Interleukin-9 (IL-9)

Ultrasensitive Immunoassay


Rules-Based Medicine internally developed and manufactured ultrasensitive immunoassay to interleukin-9 (IL-9) based on the Simoa® bead technology can accurately quantitate sub-pg/mL levels of IL-9 in human serum and plasma. IL-9 is known to be involved in several chronic inflammatory diseases and is increasingly being investigated as a biomarker to predict disease severity.

Interleukin 9 (IL-9) is predominately produced by T lymphocytes, specifically T helper 9 (Th9) cells. IL-9 plays a role in immunity and inflammation directly affecting the function/activity of multiple cell types including T cells, mast cells, and airway epithelial cells. IL-9 signaling via binding to the IL-9 receptor which results in the formation of a heterodimeric complex with the common gamma chain. Receptor dimerization activates JAK1 and JAK3 leading to the activation of STAT1, STAT3, and STAT5 transcription factor proteins and subsequent modulation of gene expression.

Th9 cells are well known to play a role in triggering allergic inflammation and asthma and promoting autoimmune diseases such as idiopathic pulmonary fibrosis, Crohn’s disease, multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis. Elevated serum IL-9 levels were shown to correlate with disease severity in asthma. Th9 cells are also reported to promote immune tolerance and protect against parasitic infections. More recently, Th9 cells have been shown to exert anti-tumor immunity.

Swiss-Prot Accession Number: P15248

Simoa™ Services
Biomarker LLOQ*
(Serum and Plasma)
(Undiluted Samples)
Volume Required
Serum or plasma Other fluids**
Interleukin-9 (IL-9)  0.35 pg/mL 0.0875 pg/mL 100 µL 150 µL

* Lower limit of quantitation (LLOQ) represents the lowest amount of an analyte that can be quantitatively determined with acceptable precision. LLOQ is determined by performing 2-fold serial dilutions of Standard to be tested in triplicate over three runs. The percent coefficient of variation (CV) is calculated for each of the dilution replicates, and the LLOQ is determined as the concentration at which the CV is 30%.

** Cerebrospinal fluid, urine, tissue culture supernatants,  bronchoalveolar lavage, synovial fluid, tissue extracts, tears, skin washings, etc.

All assay services are performed in our CLIA-certified laboratory.
Intended for Research Use Only.