Faculty Bibliography

OBJECTIVE: B cells are likely to contribute to the pathogenesis of systemic lupus erythematosus (SLE), and rituximab induces depletion of B cells. The Exploratory Phase II/III SLE Evaluation of Rituximab (EXPLORER) trial tested the efficacy and safety of rituximab versus placebo in patients with moderately-to-severely active extrarenal SLE. METHODS: Patients entered with >or=1 British Isles Lupus Assessment Group (BILAG) A score or >or=2 BILAG B scores despite background immunosuppressant therapy, which was continued during the trial. Prednisone was added and subsequently tapered. Patients were randomized at a ratio of 2:1 to receive rituximab (1,000 mg) or placebo on days 1, 15, 168, and 182. RESULTS: In the intent-to-treat analysis of 257 patients, background treatment was evenly distributed among azathioprine, mycophenolate mofetil, and methotrexate. Fifty-three percent of the patients had >or=1 BILAG A score at entry, and 57% of the patients were categorized as being steroid dependent. No differences were observed between placebo and rituximab in the primary and secondary efficacy end points, including the BILAG-defined response, in terms of both area under the curve and landmark analyses. A beneficial effect of rituximab on the primary end point was observed in the African American and Hispanic subgroups. Safety and tolerability were similar in patients receiving placebo and those receiving rituximab. CONCLUSION: The EXPLORER trial enrolled patients with moderately-to-severely active SLE and used aggressive background treatment and sensitive cutoffs for nonresponse. No differences were noted between placebo and rituximab in the primary and secondary end points. Further evaluation of patient subsets, biomarkers, and exploratory outcome models may improve the design of future SLE clinical trials

Objectives: SLE patients (pts) with moderate-to-severe disease activity (>=1 BILAG A or >=2 BILAG B domain scores) despite background immunosuppressives and corticosteroids, were randomized to placebo (PLA) or rituximab (RTX). Although differences in primary and secondary outcome measures were not observed, an exploratory analysis was performed to evaluate the imObjectives: SLE patients (pts) with moderate-to-severe disease activity (>=1 BILAG A or >=2 BILAG B domain scores) despite background immunosuppressives and corticosteroids, were randomized to placebo (PLA) or rituximab (RTX). Although differences in primary and secondary outcome measures were not observed, an exploratory analysis was performed to evaluate the impact of RTX on disease flares. Our objectives were to assess in those pts who achieved response whether RTX affected: 1) time to moderate or severe flares, 2) annualized flare rates, and 3) prednisone usage during flares. Methods: Pts who achieved response (BILAG C, D, E scores for all domains before wk52) on monthly BILAG assessments were included in this analysis. Flares, defined as increased disease activity following achievement of response, were stratified as follows: Severe flare: >=1 BILAG A or >3 BILAG B domain scores; A flare: >=1 new BILAG A domain scores; Moderate flare: 2 BILAG B domain scores. Kaplan-Meier estimates were used to assess time-to-flare. Annualized flare rates were calculated using number of flares per patient with a Poisson regression model. Only flares that occurred after the protocol-mandated prednisone taper at 12 wks were included in the analysis of prednisone use during flares. Results: Responses were achieved in 58/88 (66.0%) PLA-treated and 127/169 (75.1%) RTX-treated pts during the study. No difference was found between rituximab and placebo in preventing or delaying moderate to severe flares. However, when BILAG A flares alone were examined, rituximab reduced the risk of an A flare after achieving a response by 52 weeks (hazard ratio=0.612; p=0.0524) and lowered the annualized A flare rate (0.86 +/- 1.47 (SD) vs 1.41 +/- 2.14; p=.038). Eighty-four of 169 (49.7%) rituximab-treated patients achieved low disease activity without subsequent A flares versus 31/88 (35.2%) patients in the placebo group (p=0.027). Prednisone rescue for A flares was similar in rituximab- (24%) and placebo-treated (14%) patients (p=.204). Conclusions: No conclusions about rituximab efficacy can be drawn from this post hoc analysis. This exploratory analysis suggests that assessment of BILAG A flares may distinguish potential treatment effects with more sensitivity than BILAG B flares, which capture modest changes in disease activity. If confirmed in other studies, this observation may help in the design of more robust clinical trial protocols

Purpose: Coagulation is one of the first pathways to be elicited by vascular injury, and its activation is followed by proinflammatory phenomena, in part due to loss of the anti-inflammatory activity of both the Protein C pathway and membrane Endothelial Protein C receptor (mEPCR). It has been recently demonstrated that mEPCR is highly expressed in the cortical peritubular capillaries of kidneys from patients (pts) with active lupus nephritis compared to normal human kidney. Profound upregulation of mEPCR was observed even in areas absent tubulointerstitial damage. This study addressed the hypothesis that changes in the microvasculature extend beyond the clinically targeted organ and that dysregulation is a fundamental characteristic of SLE. Methods: The study included SLE pts in whom renal disease was considered active as assessed by proteinuria and urinary sediment. Renal biopsies were performed in all pts. Thirty skin biopsies from non-lesional nonsunexposed skin (buttocks) were obtained in 26 pts (23 females, 3 males) and five healthy controls (4 females, 1 male). The paraffin skin sections were individually stained with specific antibodies against mEPCR and adiponectin (protective markers), ICAM-1 (proinflammatory) and CD31 (pan endothelial marker). Immunohistochemistry (IHC) was scored by counting peroxidase-brown labeled blood vessels (10-20 microns in diameter) without knowledge of the clinical information associated with the biopsy. The number of blood vessels with an intensity of at least 1+ were quantitatively scored with ranges 1-12. To account for the number of blood vessels per slide, the CD31 count had to be 12 to be included in the analysis. Results: The 28 renal biopsies comprised the following ISN/RPS classifications: 4 Class III, 7 Class IV, 8 Class V, I Class VI, 3 Class III/V, 3 Class IV/V. Nineteen percent of the pts had a GFR <60 (mean GFR, 82 ml/min). Abnormal laboratory values for complement and anti-dsDNA antibodies were reported in 72% and 75% of pts, respectively. Nephrotic range proteinuria was present in 37%. For IHC skin assessments of the controls, the mean score for mEPCR was 1 (highest 2), ICAM-1 was 4 (highest 7) and adiponectin was 1 (highest 2). In 17/25 (68%) of the SLE non-lesional non-sun exposed skin sections, mEPCR was expressed above the highest control. In 16/30 (53%) ICAM-1 staining exceeded 7. In contrast, only 6/25 (19%) expressed adiponectin above 2. For each specific stain there were no apparent differences between biopsy class, degree of proteinuria, presence of anti dsDNA or low complement levels. However, pts with mEPCR staining above 2 had higher GFR measurements than those with staining < 2 (88 ml/min +/- 31 versus 53 +/- 32, p= 0.0168). In contrast, GFR was unrelated to ICAM-1 and adiponectin expression. Conclusion: These data are consistent with the notion that there is widespread activation of the microvasculature. The capacity of endothelial cells to utilize anticoagulation pathways is not restricted to the kidney and expression of mEPCR in the microcirculation likely represents an attempt to limit microvascular inflammation in kidney and skin

INTRODUCTION: The TAM (tyro 3, axl, mer) kinases are key regulators of innate immunity and are important in the phagocytosis of apoptotic cells. Gas6 and protein S are ligands for these TAM kinases and bind to phosphatidyl serine residues exposed during apoptosis. In animal models, absence of TAM kinases is associated with lupus-like disease. To test whether human systemic lupus erythematosus (SLE) patients might have deficient levels of TAM ligands, we measured Gas 6 and protein S levels in SLE. METHODS: 107 SLE patients were recruited. Of these, 45 SLE patients were matched age, gender and ethnicity with normal controls (NC). Gas6 and free protein S were measured with sandwich enzyme linked immunosorbent assays (ELISAs). RESULTS: Overall, the plasma concentrations of Gas6 and free protein S were not different between 45 SLE patients and 45 NC. In SLE patients, the levels of free protein S were positively correlated with age (r = 0.2405, P = 0.0126), however those of Gas6 were not. There was no correlation between the concentrations of Gas6 and free protein S in individuals. Levels of free protein S were significantly lower in SLE patients with a history of serositis, neurologic disorder, hematologic disorder and immunologic disorder. Gas6 levels were elevated in patients with a history of neurologic disorder. The SLE patients with anti-Sm or anti-cardiolipin IgG showed lower free protein S levels. Circulating free protein S was positively correlated with complement component 3 (C3) (r = 0.3858, P < 0.0001) and complement component 4 (C4) (r = 0.4275, P < 0.0001). In the patients with active BILAG hematologic involvement, the levels of free protein S were lower and those of Gas6 were higher. CONCLUSIONS: In SLE, free protein S was decreased in patients with certain types of clinical history and disease activity. Levels of free protein S were strongly correlated with C3 and C4 levels. Gas6 levels in SLE patients differed little from levels in NC, but they were elevated in the small numbers of patients with a history of neurological disease. The correlation of decreased protein S levels with lupus disease activity is consistent with a role for the TAM receptors in scavenging apoptotic cells and controlling inflammation. Protein S appears more important functionally in SLE patients than Gas6 in this regard

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by increased type I interferons (IFNs) and multiorgan inflammation frequently targeting the skin. IFN-kappa is a type I IFN expressed in skin. A pooled genome-wide scan implicated the IFNK locus in SLE susceptibility. We studied IFNK single nucleotide polymorphisms (SNPs) in 3982 SLE cases and 4275 controls, composed of European (EA), African-American (AA), and Asian ancestry. rs12553951C was associated with SLE in EA males (odds ratio = 1.93, P = 2.5 x 10(-4)), but not females. Suggestive associations with skin phenotypes in EA and AA females were found, and these were also sex-specific. IFNK SNPs were associated with increased serum type I IFN in EA and AA SLE patients. Our data suggest a sex-dependent association between IFNK SNPs and SLE and skin phenotypes. The serum IFN association suggests that IFNK variants could influence type I IFN producing plasmacytoid dendritic cells in affected skin

OBJECTIVE: To describe a new systemic lupus erythematosus (SLE) responder index (SRI) based on a belimumab phase II SLE trial and demonstrate its potential utility in SLE clinical trials. METHODS: Data from a randomized, double-blind, placebo-controlled study in 449 patients of 3 doses of belimumab (1, 4, 10 mg/kg) or placebo plus standard of care therapy (SOC) over a 56-week period were analyzed. The Safety of Estrogens in Lupus Erythematosus: National Assessment (SELENA) version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and British Isles Lupus Assessment Group (BILAG) SLE disease activity instruments, the Short Form 36 health survey, and biomarker analyses were used to create a novel SRI. Response to treatment in a subset of 321 serologically active SLE patients (antinuclear antibodies >/=1:80 and/or anti-double-stranded DNA antibodies >/=30 IU/ml) at baseline was retrospectively evaluated using the SRI. RESULTS: SRI response is defined as 1) a >/=4-point reduction in SELENA-SLEDAI score, 2) no new BILAG A or no more than 1 new BILAG B domain score, and 3) no deterioration from baseline in the physician's global assessment by >/=0.3 points. In serologically active patients, the addition of belimumab to SOC resulted in a response in 46% of patients at week 52 compared with 29% of the placebo patients (P = 0.006). SRI responses were independent of baseline autoantibody subtype. CONCLUSION: This evidence-based evaluation of a large randomized, placebo-controlled trial in SLE resulted in the ability to define a robust responder index based on improvement in disease activity without worsening the overall condition or the development of significant disease activity in new organ systems

OBJECTIVE: To assess the safety, tolerability, biologic activity, and efficacy of belimumab in combination with standard of care therapy (SOC) in patients with active systemic lupus erythematosus (SLE). METHODS: Patients with a Safety of Estrogens in Lupus Erythematosus: National Assessment (SELENA) version of the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score >/=4 (n = 449) were randomly assigned to belimumab (1, 4, or 10 mg/kg) or placebo in a 52-week study. Coprimary end points were the percent change in the SELENA-SLEDAI score at week 24 and the time to first SLE flare. RESULTS: Significant differences between the treatment and placebo groups were not attained for either primary end point, and no dose response was observed. Reductions in SELENA-SLEDAI scores from baseline were 19.5% in the combined belimumab group versus 17.2% in the placebo group. The median time to first SLE flare was 67 days in the combined belimumab group versus 83 days in the placebo group. However, the median time to first SLE flare during weeks 24-52 was significantly longer with belimumab treatment (154 versus 108 days; P = 0.0361). In the subgroup (71.5%) of serologically active patients (antinuclear antibody titer >/=1:80 and/or anti-double-stranded DNA [anti-dsDNA] >/=30 IU/ml), belimumab treatment resulted in significantly better responses at week 52 than placebo for SELENA-SLEDAI score (-28.8% versus -14.2%; P = 0.0435), physician's global assessment (-32.7% versus -10.7%; P = 0.0011), and Short Form 36 physical component score (+3.0 versus +1.2 points; P = 0.0410). Treatment with belimumab resulted in a 63-71% reduction of naive, activated, and plasmacytoid CD20+ B cells, and a 29.4% reduction in anti-dsDNA titers (P = 0.0017) by week 52. The rates of adverse events and serious adverse events were similar in the belimumab and placebo groups. CONCLUSION: Belimumab was biologically active and well tolerated. The effect of belimumab on the reduction of SLE disease activity or flares was not significant. However, serologically active SLE patients responded significantly better to belimumab therapy plus SOC than to SOC alone

OBJECTIVE: Interleukin-21 (IL-21) is a member of the type I cytokine superfamily that has a variety of effects on the immune system, including B cell activation, plasma cell differentiation, and immunoglobulin production. The expression of IL-21 receptor (IL-21R) is reduced in the B cells of patients with systemic lupus erythematosus (SLE), while serum IL-21 levels are increased both in lupus patients and in some murine lupus models. We recently reported that polymorphisms within the IL21 gene are associated with increased susceptibility to SLE. The aim of this study was to examine the genetic association between single-nucleotide polymorphisms (SNPs) within IL21R and SLE. METHODS: We genotyped 17 SNPs in the IL21R gene in 2 large cohorts of lupus patients (a European-derived cohort and a Hispanic cohort) and in ethnically matched healthy controls. RESULTS: We identified and confirmed the association between rs3093301 within the IL21R gene and SLE in the 2 cohorts (meta-analysis odds ratio 1.16 [95% confidence interval 1.08-1.25], P=1.0x10(-4)). CONCLUSION: Our findings indicate that IL21R is a novel susceptibility gene for SLE

We targeted LYN, a src-tyosine kinase involved in B-cell activation, in case-control association studies using populations of European-American, African-American and Korean subjects. Our combined European-derived population, consisting of 2463 independent cases and 3131 unrelated controls, shows significant association with rs6983130 in a female-only analysis with 2254 cases and 2228 controls (P=1.1 x 10(-4), odds ratio (OR)=0.81 (95% confidence interval: 0.73-0.90)). This single nucleotide polymorphism (SNP) is located in the 5' untranslated region within the first intron near the transcription initiation site of LYN. In addition, SNPs upstream of the first exon also show weak and sporadic association in subsets of the total European-American population. Multivariate logistic regression analysis implicates rs6983130 as a protective factor for systemic lupus erythematosus (SLE) susceptibility when anti-dsDNA, anti-chromatin, anti-52 kDa Ro or anti-Sm autoantibody status were used as covariates. Subset analysis of the European-American female cases by American College of Rheumatology classification criteria shows a reduction in the risk of hematological disorder with rs6983130 compared with cases without hematological disorders (P=1.5 x 10(-3), OR=0.75 (95% CI: 0.62-0.89)). None of the 90 SNPs tested show significant association with SLE in the African American or Korean populations. These results support an association of LYN with European-derived individuals with SLE, especially within autoantibody or clinical subsets