SICKLE CELL ANEMIA.pdf. laboratory haematology

the slide is best on sickle cell anemia
which is an important concept in haematological studies

1. SICKLE CELL ANEMIA
Monday 14th October, 2024.

2. PRESENTED BY
❖U18MD1082
❖U18MD1083
❖U18MD1084
❖U18MD1085
❖U18MD1086
❖U18MD1087
❖U18MD1088
❖U18MD1089

★MODERATORS: Prof. SM Aminu, Dr. IU Kusfa, Dr. Nmadu, Dr. A Mohammed, Dr. I Yusuf

3. OUTLINE
❖Introduction
❖Definition of terms
❖Epidemiology
❖Etiopathogenesis
❖Common haplotypes of sickle cell disease
❖Clinical features
❖Types of crisis
❖Investigations
❖Treatment and follow-up
❖Conclusion

4. INTRODUCTION
❖Sickle cell anemia is multi systemic disease.
❖It is an inherited hemoglobin disorder caused by a mutation in the β-globin
gene.
❖This leads to the production of abnormal hemoglobin known as hemoglobin
S (HbS), which results in red blood cells to become sickle-shaped under low
oxygen conditions.
❖These mis-shaped cells have reduced flexibility, leading to blockages in
small blood vessels, pain episodes (vaso-occlusive crises), and tissue
damage.

5. DEFINITION OF TERMS
SICKLE CELL TRAIT
❖It occurs in individuals who inherit one normal hemoglobin gene (HbA) from
one parent and one sickle hemoglobin gene (HbS) from the other parent.
❖These individuals are carriers (heterozygous for the sickle gene) but usually
do not exhibit symptoms of sickle cell disease under normal conditions.

6. DEFINITION OF TERMS CONT’D
SICKLE CELL DISEASE (SCD)
❖Sickle cell disease refers to all conditions where an individual has at least
one sickle hemoglobin gene and another abnormal hemoglobin gene, which
leads to clinical symptoms.
❖The most common form of sickle cell disease is sickle cell anemia (HbSS)
❖Other forms include sickle-hemoglobin C disease (HbSC) sickle-
hemoglobin D disease (HbSD), HbSO-Arab disease, HbSE disease, and
sickle beta-thalassemia (HbS/β-thalassemia).

7. DEFINITION OF TERMS CONT’D
SICKLE CELL DISORDER
❖This is an umbrella term used to describe a group of disorders in which at
least one of the hemoglobin genes is an HbS gene.
❖The disorders are characterized by the presence of sickle hemoglobin and
include both sickle cell trait and sickle cell disease.

8. DEFINITION OF TERMS CONT’D
SICKLE CELL ANEMIA
❖Sickle cell anemia (HbSS) is the most severe form of sickle cell disease and
occurs in individuals who inherit two sickle hemoglobin genes (homozygous
for HbS).
❖This condition leads to the production of mostly hemoglobin S, which sickles
under low oxygen conditions.

9. EPIDEMIOLOGY
❖Haemoglobin S is particularly frequent in Africa, Middle East and Central and Southern
India.
❖About 300,000 children are born with sickle cell disease world wide.
❖Frequency of sickle cell gene (hbas) is 24% in nigeria with 2% of the nigerian population
having HbSS.
❖In Africa, sickle cell disease (SCD) is reported to be associated with a very high rate of
childhood mortality, 50%–90%, yet there is a lack of reliable, up-to-date information.
❖Reports of high rates of childhood mortality, 50%–90%, among African children with SCD
are specific to SS.
❖HbS has a high prevalence in those parts of the world where malaria is common, this
relationship is explained by the theory of balanced polymorphism.
❖Five haplotypes of sickle mutation have been identified by polymorphic sites in 5 regions:
Cameroon, Africa (Senegal, Benin, Bantu) and Arab-India.

10. TYPES OF CRISES IN SICKLE CELL
ANAEMIA

11. 1.Painful Vaso-Occlusive Crises

●A vaso-occlusive crisis is a common painful complication of sickle cell anemia in
adolescents and adults
● The most common complaint is of pain, and recurrent episodes may cause
irreversible organ damage
● A vaso-occlusive crisis occurs when the microcirculation is obstructed by sickled
RBCs, causing ischemic injury to the organ supplied and resultant pain
● It often involves the abdomen, bones, joints, and soft tissue, and it may present as
dactylitis , acute joint necrosis or avascular necrosis, or acute abdomen

12. 1.Vaso-Occlusive Crises
● Pain crises begin suddenly.
● The crisis may last several hours to several days and terminate as abruptly as it began.
● The pain can affect any body part.
● It often involves the abdomen, bones, joints, and soft tissue, and it may present as dactylitis
● (bilateral painful and swollen hands and/or feet in children), acute joint necrosis or
avascular necrosis, or acute abdomen.

13. ●With repeated episodes in the spleen, infarctions and auto-splenectomy
predisposing to life-threatening infection are usual.
●The liver also may infarct and progress to failure with time.
● Papillary necrosis is a common renal manifestation of vaso-occlusion, leading to
isosthenuria .

14. ●The most serious vaso-occlusive crisis is of the brain (a stroke occurs in 7% of all
patients) or spinal cord
●Pain may be accompanied by fever, malaise, and leukocytosis.
●As the child grows older, pain often involves the long bones of the extremities, sites
that retain marrow activity during childhood

15. ●Proximity to the joints and occasional sympathetic effusions lead to the belief that the pain involves the
joints.
●As marrow activity recedes further during adolescence, pain involves the vertebral bodies, especially in
the lumbar region.

16. Triggers of vaso-occlusive crisis
1.Hypoxemia
2.Dehydration
3.Acidosis
4. Changes in body temperature—whether an increase due to fever or a decrease due to environmental
temperature change. Lowered body temperature likely leads to crises as the result of peripheral
vasoconstriction

17. Visceral Sequestration Crisis
2. Visceral Sequestration Crises
Ø These are caused by sickling within organs and pooling of blood, ooften with a
severe exacerbation of anaemia.
Ø The acute sickle chest syndrome is a feared complication and the most common
cause of death after puberty.
Ø It presents with dyspnea, falling PO2, chest pain and pulmonary infiltrates on chest
x-ray.

18. 2. Visceral Sequestration Crisis
●Hepatic and girdle sequestration crisis and splenic sequestration all lead to severe
illness requiring exchange transfusions.
●Splenic sequestration is typically seen in infants and presents with an enlarging
spleen, falling haemoglobin and high reticulocyte count abdominal pain.
●Treatment is with transfusion and the patient should be monitored at regular
intervals as progression may be rapid.
●Attacks are recurrent and splenectomy is often advised.

19. 3. Aplastic Crisis



●These occur as a result of infection with parvovirus or from folate deficiency and
are characterized by a sudden fall in haemoglobin and reticulocytes, usually
requiring transfusion.
●An aplastic crisis usually occurs in children under the age of 16 years.
●An aplastic crisis in sickle cell anemia is a serious complication where the bone
marrow temporarily stops producing red blood cells.

20. 4. Haemolytic Crisis
●These are characterized by an increased rate of haemolysis with a fall in
haemoglobin but rise in reticulocytosis
●It usually accompanies a painful crisis.
●There are two types of Haemolytic crisis namely:
● Acute haemolytic and Chronic haemolytic crises.

21. TREATMENT AND
FOLLOW UP

22. Treatment
The treatment and follow-up for sickle cell anemia are many-sided, focusing on;
●preventing complications,
●managing acute crises, and
●addressing long-term health issues

23. General Management
●Counseling.
●Hydroxyurea.
●Penicillin prophylaxis.
●Pneumococcal vaccination.
●Proguanil.
●Folic acid.

24. Management of Acute Complications.
●Adequate hydration.
●Antimalarial.
●Analgesic (oral and parenteral).
●Antibiotics.
●Oxygen therapy.
●Blood transfusion.
●Bed rest.
●Others;
○Bone marrow transplantation
○Gene therapy.

25. Follow up:
●Regular clinic visitation
●Laboratory monitoring.
●Patient education
●Psychosocial support.