Immunoregulatory effects of isotretinoin in patients with acne.

BACKGROUND

In vitro studies have shown that retinoids influence T-cell differentiation.

OBJECTIVES

To study the effect of isotretinoin on T-cell differentiation markers in patients with acne.

METHODS

A total of 37 patients with acne vulgaris (25 female, 12 male, age 19.6 ± 3.7 years) and 30 age- and sex-matched healthy controls (19 female, 11 male, age 20.5 ± 4.4 years) were included in the study. Screening for biochemical parameters in serum samples were done just before initiation (pretreatment) and after 3 months of isotretinoin treatment (post-treatment) in the acne group.

RESULTS

Baseline levels of tumour necrosis factor (TNF)-α (P<0.0001), interleukin (IL)-4 (P<0.0001), IL-17 (P<0.0001) and interferon (IFN)-γ (P=0.002) were significantly higher in the acne group compared with the control group. TNF-α (P<0.0001), IL-4 (P<0.0001), IL-17 (P<0.0001) and IFN-γ (P<0.0001) levels decreased after isotretinoin treatment. TNF-α and IL-4 values after isotretinoin treatment were similar to those of the control group. However, levels of IL-17 (P<0.0001) after isotretinoin treatment were higher than those of the control group, despite a significant decline after treatment. Levels of IFN-γ (P<0.0001) after isotretinoin treatment were lower than those of the control group.

CONCLUSIONS

This study shows that isotretinoin treatment significantly decreases TNF, IL-4, IL-17 and IFN-γ levels in patients with acne. We failed to show that isotretinoin redirects naive T helper (Th) differentiation preferentially towards the Th2 cell lineage.