Which of the following is a strong chemotactic factor as well as an anaphylatoxin?

C5a is recognized as a strong chemotactic factor and an anaphylatoxin due to its pivotal role in the immune response. As a breakdown product of complement component C5, C5a elicits a robust inflammatory response by attracting immune cells to sites of infection or inflammation. Specifically, it promotes the migration of neutrophils and other leukocytes to areas where their activity is required, thus enhancing the body's ability to combat pathogens.

Additionally, C5a functions as an anaphylatoxin, which means it can trigger degranulation of mast cells and basophils, leading to the release of histamine and other mediators that contribute to acute inflammation and allergic reactions. This dual role not only amplifies the acute inflammatory response but also plays a critical part in the coordination of the overall immune system’s activities.

In contrast, while C3a is also an anaphylatoxin, it is less potent as a chemotactic agent compared to C5a. C4a, on the other hand, has limited chemotactic and anaphylactic properties, and C1q primarily plays a role in the initiation of the classical complement pathway without being a significant player in chemotaxis or anaphylaxis. This differentiates