Interleukin-6 (IL-6) is a member of the IL-6 family. It consists of polypeptide cytokines with a four–α-helix structure and a molecular mass of 21 to 28 kDa.
It is a pleiotropic, pro-inflammatory cytokine produced by a variety of cell types, including lymphocytes, monocytes, and fibroblasts.
IL-6 Stimulates acute phase reactions. These promote the activation of innate immunity, keeping tissue damage at bay.
It also helps T-cells to differentiate early in their development. It is required for progenitor cell development, and also for T-cell and NK cell activation. In addition, it helps them to achieve pathogen lysis inside the cells.
Interleukin-6 also helps B-cells differentiate and proliferate, and promotes the formation of plasma cells from B-cells. In addition, as a growth factor for these cells, it enhances antibody release, in the form of IgA and IgG.
Interleukin-6 is also vital for the development of blood cells, whether white cells, red cells or platelets. It seems to play an important role in the development of Kaposi’s sarcoma, and multiple myeloma.
IL-6 and COVID -19:
Infection by the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) induces a dose-dependent production of IL-6 from bronchial epithelial cells. COVID-19-associated systemic inflammation and hypoxic respiratory failure can be associated with heightened cytokine release, as indicated by elevated blood levels of IL-6, C-reactive protein (CRP), D-dimer, and ferritin.It is hypothesized that modulating the levels of IL-6 or its effects may alter the course of disease.
Therefore,IL-6 is a key mediator of Cytokine release syndrome and can be used potential therapeutic target by blocking IL-6 potentially beneficial for patients with severe inflammation in the lungs due to CRS.
There are two classes of Food and Drug Administration (FDA)-approved IL-6 inhibitors: anti-IL-6 receptor monoclonal antibodies (e.g., sarilumab, tocilizumab) and anti-IL-6 monoclonal antibodies (siltuximab). These classes of drugs have been evaluated for the management of patients with COVID-19 who have systemic inflammation.
The GENLISA™ ELISA kits are used for assessing the specific biomarker in samples analytes which may be serum, plasma and cell culture supernatant as validated with the kit. The kit employs a sandwich ELISA technique which leads to a higher specificity and increased sensitivity compared to conventional competitive ELISA kits which employ only one antibody. Double antibodies are used in this kit.