CRTH2 mRNA levels in peripheral blood of adult patients with nasal polyposis

Resumen

Background : Chemoattractant receptor- homologous molecule ex-pressed on Th2 cells ( CRTH2 ) is a receptor for PGD2 expressed on eosinophils, basophils, macrophages, monocytes, mast cells, Th2 cells, innate lymphoid cells type 2 (ILC2) and dendritic cells. The CRTH2 pathway is involved in asthma, nasal polyposis (NP), and aspirin- exacerbated respiratory disease (AERD). Numerous stud-ies have identified single- nucleotide polymorphisms (SNPs) asso-ciated with asthma, NP and AERD, including SNPs in the CRTH2 gene. Method : We included 67 individuals (34 patients with nasal poly-posis (NP) and 33 non- atopic controls). All individuals signed an in-formed written consent. A peripheral blood sample was obtained. Total RNA was isolated and RT- PCR was performed. CRTH2 gene expression was determined by qPCR using SYBR Green. GAPDH was used as reference gene. Calculates were made by the comparative ΔΔCt method. Results : Patients with NP showed elevated expression of CRTH2 mRNA (10.20 ± 10.36) compared to controls (4.44 ± 2.31) ( P < 0.001), of them, patient s with asthma showed elevated expression of CRTH2 (11.31 ± 11.09) ( P < 0.001). CRTH2 levels were elevated in both at-opic asthmatic patients (8.80 ± 5.80) ( P = 0.012) and non- atopic asthmatic patients (13.18 ± 13.70) ( P = 0.002) compared to con-trols. Patients with AERD also showed elevated CRTH2 expression (10.84 ± 13.70) ( P = 0.034). Remarkably, the highest expression of CRTH2 (54- fold) was observed in an atopic young patient with NP and isolated episodes of bronchospasm due to NSAID exposure. Conclusion : CRTH2 mRNA levels were significantly increased in the peripheral blood of patients with NP and asthma. Levels of CRTH2 could be useful as a possible biomarker of NP, asthma and AERD and might assist in the selection of specific antagonist therapies. Further studies are needed