The Expression of STAT3 and STAT5A Genes in Severe Refractory Asthma.

Despite being a high burden disorder, the pathogenesis of severe refractory asthma (SRA) is poorly understood. There are some evidences for the involvement of members of the signal transducer and activator of transcription (STAT) family, including STAT3 and STAT5a. Our study aimed to evaluate the gene expression of STAT3 and STAT5a in asthma and SRA to establish if there is an association. Using quantitative real-time polymerase chain reactions (qRT-PCR), the transcript levels of STAT3 and STAT5a were evaluated in peripheral blood mononuclear lymphocytes (PBML) isolated from 13 patients with SRA, 14 with mild asthma, and 30 healthy volunteers. There were no significant differences in STAT3 transcript levels between study groups. There was however a significant difference in STAT5a transcript levels between cases and controls (p-value=0.03). In comparison to healthy controls, the levels of STAT5a were notably lower in patients with mild asthma and significantly least in those with SRA. Our study found no appreciable association between STAT3 gene expression and either mild asthma or SRA. However, the STAT5a down regulation in asthmatics and especially SRA is a notable finding which denotes on association between STAT5a and different level of asthma.