What mechanism of localization is associated with Tc HMPAO tagged WBCs?

• A. Cellular migration
• B. Passive absorption
• C. Selectively bound
• D. Active filtration

Answer: (A)

The mechanism of localization associated with Tc HMPAO tagged white blood cells (WBCs) is indeed cellular migration. Tc HMPAO (hexamethyl propyleneamine oxime) is a radiopharmaceutical commonly used in imaging to visualize areas of infection or inflammation. When white blood cells are tagged with Tc HMPAO, they can migrate to sites of infection or injury within the body. This migration is a natural response of the immune system, where leukocytes actively seek out areas of inflammation to perform their function in defending the body against pathogens or healing tissue damage.

By using imaging techniques, clinicians are able to trace the movement of these tagged WBCs, thus highlighting areas where there is increased activity, such as infections or inflammatory responses. This makes cellular migration a key mechanism for understanding and diagnosing conditions that involve an immune response.

In contrast, the other mechanisms listed do not accurately describe how Tc HMPAO tagged WBCs localize. Passive absorption refers to the non-specific uptake of substances, while selectively bound would imply a more static form of localization that doesn’t account for the active nature of WBC response. Active filtration might suggest a process where substances are mechanically filtered out, which isn’t representative of the biological function of WBC