Assessment Methods
UAS7 and CU-QoL Total Score: At each visit, the subjects provided their UAS7 and CU-QoL total scores for the previous 4 weeks.
Blood Sampling: Blood samples were collected prior to any treatment intervention at all visits in EDTA tubes for total and differential counts and at visits 2 (post-placebo) and 5 (4-weeks after 3rd dose of benralizumab) in PAXgene Blood RNA (Qiagen) tubes for RNA-sequencing.
Total RNA Extraction and RNA-Seq For Differential Gene Expression Profiling from Whole Blood:Directional RNA-seq was performed by the Genomics, Epigenomics and Sequencing Core at the University of Cincinnati.27,28RNA extraction and sequencing methods are described in the supplement.
Skin Biopsy Collection, Processing, and Analysis : Two full-thickness skin biopsies were taken using Acu-Punch Kit Ultra (4mm Acu-Punch, Acuderm) from lesional (active hives) and nearby non-lesional (normal) skin from CSU subjects at visit 2 and at visit 5 for histologic and transriptomic analysis. Lesional biopsies (if present in non-responders or partial responders) and non-lesional biopsies at visit 5 were performed at locations close to the baseline samples. For complete benralizumab responders (i.e., subjects with UAS7=0 at visit 5), only non-lesional skin was biopsied. Normal skin biopsies were collected once from non-CSU control subjects using identical methods. Biopsies for histopathological analysis were transported prior to processing in formalin and for RNA-sequencing in RNAlaterâ„¢ tubes. Skin biopsy transcriptomic analyses will be presented in a subsequent manuscript.