Improvement of CXCR3 ligand CXCL11/I-TAC measurement in human plasma and serum.

The chemokine receptor CXCR3 is involved in cell trafficking dysregulation associated with several inflammatory conditions, including autoimmune and viral diseases. Downregulation of CXCR3, through binding with its ligand CXCL11 (I-TAC), represents a key mechanism in lymphocyte recruitment. Determination of circulating I-TAC can provide useful information in the investigation of inflammatory/infectious conditions. The existing commercial kit does not measure CXCL11/I-TAC in complex matrices, such as human plasma and serum, as reliably as in in vitro-generated cell culture supernatants. We here describe means which lead to an improvement of CXCL11/I-TAC measurement in human plasma and serum.