Atrophic Scar Formation in Acne Linked to Long-Acting Immune Responses
A link exists between duration and severity of inflammation and alteration of sebaceous glands leading to atrophic scar formation among certain patients with acne.
An association exists between the duration and severity of inflammation and the alteration of sebaceous gland structures in scar-prone (SP) patients with acne, according to the results of a pathophysiologic analysis conducted in Nantes, France, and published in the British Journal of Dermatology. Long-lived acne papules were found to have a B-cell infiltrate that persisted for ≥3 weeks
The investigators of the current study sought to examine the pathophysiology of scar formation among patients with acne to identify molecular and cellular pathways that can help in the development of new treatments for the prevention of acne scarring.
Among both SP and non-SP (NSP) patients with acne, large-scale gene expression profiling and immunohistochemistry analysis were performed at different points.
In 48-hour-old papules in SP and NSP populations, gene expression and immunohistochemistry analysis demonstrated a very similar immune response, which was characterized by elevated numbers of T cells, neutrophils, and macrophages.
In the SP group of patients only, however, the immune response persisted in 3-week-old papules and was distinguished by an important infiltrate of B cells. Plasma cells, which are not detected in early papules, are specifically involved in the immune response in evolved lesions in the SP population of patients with acne.
In NSP patients, transient downregulation of sebaceous gland markers associated with lipid metabolism was seen in 48-hour-old papules, which was followed by normalization after 3 weeks.
Conversely, a drastic reduction in these markers persisted in 3-week-old papules in SP patients with acne, which implies an irreversible destruction of sebaceous gland structures after inflammatory remodeling in this population.
The investigators concluded that a link exists between duration and severity of inflammation and alteration of sebaceous glands leading to atrophic scar formation among certain patients with acne. Inflammatory immune processes, including the presence of plasma cells, persist for ≥3 weeks in the lesions of SP patients with acne.
Carlavan I, Bertino B, Rivier M, et al. Atrophic scar formation in acne patients involves long-acting immune responses with plasma cells and alteration of sebaceous glands [published online April 16, 2018]. Br J Dermatol. doi: 10.1111/bjd.16680