Long-term effects of combination treatment with fludarabine and low-dose pulse cyclophosphamide in patients with lupus nephritis.

OBJECTIVES: To determine the safety and efficacy of a short course of fludarabine combined with cyclophoshamide in lupus nephritis. METHODS: A phase I/II open label pilot study. Thirteen patients with active proliferative lupus nephritis received monthly oral boluses of low-dose cyclophoshamide (0.5 gm/m(2) on day 1) and subcutaneous fludarabine (30 mg/m(2) on days 1-3) for 3-6 cycles. Concomitant prednisone was aggressively tapered from 0.5 mg/kg/day to a low-dose, alternate-day schedule. Patients were followed for at least 24 months after therapy. The primary outcome was the number of patients achieving renal remission defined as stable creatinine, proteinuria <1 gm/day and inactive urine sediment for at least 6 months. RESULTS: The study was terminated early because of bone marrow toxicity. Eleven patients who received at least three cycles were evaluated for efficacy. Ten patients improved markedly with seven patients achieving complete remission and three patients achieving partial remission. There were three serious haematological adverse events during the treatment with one death due to transfusion-associated graft vs host disease. Profound and prolonged CD4 (mean CD4: 98/microl at 7 months and 251/microl at 12 months) and CD20 lymphocytopenia was noted in most patients. Three patients developed Herpes zoster infections. CONCLUSIONS: A short course of low-dose fludarabine and cyclophoshamide can induce long-lasting remissions in patients with proliferative lupus nephritis, but severe myelosuppression limits its widespread use.

Renal flares are common in patients with severe proliferative lupus nephritis treated with pulse immunosuppressive therapy: long-term followup of a cohort of 145 patients participating in randomized controlled studies.

OBJECTIVE: Immunosuppressive agents have become the standard of therapy for proliferative lupus nephritis, but some patients may relapse after discontinuing treatment. We reviewed the cases of renal flares in a cohort of patients who participated in 2 randomized controlled clinical trials at the National Institutes of Health and explored the prevalence, outcome, and predictive factors of renal flares. METHODS: Data were obtained on 145 patients treated with pulse cyclophosphamide, pulse methylprednisolone, or the combination of both. Patients had not received immunosuppressive therapy for at least 6 months and had experienced complete or partial response according to defined criteria. Renal flares were classified as either proteinuric or nephritic based on changes in urinary protein and sediment. Most patients who experienced a flare received additional immunosuppressive therapy. RESULTS: Seventy-three patients had a complete response, and 19 had partial response/stabilization. Forty-one of these patients (45%) experienced renal flares (nephritic in 33, proteinuric in 8) after a mean followup of 117 months; 31 of them received additional immunosuppressive therapy. The median time to renal flare was 36 months in the complete responders and 18 months in the partial responders. Eleven of the 41 patients (27%) progressed to end-stage renal disease (ESRD); 9 had nephritic flares (all severe except for 1) and 2 had proteinuric flares (1 in each responder group). Compared with patients who had a complete response, those with a partial response were more likely to experience a flare, to have a severe nephritic flare, or to progress to ESRD. Low C4 at the time of response and African American ethnicity were significant independent risk factors for renal flare, by multivariate Cox proportional hazards analysis. CONCLUSION: Nephritic flares are common in patients with proliferative lupus nephritis, even in those with a complete response to therapy, but they do not necessarily result in loss of renal function if treated with additional immunosuppressive agents. Renal flares are an important feature of the natural history of lupus nephritis and provide an opportunity for additional preventive strategies, as well as measures of efficacy in future therapeutic trials.

Combination therapy with pulse cyclophosphamide plus pulse methylprednisolone improves long-term renal outcome without adding toxicity in patients with lupus nephritis.

BACKGROUND: Controlled trials in lupus nephritis have demonstrated that cyclophosphamide therapy is superior to corticosteroid therapy alone. The long-term effectiveness and side-effect profiles of pulse immunosuppressive regimens warrant further study. OBJECTIVE: To define the long-term risk and benefit of monthly treatment with boluses of methylprednisolone, cyclophosphamide, or both. DESIGN: Extended follow-up (median, 11 years) of a randomized, controlled trial. SETTING: U.S. government research hospital. PATIENTS: 82 patients with proliferative lupus nephritis. MEASUREMENTS: Rates of treatment failure (defined as need for supplemental immunosuppressive therapy or doubling of serum creatinine concentration, or death) and adverse events. RESULTS: In an intention-to-treat survival analysis, the likelihood of treatment failure was significantly lower in the cyclophosphamide (P = 0.04) and combination therapy (P = 0.002) groups than in the methylprednisolone group. Combination therapy and cyclophosphamide therapy alone did not differ statistically in terms of effectiveness or adverse events. Of patients who completed the protocol (n = 65), the proportion of patients who had doubling of serum creatinine concentration was significantly lower in the combination group than in the cyclophosphamide group (relative risk, 0.095 [95% CI, 0.01 to 0.842]). CONCLUSION: With extended follow-up, pulse cyclophosphamide continued to show superior efficacy over pulse methylprednisolone alone for treatment of lupus nephritis. The combination of pulse cyclophosphamide and methylprednisolone appears to provide additional benefit over pulse cyclophosphamide alone and does not confer additional risk for adverse events.

Rheumatoid arthritis associated autoantibodies in patients with synovitis of recent onset.

STATEMENT OF FINDINGS: An inception cohort of 238 patients having peripheral joint synovitis of less than 12 months duration was evaluated clinically and followed prospectively for 1 year to determine the clinical significance of a number of rheumatoid arthritis (RA) associated autoantibodies. Serum samples collected at the time of the initial evaluation were tested for rheumatoid factor (RF) and antibodies to Sa (anti-Sa), RA-33, (pro)filaggrin [antifilaggrin antibody (AFA)], cyclic citrullinated peptide (anti-CCP), calpastatin, and keratin [antikeratin antibody (AKA)]. RF had a sensitivity of 66% and a specificity of 87% for RA. Anti-Sa, AFA, and anti-CCP all had a specificity of more than 90%, but a sensitivity of less than 50% for this diagnosis. Overall, there was a high degree of correlation between AFA, AKA, anti-Sa or anti-CCP, this being highest between anti-Sa and anti-CCP (odds ratio, 13.3; P < 0.001). Of the 101 patients who were positive for at least one of these four autoantibodies, 57% were positive for only one. Finally, anti-SA identified a subset of predominantly male RA patients with severe, erosive disease. Anti-SA, AFA and anti-CCP are all specific for early RA but, overall, have little additional diagnostic value over RF alone. Although these antibodies may preferentially recognize citrullinated antigens, the modest degree of concordance between them in individual patient sera suggests that it is unlikely a single antigen is involved in generating these responses.

Synovitis occurs in some clinically normal and asymptomatic joints in patients with early arthritis.

OBJECTIVE: To determine if clinically asymptomatic knee joints in patients with recent onset arthritis reveal histological evidence of synovitis. METHODS: As part of a prospective study of patients with synovitis of less than one year duration, we performed blind needle biopsies on the knees of 20 patients who had synovitis elsewhere but no symptoms or detectable swelling or tenderness of the biopsied joint. RESULTS: Histologic evidence of synovitis was observed in 11 knees (55%). All patients with synovitis had evidence of synovial lining cell hyperplasia, increased vascularity, and lymphocytic infiltrates. Five of 6 patients with rheumatoid arthritis (RA) and 5 of 8 with undifferentiated arthritis had histological evidence of synovitis, but none of the 5 with reactive arthritis (ReA) had synovitis in the asymptomatic joints. Histologic evidence of synovitis persisted in some after clinical resolution of previous pain and swelling, while it occurred in others with no history of previous involvement of that knee. CONCLUSION: Even asymptomatic joints in patients with RA and undifferentiated arthritis of recent onset reveal histologic signs of synovitis. The earliest changes may occur before symptoms. Histologic changes also persist after resolution of previous early symptoms. Evidence of inflammation was not present in asymptomatic joints in our 5 patients diagnosed with ReA.

Multicentric reticulohistiocytosis: case report with immunohistochemical analysis and literature review.

This report describes the case of a patient with multicentric reticulohistiocytosis. Immunohistochemical analysis revealed prominent markers of monocyte/macrophage origin, as well as the presence of tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-12; the occurrence of the latter in this disease has not previously been reported. Clinical, laboratory, radiographic, and histologic findings in multicentric reticulohistiocytosis are reviewed. In addition, all published cases of multicentric reticulohistiocytosis which included reports of cytokine and immunohistochemical analysis are reviewed, and evidence for a monocyte/macrophage origin and role in disease pathogenesis is provided.

Update on cyclophosphamide for systemic lupus erythematosus.

Over the past decade cyclophosphamide has come to assume an increasingly prominent role in the management of severe, life-threatening manifestations of SLE. Intermittent, intravenous pulse cyclophosphamide has become the standard of treatment of diffuse proliferative lupus nephritis (WHO Class IV), and there is now substantial clinical literature to suggest an indication for intermittent cyclophosphamide therapy in most other forms of serious lupus affecting major organ systems, in particular lupus vasculitis and acute central nervous system manifestations. This update reviews the use of cyclophosphamide in the management of lupus nephritis, expands on its role in other manifestations of SLE, and discusses potential complications of the drug.

Apheresis.

The removal of pathologic humors by various methods is an ancient medical remedy used in the management of diseases whose pathophysiology is poorly understood and whose effective treatment modalities are lacking. The contemporary means for such an approach involves apheresis, which is now possible due to advances in blood banking technologies. Apheresis has been used in most of the major rheumatic diseases, in particular systemic lupus erythematosus and rheumatoid arthritis. Although numerous case reports describe clinical benefits of apheresis in rheumatologic disorders, data from clinical trials are discouraging and suggest a limited role for apheresis in rheumatic disease management.

Association of HLA alleles and clinical features in patients with synovitis of recent onset.

OBJECTIVE: To determine how HLA alleles are associated with the clinical disease patterns of patients with synovitis of recent onset. METHODS: The HLA alleles A, B, C, DRbeta1, and DQbeta1 were determined in a cohort of 211 patients (mean age 42 years, 64% female, 79% white) with recent-onset synovitis in 1 or more peripheral joints. At a mean disease duration of 33 weeks, 98 patients (46%) met the American College of Rheumatology (ACR) criteria for rheumatoid arthritis (RA), 38 (18%) met the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA), and 75 (36%) were classified as having undifferentiated arthropathy (UA). Controls were racially matched healthy individuals (n = 244). RESULTS: Shared epitope (SE) alleles were significantly more common in rheumatoid factor-positive (RF+) patients fulfilling the ACR RA criteria than in other patients with early arthritis (65% versus 35%; P < 0.001). In addition, the RA patients had by far the highest frequency of radiographic erosions (52% and 39% in RF+ and RF- RA, respectively, versus 3% and 9% in SpA and UA patients, respectively; P < 0.0001). The presence of SE alleles was a particularly strong predictor of early erosions in the RF- RA patients (odds ratio [OR] 6.8, 95% confidence interval [95% CI] 1.2-45). The presence of 2 SE alleles or an associated DQbeta1*0301 (DQ7) or DQbeta1*0302 (DQ8) allele appeared to modestly increase the risk of early erosions, although these DQ alleles were in strong linkage disequilibrium with DRbeta1*0401, both in the patient and in the control populations. B27 was linked with the presence of SE alleles in the patients, including those patients fulfilling the RA criteria, but not in the controls (12% versus 3%; P < 0.001). Enthesitis was present in 23 (11%) of 211 patients, was highly associated with B27 (OR 4.2, 95% CI 1.5-11.5), and surprisingly, was not a feature specific only to the SpA group. The B8-DR3 haplotype was significantly increased in the patient subgroups compared with controls (17% versus 7%; P < 0.01), although the clinical significance of this association is unclear. CONCLUSION: This study of HLA associations in a diverse cohort of early synovitis patients emphasizes the complex degree of genetic interaction between alleles at several major histocompatibility complex loci, which regulates clinical phenotypes. In particular, SE and B27, while predisposing patients to characteristic clinical syndromes, had an unexpected degree of association in this cohort, perhaps explaining the overlap in clinical features in many patients.

Gamma interferon and interleukin-10 gene expression in synovial tissues from patients with early stages of Chlamydia-associated arthritis and undifferentiated oligoarthritis and from healthy volunteers.

Genetically determined differences in interleukin-10 (IL-10) and gamma interferon (IFN-gamma) responses in mice correlate with clearance of Chlamydia pneumonitis infection. We measured the synovial expression of IL-10 and IFN-gamma and additional cytokine genes in patients who had recent-onset Chlamydia-associated arthritis (Chl-AA). IL-10 and IFN-gamma mRNA were relatively abundant in recent-onset Chl-AA.

Why is the ANA result positive?

Antinuclear antibody testing is a useful way to confirm the diagnosis of lupus when the clinical suspicion is high, or to exclude it in cases when SLE is in the differential diagnosis but the likelihood of it is low to moderate. Because the test is very sensitive and yet not specific for lupus, an inappropriately ordered ANA test with a positive result can cause diagnostic confusion and unnecessary anxiety for the patient and the physician.

Recombinant human Dnase I (rhDNase) in patients with lupus nephritis.

Systemic lupus erythematosus (SLE) is characterized by the production of pathogenic autoantibodies to nucleoprotein antigens, including double-stranded DNA (dsDNA). The deposition of IgG dsDNA immune complexes in glomeruli is thought to be crucial for disease pathogenesis and complement activation. rhDNase catalyzes the hydrolysis of extracellular DNA and has been shown to delay the development of dsDNA antibodies, reduce proteinuria, and delay mortality in a lupus-prone murine model. We conducted a 40d, phase Ib, randomized, double-masked, placebo-controlled trial to determine the safety and pharmacokinetics of rhDNase, and to measure any changes in markers of disease activity in 17 patients with lupus nephritis. Patients were assigned to receive either: (1) 25 microg/kg rhDNase (n = 8); (2) 125 microg/kg rhDNase (n=6); or (3) placebo (n = 3) initial single intravenous (IV) dose followed by 10 subcutaneous (SC) doses. Skin biopsies performed on nine patients pre- and post-treatment were studied for immune complex deposition by immunofluorescence. Serum cytokine levels (sIL2-R, IL-6, IL-10, and TNF-alpha) were analyzed by ELISA. Cytokine secretion and antibody production were measured by ELISPOT analysis and ELISA. Serum hydrolytic activity of rhDNase was achieved after IV administration at 25 and 125 microg/kg, but not after SC administration at either dose. A t 1/2 of 3-4h was estimated from serum concentration profiles following IV administration. Serum dsDNA antibodies were unchanged (mean values: 33 IU/mL vs 39 IU/mL [pre- and post-treatment] for the 25 microg/kg group, and 74 IU/mL vs 74 IU/mL for the 125 microg/kg group, and 14 IU/mL vs 20 IU/mL for the placebo group). Complement levels (C3 and C4) and circulating immune complexes did not change appreciably during the treatment period for any of the groups. Serum cytokine profiles by ELISA revealed no changes in sIL-2 receptor, IL-6, IL-10, or TNF-alpha. There was no change in the number of cells secreting either Th1 or Th2 specific cytokines, nor in the number of cells secreting dsDNA antibodies. Neutralizing antibodies to rhDNase were not detected in serum at any time during the study. Immune complex deposition was unchanged in pre- and post-treatment in skin biopsies in both dose groups. rhDnase was well tolerated without significant adverse events following administration, and treatment was not associated with the development of neutralizing antibodies to rhDNase. Serum rhDNase concentrations capable of hydrolytic activity of rhDNase were achieved for a few hours following IV, but not SC administration. Serum markers of disease activity were unchanged during the study period.

Randomized clinical trials and longitudinal observational studies in systemic lupus erythematosus: consensus on a preliminary core set of outcome domains.

The OMERACT module on systemic lupus erythematosus (SLE) dealt with the definition of preliminary core sets of outcome domains for randomized clinical trials (RCT) and longitudinal observational studies (LOS). After lectures introducing the problems and addressing the key issues, 6 discussion groups, 3 each for LOS and RCT, discussed and weighted more than a dozen possible items for use as outcome domains. The means of the respective 3 groups were calculated. For both RCT and LOS the same outcome domains received more than 10 of a total maximum of 100 points: disease activity, health related quality of life (HRQOL), damage, and toxicity/adverse events. However, the weights for HRQOL and damage were different for LOS and RCT. A final vote led to the acceptance of these 4 variables as a preliminary core set for outcome in SLE by more than 80% of the participants. This core set will allow for improved design, performance, and evaluation of future studies in SLE. However, a number of domains not included in the core set were regarded as important for further analysis and research.

High dose versus low dose fludarabine in the treatment of patients with severe refractory rheumatoid arthritis.

OBJECTIVE: Fludarabine, a nucleoside analog that targets both resting and proliferating lymphocytes, is a promising drug for the treatment of autoimmune diseases. We conducted a 2 dose, open label clinical trial to evaluate the toxicity/safety of the fludarabine treatment and its clinical and immunological effects. METHODS: Twenty-six patients with severe rheumatoid arthritis (RA) refractory to treatment with at least one slow acting antirheumatic drug were treated with intravenous fludarabine [20 mg/m2 body surface area (n=12) or 30 mg/m2 body surface area (n=14) per day for 3 consecutive days] given monthly for 6 months. Second line agents with the exception of glucocorticoids were discontinued at least 4 weeks before study entry. Measurements included toxicity and tolerability monitored at monthly intervals: efficacy, by both a 50% reduction in tender or swollen joint count and American College of Rheumatology (ACR) criteria for 20% response; and phenotypic analysis of peripheral blood mononuclear cells and T cell functional assays. RESULTS: Using intention-to-treat analysis, 2 of 12 (17%) patients in the low dose and 7 of 14 (50%) in the high dose groups had 50% or greater reduction in tender and/or swollen joint count after 6 months of therapy compared to baseline (p=0.09). Two of 12 (17%) in the low dose group and 5 of 14 (36%) in the high dose group met ACR criteria for 20% improvement (p=0.28). No immediate toxicity was observed. Several infections occurred, including 4 episodes of limited Herpes zoster, which responded to standard therapy. Significant lymphopenia involving T and B cells was observed in all patients. Both naive (CD4+CD45RA+) and memory CD4+ T cells (CD4+CD45RO+) were reduced (naive > memory). No significant regeneration of naive T cells was observed, which may suggest limited thymic regenerative capacity. Fludarabine decreased the proliferative response of peripheral blood lymphocytes to mitogens, as well as the production of T cell (interleukin 2 and interferon-gamma) and monocyte derived (tumor necrosis factor-alpha and IL-10) cytokines. CONCLUSION: Fludarabine treatment of patients with severe, refractory RA resulted in significant lymphopenia, suppression of lymphocyte function, and clinical improvement in the high dose group. There was no immediate toxicity; however, several infections occurred. Controlled trials are needed to substantiate the clinical improvement observed in this open label trial.

Angiotensin I converting enzyme gene polymorphisms in systemic lupus erythematosus: decreased prevalence of DD genotype in African American patients.

The presence of the D (deletion) allele at the angiotensin converting enzyme (ACE) gene has been associated with a) adverse vascular events contributing to early mortality and b) progressive deterioration of renal function in a variety of chronic glomerular diseases. We investigated the potential role of ACE polymorphisms in patients with systemic lupus erythematosus (SLE). Two hundred and sixteen (216) SLE patients (121 Caucasians; 78 African Americans; and 17 other) and 200 normal controls were studied; 134 patients had evidence of renal disease. ACE genotypes were determined by a polymerase chain reaction based assay. The frequency of genotype DD was increased in African American normal controls compared to Caucasians (55% vs. 37%, p = 0.017) and in African American normal controls vs. African American lupus patients (55% vs. 30%, p = 0.008). Trend analysis of the genotype distribution across the three African American groups (renal, non-renal, controls) revealed a trend of increased frequency of I and decreased frequency of D as likelihood of renal disease increases (p = 0.008). No association between any ACE genotype with parameters of renal disease and/or response to therapy was identified. African American patients with lupus have a lower frequency of DD genotype as compared to African American normal controls. Further studies will be necessary to address whether this is due to decreased survival of these patients, a protective effect of DD genotype from developing the disease or a chance sample effect.

Use of cytotoxic agents and cyclosporine in the treatment of autoimmune disease. Part 2: Inflammatory bowel disease, systemic vasculitis, and therapeutic toxicity.

When cytotoxic agents were introduced, their ability to disrupt nucleic acid and protein synthesis led to their effective use for the treatment of neoplastic disease. During the course of this use, however, it became apparent that these agents also suppress the immune system. This usually unwelcome effect was subsequently studied and beneficially directed toward the treatment of non-neoplastic diseases in which autoimmune mechanisms were considered important to pathogenesis. As a result of these investigations, cytotoxic agents and, more recently, cyclosporine have emerged to become an important part of the therapeutic regimen for many autoimmune diseases. Nonetheless, these medications may still cause treatment-induced illness or even death. It is therefore particularly important to weigh the benefits and risks of cytotoxic therapy when treating a non-neoplastic disease. This two-part Clinical Staff Conference reviews data on the efficacy and toxicity of cytotoxic drugs and cyclosporine in selected autoimmune diseases. In part 2, we focus on the role of these agents in treating inflammatory bowel disease and systemic vasculitis and review the toxic effects of these agents.

Use of cytotoxic agents and cyclosporine in the treatment of autoimmune disease. Part 1: rheumatologic and renal diseases.

When cytotoxic agents were initially introduced, their ability to disrupt nucleic acid and protein synthesis led to their effective use for the treatment of neoplastic disease. During the course of this use, however, it became apparent that these agents also suppress the immune system. This usually unwelcome effect was subsequently studied and beneficially directed toward the treatment of non-neoplastic diseases in which autoimmune mechanisms were considered important to pathogenesis. As a result of these investigations, cytotoxic agents and, more recently, cyclosporine have emerged to become an important part of the therapeutic regimen for many autoimmune diseases. Nonetheless, these medications may still cause treatment-induced illness or even death. It is therefore particularly important to weigh the benefits and risks of cytotoxic therapy when treating a non-neoplastic disease. This two-part Clinical Staff Conference reviews data on the efficacy and toxicity of cytotoxic drugs and cyclosporine in selected autoimmune diseases. Part 1 examines the manner in which these agents have been used to treat rheumatologic and renal diseases.

A pilot study of 2-chloro-2'-deoxyadenosine in the treatment of systemic lupus erythematosus-associated glomerulonephritis.

OBJECTIVE: To determine the safety and tolerability, as well as the clinical and immunologic effects, of 2-chloro-2'-deoxyadenosine (2-CdA) in patients with systemic lupus erythematosus-associated glomerulonephritis. METHODS: In a phase I study, 12 patients with proliferative lupus nephritis received 2-CdA either in weekly escalating intravenous treatments (0.15 mg/kg/week x 4, 0.1875 mg/kg/week x 4, 0.225 mg/kg/week x 4; n = 5) or in a continuous 7-day infusion (0.05 mg/kg/day; n = 7). Safety, renal improvement, and immunologic effects were evaluated for 12 months. RESULTS: Patients treated with 2-CdA showed peripheral lymphocyte depletion without a significant reduction in neutrophil, monocyte, or platelet numbers or hematocrit levels. Naive and memory T cells were decreased, as were lymphocytes with markers of early and late activation. Peripheral B cell depletion was not associated with significant decreases in serum immunoglobulin levels. Continuous infusion induced better clinical responses than weekly infusions, as evidenced by 1) the percentage of patients showing complete response (43% versus 0%), 2) the percentage with at least 50% reduction in proteinuria (43% versus 20%), 3) the percentage with at least a 50% reduction in urinary dysmorphic red cells (57% versus 0%), and 4) the percentage in whom cellular casts disappeared (43% versus 0%). Several infections occurred; these responded to standard antibiotic therapy. CONCLUSION: In this pilot study, 2-CdA was safely administered to 12 patients with lupus nephritis. It induced prolonged reductions in lymphocyte populations and may be efficacious in selected patients with lupus nephritis when administered as a continuous infusion.

Novel approaches in the treatment of lupus nephritis.

Lupus nephritis can be managed successfully in the majority of cases; most therapies, however, are associated with significant side-effects. Several new agents aiming at specific stages in the pathogenesis of lupus are in different phases of clinical trials. The central role of lymphocytes makes them targets of various therapeutic approaches. Lymphocyte depletion can be achieved by high-dose chemotherapy with or without bone marrow transplantation. Nucleoside analogs selectively deplete mononuclear cells; antibodies against T or B cell surface antigens target specific subsets of lymphocytes. Synchronized plasmapheresis has been used in an attempt to delete pathogenic lymphocyte clones activated by plasmapheresis. Treating patients with DNase or neutralizing pathogenic antibodies by administering specific binding peptides or inducing specific anti-idiotype antibodies may prevent immune complex formation and/or deposition. Blocking the complement cascade or some of the inflammatory mediators like thromboxane A2 may be efficacious even if immune complex deposition could not be prevented. Inducing antigen-specific tolerance or interfering with important interactions between T-lymphocytes and other cells by blocking CD40 ligand or decreasing the level of interleukin-10 are some of the other approaches currently under clinical investigation.