Is a peripheral blood smear (PBS) indicated in a male patient with anemia?

From the Guidelines

A peripheral blood smear is indicated in males with anemia as it provides valuable diagnostic information about the cause and characteristics of the anemia. This test should be performed when a complete blood count (CBC) reveals anemia, especially if the cause is not immediately apparent. The peripheral blood smear allows direct visualization of red blood cells, white blood cells, and platelets, revealing important morphological features such as red cell size, shape, color, and inclusions. For males with anemia, the smear can help distinguish between common causes like iron deficiency, vitamin B12 or folate deficiency, hemolysis, or bone marrow disorders. It can also identify specific abnormalities like sickle cells, spherocytes, or fragmented cells that point to particular diagnoses.

Key Points to Consider

• The test is particularly useful when automated CBC parameters show abnormal indices or when there are clinical features suggesting a specific type of anemia.
• The peripheral blood smear complements other laboratory tests and provides immediate information that can guide further diagnostic workup and management decisions for anemic male patients.
• As recommended by the American Society of Clinical Oncology and the American Society of Hematology, a thorough diagnostic evaluation, including a peripheral blood smear, should be conducted before initiating therapy with stimulants of erythropoiesis 1.
• This approach is crucial for identifying correctable causes of anemia and ensuring appropriate management, thereby improving patient outcomes in terms of morbidity, mortality, and quality of life.

Diagnostic Approach

• A peripheral blood smear is a fundamental component of the diagnostic workup for anemia, offering insights into the underlying cause and guiding further testing and treatment.
• The smear, in conjunction with other diagnostic tests such as iron, folate, and B12 deficiency analyses, and assessment for occult blood loss and renal insufficiency, provides a comprehensive understanding of the patient's condition 1.
• By prioritizing the use of peripheral blood smears in the diagnostic algorithm for anemia, clinicians can ensure that patients receive timely and appropriate care, ultimately reducing the risk of adverse outcomes and improving quality of life.

From the Research

Peripheral Blood Smear in Male with Anemia

• The Peripheral Blood Smear (PBS) examination plays a crucial role in evaluating hematological disorders, including anemia 2.
• Anemia is diagnosed using PBS, and it is an essential tool in the differential diagnosis of anemia 3, 2.
• The study by 4 analyzed the diagnostic value of the laboratory's blood smear reading and the incremental value of a physician's personal reading in anemic inpatients, and found that the blood smear performed no better than RBC indices in detecting probable iron deficiency or low serum levels of folate or vitamin B12.
• However, the blood smear reading performed by the hospital laboratory provided unique information in 6% of the cases and helpful information in another 25% 4.
• Another study found that reticulocyte parameters, such as MCVr, CHr, and CHCMr, could be useful in the differential diagnosis of mixed anemia from vitamin B12 deficiency, IDA, and healthy controls 5.
• In the case of microcytic anemia, the peripheral blood smear is essential in the differential diagnosis, and iron deficiency is the most common cause of microcytic anemia 6.
• The absence of iron stores in the bone marrow remains the most definitive test for differentiating iron deficiency from other microcytic states, and measurement of serum ferritin, iron concentration, transferrin saturation, and iron-binding capacity may obviate proceeding to bone marrow evaluation 6.