IL-6 ( Interleukin ) To evaluate and monitor the immune reaction in any infection to the body, IL-6 test is done.IL stands for Interleukin test.Interleukin-6(IL-6) is a protein that is released by the immune cells of the body when fighting bacteria, virusLevels of IL-6 in the blood helps to diagnose inflammation, infection, cardiovascular diseases or autoimmune disorders.