Interleukin-19 (IL-19)

Ultrasensitive Immunoassay


Rules-Based Medicine has developed and manufactured an ultrasensitive  immunoassay to interleukin-19 (IL-19) based on Simoa® bead technology. Being able to accurately quantitate sub-pg/mL levels of IL-19 in human serum and plasma is a valuable clinical research tool for pharmacodynamic analysis in oncology and autoimmune diseases.

IL-19 is classified by homology as a member of the IL-10 family. However, IL-19 is also a member of the IL-20 subfamily because it binds to the IL-20 receptor b-chain (IL-20 receptor type I). IL-19 is produced mainly by monocytes/macrophages, some B cells, epithelial cells, endothelial cells, and skin keratinocytes. Production of IL-19 can be induced by several stimulants, including bacterial pathogens, LPS, and cytokines (i.e. GM-CSF, IL-4, IL-6, IL-17, and TNFa). IL-19 can promote the T cell helper type 2 (TH2) response, including increasing TH2 T cells, promoting production of IL-4, and polarizing macrophages towards the M2 phenotype. As such, IL-19 can be considered to have anti-inflammatory effects in diseases that are mediated/potentiated by TH1 responses. IL-19 plays a role in multiple diseases and disorders, including, breast cancer, vascular diseases, asthma, psoriasis, and other autoimmune diseases.

In breast cancer, IL-19 in the tumor microenvironment has been correlated to tumor stage, higher metastasis, and poor survival, most likely through IL-19 mechanism of enhancing TH2 cytokines, which promotes tumor associated macrophages that are disadvantageous to anti-tumor immunity. However, circulating IL-19 levels have not been demonstrated to correlate similarly in breast cancer. On vascular smooth muscle cells, IL-19 is protective against inflammation and promotes cell mediated immune suppression. In atopic dermatitis, where disease is dominated by TH2 lymphocytes and their cytokines to promote production of IgE, IL-19 is highly expressed in skin lesions. A recent publication funded by Eli Lilly and Company demonstrated that a decrease in serum IL-19 may be indicative of a response to clinical therapy in psoriasis (Robert J. Konrad, et al. Scientific Reports 2019).

Swiss-Prot Accession Number: Q9UHD0

Alternate names for this biomarker include:

Melanoma differentiation-associated protein-like protein, NG.1

Simoa™ Services
Biomarker LLOQ*
(Serum and Plasma)
(Undiluted Samples)
Volume Required
Serum or plasma Other fluids**
Interleukin-19  (IL-19) 1.2 pg/mL 0.3 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.