Systemic Lupus Erythematosus (SLE) Responder Index response is associated with global benefit for patients with SLE.

A post-hoc analysis of pooled data from two Phase IIb trials (sifalimumab; NCT01283139, anifrolumab; NCT01438489) assessed the clinical significance of a Systemic Lupus Erythematosus (SLE) Responder Index (SRI(4)) response (Week 52) for 736 patients with moderate to severe SLE disease activity (study entry). SRI(4) responders achieved significantly greater improvements in clinical outcome measures (including percentages of patients with a ≥ 7-point reduction in SLE Disease Activity Index (SLEDAI)-2000 (2K), British Isles Lupus Assessment Group "A" or "2B" flare rate, and oral corticosteroid reduction to ≤7.5 mg/day; change from baseline in Physician's Global Assessment; and numbers of SLEDAI-2K organ domains with improvement), as well as in patient-reported outcomes (Patient's Global Assessment, Functional Assessment of Chronic Illness Therapy-Fatigue; Short-Form 36 Health Survey Physical Component Summary, Mental Component Summary, Vitality domain scores) vs. nonresponders. Of patients with abnormal serologies, SRI(4) responders had numerically greater improvements (baseline to Week 52) in anti-double-stranded DNA concentrations vs. nonresponders ( p = 0.051), but there were no differences in C3/C4 concentration changes between the two groups. These results confirm previous findings in a different cohort, indicating that an SRI(4) response is associated with global clinical benefit.

Computerized planimetry to assess clinical responsiveness in a phase II randomized trial of topical R333 for discoid lupus erythematosus.

BACKGROUND: R333 is a topical janus kinase and spleen tyrosine kinase inhibitor being evaluated for discoid lupus erythematosus (DLE) treatment. There is no validated measure to assess the area of active DLE lesions. OBJECTIVES: To evaluate R333 efficacy and assess a technique to measure responsiveness. METHODS: Fifty-four patients with DLE were randomized in a double-blind design to R333 or placebo. Primary end point was the proportion of patients achieving ≥ 50% decrease in erythema and scale based on lesional Cutaneous Lupus Erythematosus Disease Area and Severity IndexTM for all treated lesions at week 4. Two-dimensional (2D) area measurements for each lesion were recorded at baseline and weeks 1-6. Eighty-eight photographs (44 pre- and 44 post-treatment) were obtained from the trial and change in size of active areas was analysed by computerized planimetry and physician-assessed area change (PAAC). RESULTS: Thirty-six patients were randomized to R333 and 18 patients were randomized to placebo. Primary end point was not achieved. There was a strong association between lesion activity and physician global assessment (P < 0·001). Photos of 42 patients assessed by computerized planimetry demonstrated excellent inter- and intra-rater reliability. Area change by computerized planimetry showed a strong correlation with PAAC (Spearman r = 0·72). Area change by 2D measurements showed a weak correlation with PAAC (Spearman r = 0·29). CONCLUSIONS: Four weeks of R333 treatment did not result in significant improvement in lesion activity. Lesion activity and area change using computerized planimetry are better determinants of responsiveness than area change using 2D measurements.

Assessments of fatigue and disease activity in patients with systemic lupus erythematosus enrolled in the Phase 2 clinical trial with blisibimod.

This report evaluates the effects of blisibimod (A-623, AMG 623), a potent and selective inhibitor of B-cell activating factor (BAFF), on patient-reported fatigue and disease activity in the Phase 2b PEARL-SC clinical trial in patients with systemic lupus erythematosus (SLE). A total of 547 individuals who met the American College of Rheumatology (ACR) classification criteria for SLE, were positive for anti-double-stranded DNA or antinuclear antibodies, and had a Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) score ≥6 at baseline, were randomized to receive placebo or blisibimod for at least 24 weeks. Patient self-reported fatigue was evaluated using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale, and disease activity was evaluated using Physician's Global Assessment, SELENA-SLEDAI, and British Isles Lupus Assessment Group Score. Statistically significant improvements in FACIT-Fatigue score were observed among individuals randomized to blisibimod, especially in the 200 mg QW group where favorable effects on disease activity with blisibimod compared to placebo were observed as early as Week 8. The mean improvement from baseline of 6.9 points at Week 24, compared with 4.4 points with placebo, met the criteria for minimal clinically important improvement difference defined for patients with SLE. Despite concomitant improvements in FACIT-Fatigue, SLE Responder Index (SRI) and SLE biomarkers (reported previously), FACIT-Fatigue score correlated only weakly with disease activity. While poor correlation between fatigue and disease activity is not new, the observation that correlation remains poor despite concurrent population improvements in disease and fatigue brings a new facet to our understanding of SLE.

T-cell-directed therapies in systemic lupus erythematosus.

Drug development for the treatment of systemic lupus erythematosus (SLE) has largely focused on B-cell therapies. A greater understanding of the immunopathogenesis of SLE coupled with advanced bioengineering has allowed for clinical trials centered on other targets for SLE therapy. The authors discuss the benefits and shortcomings of focusing on T-cell-directed therapies in SLE and lupus nephritis clinical trials.

Long-Term Safety and Efficacy of Epratuzumab in the Treatment of Moderate-to- Severe Systemic Lupus Erythematosus: Results From an Open-Label Extension Study.

OBJECTIVE: The primary objective was to assess the long-term safety of repeated courses of epratuzumab therapy in patients with moderate-to-severe systemic lupus erythematosus. Secondary objectives were to assess long-term efficacy and health-related quality of life (HRQOL). METHODS: Eligible patients from the 12-week, phase IIb, randomized, placebo-controlled EMBLEM study enrolled into the open-label extension (OLE) study, SL0008. In the SL0008 study, patients received 1,200 mg epratuzumab infusions at weeks 0 and 2 of repeating 12-week cycles, plus standard of care. Safety measures included treatment-emergent adverse events (TEAEs) and serious TEAEs. Efficacy measures included combined treatment response, the British Isles Lupus Assessment Group score, the Systemic Lupus Erythematosus Disease Activity Index score, and the physician's and patient's global assessment of disease activity. Total daily corticosteroid dose and HRQOL (by the Short Form 36 health survey) were also assessed. RESULTS: A total of 113 of the 203 patients (55.7%) who entered the SL0008 study continued epratuzumab therapy until study closure (total cumulative exposure: 381.3 patient-years, median exposure: 845 days, and maximum exposure: 1,185 days/approximately 3.2 years). TEAEs were reported in 192 patients (94.6%); most common were infections and infestations (68.0%, 138 patients). Serious TEAEs were reported in 51 patients (25.1%), and 14 patients (6.9%) had serious infections. In patients treated for 108 weeks (n = 116), the median corticosteroid dose was reduced from 10.0 mg/day at OLE screening to 5.0 mg/day at week 108. Improvements in efficacy and HRQOL measures in EMBLEM were maintained in the OLE, while placebo patients exhibited similar improvements in disease activity upon a switch to epratuzumab. CONCLUSION: Open-label epratuzumab treatment was well tolerated for up to 3.2 years, and associated with sustained improvements in disease activity and HRQOL, while steroids were reduced.

Efficacy and safety of subcutaneous tabalumab, a monoclonal antibody to B-cell activating factor, in patients with systemic lupus erythematosus: results from ILLUMINATE-2, a 52-week, phase III, multicentre, randomised, double-blind, placebo-controlled study.

OBJECTIVES: To evaluate the efficacy and safety of tabalumab, a human IgG4 monoclonal antibody that neutralises membrane and soluble B-cell activating factor (BAFF). METHODS: This randomised, placebo-controlled study enrolled 1124 patients with moderate-to-severe systemic lupus erythematosus (SLE) (Safety of Estrogens in Lupus Erythematosus National Assessment- SLE Disease Activity Index ≥6 at baseline). Patients received standard of care plus subcutaneous study drug, starting with a loading dose (240 mg) at week 0 and followed by 120 mg every 2 weeks (120 Q2W), 120 mg every 4 weeks (120 Q4W) or placebo. Primary endpoint was proportion achieving SLE Responder Index 5 (SRI-5) improvement at week 52. RESULTS: Clinical characteristics were balanced across groups. The primary endpoint was met with 120 Q2W (38.4% vs 27.7%, placebo; p=0.002), but not with the less frequent 120 Q4W regimen (34.8%, p=0.051). Although key secondary endpoints (time to severe flare, corticosteroid sparing and fatigue) were not met, patients treated with tabalumab had greater SRI-5 response rates in a serologically active subset and improvements in more stringent SRI cut-offs, SELENA-SLEDAI, Physician's Global Assessment, anti-double-stranded DNA antibodies, complement, total B cells and immunoglobulins. The incidences of deaths, serious adverse events (AEs), and treatment-emergent AEs were similar in the 120 Q2W, 120 Q4W and placebo groups, but depression and suicidal ideation, albeit rare events, were more commonly reported with tabalumab. CONCLUSION: SRI-5 was met with 120 Q2W and although key secondary endpoints were not met, numerous other secondary endpoints significantly improved in addition to pharmacodynamic evidence of BAFF pathway blockade. The safety profile for tabalumab was similar to placebo, except for depression and suicidality, which were uncommon. TRIAL REGISTRATION NUMBER: NCT01205438.

A phase 2, randomised, placebo-controlled clinical trial of blisibimod, an inhibitor of B cell activating factor, in patients with moderate-to-severe systemic lupus erythematosus, the PEARL-SC study.

OBJECTIVE: To evaluate the efficacy and safety of subcutaneous blisibimod, an inhibitor of B cell activating factor, in patients with systemic lupus erythematosus (SLE) in a dose-ranging Phase 2b clinical trial. METHODS: 547 patients with SLE with anti-double stranded DNA or antinuclear antibodies and Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) score ≥6 at baseline were randomised to receive placebo or blisibimod at one of 3 dose levels. The primary end point, measured at Week 24, was the SLE Responder Index-5 (SRI-5, meeting established SRI criteria but with ≥5 point improvement in SELENA-SLEDAI). RESULTS: Although SRI-5 response rates were not significantly improved in the pooled blisibimod groups compared with placebo, they were higher in subjects randomised to the highest dose of blisibimod (200 mg once-weekly (QW)) compared with pooled placebo, from Week 16 to Week 24, reaching statistical significance at Week 20 (p=0.02). SRI response rates compared with placebo were higher still in subjects who attained SELENA-SLEDAI improvements of ≥8, and in a subgroup of patients with severe disease (SELENA-SLEDAI ≥10 and receiving corticosteroids at baseline). In subjects with protein:creatine ratios of 1-6 at baseline, significant reductions in proteinuria were observed with blisibimod. Significant (p<0.01) changes in anti-double stranded DNA antibodies, complement C3 and C4, and reductions in B cells were observed with blisibimod.No imbalances in serious adverse events or infections (4/280 and 3/266), deaths (4/280 and 3/266) and malignancies (2/280 and 2/266) were reported for blisibimod compared with placebo. CONCLUSIONS: This study successfully identified a safe, effective and convenient dose, study population and end point for evaluation of blisibimod effect in Phase 3. TRIAL REGISTRATION NUMBER: NCT01162681.

Breaking the ice in systemic lupus erythematosus: belimumab, a promising new therapy.

B lymphocyte stimulator (BLyS), a protein discovered in the 1990s that induces B cell proliferation and differentiation, promotes B cell survival, and is important in immunoglobulin class switching, was the target of a drug development program launched by Human Genome Sciences in the early part of the last decade. Belimumab, a human monoclonal antibody specific for soluble BLyS, was ultimately approved by the United States Food and Drug Administration (FDA) in March 2011 for active autoantibody patients with systemic lupus erythematosus (SLE) despite standard therapy. This program, whose studies spanned approximately 10 years from phase I through phase III, was founded on sound biology and advanced on logic and perseverance. Pre-clinical experimentation in murine models of SLE as well as observational studies in human SLE provided sufficient evidence to support the use of an inhibitor of BLyS as a novel therapy to reduce SLE disease activity. Progressing from phase I through a robust phase III program was no easy task given the complexities of SLE trial design. These challenges were overcome with the implementation of strict study entry requirements, the development of a novel responder index, and rigorous rules regarding background therapies. The success of two phase III studies and the approval of belimumab by the US Food and Drug Administration represent an unprecedented milestone in the history of SLE drug development. Belimumab was the first drug approved in SLE in over 50 years and was the first drug ever approved in SLE through the conventional route of randomized controlled trials. This article reviews the biology of BLyS, clinical trial results, and some of the emerging data from the robust phase II and III datasets.

Safety profile of belimumab: pooled data from placebo-controlled phase 2 and 3 studies in patients with systemic lupus erythematosus.

Safety data were pooled and analyzed from one phase 2 and two phase 3 double-blind, placebo-controlled, repeat-dose systemic lupus erythematosus (SLE) trials of belimumab 1, 4 (phase 2 only), and 10 mg/kg. Types and rates of adverse events (AEs) were similar across treatment groups. Rates of patients experiencing any serious AE were 16.6%, 19.5%, 13.5%, and 18.0% with placebo, and belimumab 1, 4, and 10 mg/kg, respectively; rates of serious infusion reactions (including hypersensitivity reactions) occurring on the same days as infusions were 0.4%, 0.9%, 0%, and 0.9%, and rates of serious infections were 5.5%, 7.1%, 6.3%, and 5.3%. Malignancy rates/100 patient-years (excluding non-melanoma skin cancer) were 0.29 with placebo vs. 0.20 with all belimumab doses combined; mortality rates/100 patient-years were 0.43 vs. 0.73. These data support the conclusion that belimumab in combination with standard SLE therapy was generally well tolerated in a predominantly autoantibody-positive population with active SLE.

Improvement in patient-reported outcomes in a rituximab trial in patients with severe rheumatoid arthritis refractory to anti-tumor necrosis factor therapy.

OBJECTIVE: To assess the effects of treatment with rituximab plus methotrexate on patient-reported outcomes in patients with active rheumatoid arthritis (RA) who experienced inadequate response to anti-tumor necrosis factor therapy. METHODS: Patients with active RA were randomly assigned to rituximab (1,000 mg on days 1 and 15) or placebo. The primary end point was the proportion of patients with an American College of Rheumatology 20% response at week 24. Additional goals were to assess treatment effects on pain, fatigue, functional disability, health-related quality of life, and disease activity by comparing mean changes between groups. The analysis was conducted in the intent-to-treat population. The proportion of patients who achieved the minimum clinically important difference on the Health Assessment Questionnaire (HAQ) disability index (DI), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), and Short Form 36 (SF-36) was determined. RESULTS: Rituximab patients had statistically significantly greater pain relief. The FACIT-F showed significantly greater improvement in rituximab patients than placebo patients from weeks 12 through 24. Mean improvement from baseline in functional disability (measured by the HAQ DI) was significantly greater in rituximab patients from weeks 8 to 24. The mean +/- SD change from baseline for the SF-36 Physical Component Score was 6.64 +/- 8.74 for rituximab patients and 1.48 +/- 7.32 for placebo patients (P < 0.0001). The mean change from baseline for the SF-36 Mental Component Score was 5.32 +/- 12.41 for rituximab patients and 2.25 +/- 12.23 for placebo patients (P = 0.0269). CONCLUSION: Rituximab produced rapid, clinically meaningful, and statistically significant improvements in patient-reported pain, fatigue, functional disability, health-related quality of life, and disease activity. These effects were sustained throughout the study.

Peripheral blood gene expression profiling in rheumatoid arthritis.

We carried out gene expression profiling of peripheral blood mononuclear cells (PBMCs) in 29 patients with active rheumatoid arthritis (RA) and 21 control subjects using Affymetrix U95Av2 arrays. Using cluster analysis, we observed a significant alteration in the expression pattern of 81 genes (P<0.001) in the PBMCs of RA patients compared with controls. Many of these genes correlated with differences in monocyte counts between the two study populations, and we show that a large fraction of these genes are specifically expressed at high levels in monocytes. In addition, a logistic regression analysis was performed to identify genes that performed best in the categorization of RA and control samples. Glutaminyl cyclase, IL1RA, S100A12 (also known as calgranulin or EN-RAGE) and Grb2-associated binding protein (GAB2) were among the top discriminators. Along with previous data, the overexpression of S100A12 in RA patients emphasizes the likely importance of RAGE pathways in disease pathogenesis. The altered expression of GAB2, an intracellular adaptor molecule involved in regulating phosphatase function, is of particular interest given the recent identification of the intracellular phosphatase PTPN22 as a risk gene for RA. These data suggest that a detailed study of gene expression patterns in peripheral blood can provide insight into disease pathogenesis. However, it is also clear that substantially larger sample sizes will be required in order to evaluate fully gene expression profiling as a means of identifying disease subsets, or defining biomarkers of outcome and response to therapy in RA.

Improvement in health-related quality of life in systemic lupus erythematosus patients enrolled in a randomized clinical trial comparing LJP 394 treatment with placebo.

In a 76-week, randomized controlled trial, patients received 100 mg LJP 394 or placebo weekly for 16 weeks followed by three 12-week treatment cycles of 50 mg LJP 394 or placebo weekly each separated by eight-week periods when no therapy was administered. Health-related quality of life (HRQOL) was assessed using SF-36 at baseline, 16 weeks and every 12 weeks thereafter. Analyses populations included intent to treat (ITT) (n = 179) and patients with high-affinity anti-dsDNA antibody binding (HA): 157/179; 85% active, 90% placebo. In the ITT population, there were improvements in role emotional (RE) (+7.3 versus -8.2), social functioning (SF) (+4.3 versus +0.7), and role physical (RP) (+11.3 versus +6.0) domains in the active treatment group when compared with placebo, with similar changes observed in the HA population. In 37 patients with data pre- and post-renal flares, those receiving LJP 394 reported stabilization or improvement in all but one domain compared with deterioration in all domains with placebo. Changes in RE domain scores following a flare differed by 22.7 points between the two treatment groups, favouring LJP 394 treatment. Patients receiving LJP 394 reported stable or improved HRQOL with active treatment following renal flares compared with deterioration in placebo. Differences between treatment groups in RE and SF domains are clinically important and were replicated irrespective of the protocol population analysed.

High mobility group box chromosomal protein 1: a novel proinflammatory mediator in synovitis.

OBJECTIVE: High mobility group box chromosomal protein 1 (HMGB-1) is a ubiquitous chromatin component expressed in nucleated mammalian cells. It has recently and unexpectedly been demonstrated that stimulated live mononuclear phagocytes secrete HMGB-1, which then acts as a potent factor that causes inflammation and protease activation. Macrophages play pivotal roles in the pathogenesis of arthritis. The aim of this study was to determine whether synovial macrophage expression of HMGB-1 is altered in human and experimental synovitis. METHODS: Intraarticular tissue specimens were obtained from healthy Lewis rats, Lewis rats with Mycobacterium tuberculosis-induced adjuvant arthritis, and from patients with rheumatoid arthritis (RA). Specimens were immunohistochemically stained for cellular HMGB-1. Extracellular HMGB-1 levels were assessed in synovial fluid samples from RA patients by Western blotting. RESULTS: Immunostaining of specimens from normal rats showed that HMGB-1 was primarily confined to the nucleus of synoviocytes and chondrocytes, with occasional cytoplasmic staining and no extracellular matrix deposition. In contrast, inflammatory synovial tissue from rats with experimental arthritis as well as from humans with RA showed a distinctly different HMGB-1 staining pattern. Nuclear HMGB-1 expression was accompanied by a cytoplasmic staining in many mononuclear cells, with a macrophage-like appearance and an extracellular matrix deposition. Analysis of synovial fluid samples from RA patients further confirmed the extracellular presence of HMGB-1; 14 of 15 samples had HMGB-1 concentrations of 1.8-10.4 microg/ml. CONCLUSION: The proinflammatory mediator HMGB-1 was abundantly expressed as a nuclear, cytoplasmic, and extracellular component in synovial tissues from RA patients and from rats with experimental arthritis. These findings suggest a pathogenetic role for HMGB-1 in synovitis and indicate a new potential therapeutic target molecule.

Pre-treatment affinity for LJP 394 influences pharmacodynamic response in lupus patients.

Five prospective clinical studies in lupus patients have shown that LJP 394 can reduce circulating anti-dsDNA antibody levels without causing generalized immunosuppression. The compound is currently being evaluated in a phase III clinical trial for the prevention of renal flares in patients with high-affinity antibodies to LJP 394 and a history of lupus nephritis. The current study analyzed the affinity of patient IgG for LJP 394 prior to and following 4 months of treatment with LJP 394 to determine if pretreatment affinity influenced pharmacodynamic response. Patient serum samples from a multicenter, double-blind, placebo-controlled trial were evaluated prior to and following 4 months of weekly, biweekly or monthly treatment with placebo (n = 9) or weekly treatment with 10 mg LJP 394 (n = 6) or 50 mg LJP 394 (n = 4). After treatment there was a dose-dependent reduction in affinity in the 10 mg/week and 50 mg/week groups (P < 0.05 and P < 0.01, respectively), whereas the placebo group was unchanged. This study demonstrates that weekly treatment with LJP 394 produces a dose-dependent reduction in titer-weighted average affinity. These results suggest it may be possible to use an affinity assay to define prospectively patients that are most likely to exhibit the desired pharmacodynamic response to LJP 394.

Beta2-glycoprotein I-dependent anticardiolipin antibodies preferentially bind the amino terminal domain of beta2-glycoprotein I.

Many of the autoantibodies in antiphospholipid syndrome (APS) are directed against beta2-glycoprotein I (beta2-GPI). Recent studies from our laboratories have indicated that the immunodominant binding epitope(s) for high titer, affinity purified antibodies from 11 APS patients are localized to the amino terminal domain (domain 1) of beta2-GPI. The present study employed surface plasmon resonance to localize the immunodominant domain in serum samples from a large cohort of patients with GPL values ranging from 21 to 230 units (n = 106 patients). Eighty-eight percent of patients showed > or = threefold selectivity for beta2-GPI containing domain 1 relative to the domain deletion mutant that lacked domain 1. The domain 1 binding activity in patient serum was abolished by removing the IgG fraction from the serum and the binding activity could be fully reconstituted with the IgG fraction. Thus, analysis of serum samples from a large cohort of APS patients indicates that the immunodominant binding epitope(s) for anti-beta2 antibodies are localized to the amino terminal domain of beta2-GPI.

Treatment of systemic lupus erythematosus with LJP 394.

OBJECTIVE: LJP 394 is a novel therapy under development for the treatment of systemic lupus erythematosus (SLE). We investigated the optimal LJP 394 dosing regimen required to maximally reduce serum dsDNA antibodies. We also evaluated the safety and tolerability of repeated doses of LJP 394 as well as the effects of therapy on SLE related disease activity and health related quality of life. METHODS: This was a multicenter, partially randomized, placebo controlled, double blind, dose-ranging trial. Study drug or placebo was administered at weekly, biweekly, or monthly intervals for a total of 17, 9, or 5 doses, respectively. Fifty-eight patients were randomly assigned to receive 1, 10, or 50 mg LJP 394 or placebo. After a 2 month pretreatment period, dosing visits continued for 16 weeks, after which there was a 2 month posttreatment period. RESULTS: The greatest reductions in mean dsDNA antibody titers were observed in the group of patients who received 50 mg LJP 394 weekly (38.1% and 37.1 % at Weeks 16 and 24, respectively). A reduction (29.3%) in dsDNA antibody titers was also observed at Week 24 in the group of patients who received 10 mg LJP 394 weekly. The frequencies of adverse events were comparable in the placebo and active treatment groups. CONCLUSION: This clinical trial, in which a large number of patients with SLE were treated with LJP 394, expanded the safety profile of LJP 394 and demonstrated its capacity to reduce dsDNA antibodies.

Dehydroepiandrosterone and biologics in the treatment of systemic lupus erythematosus.

Our understanding of the immune system in health and disease has greatly increased over this past decade. An outgrowth of this burgeoning knowledge has been the discovery of novel strategies to treat a variety of autoimmune diseases. As a result, significant advances have been made in the treatment of arthritis with a half-dozen new treatments approved between September, 1998 and November, 1999. Although no new therapies have been approved for the treatment of systemic lupus erythematosus (SLE), this decade has witnessed an unprecedented amount of activity in drug development for this disease. This article specifically addresses the current status of drug development in the area of hormonal and biologic therapies for SLE.

Immunoglobulin heavy chain variable region gene replacement As a mechanism for receptor revision in rheumatoid arthritis synovial tissue B lymphocytes.

Mature B cells can alter their antibody repertoires by several mechanisms, including immunoglobulin heavy chain variable region (V(H)) replacement. This process changes the antigen combining site by replacing a portion of the original V(H)/diversity/heavy chain joining region (V(H)DJ(H)) rearrangement with a corresponding portion of a new V(H) segment. This exchange can involve cryptic heptamer-like sequences embedded in the coding regions of V(H) genes. While studying the B lymphocytes that expand in the synovial tissues of patients with rheumatoid arthritis (RA), clones with V(H)DJ(H) variants that were apparently generated by V(H) replacement were identified with surprising frequency (approximately 8%). Examples of multiple independent V(H) replacement events occurring in distinct progeny clones were also identified. These secondary V(H) rearrangements were documented at both the cDNA and genomic DNA levels and involved several heptamer-like sequences at four distinct locations within V(H) (three sites in framework region 3 and one in complementarity determining region 2). The identification of blunt-ended double-stranded DNA breaks at the embedded heptamers and the demonstration of recombinase activating gene (RAG) expression suggested that these rearrangements could occur in the synovial tissues, presumably in pseudo-germinal centers, and that they could be mediated by RAG in a recognition signal sequence-specific manner. The presence of V(H) mutations in the clones that had undergone replacement indicated that these B cells were immunocompetent and could receive and respond to diversification signals. A relationship between these secondary V(H) gene rearrangements and the autoimmunity characteristic of RA should be considered.

Clonal expansion is a characteristic feature of the B-cell repetoire of patients with rheumatoid arthritis.

The present study was designed to analyze the level of B-cell clonal diversity in patients with rheumatoid arthritis by using HCDR3 (third complementarity determining region of the rearranged heavy chain variable region gene) length as a marker. A modified immunoglobulin VH gene fingerprinting method using either genomic DNA or complementary (c)DNA derived from B cells of the peripheral blood, synovial fluid, and tissues of several rheumatoid arthritis patients was employed. These assays permitted the detection and distinction of numerically expanded B-cell clones from activated but not numerically expanded B-cell clones. The present data suggest that B-cell clonal expansion is a common and characteristic feature of rheumatoid arthritis and that it occurs with increasing frequency from the blood to the synovial compartments, resulting in a narrowing of the clonal repertoire at the synovial level. These clonal expansions can involve resting, apparently memory B cells, as well as activated B cells. Furthermore, some of these individual expansions can persist over extended periods of time. These findings support the hypothesis that a chronic ongoing (auto)immune reaction is operative in rheumatoid arthritis and that this reaction, at least at the B-cell level, may be unique to each individual joint. A determination of the targets of these autoimmune reactions may provide valuable clues to help understand the immunopathogenesis of this disease

A role for the polymorphism at position 247 of the beta2-glycoprotein I gene in the generation of anti-beta2-glycoprotein I antibodies in the antiphospholipid syndrome.

OBJECTIVE: To determine the frequencies at which either a valine or leucine occurs at position 247 in the beta2-glycoprotein I (beta2GPI) gene of normal individuals of the Caucasian, African American, and Asian ethnic groups and to compare these data with those in patients with the antiphospholipid syndrome (APS), with and without anti-beta2GPI antibodies. METHODS: The DNA segment containing the position-247 polymorphism was amplified by seminested polymerase chain reaction, and the polymorphism was detected by restriction endonuclease digestion. DNA samples from 370 healthy controls of different racial backgrounds were analyzed, and the results were compared with those from 149 APS patients (66 primary; 83 secondary). Allele and genotype frequencies were compared using Fisher's exact test. When significant differences were detected, pairwise comparisons were made using Fisher's exact test with a Bonferroni adjustment. RESULTS: Allele and genotype expression was significantly different (P < 0.0001 for both) among the 3 races, with the V allele and the VV genotype occurring most often among Caucasians, less among African Americans, and least among Asians. Conversely, the V allele and the VV genotype were found more frequently among Asian APS patients than among controls (P = 0.0028 and P = 0.0023, respectively). No significant differences in allele or genotype frequencies were seen in comparisons of the Caucasian or the African American patients with appropriate controls. The differences in allele and genotype frequencies seen in the Asian APS patients were restricted to the anti-beta2GPI-positive patients (P = 0.0018 and P = 0.0005, respectively). CONCLUSION: In Asian patients with APS, expression of a V at position 247, especially in the homozygous state, is significantly associated with the presence of anti-beta2GPI antibodies and, therefore, can be viewed as a major risk factor in this ethnic group (odds ratio 9.19 and 16.33, respectively).