The laboratory professional notes about 20% spherocytes on a peripheral blood smear of a 4-year-old boy. An osmotic fragility test is performed. The control shows initial hemolysis at 0.50% NaCl and complete hemolysis at 0.35% NaCl. The patient sample has initial hemolysis 0.60% NaCl and complete hemolysis at 0.45% NaCl. What does this indicate?
A) The patient is exhibiting increased osmotic fragility.
B) The patient has AIHA.
C) The patient is not exhibiting decreased osmotic fragility.
D) The control is erroneous, so patient results are invalid.

Question

Quizplus · Accepted Answer

The results of the osmotic fragility test indicate that the patient is exhibiting increased osmotic fragility, which is consistent with the presence of spherocytes on the peripheral blood smear. Spherocytes are erythrocytes with a decreased surface to volume ratio, which makes them more susceptible to hemolysis in a hypertonic solution. This finding suggests a potential diagnosis of hereditary spherocytosis or autoimmune hemolytic anemia, but further laboratory testing including a Coombs test and erythrocyte membrane protein analysis may be necessary for definitive diagnosis.

The Laboratory Professional Notes About 20% Spherocytes on a Peripheral