Sickle cell anemia-definition, pathophysiology, hematologic, diagnostic findings and treatment

1. HEMOGLOBINOPATHY
N.R.AISHWARYA
MBBS,PIMS

2. Case 1
• A 20 year old boy complaints of episodic pain in
both upper and lower limb for past 2 months.
• Pain is associated with tenderness in both arms
and calf muscles.
• He also has fever and tachycardia during the
episode.
• 2 days back he had severe chest pain and fever
along with decrease oxygen saturation.
What is the diagnosis?

4. Objectives
• Definition
• Genetics
• Pathophysiology
• Clinical features
• Haematologic finding
• Diagnostic test
• Treatment

5. SICKLE CELL ANEMIA
• Hereditary hemoglobinopathy
• Caused by point mutation at the sixth position
of the beta β-globin chain leading to the
substitution of a valine residue for a glutamic
acid residue.
• Characterised by red blood cell
that assumes an abnormal
rigid and sickle shape.

6. Geographical distribution
• HbS is prevalent in
Africa ,Mediterranean
countries and India.
• Individuals with sickle
cell trait are resistant to
the lethal effects of
falciparum malaria

7. GENETICS

9. Pathogenesis
• When HbS is deoxygenated,molecules of Hb
polymerize to form ‘tactoid’.
• These distorts the red cell membrane and
produce the sickle shaped cell.
• Reversible-re-oxygenation.
• Irreversible-distorted red cell membrane
became permanent.
• Hb F inhibits the polymerization.

11. PATHOPHYSIOLOGY

12. If one parent has
sickle cell
trait(HbAS) and
the other does not
carry the
hemoglobin at
all(HbAA),then
none of the
children will have
sickle cell
anemia.one in
two(50%) will get
sickle cell trait

13. If both the parent
have sickle cell trait
(HbAS)there is a
one in four
(25%)children will
have sickle cell
anemia.one in four
will be
unaffected.one in
two(50%) will be
sickle cell trait.

14. If one parent has
(HbAS) and the
other has sickle
cell
anemia(HbSS)th
ere is a one in
two (50%)will get
sickle cell trait
and one in two
(50%)will get
sickle cell anemia

15. If one parent has
sickle cell
anemia(HbSS)
and the other is
completely
(HbAA)unaffected
then all the
children will have
sickle cell trait
none will have
sickle cell anemia

16. CLINICAL FEATURES
• Vaso-occlusivecrisis: bone
pain,tachycardia,sweating
• Sickle chest syndrome:bone marrow infarction -
fat emboli in lungs-causes sickling-ventilatory
failure.
• Sequestration crisis:Massive splenic enlargement
and priapism
• Aplastic crisis:Infection with human parovirus
B19-low Hb-causes heart failure-reticulocyte
count-low

18. HEMATOLOGICAL FINDINGS

20. HAEMATOLOGICAL FINDINGS
PERIPHERAL SMEAR FINDINGS:
• Anisopoikilocytosis.
• Red cells are normocytic normochromic.
• Sickle cell,Target cell,ovalocyte and howell
jolly bodies are seen.
• Howell jolly body-prominent feature of
hypofunction of spleen.

21. Howell jolly bodies
 These inclusions are
nuclear remnant seen in
redcells,intermediate/
late normoblast.
 Observed in
megaloblastic anemias
and post splenectomy
as the pitting function
of the spleen is lost.

22. Bone marrow of sickle cell anemia

23. DIAGNOSIS
• SICKLING TEST: 2%Sodium metabisulphite or
sodium dithionate to blood.
• Hb ELECTROPHORESIS
• HbF ESTIMATION
• HPLC
• HbS SOLUBILITY
• FAMILY STUDIES

24. DIAGNOSTIC TEST

25. TREATMENT
• Folic acid:supplement diet
• Educating the patient -awareness
• Hydroxyurea:Reduce the incidence of sickling
crisis-elevate the level of HbF-carry more O2
• Blood transfusion:Indicated in severe
anemia,surgery,pregnancy.

26. THANK YOU
FOR YOUR PATIENCE………