IgE anti-LJM11 sand fly salivary antigen may herald the onset of Fogo Selvagem in endemic Brazilian regions

Fogo Selvagem (FS) is an endemic form of pemphigus foliaceus (PF) which is prevalent in certain regions of Brazil (Diaz et al., 1989). Genetic and environmental factors such as insect bites may contribute to the development of FS (Aoki et al., 2004; Diaz et al., 1989; Moraes et al., 1997). Blister formation in FS is mediated by predominantly IgG4 antidesmoglein 1 (Dsg1) antibodies (Rock et al., 1989), which are predictors of FS (Qaqish et al., 2009). Our recent studies demonstrate that FS IgG4 antibodies cross-react with LJM11, a salivary protein from sand fly Lutzomyia longipalpis (Qian et al., 2012), suggesting that sand fly bites may deliver the antigen(s) that play a role in driving the development of these IgG4 autoantibodies in FS.