We found an increased percentage of IL-2-positive cells in all patients, without differences between patients with isolated HT or associated HDAC inhibition with NEAD. IFN-γ+ cells were also increased in both groups, but the median percentage of those with isolated HT was lower than in patients with HT+NEAD (19·0 versus 29·9%; P = 0·0082). An increased number of IL-4-positive cells was observed in three of 33 (9·1%) patients

with isolated HT and in 25 of 35 patients with NEAD [71%; P < 0·0001; relative risk (RR) = 3·18]. The median values of IL-4+ cells (HT = 5·0% versus HT + NEAD = 16·8%) confirmed this large difference (P < 0·0001). A clear-cut increase of IL-4+ lymphocytes characterizes patients with autoimmune thyroiditis who have associated non-endocrine autoimmune disorders. These findings may represent an initial tool to detect patients with autoimmune thyroiditis in which additional non-endocrine autoimmune disorders may be awaited. Chronic autoimmune thyroiditis may occur as a single disease or associated with further endocrine autoimmune diseases [1–3]. These polyglandular autoimmune syndromes (PAS) are classified as juvenile form (PAS I) or adult form (PAS II) [1,2]. The association of autoimmune thyroiditis with non-endocrine autoimmune disorders has also been recognized [4] (identified throughout as NEAD), sometimes included

in PA DAPT chemical structure III syndrome [5]. The association of NEAD with autoimmune thyroiditis includes atrophic gastritis/pernicious anaemia [6,7], coeliac disease (CD) [8], vitiligo [9], anti-phospholipid syndrome [10] and many other autoimmune diseases (see [5] for a review). Such an association may reflect common genetic [11] and environmental factors [12], but shared immunological features also seem to be involved [13]. The immunological characterization of these associations was often based on the presence of co-existing organ-specific autoantibodies in serum [4], but their pathogenesis is, as yet, incompletely Reverse transcriptase understood. In recent years, the role of cellular immune

responses has been characterized in some of these diseases when in isolated form [13–16]. Multi-parameter flow cytometry permits simultaneous detection of two or more cytokines, allowing direct T helper type 1 (Th1) versus Th2 determination, and has emerged as the premier technique for studying cytokine production at the single-cell level [17,18]. By using this technique, a prevalent Th1-driven autoimmune response has been clearly recognized in Hashimoto’s thyroiditis (HT) [19] and this assumption has been validated in studies where the Th1-distinctive cytokines [interferon (IFN)-γ, interleukin (IL)-2] have been measured in serum [20] and in intrathyroidal lymphocytes [21]. Recently, a mild increase in the synthesis of Th-17 cytokines in patients with HT has also been reported [22]. A Th1 lymphocyte polarization even characterizes some related autoimmune disorders (CD, atrophic gastritis, type 1 diabetes) when occurring in isolated form [14–16].