Systematic administration of chloroquine in discoid lupus erythematosus reduces skin lesions via inhibition of angiogenesis

Abstract

Discoid lupus erythematosus (DLE) is a chronic cutaneous form of lupus erythematosus, characterized by inflammation and scarring skin lesions, with lymphocyte infiltration and vasodilation. Antimalarial drugs have beneficial therapeutic effects in DLE, partially resulting from their immunomodulating and photoprotective properties. The possible influence of these drugs on angiogenesis has not been previously evaluated. To investigate the impact of chloroquine (CQ) treatment on the expression of vascular endothelial growth factor (VEGF, a major regulator of angiogenesis) and CD34 (a transmembrane glycoprotein expressed on endothelial cells and involved in tethering lymphocytes) in patients with DLE. A 3-mm skin biopsy was taken from typical skin lesions in 10 people with DLE. Another biopsy was taken from the same area after 3 months of treatment with CQ (250 mg/day). Skin sections were stained with monoclonal antibodies directed against VEGF and CD34. The intensity of epidermal VEGF expression, and the number and area of CD34-positive dermal blood vessels were assessed. CQ treatment induced a reduction in epidermal VEGF expression. It also resulted in a significant decrease in the median number of CD34+ dermal blood vessels (from 219 to 125 vessels per mm(2)). Furthermore the median vessel area was significantly lowered from 9.76 x 10(6) to 6.92 x 10(6) mm(2) per mm(2) of the dermis. These results indicate that one beneficial effect of CQ treatment in DLE may be due to its antiangiogenic properties.