Question

Whole blood is used as a sample for which test?

• A. Bacteria
• B. IGRA
• C. Genexpert
• D. Virus

Answer 1

The Correct Option is B

Whole blood is utilized in several diagnostic tests due to its composition of cells, plasma, and other components, which can be instrumental in identifying various conditions. Among the options provided, the correct test that specifically uses whole blood is the IGRA (Interferon-Gamma Release Assay).

IGRA is a crucial test in the field of pathology, primarily used to detect Mycobacterium tuberculosis infection. It measures the immune response to specific antigens associated with the tuberculosis bacteria by assessing the release of interferon-gamma from T-cells in the blood sample.

The use of whole blood in IGRA is advantageous because:

• Comprehensive Sampling: Whole blood provides a full spectrum of blood components, facilitating a broad immune response measurement.
• Immediate Testing: It allows for immediate processing and reduces the risk of antigen degradation that can occur in separated samples.
• Efficient Procedure: It simplifies the logistics of collection and handling compared to tests that require isolated components.

In comparison:

• Bacteria Identification: Typically involves cultures or other tests, not whole blood.
• Genexpert: While it is a molecular test to detect Mycobacterium tuberculosis and resistance to rifampicin, it typically uses sputum samples.
• Virus Detection: Viruses are often detected through other types of samples like serum, plasma, or swabs, specific to the virus in question.

Thus, the IGRA test stands out as the one employing whole blood effectively, underscoring its role in diagnosing latent or active tuberculosis infections.