Circulating regulatory T cells were absolutely decreased in dermatomyositis/polymyositis patients and restored by low-dose IL-2

We note with interest and express our principle agreement with the views put forward by Professor Rosenzwajg M1 in the recent Editorial ‘Immunological and clinical effects of low-dose interleukin-2 across 11 autoimmune diseases in a single, open clinical trial’ published in Annals of the Rheumatic Diseases . The authors conclude that any autoimmune or inflammatory disease denotes a regulatory T cells (Tregs) insufficiency, which is restored by low-dose interleukin (IL)−2 ((1 million IU/day) for 5 days, followed by fortnightly injections for 6 months) selectively and safely activate and expand Tregs in 11 autoimmune diseases. This study is important and deserves a practical value. In our study, the absolute changes of peripheral lymphocyte subpopulations and CD4+ T subsets, especially Tregs, and the safety and efficacy of low-dose IL-2 in dermatomyositis (DM)/polymyositis (PM), which are idiopathic inflammatory myopathies and not shown in the above article, are shared with the readers. In our study, total 147 patients with PM/DM were enrolled and 128 gender-matched and age-matched healthy adults were participated as controls from February 2016 to October 2018. The absolute numbers of T, B, natural killer (NK), CD4+ T, CD8+ T, Th1, Th2, Th17 and Tregs in peripheral blood of these individuals were detected by flow cytometry combined with standard absolute counting beads. …