Figure 3. H&E Stains of Skin Biopsies at Visit 2 (pre-benralizumab) and Visit 5 (post-benralizumab); purple-stained cells represent predominantly lymphocytes depicted by black arrows; red (eosinophilic)-stained cells represent eosinophils depicted by blue arrows. Panel A: Biopsy from a healthy non-CSU control subject showing scant numbers of perivascular lymphocytes and no eosinophils. Panels B and C: Non-lesional skin in a CSU complete responder showing scant numbers of perivascular lymphocytes and no eosinophils pre- and post- benralizumab treatment. Panels D: Representative histopathological section of lesional skin in a CSU complete or partial responder showing dense perivascular lymphocytes and eosinophils pre-benralizumab treatment (Visit 2). Panel E: Persistent but decreased perivascular lymphocytes with a complete absence of eosinophils post-benralizumab treatment (Visit 5) from hives in a partial responder. Panel F: Analysis of lymphocytic infiltrates in urticarial lesions and adjacent normal skin in all subjects completing the study (n=9). Pre-benralizumab samples (urticarial and normal skin) were taken from all nine subjects. Post-benralizumab urticarial samples (shaded yellow; n=4) include lesional skin samples from 2 partial responders and 2 non-responders. Post-benralizumab normal samples (n=9) include samples from all complete responder subjects and adjacent normal skin from partial and non-responders).