Allergic Immune Response Test - Interleukin-4 (IL-4) Test

This laboratory test measures the concentration of the cytokine interleukin-4 (IL-4) in blood serum or body fluids. IL-4 is a key signaling cytokine produced primarily by type 2 helper T cells (Th2), mast cells, and eosinophils. It plays a pivotal role in shifting the immune response toward the Th2 profile, stimulating the production of IgE antibodies and participating in allergic responses and defense against intestinal parasites. It is also involved in the activation and proliferation of B cells and mast cells.