Interleukin-6 (IL-6) is a mediator of the immune system, which has a variety of biological roles. It is also considered: B cell stimulating factor (BCSF), B cell stimulating factor 2 (BSF-2), hybridoma growth factor (HGF), hepatocyte stimulating factor (HSF), cytolytic T cell differentiation factor (CDF) ) Wait. Interleukin-6 is a protein containing 183 amino acids, modified by glycosylation and phosphorylation, and contains 2 disulfide bonds. The molecular weight of interleukin-6 is about 20kDa. Many cells can synthesize interleukin-6, such as monocytes/macrophages, fibroblasts, endothelial cells, keratinocytes, mast cells, T cells and many tumor cells. In vivo and in vitro, interleukin-6 acts as a differentiation factor for B cells, and an activator for T cells. Interleukin-6 levels are elevated in serum or plasma in the presence of diseases such as sepsis, autoimmune disease, lymphoma, acquired immunodeficiency syndrome (AIDS), alcoholic liver disease, infection, or transplant rejection. IL-6 increased rapidly after bacterial infection, PCT increased after 2h, and CRP increased rapidly after 6h.

Clinical significance

The level of IL-6 increased rapidly after bacterial infection, reaching a peak at 2 h, and its elevated level was consistent with the severity of infection. IL-6 can also be used to evaluate the severity of infection and judge prognosis, when IL-6>1 000 μg/L indicates poor prognosis. Dynamic observation of IL-6 levels also helps to understand the progression of infectious diseases and response to treatment.

IL-6 content                   Clinical application advice

<7 pg/mL                       normal

7-150 pg/mL                  indicates mild inflammation or mild infection

150-250 pg/mL              indicates general bacterial infection or systemic inflammatory response

>250 pg/mL                   suggests possible sepsis

Profile of IL-6