% |
| 16 - 20 Year | 14 | 6% |
| 21 - 25 Year | 2 | 1% |
Table 2. Gender wise Distribution of patients diagnosed as Thalassemia
| Gender Wise | Number of patients | Percentage of patients |
|---|---|---|
| Female | 114 | 49% |
| Male | 120 | 51% |
Discussion
Though it was a deadly disease, we can cure that with the emerging techniques
From January to June 2024 we retrospectively collected and analyzed a data of 234 patients from the Kauvery hospital cantonment diagnosed as thalassemia, which showed more male patients (51%) when compared with female patients (49%).
In that study population, 42% patients were between the age group of 1-5 years followed by 27% of patients on 6-7 years age group.
From the results of study conducted by Dr. Vinoth et al in kauvery hospital also confirms that the most vulnerable age group is 1-5 years (40%) followed by 6–10 years (27%). Out of this population, 12 patients were managed with single chelation therapy and 15 patients were managed by double chelation therapy.
Conclusion
Overall, the treatment landscape for Thalassemia is rapidly evolving, with gene therapies and other novel agents providing new hope for reducing transfusion requirements and managing complications like iron overload for these patients. Iron chelation therapy is crucial in managing iron overload and preventing its complications. The choice of chelating agent and the treatment plan should be tailored to each patient’s individual needs and medical conditions.
Acknowledgement
Dr. Vinod Gunasekaran
His paper on “Clinico Epidemiological profile of children with Thalassemia Major in Kauvery Hospital, Trichy, is being published in KAUVERIAN on 08 Aug 24.
Ms. Vinitha Marimuthu
Group Clinical Pharmacist