What are the findings in a peripheral smear (Peripheral Blood Smear) for Thalassemia?

From the Research

Peripheral Smear Findings in Thalassemia

The peripheral smear examination is a valuable tool in the diagnosis of thalassemia, with several key findings that can indicate the presence of this condition.

• Microcytosis: This is a characteristic feature of thalassemia, where the red blood cells are smaller than normal 1, 2.
• Hypochromia: The red blood cells may also appear pale or hypochromic, due to a reduction in hemoglobin content 1, 2.
• Erythrocytosis: An increase in red blood cell count may be observed in some cases of thalassemia 1.
• Absence of anisopoikilocytosis: The lack of variation in red blood cell size and shape can also be a feature of thalassemia 1.
• Red blood cell morphology: Abnormalities in red blood cell shape and size can provide key information in establishing a differential diagnosis, including thalassemia 3.

Diagnostic Criteria

The diagnosis of thalassemia can be confirmed through a combination of peripheral smear examination, red blood cell indices, and hemoglobin analysis.

• Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) are typically reduced in thalassemia carriers 2.
• HbA2 determination is a decisive test for β-thalassemia carrier detection, although it can be affected by δ-thalassemia defects 2.
• Molecular analysis is necessary to confirm the diagnosis of α-thalassemia and to predict severe transfusion-dependent cases 2, 4.

Laboratory Diagnosis

The laboratory diagnosis of thalassemia involves a range of tests, including:

• Red blood cell indices and morphology 1, 3, 2.
• Hemoglobin analysis by high-performance liquid chromatography (HPLC) or capillary electrophoresis (CE) 5, 2.
• Molecular analysis, including DNA sequencing and multiplex polymerase chain reaction (PCR) 5, 4.