Evaluation of neutrophil extracellular trap deregulated formation in pyoderma gangrenosum.

Pyoderma gangrenosum (PG) is a neutrophilic dermatose (ND) characterized by a dense neutrophilic infiltrate in the affected tissue. Neutrophil extracellular traps (NETs) are web-like structures released by neutrophils and composed of cytosolic and granule proteins assembled on a scaffold of decondensed chromatin. Very little is known about the role of NETosis in PG. Here, we assessed the possible implication of NETosis in the pathogenesis of PG by investigating the NETosis in the ulcers of 26 PG patients. We demonstrated that neutrophils in the PG skin lesions undergo an aberrant level of NETosis in 100% of the analysed cases (N = 26). All control and abscess biopsies were instead negative for the NETosis. In addition, neutrophils from peripheral blood of PG patients showed a significantly higher rate of spontaneous, but not induced, NETosis. Overall, this study suggests that the NETosis may contribute to systemic inflammation and tissue destruction in PG, thus representing a possible novel therapeutic target.