Introduction-Aim: Chronic Obstructive Pulmonary Disease (COPD) is a common
disease involving both the airways and lung parenchyma.RNA Binding Proteins, such as HuR(Human antigen R), TTP (Tristetraprolin), AUF-1 (AU-rich element-binding factor 1), have been reported to be differentially expressed in COPD depending on the level of eosinophilic inflammation. We aimed to investigate the association between eosinophilic inflammation and the levels of mRNA expression for the ELAVL1, Z?P36 and HNRNPD genes, which encode the HuR, TTP and AUF-1 proteins, respectively.

Methods: 39 patients diagnosed with COPD were studied in steady state. Of these,
16 patients were characterized by eosinophilic inflammation (in at least two of three consecutive
measurements, blood eosinophils were >4 % and >300/?L in absolute count) and 23
patients were characterized with non-eosinophilic inflammation. The mRNA of ELAVL1, Z?P36 and HNRNPD genes was measured in peripheral blood mononuclear cell samples.

Results: The study sample included 39 participants (59% males) with mean age 67 years (SD=9.13 years). The mRNA expression for the Z?P36 gene, ELAVL1 gene and HNRNPD gene was high in 10 patients (63%), 8 patients (50%) and 3 patients (19%) with eosinophilic inflammation respectively. COPD patients with eosinophilic inflammation had higher mRNA expression for the ZAP36 gene compared to COPD patients with non-eosinophilic inflammation (p value=0.016). The other variables were lacking statistical significance.

Conclusions: This preliminary data supports that eosinophilic inflammation in COPD patients is characterized by high mRNA expression for the Z?P36 gene.