Intravenous immunoglobulin expands regulatory T cells in autoimmune rheumatic disease.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt età la diffusion de documents scientifiques de niveau recherche, publiés ou non, ´ emanant desétablissements d'enseignement et de recherche français oú etrangers, des laboratoires publics ou privés. é Centre de R f rence des Vascularites N crosantes et Scl rodermies Syst miques 3 é é é é é H pital Cochin, Assistance publique-H pitaux de Paris ô ô (AP-HP) , Service de M decine Interne-P le M decine é ô é , 27 rue du Faubourg Saint Jacques 75679 Paris Cedex 14, FR Intravenous immunoglobulin (IVIg) therapy can benefit diverse autoimmune and inflammatory diseases via several mutually nonexclusive mechanisms ,. Recent studies both and in experimental models have also demonstrated that IVIg can [1 2 ] in vitro in vivo expand CD4 CD25 regulatory T cells (Treg), the cells that play a critical role in maintaining immune tolerance ,. Tregs maintain + + [3 4 ] immune tolerance by suppressing the activation and function of both innate and adaptive immune cells while deficiency of Tregs is associated with autoimmune and inflammatory conditions ,. Since IVIg therapy in autoimmune patients is associated with restoration [5 6 ] of immune tolerance, we hypothesize that this effect of IVIg is in part via expansion of Tregs in these patients, the immune bonafide regulators. To test our hypothesis, we analyzed Treg in paired blood samples of autoimmune rheumatic patients before and 72 96 hr after – high-dose IVIg therapy (Tegeline , 2g/kg per month). The patients broadly belonged to two groups: idiopathic inflammatory myopathy ® [1 ] (8 patients with age ranging from 22 to 57 yr; 3 male patients) and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (3 patients with age ranging from 61 to 68 yr; 2 males). The patients details are provided in. The local ethical committee approval ' Table 1 was obtained for collecting the blood samples and informed consent was taken from the patients. Peripheral blood mononuclear cells were isolated from the blood samples by ficoll-density gradient and CD4 CD25 T cells were analyzed by flow cytometry by using + high fluorescence-conjugated monoclonal antibodies (BD Biosciences, France). We found that, six …