Immunohistochemical expression HIF1α in chronic plaque psoriasis, an association with angiogenesis and proliferation.

Psoriasis is characterized by excessive cell proliferation, angiogenesis, and regions of hypoxia. Hypoxia stimulates production of hypoxia inducible factors (HIFs) such as HIF1α. The aim of the present study is to investigate the possible role of HIF1α in pathogenesis of psoriasis and to correlate its expression with angiogenesis and proliferation in involved and uninvolved skin in patients with plaque psoriasis using CD34 and Ki-67. The current study was performed on 40 skin specimens of patients presented with chronic plaque psoriasis both involved and uninvolved together with 40 specimens from age- and sex-matched healthy volunteers as a control group. The specimens were submitted for HIF1α, CD34, and Ki-67 immunostaining. HIF1α was expressed in 37.5% of normal skin with mild intensity and cytoplasmic localization instead of its expression in 72.5% and 100% of uninvolved and involved psoriatic skin, respectively. Nucleocytoplasmic pattern of HIF1α was seen in 34.5% and 37.5% of uninvolved and involved psoriatic skin, respectively. Positive and intense expression of HIF1α as well as its nucleocytoplasmic localization were significantly in favor of psoriatic skin either involved or uninvolved in comparison to normal skin (P < 0.05). Intense HIF1α was significantly associated with microvessel density in both involved and uninvolved skin (P < 0.05). Nucleocytoplasmic pattern was significantly associated with epidermal acanthosis (P < 0.05) and tended to be associated with percentage of Ki-67 of psoriatic skin (P = 0.06). The present study demonstrated that HIF1α is upregulated in the skin of psoriatic cases (involved and uninvolved) compared to normal skin indicating its role in pathogenesis of psoriasis especially its active nuclear form that showed an association with angiogenesis and proliferation.