Summary of "CCH Session 6 - Thalassemia & Other Hemoglobinopathies 25th June IAP Delhi Certificate Course"

Summary of “CCH Session 6 - Thalassemia & Other Hemoglobinopathies”

This session provides a comprehensive overview of hemoglobinopathies, focusing primarily on thalassemia and sickle cell disease, their epidemiology, diagnosis, clinical features, management, and recent advances in treatment. The speaker emphasizes the importance of early recognition and management by general pediatricians, given the high prevalence and burden of these genetic disorders in India and globally.

Main Ideas and Concepts

1. Epidemiology and Global Burden

Hemoglobinopathies are the most common genetic disorders worldwide.
India has the second-highest burden after Africa, with around 50,000 new affected births annually (12,000 thalassemia, 40,000 sickle cell disease).
A large proportion of patients live in rural and underserved communities.
Prevention is critical but challenging due to the high birth rate and genetic diversity.

2. Types of Hemoglobinopathies

Thalassemias: Quantitative defects in globin chain production (beta and alpha thalassemias).
Sickle Cell Disorders: Qualitative defects due to mutation in beta-globin gene causing abnormal hemoglobin S.
Other variants include HbE and HbD prevalent in specific Indian populations.

3. Clinical Recognition and Diagnosis

Early recognition is vital; presentations vary from asymptomatic carriers to severe transfusion-dependent anemia.

Basic laboratory work includes:

Complete blood count (CBC) with red cell indices.
Peripheral smear examination.
Screening tests (e.g., NESTROFT for thalassemia, sickling test for sickle cell).
Definitive diagnosis by High-Performance Liquid Chromatography (HPLC).
Molecular studies for confirmation and prenatal diagnosis.

Ethnicity and family history are important but not absolute due to migration and intermarriage.

4. Thalassemia Spectrum

Thalassemia Minor (Carrier State): Usually asymptomatic; important to differentiate from iron deficiency anemia.
Thalassemia Major (Transfusion Dependent): Presents early in infancy with severe anemia, growth failure, and hepatosplenomegaly.
Non-Transfusion Dependent Thalassemia (NTDT): Variable presentation; may require intermittent transfusions; management individualized.

Clinical complications arise mainly from hemolysis, ineffective erythropoiesis, and iron overload.

5. Laboratory Features

Peripheral smear in thalassemia shows microcytosis, target cells, tear drop cells.
HPLC graphs help identify hemoglobin variants and quantify fetal hemoglobin.
Alpha thalassemia diagnosis is difficult without molecular tests due to subtle changes.

6. Management of Thalassemia

Transfusion:

Initiated when hemoglobin <7 g/dL on two occasions.
Maintain pre-transfusion Hb 9.5–10.5 g/dL.

Iron Chelation:

Essential to prevent iron overload complications.
Started when ferritin >1000 ng/mL or after 10–20 transfusions.
Chelators include:
- Deferoxamine (infusion pump)
- Deferiprone (oral)
- Deferasirox (oral)

Hydroxyurea:

Used mainly in NTDT to reduce transfusion needs.

Bone Marrow Transplant (BMT):

Curative option, best outcomes in children 2–10 years old with matched donors.

Gene Therapy:

Emerging but currently expensive and limited to specialized centers.

New Drugs:

Luspatercept (recently approved) reduces transfusion burden by improving erythropoiesis.

7. Sickle Cell Disease (SCD)

Caused by a point mutation in beta-globin leading to hemoglobin S polymerization and sickling under low oxygen.
Clinical features include vaso-occlusive crises, hemolytic anemia, acute chest syndrome, stroke, infections.
Diagnosis by sickling test and confirmed by HPLC.

Management includes:

Hydroxyurea (standard of care starting as early as 9 months).
Transfusions (simple and exchange) for acute crises and stroke prevention.
Pain management with opioids, NSAIDs, ketamine, and non-pharmacological methods.
Vaccinations and infection prophylaxis.
Newer drugs: L-glutamine, crizanlizumab (P-selectin inhibitor), voxelotor (reduces hemolysis).
Screening via transcranial Doppler to prevent stroke.
BMT and gene therapy are curative options under study.

8. Other Hemoglobinopathies

HbE and HbD prevalent in northeastern India and other regions.
Usually mild clinical impact but can modify disease severity when co-inherited with other hemoglobinopathies.

9. Challenges and Future Directions

Managing iron overload and ensuring compliance with lifelong chelation is challenging.
Need for patient motivation and education.
Advances in gene therapy and new pharmacological agents offer hope.
Emphasis on newborn screening and early intervention to reduce mortality and morbidity.

Detailed Methodologies and Instructions

Diagnosis Workflow

Take detailed family and ethnic history.
Perform CBC and peripheral smear.
Conduct screening tests (NESTROFT for thalassemia, sickling test for SCD).
Confirm diagnosis with HPLC.
Use molecular genetic testing for unclear cases or prenatal diagnosis.

Transfusion Guidelines for Thalassemia

Start regular transfusions if Hb <7 g/dL on two occasions, two weeks apart.
Maintain pre-transfusion Hb between 9.5 and 10.5 g/dL.
Use leukocyte-depleted, phenotype-matched blood less than 2 weeks old.
Screen blood for infections (Hepatitis B, C, HIV, malaria).
Monitor iron overload regularly.

Iron Chelation Therapy

Start when ferritin >1000 ng/mL or after 10–20 transfusions.
Options:
- Deferoxamine: Subcutaneous infusion pump, long duration, compliance issues.
- Deferiprone: Oral, 3–4 times daily, side effects include agranulocytosis.
- Deferasirox: Oral, once daily, better compliance.
Monitor side effects and adjust therapy accordingly.
Combine chelators in severe cases.

Hydroxyurea Use

Start early in SCD (from 9 months).
Dose titrated to maximum tolerated dose (up to 30–35 mg/kg).
Monitor CBC regularly.
Also used in NTDT thalassemia with variable benefits.

Pain Management in SCD

Initiate analgesia within 1 hour of crisis onset.
Use opioids based on prior patient response.
Add NSAIDs to reduce opioid dose.
Consider corticosteroids cautiously.
Use ketamine infusions or regional anesthesia for refractory pain.
Employ non-pharmacological therapies for chronic pain.

Stroke Prevention in SCD

Annual transcranial Doppler screening from age 2.
Initiate regular transfusions if abnormal velocities detected.
Use hydroxyurea if transfusions are not feasible.

Bone Marrow Transplant (BMT)

Best outcomes in young children (<10 years), well-chelated, no organ damage.
Requires matched sibling or unrelated donor.
Pesaro scoring used to assess transplant risk.
Haploidentical transplants improving but variable success.

Speakers / Sources Featured

Primary Speaker: Dr. Ajay (presumed from Q&A references and closing remarks)
Other unnamed experts participating in Q&A
Reference to Dr. Alok Srivastava (gene therapy work at CMC)
Mention of various guideline sources:
- Thalassemia International Federation (TIF) guidelines
- American Society of Hematology (ASH) guidelines for sickle cell disease
- National Health Mission (India) guidelines

This summary encapsulates the key points, clinical pearls, and management principles discussed during the session, providing a practical guide for pediatricians and hematologists managing hemoglobinopathies.