Investigation of the correlation of serum IL-31 with severity of dermatitis in an experimental model of canine atopic dermatitis using beagle dogs.

Abstract

BACKGROUND: IL-31 is a cytokine that is believed to play an important role in atopic dermatitis (AD). IL-31 levels positively correlate with disease severity in children with AD. Currently, there is no study that has investigated such a correlation in atopic dogs. HYPOTHESIS/OBJECTIVE: The purpose of this study was to evaluate the correlation between IL-31 serum levels and severity of dermatitis. It was hypothesized that a positive correlation exists between severity of AD and circulating levels of IL-31. ANIMALS: Sixteen atopic beagles experimentally sensitized to house dust mites. METHODS: Atopic beagles were exposed to dust mites epicutaneously twice weekly for four weeks. Severity of dermatitis was scored by the Canine Atopic Dermatitis and Extent Severity Index, 3iteration (CADESI-03) on days 0 and 28. Blood samples were taken on days 0 and 28 to measure serum IL-31 using a commercially available ELISA. RESULTS: Correlation between CADESI-03 scores and serum IL-31 levels was not detected on day 0 (Pearson, r = -0.2609, P = 0.3291). After flare-up of dermatitis was induced with allergen exposure, a significant positive correlation was detected between serum IL-31 and CADESI-03 on Day 28 (r = 0.6738, P = 0.004). CONCLUSIONS AND CLINICAL IMPORTANCE: Positive correlation was detected in active disease between severity of dermatitis and circulating levels of IL-31. Additional studies are needed to investigate this correlation in other breeds of dogs and to test whether circulating levels of IL-31 may predict clinical response to biological agents aimed at IL-31.