AUTHOR=Parthasarathy Varsha , Cravero Karen , Deng Junwen , Sun Zhe , Engle Sarah M. , Auxier Autum N. , Hahn Nathan , Sims Jonathan T. , Okragly Angela J. , Alphonse Martin P. , Kwatra Shawn G. 

TITLE=Circulating plasma IL-13 and periostin are dysregulated type 2 inflammatory biomarkers in prurigo nodularis: A cluster analysis

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.1011142

DOI=10.3389/fmed.2022.1011142

ISSN=2296-858X

ABSTRACT=<sec><title>Importance</title><p>Prurigo nodularis (PN) is a chronic heterogeneous inflammatory skin disease.</p></sec><sec><title>Objective</title><p>To elucidate which components of type 2 inflammation are dysregulated systemically in PN.</p></sec><sec><title>Design</title><p>Whole blood was obtained from PN patients with uncontrolled disease and control patients without pruritus. Plasma was assayed for IL-4, IL-5, IL-13, IgE, and periostin. ANOVA was utilized to compare PN and control patients and multiple-hypothesis adjusted <italic>p-</italic>value was calculated with the significance threshold at 0.05. Clustering was performed using K-means clustering.</p></sec><sec><title>Participants</title><p>PN patients (<italic>n</italic> = 29) and controls (<italic>n</italic> = 18) from Johns Hopkins Dermatology had similar age sex, and race distributions.</p></sec><sec><title>Results</title><p>Single-plex assays of the biomarkers demonstrated elevated circulating plasma IL-13 (0.13 vs. 0.006 pg/mL, <italic>p</italic> = 0.0008) and periostin (80.3 vs. 60.2 ng/mL, <italic>p</italic> = 0.012) in PN compared to controls. IL-4 (0.11 vs. 0.02 pg/mL, <italic>p</italic> = 0.30) and IL-5 (0.75 vs. 0.40 pg/mL, <italic>p</italic> = 0.10) were not significantly elevated, while IgE approached significance (1202.0 vs. 432.7 ng/mL, <italic>p</italic> = 0.08). Clustering of PN and control patients together revealed two clusters. Cluster 1 (<italic>n</italic> = 36) consisted of 18 PN patients and 18 controls. Cluster 2 (<italic>n</italic> = 11) consisted entirely of PN patients (<italic>p</italic> &lt; 0.01). Cluster 2 had higher levels of IL-13 (0.33 vs. 0.008 pg/mL, <italic>p</italic> = 0.0001) and IL-5 (1.22 vs. 0.43 pg/mL, <italic>p</italic> = 0.03) compared to cluster 1.</p></sec><sec><title>Conclusion and relevance</title><p>This study demonstrates elevation of IL-13 and periostin in the blood of PN patients, with distinct clusters with varying degrees of type 2 inflammation. Given this heterogeneity, future precision medicine approaches should be explored in the management of PN.</p></sec>