The expression of NLR family pyrin domain containing receptor 1 in Brazilian psoriatic patients is associated with increased disease severity and pro-inflammatory cytokine release.

This study aimed to investigate the gene and protein expression of key inflammasome mediators in venous blood and skin biopsy samples from Brazilian psoriatic patients treated at the Pedro Ernesto University Hospital (HUPE). Samples were collected from both psoriatic patients and healthy controls. Gene expression was evaluated using quantitative reverse transcription polymerase chain reaction (qRT‒PCR), while protein levels were assessed through immunohistochemistry and multiplex immunoassays. Compared with those from control individuals, blood and skin biopsy samples from psoriatic patients had significantly higher mRNA levels of nucleotide-binding domain leucine-rich repeat (NLR) family pyrin domain containing receptor 1 (NLRP1), caspase-1, interleukin-1β (IL-1β), and interleukin-18 (IL-18). Immunohistochemical analysis revealed elevated protein levels of NLRP1, caspase-1, IL-1β, and IL-18 in psoriatic skin biopsies. Multiplex immunoassays revealed increased plasma levels of interferon-γ (IFN-γ), IL-1β, interleukin-17 A (IL-17 A), and tumor necrosis factor-α (TNF-α) in psoriatic patients. A positive correlation was observed between NLRP1 expression, disease severity, and the protein levels of IL-1β and TNF-α. In conclusion, in Brazilian psoriatic patients treated at HUPE, both blood and skin biopsy samples show increased expression of the NLRP1 inflammasome and its downstream mediators. Furthermore, NLRP1 expression is positively correlated with disease severity and the release of T helper 1-type cytokines, highlighting its potential role in the pathogenesis and progression of psoriasis.