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

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 β thalassemia 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 β thalassemia (β/β thalassemia)
Less common genotypes are
δβ thalassemia compound heterozygote with Hb E or β thalassemia 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/β thalassemia:
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/β thalassemia:
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/β thalassemia:
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/β thalassemia:
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
δβ/β or δβ/ δβ thalassemia: Conditions tricky to diagnose
β/β thalassemia: Hb A: 0 to variable Hb F: >15 to 99% Hb A2: Variable but <8%
δβ/β or δβ/ δβ thalassemia:
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
A2+E >12%
F <1%
A= Rest
A2 >3.7%
F <5%
A= Rest
Hb A= 0%
Hb F= <5%
A2+E= Rest
A2 <3.2
F= 5-20%
A=Rest
A2 <3.3
F <1
A= Rest
(Normal pattern)
Other patterns
Probable α thal trait when iron deficiency is excluded
Hb E trait
β thalassemia trait
Homozygous Hb E (Hb E disease)
δβ thalassemia 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 = 12
Mentzer index = 10

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?