Sickle-cell diseases are conditions where red blood cells become sickle-shaped in low oxygen environments. They result from a point mutation in the sixth position of the beta globin chain, replacing glutamic acid with valine. There are two main types: sickle cell disease (HbSS) where individuals are homozygous for the mutation, and sickle cell trait (HbAS) where they are heterozygous. Sickle cell disease causes severe anemia starting in infancy along with painful crises and organ damage, while sickle cell trait is usually asymptomatic with mild anemia. Laboratory tests can diagnose and distinguish between the two types.

1. Sickle-cell diseases (SCD)
Developed by-Dr.Abdulrazzaq Othman Alagbare
M.D M.S.c C.P - Lecturer of Hematology and Immunohematology

2. Sickle-cell syndromes
•Sickle-cell disorders are those conditions in which the red cells become
sickle-shaped when they are subjected to low oxygen tension
•Abnormalities occur in the beta chain ,
•the Beta chain is affected by a point mutation.
•in the 6th position on the  chain the normal glutamic acid has been
changed with valine
Sickle cell types
1-Sickle cell disease -HbSS
2- Sickle cell trait –HbAS

3. in the 6th position on the 
chain the normal glutamic acid
has been changed with valine
The Hb S is insoluble and forms
crystals when exposed to low
oxygen tension
The RBC live only 20-30 days

4. Cont. Sickle-cell syndromes
The normal Hb is soluble
The Hb S is insoluble and forms crystals when exposed to low oxygen tension.
The red cells sickle may block the different areas of the microcirculation or large
vessels causing infarcts of various organs.

5. Cont. Sickle-cell syndromes
The sickle cell in capillaries when exposed to low oxygen tension
The following may be caused
• Hb  crystalized
• Hb  is insoluble
• The RBC Loss  deformability
• Sickled cells  block the small vessels

6. Cont. Sickle-cell syndromes
Clinical syndrome types Type Presentation
Sickle-cell Disease
– HbSS
Homozygous
βs/βs
Onset at 6–9 months;
severe anaemia (Hb 3-5g/dl), with
painful crises,
infarction,
Haemolytic crises
symptoms are linked to anemia
and pain

7. Cont. Sickle-cell syndromes
Clinical syndrome types Type Presentation
Sickle-cell trait -
HbAS
Heterozygous
β/βs
 Usually asymptomatic;
 mild microcytic hypochromic anaemia
(Hb 10–11 g/dL)
Individuals with sickle cell disease undergo autosplenectomy during
adolescent years

8. Laboratory finding in sickle cell anemias
Test HbSS HbAS
Hb 6-8g/dl 10-11 g/dl
RBCc low Normal
WBC (WBC shift to the left) 10-20x103 /cumm Normal
Retic-count Over 20% Normal
ESR Zero Zero

9. Laboratory finding in sickle cell anemias
Blood film:
• Normochromic, normocytic anemia,
• Target cells,
• NRBC,
• Sickle cells+++
• Reticulocytosis
microcytic hypochromic anemia not observed in HbSS

10. Sickle cell screening test Types
Test Types chemicals Action:
1.sickling test sodium
metabisulfate
sodium metabisulfate remove the O2
around the RBC
Sickling test

11. Sickle cell screening test Types
Test Types chemicals Action:
2- Solubility test sodium dithionite The normal
Hb is soluble
The HbS is
Insoluble
And cause
turbidity
solubility test

12. Sickling test solubility test
NOTE about the sickling tests
Not diagnostic
Not say if the patient
homozygous or heterozygous
It is positive in each case
combined with sickle cells

13. Clinical syndrome Electrophoresis Result
 it is the diagnostic test
HbA HbA2 HbF Pathological Hb
Sickle-cell Disease –
HbSS
Zero Normal 10% HbSS 90%
Sickle-cell trait - HbAS 50-60% Normal 10% HbS 30-40%
Notes
It is very important to take care about the following categories during
the lab work
 During pregnancy
 Before anesthesia

14. ‫رب‬ ‫هلل‬ ‫الحمد‬
‫العالمين‬
‫وجه‬ ‫ابتغاء‬ ‫الجهد‬ ‫هذا‬
‫الكريم‬ ‫هللا‬