Human interleukin-6

Summary

Human interleukin-6 (IL-6) is an endogenous 212-amino-acid pleiotropic cytokine produced by various cell types including T cells, macrophages, and fibroblasts. It plays a central role in the acute-phase response, B-cell maturation, T-cell differentiation, and hematopoiesis. Recombinant human IL-6 has been studied experimentally but is not an approved therapeutic agent; rather, IL-6 and its receptor are therapeutic targets (e.g., tocilizumab, sarilumab, siltuximab).

Mechanism of Action

Pleiotropic cytokine that signals through the IL-6 receptor (IL-6R) and gp130 co-receptor, activating JAK/STAT3, MAPK, and PI3K pathways; regulates acute-phase response, immune cell differentiation, hematopoiesis, and inflammation.

Routes of Administration

Goals & Uses

• B-cell and plasma cell differentiation (research)Immunology ResearchHigh
• Thrombocytopenia (chemotherapy-induced) mitigationHematologyLow
• Acute-phase response induction (research model)Research / ImmunologyHigh
• Hematopoiesis supportHematologyModerate

Contraindications

• Active systemic infection or sepsisInfectious DiseaseHigh
• Malignancy (IL-6-dependent tumors)OncologyHigh
• Active autoimmune diseaseAutoimmunityHigh

Adverse Effects

• Injection site reactionsLocalCommon
• AnemiaHematologicUncommonLow red blood cell count or hemoglobin
• HypotensionCardiovascularUncommonLow blood pressure
• Fever / flu-like syndromeSystemicCommon
• ThrombocytosisHematologyCommon
• Fatigue and malaiseSystemicCommon

Drug Interactions

• CYP450-metabolized drugs (e.g., warfarin, cyclosporine)Moderate
• CorticosteroidsModerate
• Tocilizumab / Sarilumab (IL-6R antagonists)High

Population Constraints

• Pediatric populationsAgeRelative
• Immunocompromised patientsImmunologicRelative
• Pregnant or breastfeeding individualsReproductive SafetyRelative

Regulatory Status

• European UnionUnapprovedNot authorized by EMA as a medicinal product; used as laboratory reagent and investigational agent.
• United StatesUnapprovedRecombinant human IL-6 is not an FDA-approved therapeutic; available only as a research reagent or under IND for clinical investigation.
• United KingdomUnapprovedNot approved by MHRA; research and investigational use only.

Recombinant human IL-6 itself is not an approved drug product in any major jurisdiction. It is used as a research reagent and has been investigated in early-phase trials (e.g., to counteract chemotherapy-induced thrombocytopenia) but development as a therapeutic has largely been superseded by IL-6 pathway antagonists.

Evidence & Sources

No sources recorded yet.