Efficacy and safety of rituximab in patients with active proliferative lupus nephritis: the Lupus Nephritis Assessment with Rituximab study.

OBJECTIVE: To evaluate the efficacy and safety of rituximab in a randomized, double-blind, placebo-controlled phase III trial in patients with lupus nephritis treated concomitantly with mycophenolate mofetil (MMF) and corticosteroids. METHODS: Patients (n = 144) with class III or class IV lupus nephritis were randomized 1:1 to receive rituximab (1,000 mg) or placebo on days 1, 15, 168, and 182. The primary end point was renal response status at week 52. RESULTS: Rituximab depleted peripheral CD19+ B cells in 71 of 72 patients. The overall (complete and partial) renal response rates were 45.8% among the 72 patients receiving placebo and 56.9% among the 72 patients receiving rituximab (P = 0.18); partial responses accounted for most of the difference. The primary end point (superior response rate with rituximab) was not achieved. Eight placebo-treated patients and no rituximab-treated patients required cyclophosphamide rescue therapy through week 52. Statistically significant improvements in serum complement C3, C4, and anti-double-stranded DNA (anti-dsDNA) levels were observed among patients treated with rituximab. In both treatment groups, a reduction in anti-dsDNA levels greater than the median reduction was associated with reduced proteinuria. The rates of serious adverse events, including infections, were similar in both groups. Neutropenia, leukopenia, and hypotension occurred more frequently in the rituximab group. CONCLUSION: Although rituximab therapy led to more responders and greater reductions in anti-dsDNA and C3/C4 levels, it did not improve clinical outcomes after 1 year of treatment. The combination of rituximab with MMF and corticosteroids did not result in any new or unexpected safety signals.

Belimumab reduces autoantibodies, normalizes low complement levels, and reduces select B cell populations in patients with systemic lupus erythematosus.

OBJECTIVE: To assess the effects of the B lymphocyte stimulator (BLyS)-specific inhibitor belimumab on immunologic biomarkers, including B cell and T cell populations, and maintenance of antibody titers to prior vaccines in autoantibody-positive systemic lupus erythematosus (SLE) patients. METHODS: Pooled data from 2 phase III trials, the Study of Belimumab in Subjects with SLE 52-week (BLISS-52) and 76-week (BLISS-76) trials, comparing belimumab 1 mg/kg or 10 mg/kg versus placebo (plus standard SLE therapy for each group) were analyzed for changes in autoantibody, immunoglobulin, and complement levels. BLISS-76 patients were also analyzed for changes in B cell and T cell populations and effects on prior vaccine-induced antibody levels. RESULTS: Belimumab-treated patients experienced significant sustained reductions in IgG and autoantibodies and improvement in C3/C4 levels, resulting in greater positive-to-negative conversion rates for IgG anti-double-stranded DNA (anti-dsDNA), anti-Sm, anticardiolipin, and anti-ribosomal P autoantibodies and normalization of hypergammaglobulinemia and low C3/C4 levels. Belimumab-treated patients experienced significant decreases in the numbers of naive and activated B cells, as well as plasma cells, whereas memory B cells and T cell populations did not decrease. Belimumab did not substantially affect preexisting antipneumococcal or anti-tetanus toxoid antibody levels. Post hoc analysis showed greater reductions in SLE disease activity and the risk of severe flares in patients treated with belimumab 10 mg/kg (P≤0.01) who were anti-dsDNA positive and had low C3/C4 levels at baseline. Normalization of the C3 or anti-dsDNA level by 8 weeks, irrespective of therapy, was predictive of a reduced risk of severe flare over 52 weeks. CONCLUSION: Belimumab appears to promote normalization of serologic activity and reduce BLyS-dependent B cell subsets in serologically and clinically active SLE. Greater serologic activity may predict a better treatment response to belimumab.

Differential requirements for Vav proteins in DAP10- and ITAM-mediated NK cell cytotoxicity.

Natural killer (NK) cells express multiple activating receptors that initiate signaling cascades through DAP10- or immunoreceptor tyrosine-based activation motif-containing adapters, including DAP12 and FcRgamma. Among downstream signaling mediators, the guanine nucleotide exchange factor Vav1 carries out a key role in activation. However, whether Vav1 regulates only some or all NK cell-activating pathways is matter of debate. It is also possible that two other Vav family molecules, Vav2 and Vav3, are involved in NK cell activation. Here, we examine the relative contribution of each of these exchange factors to NK cell-mediated cytotoxicity using mice lacking one, two, or all three Vav proteins. We found that Vav1 deficiency is sufficient to disrupt DAP10-mediated cytotoxicity, whereas lack of Vav2 and Vav3 profoundly impairs FcRgamma- and DAP12-mediated cytotoxicity. Our results provide evidence that these three Vav proteins function specifically in distinct pathways that trigger NK cell cytotoxicity.

Description of 12 cases of nephrogenic fibrosing dermopathy and review of the literature.

OBJECTIVES: To review the clinical and laboratory features of 12 cases of nephrogenic fibrosing dermopathy (NFD) studied at our institution and of 70 previously described cases in the literature. METHODS: Clinical evaluation and laboratory studies of 12 patients with NFD associated with chronic hemodialysis or peritoneal dialysis for end-stage renal disease and a review of 23 previous publications describing 70 patients with this disease. RESULTS: Eleven patients undergoing chronic hemodialysis and 1 patient undergoing chronic peritoneal dialysis for end-stage renal failure developed a severe and progressive cutaneous fibrotic process with woody induration of legs, thighs, hands, and forearms, and severe loss of motion and flexion contractures in multiple joints. Several patients displayed systemic involvement including fibrosis of muscles, myocardium, and lungs and marked elevations of the erythrocyte sedimentation rate and/or C-reactive protein. Three patients died within 2 years of symptom onset. A review of previously published reports of this disorder confirmed the presence of systemic involvement and a poor prognosis with a high mortality rate. CONCLUSIONS: NFD is a severe and usually progressive systemic fibrotic disease affecting the dermis, subcutaneous fascia, and striated muscles. It also appears that the disease can cause fibrosis of lungs, myocardium, and other organs.

Blockade of interferon-γ normalizes interferon-regulated gene expression and serum CXCL10 levels in patients with systemic lupus erythematosus.

OBJECTIVE: To assess the safety and immunologic impact of inhibiting interferon-γ (IFNγ) with AMG 811, a human IgG1 monoclonal antibody against IFNγ, in patients with systemic lupus erythematosus (SLE). METHODS: Twenty-six patients with mild-to-moderate, stable SLE were administered placebo or a single dose of AMG 811, ranging from 2 mg to 180 mg subcutaneously or 60 mg intravenously. RESULTS: Similar to results previously reported following inhibition of type I IFNs, treatment of SLE patients with AMG 811 led to a dose-dependent modulation of the expression of genes associated with IFN signaling, as assessed by microarray analysis of the whole blood. The list of impacted genes overlapped with that identified by stimulating human whole blood with IFNγ and with those gene sets reported in the literature to be differentially expressed in SLE patients. Serum levels of IFNγ-induced chemokines, including IFNγ-inducible protein 10 (IP-10), were found to be elevated at baseline in SLE patients as compared to healthy volunteers. In contrast to previously reported results from studies using type I IFN-blocking agents, treatment with AMG 811 led to dose-related reductions in the serum levels of CXCL10 (IP-10). CONCLUSION: The scope and nature of the biomarkers impacted by AMG 811 support targeting of IFNγ as a therapeutic strategy for SLE.

Effect of belimumab on vaccine antigen antibodies to influenza, pneumococcal, and tetanus vaccines in patients with systemic lupus erythematosus in the BLISS-76 trial.

OBJECTIVE: In patients with systemic lupus erythematosus (SLE), evidence suggests that most vaccines (except live-virus vaccines) are safe, although antibody response may be reduced. This substudy from the phase III, randomized, double-blind, placebo-controlled BLISS-76 trial evaluated the effects of belimumab on preexisting antibody levels against pneumococcal, tetanus, and influenza antigens in patients with SLE. METHODS: In BLISS-76, patients with autoantibody-positive, active SLE were treated with placebo or belimumab 1 or 10 mg/kg every 2 weeks for 28 days and every 28 days thereafter, plus standard SLE therapy, for 76 weeks. This analysis included a subset of patients who had received pneumococcal or tetanus vaccine within 5 years or influenza vaccine within 1 year of study participation. Antibodies to vaccine antigens were tested at baseline and Week 52, and percentage changes in antibody levels from baseline and proportions of patients maintaining levels at Week 52 were assessed. Antibody titers were also assessed in a small number of patients vaccinated during the study. RESULTS: Consistent with preservation of the memory B cell compartment with belimumab treatment, the proportions of patients maintaining antibody responses to pneumococcal, tetanus, and influenza antigens were not reduced. In a small group receiving influenza vaccine on study, antibody responses were frequently lower with belimumab, although titer levels were > 1:10 in all patients treated with 10 mg/kg and in the majority treated with 1 mg/kg. CONCLUSION: Treatment with belimumab did not affect the ability of patients with SLE to maintain antibody titers to previous pneumococcal, tetanus, and influenza immunizations. [ClinicalTrials.gov registration number NCT 00410384].

Efficacy and safety of rituximab in moderately-to-severely active systemic lupus erythematosus: the randomized, double-blind, phase II/III systemic lupus erythematosus evaluation of rituximab trial.

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.

14. Immunologic rheumatic disorders.

We provide the basics for the clinician who might be called on to consider the diagnosis of diseases such as systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) in their practice. We will emphasize clinical recognition and first-line laboratory testing. Only characteristics of the classic rheumatic inflammatory diseases, RA, SLE, Sjögren syndrome, scleroderma, and dermatomyositis/polymyositis, will be covered. In the past decade, RA is the only disease for which treatment has substantially improved. The treatment of RA has been revolutionized by the use of methotrexate and, more recently, tumor necrosis factor inhibitors. The goal of RA treatment today is to induce a complete remission as early as possible in the disease process, with the mantra being "elimination of synovitis equals elimination of joint destruction." The hope is that if the major mediators of Sjögren syndrome or SLE or scleroderma can be identified and then blocked, as in the example of tumor necrosis factor inhibitors in RA, more specific treatments will become available. Thus, RA has become an excellent model of this evolving paradigm. Through the identification of major mediators in its pathogenesis, novel and highly efficacious therapeutic agents have been developed.

Dialysis-associated systemic fibrosis (nephrogenic fibrosing dermopathy): study of inflammatory cells and transforming growth factor beta1 expression in affected skin.

OBJECTIVE: Nephrogenic fibrosing dermopathy (NFD) is a newly recognized cutaneous fibrotic disorder occurring in individuals with end-stage renal disease (ESRD). The aim of the present study was to describe the clinical and histopathologic features of 9 new cases and to characterize the inflammatory cells and expression of transforming growth factor beta1 (TGFbeta1) in affected skin. METHODS: Clinical and laboratory assessments, including serology and pulmonary function studies, were performed in 9 patients undergoing long-term dialysis (8 hemodialysis; 1 peritoneal dialysis) for ESRD of diverse etiologies. Skin, fascia, striated muscles, lungs, and heart were examined by histopathology. Inflammatory cells were characterized by immunophenotyping using specific monoclonal antibodies. TGFbeta1 expression was determined by in situ hybridization. RESULTS: All patients displayed cutaneous features resembling both systemic sclerosis and diffuse fasciitis, with severe loss of motion and flexion contractures in multiple joints. Six patients displayed woody induration of the muscles of the legs, thighs, and forearms. Five of the 6 patients with lung involvement had a reduced diffusion capacity for carbon monoxide on pulmonary function testing. Marked elevations of the erythrocyte sedimentation rate and/or C-reactive protein level were found in 6 patients. Antinuclear antibodies were present at low titers in 4 patients. Histopathologic studies indicated that in addition to the dermis, the fibrotic process affected the subcutaneous tissue, fascia, striated muscles, lungs, and myocardium. Large numbers of CD68+/factor XIIIa+ dendritic cells and increased expression of TGFbeta1 were found in affected skin and muscle. CONCLUSION: Our findings indicate that the fibrotic process of NFD affects not only the dermis, but also the subcutaneous tissues, fascia, and other organs, including striated muscles, heart, and lungs. We therefore believe this is a systemic fibrosing process, and we suggest that dialysis-associated systemic fibrosis would be a better term for the condition.