Therapeutic plasmapheresis in systemic lupus erythematosus. Effect on immune complexes and antibodies to DNA

Therapeutic Plasma Exchange Versus FcRn Inhibition in Autoimmune Disease

Therapeutic plasma exchange (TPE or PLEX) is used in a broad range of autoimmune diseases, with the goal of removing autoantibodies from the circulation. A newer approach for the selective removal of immunoglobulin G (IgG) antibodies is the use of therapeutic molecules targeting the neonatal Fc receptor (FcRn). FcRn regulates IgG recycling, and its inhibition results in a marked decrease in circulating autoantibodies of the IgG subtype. The difference between FcRn inhibition and PLEX is often questioned. With anti-FcRn monoclonal antibodies (mAbs) and fragments only recently entering this space, limited data are available regarding long-term efficacy and safety. However, the biology of FcRn is well understood, and mounting evidence regarding the efficacy, safety, and potential differences among compounds in development is available, allowing us to compare against nonselective plasma protein depletion methods such as PLEX. FcRn inhibitors may have distinct advantages and disadvantages over PLEX in certain scenarios. Use of PLEX is preferred over FcRn inhibition where removal of antibodies other than IgG or when concomitant repletion of missing plasma proteins is needed for therapeutic benefit. Also, FcRn targeting has not yet been studied for use in acute flares or crisis states of IgG-mediated diseases. Compared with PLEX, FcRn inhibition is associated with less invasive access requirements, more specific removal of IgG versus other immunoglobulins without a broad impact on circulating proteins, and any impacts on other therapeutic drug levels are restricted to other mAbs. In addition, the degree of IgG reduction is similar with FcRn inhibitors compared with that afforded by PLEX. Here we describe the scientific literature regarding the use of PLEX and FcRn inhibitors in autoimmune diseases and provide an expert discussion around the potential benefits of these options in varying clinical conditions and scenarios.

Risk factors of diffuse alveolar hemorrhage in Chinese patients with systemic lupus erythematosus

This study aimed to investigate the frequency and features of diffuse alveolar hemorrhage (DAH) in Chinese patients with systemic lupus erythematosus (SLE) and evaluate the association of DAH with the features. A total of 943 patients with SLE were categorized into two groups: 896 patients without DAH and 47 patients with DAH. The demographic data, clinical and laboratory findings, and SLE disease activity index 2000 of all patients were statistically analyzed. The DAH frequency in patients with SLE was 4.98%, and the mortality rate of DAH was 42.55%. The clinical features with statistical differences between the two groups were analyzed by multivariate logistic regression, and the results suggested that shorter disease duration [odds ratio (OR): 0.972, 95% confidence interval (CI) 0.946, 0.998], younger age (OR: 0.867, 95% CI 0.764, 0.984), moderate (OR: 25.949, 95% CI 3.316, 203.065) or severe (OR: 24.904, 95% CI 2.675, 231.859) anemia, abnormally elevated levels of urine protein (OR: 10.839, 95% CI 1.351, 86.938) and serum creatinine (OR: 14.534, 95% CI 5.012, 42.142), interstitial lung disease (OR: 6.569, 95% CI 2.053, 21.021), and infection (OR: 8.890, 95% CI 3.580, 22.077) were independent risk factors for the occurrence of DAH in patients with SLE. Moderate or severe anemia was highly suggestive of DAH.

Optic neuritis with potential for poor outcome

The Optic Neuritis Treatment Trial previously reported that corticosteroids accelerated visual recovery in optic neuritis (ON) without improving outcome. This finding related largely to multiple sclerosis (MS), and subsequently neurologists tended to await spontaneous recovery in ON. Since then, non-MS cases of ON have been identified with antibodies to aquaporin-4 (AQP4) or myelin oligodendrocyte glycoprotein (MOG). These disorders can closely mimic multiple sclerosis-associated or idiopathic demyelinating optic neuritis (MS/IDON) initially but risk a worse visual outcome. Scrutinising the clinical features and neuroimaging often enables differentiation between MS/IDON and other causes of ON. Early treatment with high-dose corticosteroids is an important determinant of visual outcome in non-MS/IDON. Prompt use of plasma exchange may also save sight. In this review, we contrast the presentations of myelin oligodendrocyte glycoprotein associated optic neuritis (MOG-ON) and aquaporin 4 associated optic neuritis (AQP4-ON) with MS/IDON and provide an approach to acute management while awaiting results of antibody testing.

Plasma Exchange in Patients with Guillain-Barré Syndrome: Clinical Improvement in Patients with Serum IgG Antibodies to Peripheral Nerve Tissue

The mixed hemagglutination technique was used to demonstrate IgG antibodies to peripheral nerve tissue in sera from patients with Guillain-Barré syndrome. The clinical effect and the effect on the antibodies of plasma exchange (PE) were examined in 24 patients, 16 patients with acute form and 8 patients with the chronic form of the disease. Neurological examination with muscle testing and neurophysiological examination of the patients were performed before and immediately after the PE. Before PE antibodies were detected in sera from 15 of the patients. These patients showed clinical improvement during the treatment, however in one of the patients only after a time interval of 2 weeks. After PE, antibodies were detected in sera from only 3 of the patients. The 9 patients without detectable antibodies showed no clinical improvement.

The mechanisms of action of plasma exchange

The initial description of therapeutic plasma exchange (TPE) in an animal model was published almost 100 years ago. Since that time, this treatment has been applied to a wide variety of diseases but limited research has been published examining the mechanisms of action of TPE. The therapeutic effects of TPE could include the removal of pathological substances from the blood, such as monoclonal paraproteins and autoantibodies, as well as the replacement of deficient plasma components when plasma is used as a replacement fluid. Beyond these potential mechanisms, other possible mechanisms include possible alterations in lymphocyte proliferation and function that could sensitize these cells to immunosuppressant and chemotherapeutic agents and alterations in the immune system including changes in B and T cell numbers and activation, increased T suppressor function, and alteration in T-helper cell type 1/2 (Th1/Th2) ratio. Much remains unknown about the mechanisms of action of TPE, indicating a need for basic research into this therapy.

Therapeutic plasma exchange: a technical and operational review

Therapeutic plasma exchange (TPE) is an extracorporeal blood purification technique designed for the removal of large molecular weight substances. Examples of these substances include pathogenic autoantibodies, immune complexes, cryoglobulins, myeloma light chains, endotoxin and cholesterol containing lipoproteins. The basic premise of the treatment is that removal of these substances will allow for the reversal of the pathologic processes related to their presence. This review will cover the techniques for performing TPE, the kinetics of the removal of large molecules from the plasma and the benefits and risks of the different types of replacement fluids.

The severity of systemic lupus erythematosus negatively correlates with the increasing number of CD4+CD25(high)FoxP3+ regulatory T cells during repeated plasmapheresis treatments of patients

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by increased pathologic autoantibody production. A decrease in the number of CD4+CD25(high)FoxP3+ regulatory T cells can play a key role in the loss of tolerance to self antigens. Our aim was to determine the absolute number of peripheral CD4+CD25(high)FoxP3+ T cells in 44 patients with SLE, furthermore, to measure the changes in the number of CD+CD25(high)FoxP3+ T cells in 5 patients with severe SLE treated with repeated plasmapheresis for 4-6 days in comparison to the changes in the activity of disease (SLEDAI). Percent of CD4+CD25(high)FoxP3+ T cells were measured by flow cytometry. The absolute number of peripheral CD4+CD25(high)FoxP3+ T cells was significantly decreased in the 44 patients with SLE compared to the healthy controls n = 32 (0.012 +/- 0.006 vs. 0.038 +/- 0.017 G/L, p < 0.05). In the 5 patients with severe SLE the repeated plasmapheresis treatments increased the peripheral number of CD4+CD25(high)FoxP3+ T cells. As the number of CD4+CD25(high)FoxP3+ T cells increased during the treatment, the activity of disease (the value of SLE activity index) decreased. In the peripheral blood of SLE patients not only the ratio was decreased (as it was published earlier) but also the absolute number of these regulatory T cells. The repeated plasmapheresis treatments of SLE patients induced a significant increase in the number of peripheral CD4+CD25(high)FoxP3+ T cells in parallel to the decrease in the values of SLEDAI (the activity of disease). This phenomenon is, among others, possibly due to the elimination of interpheron-alpha and lymphocytotoxic antibodies during plasmapheresis.

Plasma exchange for systemic lupus erythematosus

Efficacy of plasma exchange in patients with systemic lupus erythematosus has not been supported by the results of the first non-controlled and retrospective studies. Nonetheless, they remain relevant for some selected patients with life-threatening manifestations and/or severe therapy-resistant manifestations. They can be used as an adjuvant therapy in combination with corticosteroids and, when required, other immunosuppressant(s) for refractory renal disease, alveolar hemorrhage, some neuropsychiatric manifestations, thrombotic thrombocytopenic purpura, catastrophic antiphospholipid syndrome, hyperviscosity syndrome or symptomatic cryoglobulinemia. The use of newer technologies, like immunoadsorption, possibly in combination with recent biologics, might, in the future, offer some new perspectives for extracorporeal therapy of systemic lupus erythematosus.

Indications for plasma exchange in systemic lupus erythematosus in 2005

Plasma exchange can remove putative pathogenic autoantibodies and circulating immune complexes from the blood of patients with systemic lupus erythematosus (SLE). However, their efficacy has only been supported by noncontrolled and/or retrospective studies. Nonetheless, PE may still be of relevance in some selected SLE patients and as adjunctive therapy, in combination with corticosteroids (CS) and other immunosuppressant(s). We review herein the principal historical steps of the use of plasma exchange to treat SLE, based upon the main trials and case reports that have highlighted its most pertinent indications. Acute life-threatening manifestations and severe therapy-resistant manifestations, like refractory SLE renal disease, diffuse alveolar hemorrhage, neuropsychiatric SLE, thrombotic thrombocytopenic purpura, catastrophic antiphospholipid syndrome, hyperviscosity syndrome and cryoglobulinemia, are the indications for which plasma exchange might have a beneficial therapeutic role. Although few SLE patients undergo plasma exchange each year nowadays (10-20 per year in France), adverse events are very rare and recent advances in plasma exchange technologies, like immunoadsorption, might, in the future, counterbalance their cost and broaden their place in the therapeutic armamentarium for SLE.

Pilot clinical study of Adacolumn cytapheresis in patients with systemic lupus erythematosus

The aim of this study is to investigate the clinical effects of cytapheresis using the Adacolumn system (selective removal of circulating monocytes and granulocytes by means of an extracorporeal type column) in patients with active systemic lupus erythematosus (SLE). An open uncontrolled multicenter pilot study was conducted in 18 SLE patients who were showing a SLEDAI score of 8 or more under conventional medication. Patients with lupus nephritis (>class 1, WHO classification) were excluded. Extracorporeal cytapheresis with the Adacolumn system was administered once a week for five consecutive weeks. The efficacy of the treatment was evaluated using the SLEDAI for 10 weeks after the first cytapheresis session. The median SLEDAI decreased from 16 at baseline to six at week 11 (10 weeks after the first apheresis) (p<0.001). Significant improvements in musculoskeletal and dermal systems were observed. Arthritis and alopecia were present in 14 and nine patients at baseline and this number decreased to five and one patients, respectively by week 11. Three mild and one moderate adverse events out of the 42 reported events were judged 'probably related' to the treatment; no serious adverse events were reported. Selective removal of monocytes and granulocytes from the blood in an extracorporeal circulation system was associated with clinical improvement in this small series of patients with SLE. Since this approach seems not to have the disadvantages of pharmacological immunosuppression, further controlled studies of Adacolumn cytapheresis are warranted in SLE.

The use of apheresis in immune renal disorders

Rapidly progressive glomerulonephritis (RPGN) is often associated with the presence of autoantibodies. Included in this group are the glomerulonephritides associated with anti-GBM antibody (Goodpasture's syndrome). IgA mesangial deposition (the renal component of Henoch-Schönlein purpura), lupus erythematosus, cryoglobulinemia and the antineutrophil cytoplasmic antibody (ANCA)-associated pauci-immune group. In each of these cases, apheresis may provide a therapeutically useful option. Apheresis has also been found useful in certain types of antibody-mediated transplant rejection and in lowering the levels of preformed cytotoxic antibodies which may preclude transplantation. Finally, there are renal diseases in which the immune component is less clearly involved with pathogenesis but for which apheresis may offer a clear benefit, such as in the renal failure associated with 'cast nephropathy' (multiple myeloma) or the recurrence of FSGS (focal segmental glomerulosclerosis) in transplanted kidneys. It is the purpose of this paper to review the evidence supporting the use of apheresis in immune-related diseases.

An approach to evidence-based therapeutic apheresis

This review is derived from a memorial lecture honoring Dr. Francis Morrison, a former President of the American Society For Apheresis (ASFA). The author had numerous professional contacts with Dr. Morrison through ASFA in the early 1990s, having served with him on the Board of Directors and followed him as President, and also came to know him well on a personal level. Professionally, Dr. Morrison stood out as a courtly gentleman with a marvelous baritone voice whose ability to facilitate organization contributed to a growing sense of dignity and purpose in the affairs of the society. On the personal side, however, there wasn't an ounce of pretension in him. He was accessible and down-to-earth; a genuine character with an active and appealing sense of humor. Not surprisingly, he seemed to have a wealth of insight and "common sense," and since the topic of this study is a kind of common sense approach to assessing the effectiveness of therapeutic apheresis, it seems a fitting way to honor his memory.

[Dilated cardiomyopathy and autoimmunity: an overview of current knowledge and perspectives]

The diagnosis of idiopathic dilated cardiomyopathy is assigned to patients with left ventricular systolic dysfunction and dilatation in the absence of any other documented cause. Idiopathic dilated cardiomyopathy is presumed to have a multifactorial origin, possibly including autoimmune mechanisms. We reviewed the current state of knowledge of this topic, including a pathophysiological hypothesis postulating a relation between an autoimmune process and sympathetic over-stimulation and systolic dysfunction. The implications for therapy are considered in the light of experience with other autoimmune diseases. The results of immunosuppressant treatment and preliminary experiences with immunoadsorption are reviewed and their future perspectives are discussed.

The effectiveness of intravenous human immunoglobulin treatment after plasmapheresis in restoring serum immunoglobulin levels: a preliminary study

This study was performed to examine the effects of intravenous human immunoglobulin (IVIG) on the level of serum immunoglobulin G (IgG) and its subclasses after plasmapheresis in patients with autoimmune disorders. Twenty-nine patients with predominantly rheumatoid arthritis were enrolled in this study. The plasmapheresis was performed by the use of double-filtration plasmapheresis (DFPP). Immediately after DFPP, IVIG (2.5 g, 50 ml) was intravenously administered. The treatment with IVIG had almost no effect on subjective and objective symptoms. Immediately after DFPP, the total of serum IgG was decreased by approximately 40%. After 24 h, the total of serum IgG recovered to 16% reduction in IVIG-treated patients whereas it remained at 32% reduction in nontreated patients. The beneficial effect of IVIG was significantly observed in patients who had shown 1,000-1,800 mg/dl IgG in their sera. After DFPP, IgG subclasses were decreased without change in the ratio of subclasses. Twenty percent to 30% of IgG subclasses were supplemented by the treatment with IVIG without change in the ratio of subclasses. These results suggested that the treatment with IVIG at minimal amount was safe and effective to supplement IgG for hypogammaglobulinemia after DFPP.

Apheresis for lupus erythematosus: state of the art

PP is a safe, expensive, labor-intensive procedure. Its absolute SLE indications include hyperviscosity, cryoglobulinemia, pulmonary hemorrhage and TTP. PP may be useful in cyclophosphamide-resistant, serious, organ-threatening disease. It may be potentially useful in the antiphospholipid syndrome or mothers or children at risk for congenital heart block. Refinements in apheresis technology may expand the indications for PP.

Apheresis for Renal Disease

Many primary renal diseases are associated with either antibody deposition within the glomerulus or an antibody associated autoimmunity, as may be seen with certain vasculitidies. Examples of these diseases include Goodpasture's syndrome, cryoglobulinemia, antineutrophil cytoplasmic antibody positive syndromes, and other forms of rapidly progressive glomerulonephritis. Immunoglobulins also may be nephrotoxic to the tubules such as is the case with myeloma related light chains. Given the rapid removal of immunoglobulins by therapeutic plasma exchange, this modality has been considered an appealing management option in the treatment of these renal diseases. Although not classically considered as autoimmune diseases, thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are related syndromes which often involve the kidneys. Although previously unexplained, it has been long appreciated that therapeutic plasma exchange (PE) can be a useful treatment for these microangiopathic hemolytic anemias, but the most recent insights into their pathogenesis suggest that PE may be beneficial by replacing a missing enzyme or removing pathogenic autoantibodies.

In vitro removal of human IgG autoantibodies by affinity filtration using immobilized L-histidine onto PEVA hollow fiber membranes

Histidine was immobilized onto PEVA membrane to obtain an affinity support for human IgG removal from serum with a view to clinical apheresis for the treatment of autoimmune diseases. These membranes were able to remove in vitro several autoantibodies from the serum of SLE patients.

Life-threatening acute systemic lupus erythematosus: survival after multiple extracorporeal modalities: a place for the multipotential extracorporeal service

Diffuse alveolar hemorrhage secondary to systemic lupus erythematosus (SLE) may cause life-threatening respiratory failure and may be associated with multiple organ failure. Extensive support may be necessary to sustain life while systemic therapy becomes effective. We report here a patient with profound respiratory failure secondary to SLE associated with multiorgan failure, who was supported with veno-arterial extracorporeal lung assist (ECLA), veno-venous ECLA, and multiple continuous renal replacement therapies during plasmapheresis. The full spectrum of extracorporeal life support and treatment modalities was performed seamlessly by a single service within the critical care department.

Effect of plasmapheresis on ligand binding capacity and expression of erythrocyte complement receptor type 1 (CR1) of patients with systemic lupus erythematosus (SLE)

The functional activity and the expression of CR1 on the erythrocytes (E) of patients with SLE were, respectively, determined by measuring the binding to E of either complement-opsonized bovine serum albumin (BSA)-anti-BSA immune complexes (ICC) or specific anti-ECR1 MoAbs. We found that both the functional activity and levels of ECR1 in SLE patients homozygous for ECR1 high density allele were significantly lowered compared with healthy controls having the same allele. Soon after plasmapheresis there was a significant increase in E ICC binding activity, and this increased functional activity was stable. Moreover, plasmapheresis reduced the level of immune complexes demonstrable in the circulation of the patients. The expression of ECR1 determined with several different anti-CR1 MoAbs was also elevated as a consequence of plasmapheresis. This elevation was observed for both MoAb 1B4, which competes for the ICC binding site of ECR1, and for MoAb HB8592, which does not, but the time course for the increase in binding of the two MoAbs was different, in that the epitope recognized by MoAb 1B4 increased more rapidly. The present results, considered in the context of previous findings, suggest that more than one mechanism may be operative with respect to the effects of the plasmapheresis in increasing ECR1 levels defined by different epitopes on the molecule.

Apheresis for lupus erythematosus

Indications for the use of apheresis technologies in managing lupus erythematosus have undergone numerous conceptual changes since the procedure was automated in the 1960s and first attempted for systemic lupus erythematosus (SLE) in 1974. Once thought to be a promising treatment for a variety of aspects of SLE, apheresis has been relegated to occupying a few important niches as an adjunct in managing the disorder. This article will review the history, physiology and rationale of apheresis pertaining to SLE. A focused critical review of pertinent literature is presented, along with specific recommendations relating to the place of apheresis in the lupus therapeutic spectrum.

Therapeutic apheresis for renal disorders

Many primary renal diseases are associated with either antibody deposition within the glomerulus or an antibody associated autoimmunity, as may be seen with certain vasculitidies. Other immunoglobulins may be nephrotoxic or glomerulopathic; such may be the case with myeloma related light chains or cryoglobulins. Given the rapid removal of immunoglobulins by therapeutic plasma exchange, this modality has been considered an appealing management option in the treatment of these autoimmune related renal diseases. Although not classically considered as autoimmune diseases, thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are related syndromes which often involve the kidneys. In many cases therapeutic plasma exchange has been found to be a useful treatment modality for these microangiopathic hemolytic anemias. This paper will provide a concise review of the renal indications for therapeutic plasma exchange.

Therapeutic plasma exchange for the treatment of rapidly progressive glomerulonephritis

Therapeutic plasma exchange (TPE) has been widely accepted as a successful means of removing the antiglomerular basement membrane (anti-GBM) antibodies that result in the rapidly progressive glomerulonephritis (RPGN) of Goodpasture's syndrome. TPE has also been investigated as a means of removing the immune complexes associated with the glomerulonephritides of systemic lupus erythematosus, IgA nephropathy, Henoch Schönlein purpura, and cryoglobulinemia. Recently, an antineutrophil cytoplasmic antibody (ANCA) has been implicated in the pathogenesis of RPGN associated with such diseases such as Wegener's granulomatosis and periarteritis nodosa. ANCA has also been found in many cases of RPGN formally considered to be idiopathic. The identification of this autoantibody has given new credence to the possibility that TPE may be beneficial in the treatment of these diseases. This article reviews the data regarding the use of TPE for RPGN.

Recovery of both acute massive pulmonary hemorrhage and acute renal failure in a systemic lupus erythematosus patient with lupus anticoagulant by the combined therapy of plasmapheresis plus cyclophosphamide

Acute massive pulmonary hemorrhage (AMPH) is a rare and highly fatal complication in systemic lupus erythematosus (SLE). We report here survival in a case of AMPH in a SLE patient with both rapidly progressive glomerulonephritis and lupus anticoagulant. The AMPH occurred while the nephritis was refractory to 2 courses of pulse methylprednisolone therapy. After combined therapy with plasmapheresis plus cyclophosphamide, circulating immune complex levels declined, AMPH recovered, and serum creatinine levels returned to normal. In conclusion, the combined therapy of plasmapheresis plus cyclophosphamide should be considered for treating AMPH especially in those SLE patients with rapidly progressive glomerulonephritis.

A controlled trial of plasmapheresis therapy in severe lupus nephritis. The Lupus Nephritis Collaborative Study Group

BACKGROUND

The prognosis of patients with systemic lupus erythematosus who have glomerulonephritis is poor, despite treatment with immunosuppressive therapy. Plasmapheresis therapy has been used, but there have been few controlled clinical observations of its efficacy.

METHODS

We carried out a randomized, controlled trial comparing a standard-therapy regimen of prednisone and cyclophosphamide (standard therapy) with a regimen of standard therapy plus plasmapheresis in 86 patients with severe lupus nephritis in 14 medical centers. The patients underwent plasmapheresis three times weekly for four weeks. Drug therapy was standardized, with strict adherence to nine detailed medical-management protocols.

RESULTS

Forty-six patients received standard therapy, and 40 patients received standard therapy plus plasmapheresis. The mean follow-up was 136 weeks. Six patients (13 percent) in the standard-therapy group and eight patients (20 percent) in the plasmapheresis group died. Renal failure developed in 8 patients (17 percent) in the standard-therapy group, as compared with 10 (25 percent) in the plasmapheresis group. Thirty patients (35 percent) reached stopping points--14 (30 percent) in the standard-therapy group and 16 (40 percent) in the plasmapheresis group. A similar number of patients in each group had a decrease in both the serum creatinine concentration and urinary protein excretion to approximately normal values. Patients treated with plasmapheresis had a significantly more rapid reduction of serum concentrations of antibodies against double-stranded DNA and cryoglobulins.

CONCLUSIONS

Treatment with plasmapheresis plus a standard regimen of prednisone and cyclophosphamide therapy does not improve the clinical outcome in patients with systemic lupus erythematosus and severe nephritis, as compared with the standard regimen alone.

Plasmapheresis and subsequent pulse cyclophosphamide versus pulse cyclophosphamide alone in severe lupus: design of the LPSG trial. Lupus Plasmapheresis Study Group (LPSG)

A group of clinics are collaborating in the Lupus Plasmapheresis Study Group (LPSG) to investigate whether repeated plasmapheresis prior to pulse cyclophosphamide improves the therapeutical results in severe systemic lupus erythematosus (SLE). The underlying rationale is the hypothesis that plasmapheresis 1) eliminates pathogenic autoantibodies and immune complexes and 2) induces compensatory lymphocyte activation via feedback mechanisms between circulating antibodies and their respective clones ("antibody rebound"). It should be possible to utilize this enhanced activity for increased clonal deletion if pulse cyclophosphamide is applied shortly after plasmapheresis. Accordingly, in a randomized study, the LPSG will be comparing the repeated application of pulse cyclophosphamide alone with a treatment involving repeated plasmapheresis prior to the cyclophosphamide pulses in severe SLE. A third arm of the study will be gathering experience with a more intensified procedure. This overview summarizes the most important details of the planned study.

Apheresis enhances the selective removal of antinuclear antibodies in systemic lupus erythematosus

Apheresis suppresses clinical manifestations of lupus and reduces levels of antinuclear antibodies implicated in the pathogenesis of systemic lupus erythematosus (SLE). It is not known, however, if reduced levels of antinuclear antibodies are due to nonspecific removal, or specific mechanisms associated with decreased production, or enhanced clearance from the circulation. In order to distinguish between specific and nonspecific effects of apheresis on antinuclear antibodies in SLE, we compared plasma levels of IgG antibodies to DNA and IgG antibodies to microbial antigens in 13 SLE patients before and after apheresis. Although apheresis lowered plasma levels of IgG (21% mean reduction), there was a disproportionate reduction in IgG antibodies to DNA (42% mean reduction, p less than 0.13). In marked contrast, reduction in antibodies to microbial antigens did not exceed those of plasma IgG. A rapid rebound of serum anti-DNA antibodies following apheresis in certain SLE patients suggests that the selective reduction in anti-DNA antibodies is due to enhanced clearance from the circulation rather than decreased production. These results indicate that apheresis enhances selective removal of antinuclear antibodies in some patients with SLE.

Selective removal of anti-double-stranded DNA antibodies by immunoadsorption with dextran sulphate in a patient with systemic lupus erythematosus

A dextran sulphate gel column removed anti-double-stranded DNA antibodies (anti-dsDNA) selectively, efficiently, and safely from the circulation of a patient with systemic lupus erythematosus (SLE). The mechanism of the removal is thought to be due to cross reactivity of anti-dsDNA with dextran sulphate, which has negatively charged units. Selective removal of anti-dsDNA is expected to contribute not only to the treatment but also to elucidation of the pathogenesis of SLE.

The treatment of lupus nephritis

The literature on the treatment of lupus nephritis is scattered, much of it in rheumatological rather than nephrological journals. Whatever our ignorance of the nature and genesis of lupus nephritis, under empirical treatment the prognosis, especially for severe forms, has improved dramatically during the past 20 years. For severe lupus nephritis, the evidence that the addition of cytotoxic agents to corticosteroids improves outcome is now secure, and discussion centres mainly on which drug to use and by what route. Intravenous methylprednisolone is at least as effective as high-dose tapering oral therapy for initial treatment, and carries fewer side-effects. The role of plasma exchange in lupus remains undefined: it may have a role in the treatment of cerebral manifestations or otherwise resistant patients, but controlled trials have failed to show benefit. Future developments will probably centre around the use of specific monoclonal antibodies which target specific groups and subgroups of cells, "humanised" by the splicing of human Fc piece to rodent (fab)2, perhaps bearing toxins. To use these agents to best advantage, however, we will have to understand better than we do today the nature of the cellular defects in the immune response which underlie the lupus syndrome.

Immune complex assays: diagnostic and clinical application

The presence of circulating immune complexes have been described in many different human disease states but the significance of their presence has always been a subject for debate. Improvements in the methods of detecting immune complexes have demonstrated a wide degree of heterogeneity, which accounts for the difficulty in obtaining accurate and reproducible measurements, even in the same individual. Techniques for isolating individual complexes, characterizing their pathophysiological properties, and biochemically analyzing the nature of the complexed antigen are now being used to provide data that is helping to clarify the role of immune complexes in the pathogenesis of disease. In addition, such studies are also providing data which is proving that immune complexes have a potential role in immune regulation.

Plasma exchange improves the glomerulonephritis of systemic lupus erythematosus in selected pediatric patients

The effects of short-course plasma exchange (PE) followed by tapering dose prednisone therapy was assessed in six children with systemic lupus erythematosus (SLE) and severe glomerulonephritis. All patients received pulse methylprednisolone therapy and three patients were treated with cytotoxic drugs prior to PE, but none had exhibited a good response. PE resulted in a rapid and sustained (greater than 1 year) remission of renal failure in the three patients with renal failure and severe glomerulonephritis. All six patients had severe nephrotic syndrome and five of six experienced a complete and sustained (greater than 1 year) remission post-PE (the sixth patient has greater than 4 month remission at the time of writing). Of interest was the high frequency of membranous [World Health Organization (WHO) Type V] and mixed membranous and diffuse proliferative SLE nephritis (WHO Type IV) on renal biopsy (4/6 patients). In addition, the severe anemia and leukopenia seen in most patients responded favorably to PE. Five of the six patients are currently managed on low-dose prednisone (0.25-0.5 mg/kg) every other day. One patient progressed to renal failure and dialysis more than 1 year post-PE. One patient required cytotoxic drug therapy post-PE (6 weeks). No significant complications were encountered; in fact, all patients eventually received their PE treatments as outpatients. We conclude that PE may provide a safe and effective therapeutic option for the treatment of severe progressive SLE nephritis in selected children who are unresponsive to steroid or cytotoxic drug therapy.

Infective complications of plasma exchange: a prospective study

We examined the incidence and types of infective complications which occurred in 41 patients whose medical management included plasma exchange (PX) by intermittent cannulation; femoral, subclavian, or internal jugular catheter; or arteriovenous shunt. A high incidence of positive cultures from vascular access catheters was demonstrated. Of 23 patients for whom data were available, 13 had positive cultures, and results on 3 of these showed greater than 1 species. Gram-positive cocci were typically found. Of the 34 patients who received drug immunosuppression with PX, 1 patient developed severe shunt-site infection, and an additional 4 developed bacteremia. Seven patients were given PX alone, and none of these developed clinically significant infection; however, this difference in infection rate did not reach statistical significance. Clinically significant access-related infection remains an infrequent but potentially important hazard of therapeutic PX.

Plasmapheresis in acute liver failure

A series of 9 patients with acute hepatic failure and Grade IV hepatic coma received daily plasmapheresis until they recovered or death ensued. Of the nine, seven (77%) showed an improvement in coma grade and five (55%) survived to leave hospital. Plasmapheresis significantly decreased serum bilirubin, aspartate aminotransferase and plasma ammonia concentrations. Survival following plasmapheresis appeared substantially better than in a non randomized group of similar patients not plasmapheresed. The simplicity of the procedure, biochemical improvements observed and apparent efficacy, suggest that further evaluation of the technique as a means of providing temporary hepatic support is indicated.

Therapeutic plasmapheresis and plasma exchange

Plasma exchange is a process in which large volumes of plasma, usually equivalent to one plasma volume, are exchanged with donor plasma or a plasma substitute. This permits the removal of antibody, immune complexes, inflammatory mediators, paraproteins, drugs, toxins, and other plasma constituents. Plasma exchange may also have an effect on the immune system by enhancing the function of the reticuloendothelial system, removing blocking antibody, increasing clearance of tumor cells, and making lymphocytes more vulnerable to immunosuppressive drugs. Over 100 diseases have been treated with plasma exchange with variable success. Results of controlled studies are less dramatic than those of earlier uncontrolled case reports. Reports of complications and even death have tempered initial enthusiasm. Now, over a decade since the initial promising reports began to appear in the literature, the role of plasma exchange remains undefined.