Which immune cells increase in number several days after infection or inflammation?

Which immune cells increase in number several days after infection or inflammation?

• A. Eosinophils
• B. Monocytes
• C. Neutrophils
• D. Lymphocytes

Answer: (B)

The timing of white blood cell responses matters in infections. Neutrophils rush in first, rising within hours to quickly attack bacteria. Eosinophils come into play with parasites and allergic inflammation, and lymphocytes often dominate later in viral infections or chronic immune responses. Monocytes, which circulate in the blood and mature into macrophages when they enter tissues, rise several days after infection begins. Once at the site, they become macrophages that perform ongoing phagocytosis, clean up debris, and present antigens to T cells to coordinate the longer-term immune response. This delayed but sustained involvement is why monocytes are the cells that increase after a few days of infection or inflammation.

The timing of white blood cell responses matters in infections. Neutrophils rush in first, rising within hours to quickly attack bacteria. Eosinophils come into play with parasites and allergic inflammation, and lymphocytes often dominate later in viral infections or chronic immune responses. Monocytes, which circulate in the blood and mature into macrophages when they enter tissues, rise several days after infection begins. Once at the site, they become macrophages that perform ongoing phagocytosis, clean up debris, and present antigens to T cells to coordinate the longer-term immune response. This delayed but sustained involvement is why monocytes are the cells that increase after a few days of infection or inflammation.