Tofacitinib treatment of rheumatoid arthritis increases senescent T cell frequency in patients and limits T cell function in vitro.

Unraveling the immune signatures in rheumatoid arthritis (RA) patients receiving various treatment regimens can aid in comprehending the immune mechanisms' role in treatment efficacy and side effects. Given the critical role of cellular immunity in RA pathogenesis, we sought to identify T-cell profiles characterizing RA patients under specific treatments. We compared 75 immunophenotypic and biochemical variables in healthy donors (HD) and RA patients, including those receiving different treatments as well as treatment-free patients. Additionally, we conducted in vitro experiments to evaluate the direct effect of tofacitinib on purified naïve and memory CD4+ and CD8+ T cells. Multivariate analysis revealed that tofacitinib-treated patients segregated from HD at the expense of T-cell activation, differentiation, and effector function-related variables. Additionally, tofacitinib led to an accumulation of peripheral senescent memory CD4+ and CD8+ T cells. In vitro, tofacitinib impaired the activation, proliferation, and effector molecules expression and triggered senescence pathways in T-cell subsets upon TCR-engagement, with the most significant impact on memory CD8+ T cells. Our findings suggest that tofacitinib may activate immunosenescence pathways while simultaneously inhibiting effector functions in T cells, both effects likely contributing to the high clinical success and reported side effects of this JAK inhibitor in RA.

PD-L1+ Regulatory B Cells Are Significantly Decreased in Rheumatoid Arthritis Patients and Increase After Successful Treatment.

Background: B cells play an important role in the development and maintenance of rheumatoid arthritis (RA). Although IL-10-producing B cells represent a major subset of regulatory B cells (Bregs) able to suppress autoimmune and inflammatory responses, recent reports showed that B cell-mediated immune suppression may also occur independent of IL-10. For instance, B cells can modulate T cell immune responses through the expression of regulatory molecules such as PD-L1. So far, PD-L1-expressing B cells have not been analyzed in RA patients. Objective: To analyze the frequency of PD-L1-expressing B cells in the peripheral blood of RA patients compared to healthy controls (HC) matched for sex and age, their function on T cell response and their changes in response to therapy. Methods: Fresh peripheral blood B cells from RA patients and HC were characterized by flow cytometry and their functionality assessed in a co-culture system with autologous T cells. Results: The frequencies of CD19+PD-L1+ B cells, CD24hiCD38-PD-L1+ and CD24hiCD38hiPD-L1+ B cells were significantly lower in untreated RA patients than in HC. In a follow-up study, the frequencies of PD-L1+ B cells (CD19+PD-L1+ B cells, CD24hiCD38-PD-L1+ and CD24hiCD38hiPD-L1+ B cells) increased significantly after treatment in good responder patients, although the frequency of total CD24hiCD38hi B cells decreased. CD19+ B cells from untreated RA patients and HC upregulated PD-L1 expression similarly upon stimulation with CpG plus IL-2 and were able to suppress, in vitro, CD8+ T cell proliferation and cytokine production in a PD-L1-dependent manner. Conclusions: Our results show that PD-L1+ B cells exhibiting T cell suppressive capacity are significantly decreased in untreated RA patients but increase in response to successful treatment. PD-L1 expression on B cells from RA patients can be modulated in vitro and PD-L1+ B cells could thus provide new perspectives for future treatment strategies.

[Use of intravenous humana immunoglobulin in rheumatic diseases]. / Uso de inmunogtlobulina G humana endovenosa(IGEV) en enfermedades reumáticas.

INTRODUCTION: Preparations of intravenous immunoglobulin (IVIG) are used as treatment in different diseases such primary and secondary immunodeficiencies, autoimmune diseases, systemic inflammatory diseases, infectious diseases and allergic diseases among others. OBJECTIVE: to present 13 of our cases with the use of IVIG in different rheumatic diseases. PATIENTS AND METHODS: we retrospectively studied 13 patients (10 women and 3 men), mean age 29 years with different rheumatic diseases, that underwent conventional treatments without positive response. They received IVIG pulses, trying to improve or induce remission of their previous clinical situation. 6/13 patients met criteria for systemic lupus erythematosus (SLE), 2/13 had primary antiphospholipid syndrome (APL)one had polydermatomyositis (PDM), 1 juvenile arthritis, 1 panarteritis nodosa (cutaneous PAN), one Evans syndrome, and one with autoimmune uveitis. RESULTS: 7 of them had a positive response to therapy with IGEV evaluated by clinical and biochemical parameters. They remained with conventional treatments. One patient received a new IG EV pulse after 24 months, because of panniculitis reactivation. Clinical and biochemical response was poor in 4 of them, and 2 patients died. CONCLUSION: IVIg may be usefull in autoimmune rheumatic diseases when conventional therapies have failed. The therapeutic success is also limited. Only the 55 percent of our patients had a positive clinical response.