Effect of oral retinoid treatment on human natural killer cell activity

Peripheral blood natural killer (NK) cell activity was screened in patients with non-malignant disorders of the skin who took oral etretinate or 13-cis-retinoic acid for up to 11 months. Compared to pretreatment values, the basic NK activity rose during the first 2 months of treatment, but thereafter returned to starting values. Interferon reactivity (IFN-alpha, IFN-gamma) was essentially unaltered by the treatment. It is concluded that moderate oral retinoid doses cause a mild, transient stimulation of this natural immune surveillance system in man.