Background: There are very few data addressing the mechanisms of antimalarial treatment benefit locally within the skin of patients with lupus erythematosus, at the level of cytokine messenger RNA (mRNA) expression.
Objectives: The aim of this study was to evaluate whether 3 months of monotherapy with chloroquine influences the mRNA skin expression of interleukin (IL)-1beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) in nonirradiated and locally ultraviolet B (UVB) irradiated nondiseased skin of patients with systemic lupus erythematosus (SLE).
Patients/methods: Skin biopsies were collected from 14 patients with SLE 24 h after irradiation at one site and from an adjacent unirradiated site, before and after 3 months of chloroquine treatment. Messenger RNA levels for IL-1beta, IL-6 and TNF-alpha were determined by relative quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).
Results: There were no significant differences in the levels of mRNA cytokine expressions in the unirradiated sites before and after 3 months of chloroquine administration. In the irradiated sites, the expression of all three cytokine mRNA levels was significantly higher than in the unirradiated group, approximately 24 h after irradiation, before chloroquine treatment. Significantly lower expression of IL-1beta, IL-6 and TNF-alpha mRNAs was noted in irradiated skin samples after 3 months of chloroquine treatment.
Conclusions: These results demonstrate the local inhibitory effects of chloroquine on UVB-induced upregulation in the mRNA expression of proinflammatory cytokines in irradiated skin of SLE patients, and provide further insight into the apparent immunomodulatory, anti-inflammatory and photoprotective properties of chloroquine.