The POLARIS study demonstrates that omalizumab is an efficacious and well-tolerated add-on therapy in Japanese and Korean H1AH-refractory patients with CSU.

Bullous pemphigoid antigen 2 (BPAG2) is targeted by autoantibodies in patients with bullous pemphigoid (BP) and absent in patients with one type of epidermolysis bullosa (OMIM #226650). A keratin 14 promoter construct was used to produce transgenic (Tg) mice appropriately expressing human BPAG2 (hBPAG2) in murine epidermal basement membrane (BM). Grafts of Tg skin placed on gender-matched, syngeneic wild type (Wt) or MHC I-/-mice elicited IgG that bound human epidermal BM and BPAG2. Production of such IgG in grafted mice was prompt (detectable within 16±2 days), robust (titer ≥ 1280), durable (present ≥ 380 days), and correlated with the involution and loss of Tg skin grafts. MHC II-/-mice grafted with Tg skin did not develop anti-hBPAG2 IgG or graft loss indicating that MHC II:CD4+ T cell interactions were crucial for these responses. Tg skin grafts on Wt mice developed neutrophil-rich infiltrates, dermal edema, subepidermal blisters, and deposits of immunoreactants in epidermal BM. This model shows fidelity to alterations seen in patients with BP, has relevance to immune responses that may arise in patients with epidermolysis bullosa following BPAG2 gene replacement, and can be used to identify interventions that may block production of IgG against proteins in epidermal BM.

Oral tolerance plays a protective role in the development of AD in a murine model by modulating immune microenvironments to be more favorable for immune regulation. This modulation involves inhibition of ILC2 infiltration in skin lesions.

These findings are consistent with the presence of both neoepitopes and cross-reactive epitopes on the ectodomain of type XVII collagen. The finding that sera from patients with LAD showed specific reactivity to epidermal basement membrane suggests that such neoepitopes are present in human skin and that their targeting by autoantibodies may contribute to disease pathogenesis.