PPAR-Gamma Agonist Pioglitazone Reduced CD68+ but Not CD163+ Macrophage Dermal Infiltration in Obese Psoriatic Patients

Abstract EN

Background.

Macrophages are of great importance in the development of obesity and psoriasis.

Signaling via PPAR-γ in certain macrophage populations is associated with M2-like features and anti-inflammatory profile.

In this research, we evaluated the anti-inflammatory action of pioglitazone by the immunohistochemical study of M1 and M2 macrophages in psoriasis-affected skin in obese patients.

Methods.

We used immunohistochemistry to characterize CD68+ and CD163+ macrophages and pathomorphological description of skin biopsy, obtained from 6 obese psoriatic patients before and after treatment with 15, 30, and 45 mg pioglitazone, once a day during 6 months.

Two patients with conventional therapy and without pioglitazone served as control.

Results.

Generally, CD163+ cell quantities in psoriasis-affected skin significantly dominated over CD68+ before and after all treatment regiments.

Among patients who received pioglitazone, some of them clearly responded to treatment from lowest to highest doses by decreasing CD68+ cells.

In the group with 30 mg pioglitazone regiment, we detected a significant reduction of CD68+ cells in dermal infiltrates: CI 95% (16–32) before versus CI 95% (2–7) after treatment.

Pioglitazone dose escalation led to certain normalization of skin morphology.

Conclusion.

The immunohistochemical study allows us to show the anti-inflammatory effect of pioglitazone in psoriatic obese patients, which can be mediated by reducing the number of СD68+ macrophages, but not СD163+ macrophages, in the affected dermis.