102 Citrullinated histone H3, a marker for neutrophil extracellular traps, is associated with poorer prognosis in recessive dystrophic epidermolysis bullosa patients with cutaneous squamous cell carcinoma

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe hereditary skin disease characterized by and mucosa fragility with blister formation due to type VII collagen deficiency. The major complication in RDEB patients the development of squamous cell carcinoma (SCC) leading premature mortality. Our study aims correlate immune profiles SCCs clinico-histopathological features cohort patients. profile was assessed immunohistochemical analyses on 33 from 19 included between March 2016 December 2021. RDEB-SCCs were subdivided into 4 groups according first occurrence (primary) or recurrence status, their grading determined aggressiveness criteria. tumor microenvironment high-grade primary associated higher proportion infiltrated neutrophils lymphocytes comparison low-grade recurrent SCCs. analysis revealed presence fibers expressing myeloperoxidase citrullinated histone H3, neutrophil extracellular trap marker (NET), suggesting induction NETosis. Finally, circulating H3 levels increased serum This defect response poorest prognosis, an ratio enhanced NET serum.