Laboratory diagnosis for sickle cell
anemia
Prepared by
Hadeel Al Sadoun
Sickle cell anemia
 Chronic hemolytic anemia
 Classified as normochromic normocytic
anemia
 Characterized by the presence of crescent
shape cells with pointed ends (sickle cells)
Blood film HbS hetrozygose
 All CBC parameter are normal
 Blood film normal +/- target cells
 Positive sicklling test , Hemoglobin solubility
test.
 Hgb Electrophoresis HbS
 Can be confirmed by HPLC and molecular
studies.
Blood film HbS disease
 +++ poikilocytosis
 +++anisocytosis
 +, ++, +++ Sickle cells (based on severity)
 ++ nucleated RBC
 Few spherocytes , basophilic stippling, Pappenheimer
bodies, howell-jolly bodies.
 ++ target cells.
 +++ polychromasia , reticlocytes count 10-25 %
Blood film
 Moderate luckocytosis with mild left shift.
 Left shift:
 Increased immature forms of WBC (bands and
metamyelocytes)
 Bone marrow:
 Erythroid hyperplasia to compensate for anemia.
 Result in :
 Polychromasia,
 Increased retics
 Increased nRBC
Sickle cell anemia blood film
IDA blood film
B thal-sickle cell disease
Hemoglobin solubility test
 Principle:
 Decreased solubility of deoxygenated Hgb S form
the basis for this test.
 Method:
 Blood is added to reducing agent Sodium
dithionate and lysing agent that release hemoglobin
from RBC.
 The whole mixture is incubated for 15 minutes.
Results
 Deoxy HbS is insoluble and precipitate in the
solution lead to turbidity.
 False positive results:
 Lipidemia
 False negative results :
 Inadequate number of RBC or Low Hct.