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Objective To assess circulating follicular helper T (Tfh)-like CD4+ T cells in patients with systemic lupus erythematosus (SLE) and determine their relationship to disease activity. Methods Blood samples from patients with SLE, as well as blood samples from patients with Behçet's disease (BD) and healthy individuals as controls, were analyzed. In all samples, circulating Tfh-like cells were enumerated by flow cytometry, using, as markers, expression of CXCR5, inducible T cell costimulator (ICOS), and programmed death 1 (PD-1) protein, as well as secretion of interleukin-21 (IL-21). The frequency of circulating Tfh-like cells was compared to that of circulating plasmablasts (CD19+IgD−CD38+). In addition, the possible association of circulating Tfh-like cells with the SLE Disease Activity Index (SLEDAI) was evaluated. Results The subset of circulating Tfh-like T cells, identified as CXCR5highICOShighPD-1high, was expanded in the blood of SLE patients compared to controls. Circulating Tfh-like cells were found to produce IL-21 and had lower expression of CCR7 as compared to that in circulating CXCR5high central memory T cells, thereby enabling their distinction. Expression of PD-1, but not ICOS or CXCR5, was significantly elevated in circulating Tfh-like cells from SLE patients compared to controls. PD-1 expression among CXCR5high circulating Tfh-like cells correlated with the SLEDAI, frequency of circulating plasmablasts, and anti-double-stranded DNA antibody positivity, but not with disease duration or past organ injury; rather, this cell profile appeared to be a reflection of current active disease. Conclusion Circulating Tfh-like cells are associated with disease activity in SLE, suggesting that their presence indicates abnormal homeostasis of T cell-B cell collaboration, with a causal relationship that is central to disease pathogenesis. These findings also suggest that circulating Tfh-like cells provide a surrogate for aberrant germinal center activity in SLE, and that their PD-1 expression offers a tool for measuring disease activity and monitoring the response to therapies. [ABSTRACT FROM AUTHOR]

Objective. To assess the efficacy and safety of pandemic 2009 influenza A (H1N1) in SLE under different therapeutic regimens.Methods. A total of 555 SLE patients and 170 healthy controls were vaccinated with a single dose of a non-adjuvanted preparation. According to current therapy, patients were initially classified as SLE No Therapy (n = 75) and SLE with Therapy (n = 480). Subsequent evaluations included groups under monotherapy: chloroquine (CQ) (n = 105), prednisone (PRED) &geq;20 mg (n = 76), immunosuppressor (IS) (n = 95) and those with a combination of these drugs. Anti-H1N1 titres and seroconversion (SC) rate were evaluated at entry and 21 days post-vaccination.Results. The SLE with Therapy group had lower SC compared with healthy controls (59.0 vs 80.0%; P < 0.0001), whereas the SLE No Therapy group had equivalent SC (72 vs 80.0%; P = 0.18) compared with healthy controls. Further comparison revealed that the SC of SLE No Therapy (72%) was similar to the CQ group (69.5%; P = 0.75), but it was significantly reduced in PRED &geq;20 mg (53.9%; P = 0.028), IS (55.7%; P = 0.035) and PRED &geq;20 mg + IS (45.4%; P = 0.038). The concomitant use of CQ in each of these later regimens was associated with SC responses comparable with SLE No Therapy group (72%): PRED &geq;20 mg + CQ (71.4%; P = 1.00), IS + CQ (65.2%; P = 0.54) and PRED &geq;20 mg + IS + CQ (57.4%; P = 0.09).Conclusion. Pandemic influenza A H1N1/2009 vaccine response is diminished in SLE under immunosuppressive therapy and antimalarials seems to restore this immunogenicity.Trial registration. www.clinicaltrials.gov, NCT01151644. [ABSTRACT FROM PUBLISHER]