IL6

From Ganfyd

Introduction

Interleukin-6 (IL-6, Interleukin 6, B-cell stimulatory factor 2, BSF-2, BSF2, IFNB2, interferon beta 2, hybridoma growth factor, HGF, HSF) is a key mediator of the acute inflammatory response. It is a glycoprotein cytokine coded for at 7p21 by the IL6 gene with both pro-inflammatory and anti-inflammatory properties. It has hormonal properties, as for example with its release from muscles on exercise.

Function

It activates the interleukin-6 receptor and thus the interleukin-6 pathway acute phase response with the membrane bound form of the receptor or the alternative trans-signalling pathway with the soluble form of the receptor (mainly in endothelial or smooth muscle cells).Interleukin-6 pathway activation causes:

• Final differentiation of B cells into Ig-secreting cells
• Macrophage reaction to pathogen associated molecular patterns
• Nerve cell differentiation
• Hepatocyte release of acute phase reactants
• Myokine
  • Energy mobilization
• Stimulates osteoclast formation

Pathology

• Induces myeloma and plasmacytoma growth
• Necessary for resistance against common gram positive pathogens like Streptococcus pneumoniae
• Genetic variations associated with:
  • Osteoporosis (bone mineral density)
  • Stills disease (juvenile rheumatoid arthritis)
  • Kaposi sarcoma

Linkage associations

These include:

• Systemic lupus erythematosus and many other rheumatological diseases
• Osteopenia and osteoporosis
• Obesity
• Kaposi sarcoma (IL6 -174G-C promoter polymorphism in HIV positive individuals)
• Type 1 diabetes mellitus eg IL6 -174CC genotype
• Type 2 diabetes mellitus
• Growth failure in childhood chronic disease
• Intracranial haemorrhage with brain arteriovenous malformations