Immunohistochemical features in the skin of patients with severe psoriasis

Zdzitovetskaya N.D., Ruksha T.G., Karachyova Yu.V.

V.F. Voino-Yasenetsky Krasnoyarsk state medical university of Russian Federation Ministries of Health, Krasnoyarsk, Russia

Introduction. The basis for maintaining homeostasis in the body is the balance between two opposing processes of cell activity – proliferation and death. Cell cycle disorders are one of the fundamental links in the pathogenesis of hyperproliferative diseases. One of the most accessible methods for assessing the severity of cell division and aging processes is immunohistochemistry.

Objective of the study was to determine the expression of Ki-67 and β-GAL proteins in the epidermis of patients with severe psoriasis (Psoriasis Area and Severity Index (PASI)> 20) depending on the effectiveness of methotrexate therapy.

Materials and methods. The study involved 70 patients with severe psoriasis based on PASI>20. All subjects underwent excision of biopsy specimens from the pathological lesion with subsequent immunohistochemical determination of Ki-67 and β-GAL proteins. The patients were divided into 3 study groups: patients before methotrexate treatment; patients receiving methotrexate for at least 3 months and achieving a clinical response (PASI variation < 25%); patients receiving methotrexate for at least 3 months and not achieving a clinical response (PASI variation < 25%). The patients' results were compared with the control group, represented by 10 healthy skin biopsies.

Results. In patients with a weak response to methotrexate (PASI variation < 25%), a higher percentage of Ki-67 (+) cells and a low percentage of β-GAL (+) cells were detected compared to the group of patients with a positive effect (PASI variation < 25%). Patients with a high average % of Ki-67 (+) cells and a low average % of β-GAL (+) cells before treatment had a reduced effect of methotrexate therapy, while patients with a low level of Ki-67 and high β-GAL levels had an increased effect from therapy.

Conclusion. Immunohistochemical determination of the expression of Ki-67 and β-GAL proteins in keratinocytes can be used in clinical practice to predict the efficacy of methotrexate therapy.