Inflammasome activation and vitiligo/nonsegmental vitiligo progression

Background Polymorphisms of NLR (nucleotide-binding domain and leucine rich repeat containing) family, pyrin domain containing protein 1 (NLRP1) have been found in patients with vitiligo/nonsegmental vitiligo (NSV), and increased NLRP1 expression has been detected in the leading edge of lesional skin biopsies. Objectives To evaluate the presence and intensity of NLRP1 immunostaining in lesional and perilesional skin of patients with vitiligo/NSV and to search for possible correlations between NLRP1 and interleukin (IL)-1β expression, lymphocytic infiltrates and disease activity. Methods Of 14 consecutive vitiligo/NSV patients, eight had active disease [Vitiligo European Task Force (VETF) spreading score +1 to +5], one patient had stable disease and five patients had regressive disease (VETF spreading score -1 to -3). We performed immunostaining for NLRP1, B and T lymphocytes, IL-1β and kallikrein 7 on lesional and perilesional vitiligo skin. Results NLRP1 and IL-1β immunostaining in perilesional vitiligo/NSV skin was significantly associated with progressive disease (P = 0·009 and 0·04, respectively) and performed better than the simple detection of lymphocytic infiltrates. Conclusions Our findings suggest that markers of the NLRP1 inflammasome could be a useful test for assessing disease activity in addition to the detection of inflammatory infiltrates in the progressing margins of vitiligo/NSV lesions. What's already known about this topic? Lymphocytic infiltrates in the leading edge of vitiligo lesions are considered as markers of disease progression. What does this study add? The immunostaining of NLRP1 and interleukin-1β in perilesional lesions of progressive vitiligo adds significant information with regard to lymphocytic infiltrates and may be useful for making clinical decisions (such as performing surgery).