Analysis of Immunohistochemical Expression of Bcl-2 in Cases of Psoriasis and Psoriasiform Dermatitis

Introduction Psoriasis involves rapid cell growth and abnormal differentiation of skin cells. Dysregulation of apoptosis has been proposed in the pathogenesis of psoriasis. The role of Bcl-2 as an anti-apoptotic protein in pathogenesis has not been studied in detail in these cases. Our study aims to evaluate the expression of Bcl-2 in different skin compartments in psoriasis and psoriasiform dermatitis cases. Materials and methodology An analytical cross-sectional study was performed using paraffin blocks of psoriasis and psoriasiform dermatitis patients between 2022 and 2023. For light microscopy screening, sections were initially stained with hematoxylin and eosin stains. In further sections, a primary antibody against Bcl-2 was applied. The level of Bcl-2 expression in keratinocytes of supra-basal and basal epidermal layers and dermal lymphocytes was evaluated using a scoring system. Results Sixty patients, 30 with psoriasis and 30 with psoriasiform dermatitis were included. Among the histopathological features, parakeratosis (p - 0.038), Munro's microabscesses (p - 0.001), supra-papillary plate thinning (p - 0.004), and increased dermal vasculature (p - 0.001) were significantly associated with psoriasis when compared with psoriasiform dermatitis. Most psoriatic lesions had hypogranulosis whereas it was alternating hypo and hypergranulosis in psoriasiform dermatitis (p - 0.001). Acanthosis was regular in psoriasis lesions (p - 0.036). Bcl-2 expression was seen in dermal lymphocytes in all psoriasis and psoriasiform lesions with significantly stronger positive expression compared to basal and supra-basal layers. Psoriasis cases demonstrated more significant Bcl-2 positivity in dermal lymphocytes and basal layers than psoriasiform dermatitis cases. Conclusion Bcl-2 has stronger expression in dermal lymphocytes and basal layers than supra-basal layers, which comply with the proposed pathogenesis. Increased Bcl-2 expression in psoriasis cases compared with other psoriasiform dermatitis lesions implies the more chronic and recurrent nature of the disease.