Abstract
Objectives:
Investigate whether OX40 Ligand is more expressed in sinus tissue from subjects with CRSwNP, compared to chronic rhinosinusitis without nasal polyps (CRSsNP) and whether OX40L expression is related to eosinophilic sinus infiltration.
Methods:
In 2011, 20 patients with CRS (11 CRSwNP, 9 CRSsNP) were recruited for FESS, and 7 subjects who underwent cosmetic rhinoplasty and served as control group, were consecutively enrolled. Messenger RNA expression for thymic stromal lymphopoietin (TSLP), TSLP Receptor, OX40L was analyzed by real time PCR in sinus biopsies of all patients. Immunoreactivity score (IRS) for OX40L and eosinophil count by Wright-Giemsa staining were obtained in sinus biopsies of the same patients.
Results:
The mRNA expression of OX40L was higher in CRSwNP (2.4 ± 0.26) compared to CRSsNP (1.38 ± 0.19, p<0.05) and controls (0.49 ± 0.14), P < 0.001. The mRNA expression of TSLP and TSLPR was significantly higher in CRSwNP compared to controls (2.5 ± 0.32 vs 0.98 ± 0.17, P < 0.01 and 1.42 ± 0.31 vs 0.25 ± 0.07, P < 0.001, respectively) but not significantly higher compared to CRSsNP. IRS for OX40L was significantly higher in CRSwNP as compared to CRSsNP (P < 0.05) and controls (P <0.001), and there was a significant correlation between the OX40L IRS, as well the number of OX40L positive cells, and the number of eosinophils in sinus biopsies (r=0.69; p<0.0001 and r=0.52, p=0.007 respectively).
Conclusions:
TSLP/OX40L axis is upregulated in CRSwNP and it is related to the intensity of eosinophilic inflammation. Whether these costimulatory molecules present new therapeutic targets require further investigation.