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

Thalassemia Spectrum

Thalassemia Spectrum

Thalassemia Spectrum

Thalassemia: Phenotypes Thalassemia Minor

Thalassemia: Phenotypes ThalassemiaIntermedia Thalassemia Minor

Thalassemia: Phenotypes ThalassemiaMajor Thalassemia Intermedia Thalassemia Minor

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.

Pathophysiology of Phenotypic Heterogenecity of β Thalassemia: A Glimpase

Present talk will principally cover β thalassemia and related disorders

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.

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

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

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

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.

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.

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.

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

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

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

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

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%

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%

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%

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?

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

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.

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

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.

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

Red cell indices in thalassemia minor

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

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

Carrier Detection: Hb Electrophoresis (capillary) β thalassemia trait

Carrier Detection: Hb Electrophoresis (capillary) δβ thalassemia trait

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

Carrier Detection: Hb Electrophoresis (capillary) Hb E trait

Carrier Detection: Hb Electrophoresis (capillary) Hb E trait

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

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