Decreases in anti-double-stranded DNA levels are associated with concurrent flares in patients with systemic lupus erythematosus

Concentration of antibodies to extractable nuclear antigens and disease activity in systemic lupus erythematosus

A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-extractable nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2–9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration ( r = 0.57, NS), but no relation with the other anti-ENA antibodies. In a small number of patients, there appeared to be either a positive (Ro, Sm) or negative (La, Sm, RNP) association between ENA antibody concentration and disease activity over time; however, this was not apparent for the majority of individuals. These results show that in SLE, clinically significant changes in disease activity do not correlate well with concentrations of anti-ENA antibodies, either within the population as a whole or on an individual basis. Repeated quantitative measurement of anti-ENA antibodies does not therefore appear to provide useful additional information in assessing disease activity in SLE. The widespread application of commercial quantitative assays to routine clinical practice is not recommended.

Mycophenolate mofetil is effective in reducing disease flares in systemic lupus erythematosus patients: a retrospective study

Mycophenolate mofetil (MMF) is effective in the treatment of patients with active systemic lupus erythematosus (SLE). We sought to evaluate its efficacy in reducing the number of disease flares in adults with SLE. For this retrospective study, all patients seen at our institution over a six year period, 1999–2005, with the diagnosis of SLE treated with MMD were identified. Data regarding lupus flare was obtained for patients at least one and up to two years prior to starting MMF. The number of flares prior to MMF therapy was compared to the number of lupus flares in the one to two year period after starting MMF. Clinical assessment was performed with the SELENA-SLEDAI instrument. Differences between groups were compared using the signed rank test. The rate of flares (flares per person-year), before and after the introduction of MMF were compared assuming the occurrence of flares followed a Poisson distribution. In the evaluable 67 patients, the mean time period of followup prior to starting MMF was 14.1 months (range 0.3–24), mean time period of follow-up after starting MMF was 14.8 months (range 1.5–24); and mean MMF dose was 1328 mg/day (range 250–3000). The mean flare rate was reduced from 8.9 to 5.3 per 10 personyears and the mean prednisone dose was reduced on average 7.3 mg/day after starting MMF therapy. MMF treatment significantly reduced the total number of lupus flares and prednisone requirements. Even with the reduction in mean daily prednisone dose, both the SLEDAI and physican global assessment also improved during MMF therapy.

Abetimus sodium for renal flare in systemic lupus erythematosus: results of a randomized, controlled phase III trial

OBJECTIVE

To investigate whether treatment with abetimus delays renal flare in patients with lupus nephritis. Secondary objectives included evaluation of the effect of abetimus on C3 levels, anti-double-stranded DNA (anti-dsDNA) antibody levels, use of high-dose corticosteroids and/or cyclophosphamide, and major systemic lupus erythematosus (SLE) flare.

METHODS

We conducted a randomized, placebo-controlled study of treatment with abetimus at 100 mg/week for up to 22 months in SLE patients. Three hundred seventeen patients with a history of renal flare and anti-dsDNA levels >15 IU/ml were randomized to a treatment group (158 abetimus, 159 placebo); 298 (94%) were enrolled in the intent-to-treat (ITT) population (145 abetimus, 153 placebo), based on the presence of high-affinity antibodies for the oligonucleotide epitope of abetimus at baseline screening.

RESULTS

Abetimus did not significantly prolong time to renal flare, time to initiation of high-dose corticosteroid and/or cyclophosphamide treatment, or time to major SLE flare. However, there were 25% fewer renal flares in the abetimus group compared with the placebo group (17 of 145 abetimus-treated patients [12%] versus 24 of 153 placebo-treated patients [16%]). Abetimus treatment decreased anti-dsDNA antibody levels (P < 0.0001), and reductions in anti-dsDNA levels were associated with increases in C3 levels (P < 0.0001). More patients in the abetimus group experienced > or =50% reductions in proteinuria at 1 year, compared with the placebo group (nominal P = 0.047). Trends toward reduced rates of renal flare and major SLE flare were noted in patients treated with abetimus who had impaired renal function at baseline. Treatment with abetimus for up to 22 months was well tolerated.

CONCLUSION

Abetimus at 100 mg/week significantly reduced anti-dsDNA antibody levels but did not significantly prolong time to renal flare when compared with placebo. Multiple positive trends in renal end points were observed in the abetimus treatment group.

Pharmacokinetics of high-dose abetimus sodium in normal subjects with specific assessment of effect on coagulation

Abetimus sodium is an oligonucleotide-based investigational drug designed to treat patients with lupus nephritis by specifically reducing anti-double-stranded DNA antibody levels. The safety and pharmacokinetics of abetimus were evaluated in 24 healthy volunteers at intravenous doses of 600 mg, 1200 mg, and 2400 mg. The mean half-life ranged from 0.8 to 1.5 hours. Maximum exposure assessed by maximum observed plasma concentration was dose proportional. Total exposure assessed by area under the plasma concentration-time curve was dose proportional between 1200-mg and 2400-mg doses and greater than proportionate between the 600-mg and 1200-mg doses. Abetimus was well tolerated in all dose groups, with adverse events observed in 33.3% (2/6) of placebo subjects and 16.7% (3/18) subjects receiving abetimus. No clinically significant effects were observed on laboratory values, vital signs, or electrocardiogram, with the exception of a transient, dose-dependent, prolongation in activated partial thromboplastin time. In vitro coagulation studies suggested that the effect on activated partial thromboplastin time was attributable to a nonspecific interaction rather than specific factor depletion. Exposure to abetimus at intravenous doses of 600 mg, 1200 mg, and 2400 mg was well tolerated. Total exposure assessed by area under the plasma concentration-time curve was greater than dose proportional across the dose range of 600 mg to 2400 mg.

Lymphocytotoxic antibodies in systemic lupus erythematosus are associated with disease activity irrespective of the presence of neuropsychiatric manifestations

OBJECTIVES

To evaluate the association of the presence of lymphocytotoxic, anti-beta2-glycoprotein I (anti-beta2-GPI) and anti-ribosomal P (anti-P) antibodies in patients with systemic lupus erythematosus (SLE), presenting or not neuropsychiatric (NP) manifestations, stratified according to the activity of the disease.

METHODS

A total of 138 patients with SLE (59 with active NPSLE, 49 with active non-NPSLE, and 30 with inactive disease) and 57 healthy controls were studied. Disease activity was assessed by the SLE Disease Activity Index (SLEDAI). The presence of lymphocytotoxic antibodies was assessed using a complement-dependent lymphocytotoxicity assay. The presence of anti-beta2-GPI and anti-P antibodies was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Lymphocytotoxic antibodies were detected primarily in patients with active disease, that is in 35 out of 59 (59.3%) NPSLE and 23 out of 49 (46.9%) non-NPSLE patients, whereas only four out of 30 (13.3%) inactive SLE patients and none of the healthy controls exhibited the autoantibody. The frequency of lymphocytotoxic antibodies in active SLE patients, considered as a whole or stratified into NPSLE or non-NPSLE, was significantly increased in relation to inactive SLE patients (p<0.001 for each comparison). No significant difference was observed when comparing active NPSLE with non-NPSLE patients. No associations were observed between the presence of anti-beta2-GPI or anti-P antibodies and the activity of SLE or the presence of lymphocytotoxic antibodies.

CONCLUSIONS

Lymphocytotoxic antibodies occurred more frequently in patients with active SLE than in patients with inactive disease, irrespective of the presence of NP manifestations, a finding that is similar to classical biomarkers of lupus activity (anti-dsDNA and complement). These results indicate that the assessment of the presence of lymphocytotoxic antibodies may be an additional useful tool for the evaluation of SLE activity.

Disease activity assessment in SLE: do we have the right instruments?

No new therapy has been approved for systemic lupus erythematosus (SLE) in decades. Interest in SLE by pharmaceutical and biotechnology companies has increased, leading to multiple clinical trials. Unfortunately, we have now compiled quite a long list of "failed" trials. If this was due to the fact that the studied therapy did not work in SLE, we could accept it and move on. Of concern, however, is that many of the "failed" treatments had a strong "signal" of efficacy, often in subgroup analyses that made logical sense, given what was known about the mechanism of action of the treatment. This has led, understandably, to concern that there is something wrong with SLE trial designs, particularly with SLE disease activity indices.

Monitoring systemic lupus erythematosus in standard clinical care

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with a fluctuating and unpredictable course. Monitoring SLE in the routine clinic setting is a challenge because both the disease and its treatment can result in organ damage. Disease activity indices and a cumulative history summary can be used to track complicated patients over time. Monitoring guidelines for damage from the disease and for the toxicity of treatment are available.

Quantitation of autoantibodies in systemic autoimmune diseases: clinically useful?

Serial assessment of levels of autoantibodies has been proposed as being clinically useful in certain systemic autoimmune diseases. In particular, attention has been given to anti-dsDNA antibodies in systemic lupus erythematosus (SLE) and ANCA in the ANCA-associated vasculitides (AAV). Much controversy exists, however, concerning the value of serial testing in these diseases. We here review the various tests available for quantitation of anti-dsDNA and ANCA, and their capacity to detect changes in autoantibody levels that are associated with changes in clinical disease activity of the respective diseases. It is concluded that changes in anti-dsDNA as measured by the Farr assay and changes in ANCA as assessed by ELISA have predictive value for the occurrence of disease relapses, although this relationship is far from absolute. Consequently, treatment based on changes in levels of the respective autoantibodies only seems at present not justified, in view of the toxicity of currently available immunosuppressive regimens.

The effect of moderate-dose corticosteroids in preventing severe flares in patients with serologically active, but clinically stable, systemic lupus erythematosus: findings of a prospective, randomized, double-blind, placebo-controlled trial

OBJECTIVE

Serial measurements of anti-double-stranded DNA (anti-dsDNA) and complement are routine in the management of systemic lupus erythematosus (SLE), but their utility as biomarkers in preemptive treatment to prevent flares remains a subject of controversy. We hypothesized that concomitant elevation of anti-dsDNA and C3a can predict SLE activity in patients with stable or inactive disease and that short-term treatment with corticosteroids can avert flares.

METHODS

In this prospective, randomized, double-blind, placebo-controlled trial, 154 patients were evaluated monthly for up to 18 months, with measurements of C3a, C3, C4, CH50, and anti-dsDNA levels. Patients who remained clinically stable but showed serologic evidence of an SLE flare (elevation of both the anti-dsDNA level by 25% and the C3a level by 50% over the previous 1-2 monthly visits) were randomized to receive either prednisone or placebo therapy at a dosage of 30 mg/day for 2 weeks, 20 mg/day for 1 week, and 10 mg/day for 1 week.

RESULTS

Forty-one patients (21 randomized to prednisone and 20 randomized to placebo) experienced a serologic flare. Analysis of severe flares occurring <or=90 days from randomization revealed that 6 occurred in patients taking placebo and none occurred in patients taking prednisone (P = 0.007). Severe flares resulted in an increase in the prednisone dosage to >40 mg/day and/or the addition of an immunosuppressive agent. Furthermore, improvement in scores on the Systemic Lupus Erythematosus Disease Activity Index, decreased levels of anti-dsDNA antibodies, and increased levels of C4 occurred 1 month after initiation of prednisone treatment.

CONCLUSION

These preliminary data support our hypothesis that in a subset of clinically stable SLE patients with a combination of elevated C3a and anti-dsDNA levels, short-term corticosteroid therapy may avert a severe flare.

Systemic lupus erythematosus in a multiethnic cohort: LUMINA XXXV. Predictive factors of high disease activity over time

AIM

To ascertain the predictive factors of high levels of disease activity in systemic lupus erythematosus (SLE).

PATIENTS AND METHODS

Patients with SLE (American College of Radiology criteria), aged >or=16 years, with disease duration <or=5 years and of Hispanic (Texas and Puerto Rico), African American and Caucasian ethnicities, were included. The outcome was high disease activity at any time (Systemic Lupus Activity Measure-Revised >10). A basic multivariable model (including age, sex, ethnicity, health insurance, social support, abnormal illness-related behaviours, helplessness and prior disease activity) was first examined. Additional models were built by including other variables.

RESULTS

554 patients (100 Hispanics from Texas, 94 Hispanics from Puerto Rico, 199 African Americans, 161 Caucasians) and 2366 visits were analysed; 47% of the patients and 29% of the visits met the definition of high disease activity (more common among African Americans (72.0%) and Hispanics from Texas (71.3%) than among Caucasians (43.9%) and Hispanics from Puerto Rico (31.9%)). Variables found to predict high levels of disease activity were Hispanic (from Texas) and African American ethnicities, lack of health insurance, helplessness, abnormal illness-related behaviours and poor social support; age was negatively associated with high levels of disease activity. African admixture and anti-double-stranded DNA antibodies also predicted high levels of disease activity, as did prior disease activity. None of the human leucocyte antigen variables were retained in the models.

CONCLUSIONS

Socioeconomic-demographic (age, ethnicity, health insurance), behavioural and psychological variables are important mediators of high levels of disease activity in SLE during its course. Interventions aimed at modifiable factors may improve the outcomes of SLE.

Lessons learned from clinical trials in SLE

It is difficult to assess outcomes in randomized controlled trials in SLE. Its cyclic nature and multiorgan involvement complicate the identification and reproducibility of outcome measures. Disease activity indices do not necessarily reflect disease outcome in the generally short timeframes of protocol treatment. Patient and physician assessments of disease may not correlate well. Responder analyses do not function well if they are proposed in the absence of data from RCTs. Changes in medical practice may affect patient selection and make it difficult to replicate findings in a subsequent protocol. Background therapy even if stable during protocol participation may confound treatment effects. While objective outcome measures are well defined in renal and hematologic disease, few SLE patients have isolated organ system involvement at any one time. Protocol designs must anticipate changes in disease activity and need for treatment of emergent disease manifestations. Despite these difficulties, a body of evidence derived from RCTs has developed. Although limited and yet to result in an approved therapy, early markers of treatment response have been defined and shown to correlate with longer term clinical outcomes. Biomarkers are an appealing idea to assess biologic effects of study treatment and hopefully predict clinical outcome.

Abetimus sodium: a new therapy for delaying the time to, and reducing the incidence of, renal flare and/or major systemic lupus erythematosus flares in patients with systemic lupus erythematosus who have a history of renal disease

The safety and efficacy of abetimus sodium (abetimus) has been evaluated in 13 controlled and uncontrolled clinical trials involving > 800 patients or subjects. The two pivotal trials enrolled a total of 547 patients with systemic lupus erythematosus (SLE) who had a history of lupus nephritis. Evidence of clinical effectiveness of abetimus comes from analyses of data from patients with SLE and high-affinity antibodies to the DNA epitope of abetimus at baseline; a retrospective subgroup in the pivotal Phase II/III LJP-394-90-05 trial (90-05 trial) and the intent-to-treat population in the Phase III LJP-394-90-09 trial (90-09 trial). These studies enrolled SLE patients who had experienced prior renal manifestations of their disease and had elevated anti-dsDNA antibodies at baseline by Farr assay. Both were long-term studies, with a mean duration of treatment participation of 371 days in 90-05 and 310 days in 90-09 for the population of patients with high-affinity antibodies at baseline. The 90-05 and 90-09 studies, as well as all other clinical studies of abetimus, consistently showed that treatment with abetimus resulted in durable and persistent reductions in anti-dsDNA antibodies in SLE patients. Treatment with abetimus was associated with statistically significant decreases in anti-dsDNA antibody levels from baseline compared with placebo in both the 90-09 and 90-05 trials. Positive trends were noted for the incidence of renal flares and major SLE flares in patients treated with abetimus. Abetimus appeared to be well tolerated for treatment periods of < or = 22 months.

Association of antinucleosome antibodies with disease flare in serologically active clinically quiescent patients with systemic lupus erythematosus

OBJECTIVE

To identify the prevalence of serologically active clinically quiescent (SACQ) patients in a cohort of 290 patients with systemic lupus erythematosus (SLE). We investigated if the presence of anti-double-stranded DNA (anti-dsDNA) or antinucleosome (anti-NCS) antibodies during the SACQ period was associated with future flares.

METHODS

SACQ patients defined as clinically inactive for 6 months (global British Isles Lupus Activity Group index [BILAG] scores <6) and serologically active (anti-dsDNA antibodies >50 units/ml on at least 2 occasions by enzyme-linked immunosorbent assay [ELISA]) were identified. Patient sera collected during the defined SACQ period were also tested for anti-NCS antibodies (ELISA). We retrospectively reviewed patient clinical details and episodes of flare using the BILAG activity index.

RESULTS

Twenty-seven (9%) patients were SACQ. Seventeen (81%) patients experienced a flare (total of 91 flares, up to 12 flares per person) in the next 5 years. Median duration to first flare was 15 months (range 2-46). Time to first flare after SACQ period was significantly correlated with the presence of anti-NCS (P = 0.0012), high anti-NCS antibody titers (P = 0.0006), and anti-dsDNA titers 5 times above the normal limit (P = 0.02). Patients with higher absolute anti-NCS antibody titers showed a significant correlation with the number of flares (r = 0.57, P = 0.007).

CONCLUSION

A minority of patients with SLE are SACQ. The majority of these patients experience a flare in the next 5 years and close followup is recommended. Anti-NCS antibodies may be a better predictor than anti-dsDNA antibodies for future flares.

Clinical and prognostic value of autoantibodies in puerto Ricans with systemic lupus erythematosus

The aim of this study was to determine the association between lupus autoantibodies and the clinical manifestations and outcome in a cohort of Puerto Ricans patients with systemic lupus erythematosus (SLE). All patients fulfilled the American College of Rheumatology classification criteria for SLE. Demographic parameters, clinical manifestations over time and damage accrual were obtained at the last study visit. Disease damage was assessed with the Systemic Lupus International Collaborating Clinics Damage Index (SDI). ANA, ANA pattern, and anti-dsDNA, anti-Smith, anti-Ro (SSA), anti-La (SSB) and anti-snRNP antibodies were measured at the time of SLE diagnosis. Chi-square test, Fisher exact test, ANOVA, logistic regression and general lineal model analyses were used to evaluate these associations. Ninety-six percent of patients were females. The cohort had a mean age of 40.2 +/- 12.0 years and mean disease duration of 9.6 +/- 7.0 years. Patients with elevated anti-dsDNA antibodies were more likely to have vasculitis, pericardial effusion, renal involvement, anaemia, leukopenia, lymphopenia and thrombocytopenia. Anti-Smith antibodies were positively associated with skin ulcerations, elevated liver enzymes, renal involvement and thrombocytopenia. Anti-Ro antibodies were related with the presence of discoid lupus, serositis, pneumonitis, elevated liver enzymes, hemolytic anaemia, leukopenia and lymphopenia. No positive associations were found for anti-snRNP or anti-La antibodies. The presence of anti-dsDNA, anti-Smith and anti-Ro antibodies was associated with higher SDI scores. In conclusion, anti-dsDNA, anti-Smith and anti-Ro antibodies are associated with several clinical manifestations and more damage accrual in Puerto Ricans with SLE. These findings provide valuable clinical and prognostic information for this ethnic population.

Assessment of patients with systemic lupus erythematosus and the use of lupus disease activity indices

The assessment of disease activity in systemic lupus erythematosus (SLE) is a task faced by clinicians in every day care, but it is also required for clinical research and in randomised controlled trials. It is crucial to distinguish disease activity from infection, chronic damage and co-morbid disease. Over the past 20 years, many indices have been developed to objectively measure lupus disease activity and several of these have been validated. The most widely used indices are the British Isles Lupus Assessment Group (BILAG) index, the European Consensus Lupus Activity Measurement (ECLAM), the Systemic Lupus Activity Measure (SLAM), the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the Lupus Activity Index (LAI). All these indices have been validated and have excellent reliability, validity and responsiveness to change. In addition to the assessment of disease activity, the evaluation of damage using the validated SLICC/ACR damage index and health-related quality of life is advised for clinical research.

Is antibody clustering predictive of clinical subsets and damage in systemic lupus erythematosus?

OBJECTIVE

To examine autoantibody clusters and their associations with clinical features and organ damage accrual in patients with systemic lupus erythematosus (SLE).

METHODS

The study group comprised 1,357 consecutive patients with SLE who were recruited to participate in a prospective longitudinal cohort study. In the cohort, 92.6% of the patients were women, the mean +/- SD age of the patients was 41.3 +/- 12.7 years, 55.9% were Caucasian, 39.1% were African American, and 5% were Asian. Seven autoantibodies (anti-double-stranded DNA [anti-dsDNA], anti-Sm, anti-Ro, anti-La, anti-RNP, lupus anticoagulant (LAC), and anticardiolipin antibody [aCL]) were selected for cluster analysis using the K-means cluster analysis procedure.

RESULTS

Three distinct autoantibody clusters were identified: cluster 1 (anti-Sm and anti-RNP), cluster 2 (anti-dsDNA, anti-Ro, and anti-La), and cluster 3 (anti-dsDNA, LAC, and aCL). Patients in cluster 1 (n = 451), when compared with patients in clusters 2 (n = 470) and 3 (n = 436), had the lowest incidence of proteinuria (39.7%), anemia (52.8%), lymphopenia (33.9%), and thrombocytopenia (13.7%). The incidence of nephrotic syndrome and leukopenia was also lower in cluster 1 than in cluster 2. Cluster 2 had the highest female-to-male ratio (22:1) and the greatest proportion of Asian patients. Among the 3 clusters, cluster 2 had significantly more patients presenting with secondary Sjögren's syndrome (15.7%). Cluster 3, when compared with the other 2 clusters, consisted of more Caucasian and fewer African American patients and was characterized by the highest incidence of arterial thrombosis (17.4%), venous thrombosis (25.7%), and livedo reticularis (31.4%). By using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, the greatest frequency of nephrotic syndrome (8.9%) was observed in patients in cluster 2, whereas cluster 3 patients had the highest percentage of damage due to cerebrovascular accident (12.8%) and venous thrombosis (7.8%). Osteoporotic fracture (11.9%) was also more common in cluster 3 than in cluster 2.

CONCLUSION

Autoantibody clustering is a valuable tool to differentiate between various subsets of SLE, allowing prediction of subsequent clinical course and organ damage.

Prior anti-dsDNA antibody status does not predict later disease manifestations in systemic lupus erythematosus

OBJECTIVES

To determine if the past presence of anti-double-strand (ds)DNA antibody (Ab) will predict subsequent disease activity in patients with systemic lupus erythematosus (SLE).

METHODS

A longitudinal study of clinical and serological disease manifestations registered during 2,412 patient months of follow-up in a well-defined lupus cohort. Organ-specific disease manifestations, the modified SLE disease activity index (M-SLEDAI) score, disease flares (M-SLEDAI increase > or =3) and predictive value of anti-dsDNA Ab testing [by enzyme-linked immunoabsorbent assay (ELISA) and Crithidia luciliae immunofluorescence (CLIFT) assays] were related to past anti-dsDNA Ab status.

RESULTS

Anti-dsDNA Ab was previously demonstrated in 54 (57%) patients (group 1), while they were not earlier detected in 40 (43%) patients (group 2). The number of patients experiencing flares (46 vs 25%, p<0.01), the total number of flares (75 vs 17, p<0,001) as well as overall (60 vs 24 per 100 patient years, p<0,001) and organ-specific flare rate were higher in group 1. After adjustment for control frequency, group 1 remained at a higher risk for renal flares [odds ratio (OR) 2.4; confidence interval (CI) 1.5-4.1], and group 2 was at a higher risk for skin flares (OR 0.7; CI 0.5-0.8). While anti-dsDNA Ab testing overall was performed slightly more often in group 1 (OR 1.45; CI 1.0-4.6), anti-dsDNA Ab testing during flares was similar in both groups.

CONCLUSION

The past presence of anti-dsDNA Ab identified patients with an increased risk of subsequent renal flares. However, as a new onset of anti-dsDNA Abs occurred late in the disease course, prior anti-dsDNA status was not adequate to predict disease flares.

Relationship between anti-double-stranded DNA antibodies and exacerbation of renal disease in patients with systemic lupus erythematosus

OBJECTIVE

To examine the relationship between changes in anti-double-stranded DNA (anti-dsDNA) antibody levels and the risk of renal flare in patients with systemic lupus erythematosus (SLE), using data from 2 randomized, controlled trials.

METHODS

Analyses were based on 487 patients with SLE and a history of lupus nephritis who had an anti-dsDNA antibody titer >/=15 IU/ml at baseline, as measured by Farr assay. Results are presented for the combined population of patients, the placebo arms, and the drug treatment arms in which a dsDNA-based bioconjugate (abetimus sodium; LJP 394) was used.

RESULTS

Changes in anti-dsDNA antibody levels were inversely correlated with changes in the C3 level (P < 0.0001 in both trials). Cox proportional hazards regression models showed that changes in anti-dsDNA antibody levels correlated with the risk of renal flare. The models predicted that a point estimate of a 50% reduction in anti-dsDNA antibody levels is associated with a 52% reduction (95% confidence interval [95% CI] 26-68%, nominal P = 0.0007) and a 53% reduction (95% CI 33-69%, nominal P < 0.0001) in the risk of renal flare in the 2 trials, respectively. In the 2 trials, the incidence of renal flare was lower in patients with sustained reductions in anti-dsDNA antibodies (3.0% and 4.1%, respectively) than in patients with stable or increasing antibody levels (21.3% and 20.3%, respectively).

CONCLUSION

Changes in anti-dsDNA antibody levels were directly correlated with the risk of renal flare and inversely correlated with changes in the C3 level. Reducing anti-dsDNA antibody levels may represent a therapeutic objective in SLE patients with lupus nephritis, because it is associated with a reduced risk of renal flare.

High-throughput methods for measuring autoantibodies in systemic lupus erythematosus and other autoimmune diseases

Numerous groups have now validated high-throughput approaches to autoantibody profiling in a variety of systems. Recently, we have used autoantigen microarray technology to identify distinct autoantibody profiles in H-2 congenic MRL/lpr mice (Sekine et al., manuscript in preparation), and we are expanding this platform to study human and mouse models of IDDM and RA. We are also developing protein arrays for multiplex analysis of serum antibody isotypes. Multiplexed methods for autoantibody profiling will undoubtedly continue to uncover novel aspects of autoimmunity and B cell biology. It is now time to move these technologies beyond the proof-of-concept phase, and start addressing the next series of important questions. These include, but certainly are not limited to: identifying "autoantibody signatures" associated with disease state or outcome; profiling autoantibodies during the natural course of murine and human disease; and monitoring changes in autoantibody profiles of patients in response to therapeutic intervention. However, the next set of challenges is just right around the corner. As data and statistical analysis tools become more robust, it will be possible to generate and approach new hypotheses at an unprecedented pace.

Anti-dsDNA antibodies: still a useful criterion for patients with systemic lupus erythematosus?

The presence of antibodies to dsDNA has been a criterion for systemic lupus erythematosus (SLE) in each of three attempts to classify the disease that have been undertaken by the American College of Rheumatology. The generally good specificity of the test, the fact that it is widely available and often undertaken by an enzyme linked immunosorbent assay (ELISA) which is relatively cheap and easy to perform have encouraged its continued presence in the list of lupus criteria. The detection of anti-dsDNA antibodies is not, however, straightforward and the real significance of the presence of these antibodies, their true specificity (or otherwise), the question of whether they are truly linked to disease pathogenicity and how accurately they reflect disease activity are all questions that have been posed in the past 20 years.

Lupus nephritis: a review of the current pharmacological treatments

Proliferative lupus glomerulonephritis World Health Organization Class III and IV patients should benefit from an induction and maintenance therapy with a combined immunosuppressive treatment. Cyclophosphamide is the main recommended drug in induction therapy for a 3- to 6-month treatment period. Refractory lupus nephritis may be considered for immunoablative cyclophosphamide treatment with or without haematopoietic CD34(+) stem-cell transplantation or rituximab. Maintenance therapy should contain either quarterly cyclophosphamide pulses, azathioprine or mycophenolate mofetil for a total treatment duration of at least 2 years. Recent studies suggested a similar efficacy of mycophenolate mofetil and cyclophosphamide in induction and maintenance therapy. This result has to be confirmed in long-term studies.

IFN-α Induces Early Lethal Lupus in Preautoimmune (New Zealand Black × New Zealand White)F1but Not in BALB/c Mice

Recent studies indicate that IFN-alpha is involved in pathogenesis of systemic lupus erythematosus. However, direct proof that IFN-alpha is not only necessary, but also sufficient to induce lupus pathogenicity is lacking. In this study, we show that in vivo adenovector-mediated delivery of murine IFN-alpha results in preautoimmune (New Zealand Black (NZB) x New Zealand White (NZW))F(1), but not in normal, mice, in a rapid and severe disease with all characteristics of systemic lupus erythematosus. Anti-dsDNA Abs appeared as soon as day 10 after initiation of IFN-alpha treatment. Proteinuria and death caused by glomerulonephritis occurred in all treated mice within, respectively, approximately 9 and approximately 18 wk, at a time when all untreated (NZB x NZW)F(1) did not show any sign of disease. IFN-alpha in vivo induced an overexpression of B lymphocyte stimulator in circulation at similar levels in both the preautoimmune and the normal mouse strains. All effects elicited by IFN-alpha were dose dependent. (NZB x NZW)F(1) infused with purified murine IFN-alpha also showed acceleration of lupus. Thus, prolonged expression of IFN-alpha in vivo induces early lethal lupus in susceptible animals.

Biomarkers in systemic lupus erythematosus

Despite the longstanding interest and large number of publications on biomarkers in lupus, there are no validated and widely accepted biomarkers of systemic lupus erythematosus to date. To achieve the ultimate goal, to have a biomarker as a surrogate endpoint in clinical studies, candidate biomarkers have to first be validated in a statistically rigorous way. However, to qualify as a surrogate endpoint, even validated biomarkers have to go through a process that demonstrates that they accurately reflect a clinically important outcome. These goals can only be achieved in large multicenter, properly conducted studies. We reviewed the difficulties involved in developing validated biomarkers for systemic lupus erythematosus and summarized the available data on the most promising biomarker candidates of disease susceptibility and disease activity. We also report on the current status of a multicenter initiative to concentrate efforts of biomarker development.

Evaluation of systemic lupus erythematosus activity during pregnancy

Due to our increasing knowledge on the pathophysiological basis of autoimmunity and the development of combined medical-obstetric clinics, pregnancy is becoming common among women with systemic lupus erythematosus (SLE). However, whether lupus worsens during pregnancy continues to be a controversial issue. SLE assessment during pregnancy is sometimes difficult due to physiological changes during this period, and common tools for measuring lupus activity during pregnancy were not available until recently. Several lupus activity scales in common use have been adapted for pregnancy [systemic lupus erythematosus in pregnancy activity index (SLEPDAI), modified lupus activity measurement (m-SLAM) and lupus activity index in pregnancy (LAI-P)]. All of them take into account the influence of pregnancy on clinical manifestation and common biochemical tests. LAI-P also accounts for specific manifestations of antiphospholipid syndrome in order not to score them as due to SLE activity. LAI-P has recently been validated for use in SLE pregnancy and could be used in future studies. However, daily assessment and management of individual pregnant women with lupus still relies on the clinical skills of attending physicians.

First clinical trials of a new heteropolymer technology agent in normal healthy volunteers and patients with systemic lupus erythematosus: safety and proof of principle of the antigen-heteropolymer ETI-104

BACKGROUND

The heteropolymer technology was developed to remove pathogens from the circulation.

OBJECTIVES

To evaluate the safety and tolerability of a single administration and to establish proof of principle for ETI-104 in normal healthy volunteers (NHV) and patients with systemic lupus erythematosus (SLE) METHODS: The drug was given intravenously to 11 NHV and six patients with SLE. Over 28 days, vital signs were noted, a haematological and chemical analysis of blood and urine was carried out, and adverse events were recorded. CR1 receptor numbers, the ability of antigen based heteropolymers to bind to red blood cells (RBCs), and the clearance of high avidity and total anti-dsDNA antibodies were measured by Farr assays and FACS analysis.

RESULTS

No safety measure differed significantly from normal in both groups; no drug related serious adverse events occurred. ETI-104 rapidly bound to RBCs in NHV and patients with SLE. Binding of the drug to RBCs of patients with SLE also caused a rapid reduction of circulating anti-dsDNA antibodies in the plasma 15 minutes after administration, with a maximum reduction of 55% (range 43-62). At 28 days statistically significant decreases were maintained in three patients, while in the other three the values had returned to baseline levels.

CONCLUSION

These clinical trials established the safety and the proof of principle of the new immunoconjugate ETI-104. This provides the basis for further development of this technology for numerous indications-for example, therapeutic options for autoimmune diseases or viral and bacterial infections.

Measuring systemic lupus erythematosus activity during pregnancy: validation of the lupus activity index in pregnancy scale

OBJECTIVE

To validate the Lupus Activity Index in Pregnancy (LAI-P) scale as a diagnostic tool for lupus flares during pregnancy and the puerperium.

METHODS

The LAI-P is a modified activity scale specific for pregnancy. Thirty-eight pregnant women with systemic lupus erythematosus (SLE) were prospectively followed in 3 clinics specific for lupus in pregnancy. On each visit, LAI-P was calculated. A modified physician global assessment (m-PGA) scale was used as gold standard (0 = no activity, 1 = mild-moderate activity, 2 = severe activity). A change > or = 0.25 in LAI-P was predefined as a flare according to previous studies in nonpregnant patients. For the purposes of the study, each visit was considered as an independent case.

RESULTS

During the study period, 158 visits took place for a total 621 patient-weeks. Sensitivity to change was high (standardized response mean for LAI-P = 1.6). We found a significant association between LAI-P and m-PGA (P < 0.002 in all regression models performed). Sensitivity, specificity, and positive and negative predictive values were 0.93, 0.98, 0.88, and 0.99. Positive and negative likelihood ratios were 49 and 0.07, respectively.

CONCLUSIONS

LAI-P has a high sensitivity to changes in lupus activity, a significant correlation with m-PGA, and high sensitivity, specificity, predictive values, and likelihood ratios for diagnosing SLE flares during pregnancy and the puerperium.

B lymphocytes and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by B cell hyperactivity in association with autoantibodies, most prominently those directed to components of the cell nucleus. The source of the antigens that drive B cell responses in SLE is unknown, although recent studies suggest mechanisms by which the self-antigens become immunogenic and stimulate responses. Among these mechanisms, abnormalities in the generation of apoptotic cells or their clearance may increase the availability of nuclear antigens to drive responses. In addition, autoantibody crossreactivity may promote induction of responses to disparate antigens, foreign and self, and enable a single autoantibody to cause disease by crossreactive binding. In addition to reflecting increased exposure to self-antigen, autoantibody responses in SLE may result from abnormalities in B cell signaling and regulation by cytokines. New approaches to therapy aim to abrogate autoantibody production by targeting specific steps in B cell activation, including blockade of T cell costimulation.

Concentrations of circulating matrix metalloproteinase 9 inversely correlate with autoimmune antibodies to double stranded DNA: implications for monitoring disease activity in systemic lupus erythematosus

AIMS

To compare circulating matrix metalloproteinase (MMP) concentrations with antibodies to single and double stranded DNA (ssDNA and dsDNA) to determine their relation in inflammatory arthritic diseases, such as systemic lupus erythematosus (SLE).

METHODS

Fibroblast MMP-2 and neutrophil MMP-9 were resolved by gelatin zymography and measured by densitometry. Anti-ssDNA and anti-dsDNA were determined by enzyme immunoassay and samples grouped on antibody content as follows: low anti-ssDNA/low anti-dsDNA antibodies (group 1); high anti-ssDNA/low anti-dsDNA antibodies (group 2); and high anti-ssDNA/high anti-dsDNA antibodies (group 3).

RESULTS

Group 3 samples contained significantly lower amounts of MMP-9 when compared with group 1 samples. Higher molecular weight MMP-9 forms (130 and 225 kDa) were virtually absent. Group 2 samples contained intermediate MMP-9 concentrations. Fibroblast MMP-2 was unchanged in all groups. Mean complement C3 and C4 concentrations showed a consistent, but variably significant, decrease with increasing anti-ssDNA and anti-dsDNA antibodies. The mean erythrocyte sedimentation rate was raised in all patient groups.

CONCLUSIONS

Neutrophil MMP-9, an inflammatory marker, inversely correlates with anti-dsDNA antibodies, which are a specific marker for SLE, and may be important in monitoring disease activity during antibody deposition in tissues.

Clinical laboratory assays for measuring anti-dsDNA antibodies. Where are we now?

It is over 40 years since anti-dsDNA antibodies were first described in patients with lupus. A wide variety of methods for detecting these immunoglobulins have been established. In this review, we consider the utility and practical problems that the main assays present. The clinical correlations between anti-dsDNA antibodies and clinical activity in patients with lupus is discussed.

Lowering anti-dsDNA antibodies--what's new?

Antibodies to dsDNA are specific to SLE and are pathogenic, both due to their ability to deposit in tissues through a variety of mechanisms, and to their ability, when present in immune complexes, to activate inflammatory cells. The relationship of serum anti-dsDNA antibody levels to disease activity is a complex one and the factors that determine whether or not such antibodies will be pathogenic in an individual SLE patient are incompletely understood. Although anti-dsDNA antibodies can be made by naïve B cells and B cells belonging to the B1 and marginal zone subsets, pathogenic anti-dsDNA antibodies have the hallmarks of germinal center development and exposure to T cell help, including accumulation of somatic mutations and class switching to the IgG isotype. Epitope spreading may result in aquisition of cross-reactivities with multiple target organ antigens and aquisition of a memory phenotype will allow these B cells to acquire antigen presentation functions that amplify the autoreactive response. In the early stages of disease, or after remission induction protocols, autoreactive B cells may be susceptible to treatments that target T cell costimulation or that deplete or tolerize naïve and mature B cells. Therapeutic approaches targeting innate immune responses or regulatory T cells are starting to be tested in pre-clinical models. In later disease stages, memory and plasma cell accumulation may render patients more resistant to this type of therapeutic approach. Deposition of anti-dsDNA antibodies in target tissues can stimulate an inflammatory cascade that leads to tissue damage. A number of murine models have now been developed that show that interruption of this cascade can prevent or reverse such damage. This type of approach may be beneficial for individuals with established disease. As we learn more about the specific defects that cause SLE, it may become possible to individualize therapy based on patient specific biologic markers.

Mycophenolate mofetil prevents a clinical relapse in patients with systemic lupus erythematosus at risk

BACKGROUND

Systemic lupus erythematosus (SLE) is characterised by the presence of antibodies to double stranded DNA (dsDNA), which are involved in the pathogenesis of SLE. Previous studies showed that at least two thirds of patients develop a clinical relapse within six months after a significant rise in the anti-dsDNA level, and most relapses were prevented by the administration of corticosteroids at the time of the rise.

OBJECTIVE

To determine whether mofetil mycophenolate (MMF) can prevent a clinical relapse without the side effects associated with corticosteroids.

METHODS

36 patients with SLE were examined monthly to determine whether a rise in anti-dsDNA level had occurred. A rise was defined as an increase of 25% of the level of the previous sample of at least 15 IU/ml within a four month period. After a rise patients were treated with MMF 2000 mg daily for six months. Patients were monitored monthly for the occurrence of a clinical relapse and to assess the serological activity and state of activation of CD4+, CD8+, and CD19+ lymphocyte subsets.

RESULTS

Anti-dsDNA rose in 10 patients. Treatment with MMF was started in all these patients, and after six months no clinical relapse had occurred. Side effects were minimal. Antibodies to dsDNA decreased during the treatment (p<0.001), associated with a decrease in the state of activation of CD19+ lymphocytes. No changes were found in the state of activation of CD4+ or CD8+ lymphocyte subsets.

CONCLUSION

Administration of MMF after a rise in antibodies to dsDNA is well tolerated, decreases anti-dsDNA and B cell activation, and seems to prevent the occurrence of a clinical relapse in patients with SLE.

The use of fluorometric assays to assess the immune response to DNA in murine systemic lupus erythematosus

Antibodies to DNA (anti-DNA) play an important role in the pathogenesis of systemic lupus erythematosus (SLE). In blood, these antibodies may exist in a free, unbound state or as part of complexes with DNA. Furthermore, circulating DNA may be either complexed or free. Because of the central role of these immunoreactants (anti-DNA and DNA) in the disease, monitoring of their levels could provide valuable information for both clinical and investigative purposes. In these studies, we have explored the use of a DNA-binding dye, PicoGreen, for the detection of circulating DNA, either total or immune complex bound. In addition, we have used this dye for Farr-type antibody assays. Using autoimmune MRL/lpr mice as a model, we have shown that, while the levels of free DNA in the plasma of these mice were comparable with those of normal BALB/c mice, the amounts in complexes precipitable by ammonium sulfate were significantly greater. Furthermore, we showed that Farr assays using PicoGreen reliably detect levels of free anti-DNA, with values correlated with anti-DNA levels by an enzyme-linked immunosorbent assay. Together, our results suggest that a fluorometric dye can accurately monitor DNA and anti-DNA antibody levels in SLE and may provide important information on immunopathogenesis.

Epidemiology of systemic lupus erythematosus

Several recent studies have suggested that the incidence of systemic lupus erythematosus (SLE) is increasing. The female to male ratio varies from 4.3 to 13.6. SLE is more common in African-Americans, African-Caribbeans, and Asians, than in Caucasians. The age at diagnosis is younger in African-Americans than in Caucasians. Improvement in survival levelled off in the 1980s; 20-year survival is only 53-61%.

Genome scan stratified by the presence of anti-double-stranded DNA (dsDNA) autoantibody in pedigrees multiplex for systemic lupus erythematosus (SLE) establishes linkages at 19p13.2 (SLED1) and 18q21.1 (SLED2)

Anti-double-stranded DNA (anti-dsDNA) is arguably one of the most specific autoantibodies in systemic lupus erythematosus (SLE). This antibody is associated with more severe SLE and with glomerulonephritis. From 196 pedigrees multiplex for SLE, we selected those that had any SLE affected positive for anti-dsDNA by the Crithidia luciliae kinetoplast imunofluorescence assay. This stratification strategy tested the hypothesis that anti-dsDNA would identify a more genetically homogeneous group of pedigrees, in which previously undetected linkage effects could be established. A genome screen data for linkage to SLE was available at 307 microsatellite markers for this selected group of 71 pedigrees: 37 European-American, 29 African-American, and five others. The most significant results were obtained at 19p13.2 (LOD(max) = 4.93), named SLED1, in the 37 European-American pedigrees using a dominant model with mixed penetrances (92% for females and 49% for males) at 100% homogeneity (theta = 0). A second linkage effect, SLED2, was established in the 29 African-American pedigrees at 18q21.1 (LOD(max) = 3.40) using a recessive model with 100% penetrance (theta = 0.1). Parametric and non-parametric multipoint analyses were performed, which provided further evidence and support of susceptibility genes residing in these regions. In conclusion, two powerful linkages have been detected with SLE based on the presence of anti-dsDNA. These findings show SLE to be a richly complicated disease phenotype that is now ripe for important new discovery through a genetic approach.