Serum IL‐17 level in systemic lupus erythematosus patients

Abstract

Dear Sir,In the review article titled ‘Th17 cells in rheumatoid arthritis and systemic lupus erythematosus’, Pernis highlight the recent studies that have begun elucidating the factors that regulate the development of Th17 cells and summarized the role of Th17 cells in RA and SLE. This article suggests that the newly-discovered CD4+ T cell subset, termed ‘Th17’, may provide a mechanistic explanation underlying SLE and also provide possible therapeutic targets for anti-cytokine therapy to treat this disease [1]. However, I have several concerns regarding the discussion ‘Increased levels of IL-17 have been detected in the serum of SLE patients in some studies’ [2–4]. First, a recent paper provides evidence for increased serum levels of IL-17 in SLE patients; namely, Zhao et al. Mol Biol Rep 2009 Apr 4. [5], should be mentioned. Secondly, the reference of Kurasawa et al. was incorrectly cited. In fact, their results demonstrated that IL-17 messenger RNA was expressed in unstimulated PBL and lymphocytes from the skin and lungs of SSc patients, but not in similar samples from patients with SLE. IL-17 levels were increased in the serum of SSc patients, but not in that of SLE patients.