Efficacy of Omalizumab for the treatment of Bullous Pemphigoid. Spanish multicenter real-world experience.

BACKGROUND: Bullous Pemphigoid (BP) is the most common autoimmune blistering disease. Most patients are elderly and associate multiple comorbidities. Topical and systemic corticosteroids are considered as the first-line treatment for BP and immunosuppressors are used as steroid-sparing treatments but both have side effects and contraindications which are even more common in this elderly population. New treatments targeting interleukins and receptors related to BP pathogenesis have been proposed to decrease this side effects while achieving equal or better effectiveness response rates.Omalizumab is a monoclonal antibody that targets IgE that has been proposed for the treatment of BP due to the evidence that IgE autoantibodies play an essential role in BP pathogenesis. OBJECTIVES AND METHODOLOGY: To assess the efficacy and security of Omalizumab for the treatment of BP, we carried out a multicenter, retrospective, observational study including patients diagnosed of BP who received omalizumab for at least 3 months from 15 tertiary hospitals in Spain. IgE levels prior to treatment was measured and we evaluate the possible correlation with clinical response. We excluded patients treated with Omalizumab for less than 3 months as we consider this duration is insufficient for a comprehensive assessment of its efficacy. To evaluate the effectiveness of the treatment we used the percentage of BSA improvement. RESULTS: We included 36 patients. The vast majority associate multiple comorbidities and all patients had used other systemic therapies apart from corticoids before Omalizumab.83% experienced some kind of treatment response and 42% of all patient treated achieved complete response.We did not find any correlation between higher levels and a better response (p=0,1791).All patients tolerated Omalizumab without reported side-effects. CONCLUSIONS: Omalizumab is a good therapeutic alternative for BP as it obtained clinical response in most patients and nearly half of the cases achieving complete response. It showed no side effects which is crucial in elderly patients suffering from BP.

Monopathogenic vs multipathogenic explanations of pemphigus pathophysiology.

This viewpoint highlights major, partly controversial concepts about the pathogenesis of pemphigus. The monopathogenic theory explains intra-epidermal blistering through the "desmoglein (Dsg) compensation" hypothesis, according to which an antibody-dependent disabling of Dsg 1- and/or Dsg 3-mediated cell-cell attachments of keratinocytes (KCs) is sufficient to disrupt epidermal integrity and cause blistering. The multipathogenic theory explains intra-epidermal blistering through the "multiple hit" hypothesis stating that a simultaneous and synchronized inactivation of the physiological mechanisms regulating and/or mediating intercellular adhesion of KCs is necessary to disrupt epidermal integrity. The major premise for a multipathogenic theory is that a single type of autoantibody induces only reversible changes, so that affected KCs can recover due to a self-repair. The damage, however, becomes irreversible when the salvage pathway and/or other cell functions are altered by a partnering autoantibody and/or other pathogenic factors. Future studies are needed to (i) corroborate these findings, (ii) characterize in detail patient populations with non-Dsg-specific autoantibodies, and (iii) determine the extent of the contribution of non-Dsg antibodies in disease pathophysiology.