Thalassemia: Types, Symptoms, Diagnosis And Treatment

Thalassemia: Types, Symptoms, Diagnosis and Treatment

Question. Write short note on thalassemia.
Answer.

• Thalassemias are genetic disorders of hemoglobin synthesis in which there is reduced production of one or more chains of hemoglobin.
• This results in a relative excess production of either a chains or b chains, which, without their partner chain,s are unstable and precipitate in RBCs or their precursors.
• The inclusion bodies produced by this process increase the rigidity of RBCs and result in their destruction, either in the marrow or the circulation or both. Hence the anaemia of thalassemia results from ineffective erythropoiesis due to intramedullary RBC destruction, and a shortened RBC survival caused by haemolysis.
• Thalassemias are classified according to the particular globin chain that is inefficiently produced.
• In alpha thalassemia there is reduced rate of chain synthesis.
  Beta thalassemias are associated with the synthesis of beta chains.
• Beta thalassemias is divided into two forms i.e. thalassemia minor and thalassemia major

Thalassemia: Types, Symptoms, Diagnosis, and Treatment

Thalassemia Clinical Features

• Onset: Affcted children fail to thrive from about third month and become progressively more anaemic.
• Increasing pallor is present
• Splenomegaly: Haern siderosis with extramedullary haematopoiesis
• Facies: Frontal bossing due to thickening of cranial bones and prominent cheek bones due to overgrowth of zygomatic bones.
• Mild haemolytic jaundice
• Increased susceptibility to infections
• Hepatomegaly: Due to extramedullary haemopoiesis in fist 3-4 years. Later on further enlargement due to haemosiderin deposits in Kupffr cells.
• Cardiac involvement: Myocardial haemosiderin may result in arrhythmias and cardiac failure.
• Endocrines:

• Stunted growth from growth hormone defiiency
• Delayed puberty due to hypothyroidism
• Hypoparathyroidism can cause osteoporosis and fractures
• Diabetes mellitus due to iron deposits in Islet of Langerhans

Types of Thalassemia and Their Symptoms

Thalassemia Investigations

Hematological:

1. Anemia: It is moderate-to-severe with 10 to 12 g/dL.
   RBCs are microcytic hypochromic. Target cells are present and basophilic stippling is common. Also presence of tear drop, elliptical, fragments in red cells and at times red cell with Howell­Jolly body.
2. Reticulocytosis is present.
3. Leucocytosis with few metamyelocytes and myelocytes

Biochemical:

• Reduced serum haptoglobins
• Bilirubin (unconjugated) increased and urine urobilinogen increased
• Iron status

• Serum iron and ferritin markedly increased.
• Total iron binding capacity (TIBC) is reduced.

Bone marrow:

• Erythroid hyperplasia with reversed M : E ratio
• Normoblastic erythropoiesis
• Ineffctive erythropoiesis — Some normoblasts die in the marrow without maturing into red cells
• Myelopoiesis and Megakaryopoiesis
• Increased bone marrow iron

Thalassemia Other special tests:

• HbF levels are high.
• Hb electrophoresis: Bands of both HbA and HbF in β-thalassemia.
• Global chain synthesis: α-β globin chain synthesis ratio altered (normal l : l) due to lack ofsynthesis ofβ chains.
• DNA analysis­useful for predicting disease severity and diagnosis.
• Liver spectrometry for detecting hemosiderosis of liver.

Thalassemia Diagnosis and Treatment Options

Thalassemia Management

• Blood transfusions should be done to keep level of hemoglobin between 9–11 gm%, if infant’s Hb. 6–7 gm% and failure to thrive. Transfusions are given every 2 to 4 weeks.
• Chelating agent such as desferrioxamine as S.C. infusion using a syringe driver pump/infuser.
• Splenectomy: Hypersplenism due to splenomegaly causes neutropenia and increased need for blood transfusion.
  Splenectomy reduces severity of neutropenia and subsequent infections. Splenectomy should be done as late as possible.
• Bone marrow transplantation: Indication for bone marrow transplantation in cases where matched siblings are available in a family, if not available, to look for a matched related donor. This is curative for the patient.
• Folic acid supplements should be given to the patient.