Diagnosis of Thalassemia and Related Hemoglobin Disorders

1. Diagnosis of Thalassemia and Related Hemoglobin Disorders Dr. Akhil Ranjon Biswas Associate Professor, BMT Dept. of Hematology Dhaka Medical College & Hospital akhil.biswas@yahoo.com

2. Thalassemia Spectrum

3. Thalassemia Spectrum

4. Thalassemia Spectrum

5. Thalassemia: Phenotypes Thalassemia Minor

6. Thalassemia: Phenotypes ThalassemiaIntermedia Thalassemia Minor

7. Thalassemia: Phenotypes ThalassemiaMajor Thalassemia Intermedia Thalassemia Minor

8. Pathophysiology of Phenotypic Heterogenecity: A Glimpase Stable hemoglobin molecule in adult is a tetramer formed of- • 2 alpha globin chain, with, • 2 beta (Hb A), gamma (Hb F) or delta (Hb A2) globin chain. Quantitative imbalance between alpha and non-alpha globin chain are responsible for clinical expression of thalassemia.

9. Pathophysiology of Phenotypic Heterogenecity of β Thalassemia: A Glimpase

10. Present talk will principally cover βthalassemia and related disorders

11. According to Disease Potential Thalassemias are • Symptomatic Thalassemia: Thalassemia Major & Thalassemia Intermedia • Asymptomatic and silent carrier From here on, term ‘thalassemia’ will be used for symptomatic thalassemias.

12. Diagnosis of symptomatic thalassemia (Thalassemia Major & Thalassemia Intermedia) typically relies on • Clinical features (symptoms and signs): Few unique but mostly non-specific • Typical lab findings

13. Clinically Popular Features of Thalassemia • Moderate to severe pallor/anemia • Mild jaundice • Splenomegaly • Hepatomegaly • Stunted growth • Typical facial changes: frontal bossing, prominent maxilla and zygoma, depressed nasal bridge. • Poorly developed or undeveloped secondary sexual character • Typical radiological finding

16. Most of those popularly known pictures are associated with mostly irreversibly complicated thalassemia major, certainly destined to deadly outcome shortly. For successful and meaningful management of thalassemia we must be able to diagnose symptomatic thalasemmia before appearance of those popular picture So, clinical features of thalassemias to be redefined

17. Clinical features of thalassemia Clinical features of thalassemia necessarily mean clinical features of symptomatic thalassemias, namely thalassemia major and thalassemia intermedia. Though thalassemia major and intermedia present generally almost similar features but in significantly different spectrum.

18. Clinical features of thalassemia • Features of thalassemia major • Should present within 2 years of age if addressed properly • Failure to thrive • Repeated infection • Pallor • Splenomegaly (and hepatomegaly if not transfused sufficiently) • May have clinically evidenced jaundice • Regular transfusion required before 2 year of age for normal growth and development • Bony expansion causing frontal bossing, malar prominence etc along with growth retardation revealed later in childhood if not transfused sufficiently.

19. Clinical features of thalassemia • Features of thalassemia intermedia • Very diverse spectrum of expression, in one end it merge with thalassemia major and on the milder end it merge with thalassemia minor. • Pallor, splenomegaly etc become clinically evident after 2 year of age • Heterogeneous clinical expression: some patients require transfusion since early childhood and some patient may be able to maintain normal growth and development without any transfusion. • Some patient may present in adulthood with paraplegia due to extramedullary hemopoiesis in spinal canal, with features related to iron loading, chronic jaundice, episodic or chronic fatigue etc. • Growth retardation, bone deformity, hepatomegaly only seen in more severe form of poorly treated or untreated cases.

20. Laboratory investigation • CBC: • Hb <9 g/dl • MCV - low/variable • MCH- low • MCHC- low or normal • RDW- markedly raised • WBC & Plt generally normal • PBF : Gross anisopoikilocytosis, tear drop cells, target cells, normoblast, basophilic stippling etc

21. Laboratory Diagnosis • Hemoglobin electrophoresis: • Common thalassemia genotypes are • Compound heterozygous HbE/ β thalassemia • Double heterozygous/homozygous βthalassemia (β/βthalassemia) • Less common genotypes are • δβ thalassemia compound heterozygote with Hb E or βthalassemia or homozygous δβ • Hb Lepore/Hb E, Hb Lepore/β, Hb Lepore/Hb Lepore • Hb H disease *Hb S/β thalassemia is a sickling disorder rather than thalassemia

22. Laboratory Diagnosis: Hb Electrophoresis β/βthalassemia: Hb A: 0 to variable Hb F: >15 to 99% Hb A2: Variable but <8% Most likely β thalassemia major

23. Laboratory Diagnosis: Hb Electrophoresis β/βthalassemia: Hb A: 0 to variable Hb F: >15 to 99% Hb A2: Variable but <8% Most likely β thalassemia intermedia

24. Laboratory Diagnosis: Hb Electrophoresis Hb E/βthalassemia: Hb A: 0 to variable Hb F: >15 to variable Hb E: > 40 to variable Hb A2: Variable but <8%

25. Laboratory Diagnosis: Hb Electrophoresis Hb E/βthalassemia: Hb A: 0 to variable Hb F: >15 to variable Hb E: > 40 to variable Hb A2: Variable but <8%

26. Laboratory Diagnosis: Hb Electrophoresis β/βthalassemia: Hb A: 0 to variable Hb F: >15 to 99% Hb A2: Variable but <8% δβ/β or δβ/ δβ thalassemia: Conditions tricky to diagnose δβ/β or δβ/ δβthalassemia: Hb A: 0 to variable Hb F: >15 to 99% Hb A2: <3%

27. Laboratory Diagnosis: Hb Electrophoresis • 26 year old lady • Height 160 cm • Well developed 2ndary sexual character • Occasional transfusion requirement • Hb 7.5 gm/dl with typical PBF of thalassemia Diagnosis?

28. Laboratory Diagnosis: Hb Electrophoresis This type of electrophoretic pattern with thalassemia intermedia like clinical expression suggest δβ/β or δβ/ δβ thalassemia

29. Laboratory Diagnosis: Hb Electrophoresis Significant aberration from classical electrophoretic pattern is not uncommon. So, electrophoresis pattern should always be interpreted in the context of clinical features, PBF and transfusion history. Parent screening may be needed in some cases.

30. Laboratory Diagnosis: Additional • Serum bilirubin: total (raised but not >5 mg/dl), direct (normal unless complicated) & indirect (raised) • Retculocyte count: relative reticulocytopenia • Serum ferritin: usually raised *Lot more investigations are related to management issues and to be discussed in relevant sections

31. Carrier Detection • Detection of asymptomatic/silent carriers are primarily driven by CBC and almost certainly confirmed by Hb Electrophoresis (capillary preferred) • There are some other cheaper and easily accessible methods those are less specific and sensitive • Relevant types in Bangladesh are • Hb E trait • β thalassemia trait • Homozygous Hb E (Hb E disease) • δβ thalassemia trait • Hb Lepore trait * α thalassemia traits can’t be diagnosed but suspected from blood picture and electrophoresis.

32. Apparently Healthy • Age >12 year • No red cell transfusion in preceding 4 month MCV <78 fl or MCH <27 pg CBC MCV <72fl + Normal MCHC Capillary Hemoglobin Electrophoresis Other patterns A2 <3.3 F <1 A= Rest (Normal pattern) A2+E >12% F <1% A= Rest Hb A= 0% Hb F= <5% A2+E= Rest A2 >3.7% F <5% A= Rest A2 <3.2 F= 5-20% A=Rest Probable α thal trait when iron deficiency is excluded δβ thalassemia trait β thalassemia trait Homozygous Hb E (Hb E disease) Hb E trait Expert Consultation

33. Red cell indices in thalassemia minor

34. Mentzer index ≤12 is most specific but not very sensitive predictor of thalassemia minor • Mentzer Index = MCV÷ RBC (million/cmm) • MCV cut off value <72 fl is the most sensitive but very unspecific predictor of thalassemia minor

35. Red cell indices in thalassemia minor Mentzer index = 10 Mentzer index = 12

36. Carrier Detection: Hb Electrophoresis (capillary) β thalassemia trait

37. Carrier Detection: Hb Electrophoresis (capillary) δβ thalassemia trait

38. Carrier Detection: Hb Electrophoresis (capillary) Homozygous Hb E (Hb E disease)

39. Carrier Detection: Hb Electrophoresis (capillary) Hb E trait

40. Carrier Detection: Hb Electrophoresis (capillary) Hb E trait

41. Interpretation of Hb Electrophoresis sometimes may be tricky rather than straightforward. Hope to discuss few such tricky tracing in last session.

42. Carrier Detection: Hb Electrophoresis (capillary) Thanks for Patience Hearing Question?