Antibodies against extractable components from Propionibacterium acnes in humans with and without acne vulgaris.

Acidic polysaccharides (AP) are released from Propionibacterium acnes I and II during growth. Similar antigens are released from two strains of P. avidum, but in a smaller amount. Furthermore, prostaglandin-like substances (PLS) have been isolated from the lipid fraction of P. acnes. The AP antigens give rise to a precipitation reaction against a large proportion of normal sera. However, significantly higher antibody titre levels towards the AP fraction were found in patients with severe acne vulgaris. No rise of antibodies was found towards PLS. These findings suggest that AP's may contribute to the inflammatory response in acne vulgaris as antigens, whereas PLS, as one of the potential mediators trigger development of the initial lesions.