Complement C3 and immunoglobulin in inflammatory acne vulgaris

Abstract

In patients with moderate to severe inflammatory acne, complement (C3) was detected by immunofluorescence in 16 of 16 early inflammatory acne lesions but in only 1 of 13 biopsies of non-inflamed skin from acne sites. C3 deposition occurred, particularly in the walls of small dermal blood vessels and at the dermo-epidermal junction. Ig[immunoglobulin]M was identified in vessel walls in 4 of 16 early lesions. In 8 late inflammatory lesions, C3 deposition was much less prominent and was present in vessel walls in only 2. None of the late lesions showed vascular deposition of IgM. The observations indicate that complement activation occurs in inflammatory acne and it is suggested that this may play a pathogenic role in the inflammation.