Studies on the level of regulatory T (Treg) cells in psoriatic arthritis (PsA) have been controversial, leading to disagreement regarding the role Treg cells play in the pathogenesis of the disease. To clarify the status of Treg cells in patients with PsA, we performed a meta-analysis to determine the levels of Treg cells and serum Treg-associated cytokines in PsA patients.
According to published data from PubMed, Web of Science, Embase, Clinical Trials.gov, MEDLINE, Web of Knowledge, Cochrane Library, and FDA.gov, we determined the Treg and Treg cytokine levels in patients with PsA. The effect estimates were pooled using a random-effects model.
This meta-analysis included 12 studies. Compared to healthy controls (HCs), the proportions of Treg cells had no significant difference in patients with PsA (based on standardized means[SMD] = - 1.038, 95% confidence intervals[CI] =  - 2.165 to 0.089, p = 0.071). On the basis of subgroup analysis, patients with PsA had a lower percentage of CD4+ Treg cells (SMD = - 1.501, 95% CI - 2.799 to - 0.202, p = 0.023) than OKT8+ Treg (SMD = 0.568, 95% CI - 2.127 to 3.263, p = 0.679). Besides, CD4+CD25+FoxP3+ Treg cells and CD4+CD25highCD127low Treg cells were both significantly decreased on the levels of PBMCs in patients with PsA (SMD = - 0.764, 95% CI - 1.404 to - 0.125, p = 0.019; SMD = - 5.184, 95% CI - 6.955 to - 3.412, p < 0.001). CD4+CD25+FoxP3+ Treg cells were particularly more abundant in the synovial fluid thanin peripheral blood (SMD = 3.288, 95% CI 2.127 to 4.449, p < 0.001). No significant difference was observed in the proportion of CD4+CD25+ Treg cells in peripheral blood and CD4+CD25+FoxP3+ Treg cells in CD4+ T cells (SMD = - 2.498, 95% CI - 7.720 to 2.725, p = 0.349; SMD = - 0.719, 95% CI - 2.525 to 1.086, p = 0.435). PsA patients had decreased cytokines such as transforming growth factor-β (TGFβ) (SMD = - 2.199, 95% CI - 3.650 to - 0.749, p = 0.003).
Treg definition markers influence the scale of Treg cells in patients with PsA. Pathogenesis of PsA may be attributed to an insufficient or malfunctioning Treg population.

BACKGROUND: Idiopathic membranous nephropathy (MN) is a common immune-mediated glomerular disease and the main cause of nephrotic syndrome (NS) in Caucasian adults. Rituximab (RTX) has been reported to safely reduce proteinuria in patients with primary MN and severe NS. However, the effects of RTX treatment on T-cells including regulatory T-cells (Treg) in MN have not been fully determined.
METHODS: Seventeen patients [mean age 67 (29-86) years, 6 women, 11 men] with biopsy-proven MN, and persistent proteinuria >3.5 g/24h were prospectively enrolled and received RTX, 375 mg/m(2) (iv) on days 1, 8, 15 and 22. Changes in circulating B and T cell homeostasis were examined in the peripheral blood by flow-cytometry studies; serum levels of IL-35 were measured using a high-sensitivity ELISA kits (baseline, at month 3, 6, 9 and 12).
RESULTS: Patients had been followed-up for a mean of 36.3 months (24-48). Proteinuria decreased from 5.6 (3.5-8) g/24h to 2.4 (0.06-13) g/24h at 6 months (p<0.05) and to 1.3 (0.06-8) at 12 months (p<0.01), respectively after therapy with RTX. Four patients received a 2nd course of RTX (one at 6 months because of persistent NS, and three at 12, 18, or 30 months for relapse). The three relapsing patients became proteinuria-free (<0.5 g/24h) in the following 6 months. Serum creatinine remained stable during the follow-up: median 1mg/dl (0.7-1.6) at 12 months and 1.1 (0.7-1.7) at 24 months as compared to 1 (0.5-2.4) at baseline. At 6 months after RTX, complete remission (CR) was observed in 7 patients, partial remission (PR) in 4, while 6 were non responders (NR) non responder (NR). At the end of the follow-up, 14 patients were in CR, 1 in PR, while 2 were NR. In the T-cell compartment, upon detection of B cell depletion, there was an increase in Treg up to 10-fold when comparing baseline and at month 12 (mean ± SD 1.2 ± 0.6%, and 5.8 ± 0.7% p=0.02, respectively). When stratifying patients in responders (CR+PR) and NRs at month 12, we observed a significant increase in Treg cells from month 6 which persisted till 12 months only in the responder group (5.5 ± 0.6% and 1.1 ± 0.6%, p=0.04, respectively in responders and NRs). A statistically significant decrease in the levels of active T-lymphocytes (HLA-DR+CD8+ cells) was observed, with a maximum reached at 12 months after treatment with RTX [6 ± 1.1% baseline, 4.7 ± 1.7% at 6 months (p=0.043) and 1.5 ± 1.4% at 12 months (p=0.05)]. A marked increase in IL-35 levels [defined as delta >40% (serum values at 6 months minus baseline values)] was seen in 68% of the patients who achieved clinical response (CR or PR) at 12 month, but in none of the patients who failed to respond (p=0.034).
CONCLUSIONS: Our findings and data from literature support the idea that RTX can be envisaged as a first-line therapy for patients at risk of progression because of persistent NS due to idiopathic MN. Insights into the putative T cell-related mechanisms of action have been discussed.

A large body of evidence has been accumulated from experimental models in the past decade to support the critical role of Foxp3-expressing regulatory T cells (Tregs) in the suppression of alloimmune responses. This has prompted transplant clinicians to investigate whether Foxp3 analysis might be used as an immunodiagnostic tool for better assessment of the significance of graft infiltrate and to predict its impact on graft outcome. However, conflicting results have emerged from these studies and may have generated more confusion than clarification. Foxp3 expression has been antagonistically correlated with either good or poor prognosis. We discuss here how methodological issues and specific clinical settings may have accounted for the discrepancies between the results of these studies. Depending on many factors, including the techniques used, the method of sampling normalization, the extent of intra-graft inflammation, the immunosuppressive regimen and the depletion or repletion of T lymphocyte compartment, the significance of Foxp3 expression may vary. We propose here the conditions to be fulfilled in order to use Foxp3 analysis as a relevant biomarker for graft outcome assessment. Far from challenging the key role of Tregs in dampening alloimmune responses, this review highlights the need for technical harmonization and standards.

Our traditional understanding of the T-helper (Th)1/Th2 paradigm in periodontal disease has undergone considerable changes in recent years. This review focuses on the Th subsets, including the recently identified cells of the CD4 lineage, their activation pathways and effector function in periodontal disease. The roles of Th17 and regulatory T (Treg) cells in disease pathogenesis have been explored. Newer Th subsets such as Th9 and Th22 cells and their potential role in periodontal disease have also been outlined.