Nuclear factor kappa B and cyclo-oxygenase-2: two concordant players in psoriasis pathogenesis.

Nuclear factor kappa B (NFκB) is a key regulatory element in a variety of immune and inflammatory pathways, cellular proliferation, differentiation and apoptosis. Cyclo-oxygenase 2 (COX2) is one of the downstream targets of NFκB. The current work aimed to explore the possible role of NFκB and COX2 in psoriasis pathogenesis through their immunohistochemical (IHC) expression in skin biopsies of this disease and correlating this expression with clinico-pathological parameters of studied cases. 103 subjects were studied; including 58 cases with psoriasis vulgaris (lesional and perilesional skin) and 45 normal, age- and gender-matched subjects, as a control group. NFκB and COX2 expressions were evaluated using standard IHC techniques. NFκB and COX2 were upregulated in psoriasis lesional skin compared to perilesional (p < 0.001 for both) and control skin (p < 0.001 for both). Higher NFκB and COX2 H scores were significantly associated with absent granular cell layer (p = 0.02 for both), severe degree of perivascular inflammatory infiltrate (p = 0.03 and 0.002, respectively) and thin suprapapillary epidermis (p = 0.003 and 0.006, respectively). Significant positive correlation was noted between NFκB and COX2 H scores in epidermis (r = 0.41, p = 0.02) and dermis (r = 0.6, p = 0.04) of lesional skin. Significant positive correlation between NFκB H score and PASI score (r = 0.38, p = 0.04) and between COX2 H score and PASI score (r = 0.52, p < 0.001) were detected in lesional epidermis. In conclusion, both NFκB and COX2 play a role in the pathogenesis of chronic plaque psoriasis. This may open an avenue for research for new therapeutic modalities based on their inhibition.