Systemic lupus erythematosus: modern strategies for management – a moving target

Belimumab for systemic lupus erythematosus: a practice-based view

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with multiple organ involvement. B-lymphocyte activity plays a pivotal role in the development and course of the disease. A newly developed agent called belimumab has recently been approved to treat active, autoantibody positive SLE as an add-on to standard therapy. Specifically binding to soluble B-lymphocyte stimulator protein, it reduces the formation of immunoglobulins and autoantibodies. Its effects have been studied in one phase II and two phase III clinical trials, showing sustained improvement across various clinical indicators and no evidence of increased risk of serious adverse events. Further post-hoc analyses indicate that treatment with belimumab lowers levels of autoimmune antibodies, normalizes low complement and improves SLE activity predominantly in musculoskeletal and mucocutaneous organ domains. Further studies are needed to determine the efficacy of belimumab for patients with severe lupus nephritis and with active involvement of the central nervous system. The introduction of belimumab as the first biological drug approved for the management of SLE likely heralds a surge in the development and use of selectively addressed agents for this heterogeneous and complex disease.

Inhibition of aberrant circulating Tfh cell proportions by corticosteroids in patients with systemic lupus erythematosus

OBJECTIVE

To observe the proportion of peripheral T follicular helper (Tfh) cells in patients with systemic lupus erythematosus (SLE) and to assess the role of steroids on Tfh cells from SLE patients.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 42 SLE patients and 22 matched healthy subjects were collected to assess proportions of circulating CXCR5(+)PD1(+)/CD4(+) T cells (Tfh), CD4(+)CCR6(+) T cells (Th17-like) and CD19(+)CD138(+) plasma cells by flow cytometry. 8 of the patients had their blood redrawn within one week after receiving methylprednisolone pulse treatment. Disease activity was evaluated by SLE disease activity index. To test the effect of IL-21 and corticosteroids on Tfh cells in vitro, PBMCs harvested from another 15 SLE patients were cultured with medium, IL-21, or IL-21+ dexamethasone for 24 hours and 72 hours. PBMCs from an independent 23 SLE patients were cultured with different concentrations of dexamethasone for 24 hours.

RESULTS

Compared to normal controls, percentages of circulating Tfh cells, but not Th17 cells, were elevated in SLE patients and correlated with disease activity. Proportions of Tfh cells in SLE patients were positively correlated with those of plasma cells and serum levels of antinuclear antibodies. After methylprednisolone pulse treatment, both percentages and absolute numbers of circulating Tfh cells were significantly decreased. In vitro cultures showed an increase of Tfh cell proportion after IL-21 stimulation that was totally abolished by the addition of dexamethasone. Both 0.5 and 1 µM dexamethasone decreased Tfh cells dose dependently (overall p = 0.013).

CONCLUSIONS

We demonstrated that elevated circulating Tfh cell proportions in SLE patients correlated with their disease activities, and circulating levels of plasma cells and ANA. Corticosteroids treatment down-regulated aberrant circulating Tfh cell proportions both in vivo and in vitro, making Tfh cells a new treatment target for SLE patients.

Belimumab: a BLyS-specific inhibitor for the treatment of systemic lupus erythematosus

Belimumab (Benlysta), which recently received marketing approval, is the first of a new class of immunomodulators with a novel mechanism of action. It is a specific inhibitor of the soluble B-lymphocyte stimulator (BLyS) cytokine, which has been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Two large phase III randomized controlled clinical trials evaluated the safety and efficacy of belimumab combined with standard therapy and showed that the efficacy of this treatment was significantly superior to placebo plus standard therapy. Belimumab is an evidence-based therapeutic option for patients with general lupus disease activity and may signal a shift in the existing treatment paradigm from therapeutic selection targeting specific organ involvement to an approach directed at tackling multisystem disease activity and preventing the disease from worsening.

Glucocorticoid-induced diabetes mellitus in patients with systemic lupus erythematosus treated with high-dose glucocorticoid therapy

The aim of this study was to investigate the prevalence and associated factors of glucocorticoid-induced diabetes mellitus (GDM) in patients with systemic lupus erythematosus (SLE) receiving high-dose glucocorticoid therapy. Patients with SLE who had received high-dose glucocorticoid therapy (prednisolone ≥1 mg/kg/day) at Yonsei University Medical Center, Seoul, Korea, were recruited between January 1999 and June 2009. In total 127 patients with SLE were evaluated. Sixteen (12.6%) of them developed GDM after high-dose glucocorticoid therapy (95% confidence interval, 6.8-18.4%). Univariate analysis showed that old age, family history of diabetes mellitus (DM), hypertension, higher body mass index, higher mean dose of prednisolone before high-dose glucocorticoid therapy, and concurrent use of mycophenolate mofetil (MMF) were factors that would increase the likelihood of GDM. Multivariate analysis determined that age, family history of DM, mean dose of prednisolone before high-dose glucocorticoid therapy and concurrent use of MMF were independent associated factors for GDM. In summary, GDM was developed among 12.6% of patients with SLE after high-dose glucocorticoid therapy. Old age, family history of DM, higher mean dose of prednisolone before high-dose glucocorticoid therapy and concurrent use of MMF were determined to be factors responsible for increasing the risk of developing GDM.