Treatment of refractory Wegener's granulomatosis with humanized monoclonal antibodies

Treatment of autoimmunity: The impact of disease-modifying therapies in multiple sclerosis and comorbid autoimmune disorders

More than 10 disease-modifying therapies (DMT) are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for the treatment of multiple sclerosis (MS) and new therapeutic options are on the horizon. Due to different underlying therapeutic mechanisms, a more individualized selection of DMTs in MS is possible, taking into account the patient's current situation. Therefore, concomitant treatment of various comorbid conditions, including autoimmune mediated disorders such as rheumatoid arthritis, should be considered in MS patients. Because the pathomechanisms of autoimmunity partially overlap, DMT could also treat concomitant inflammatory diseases and simplify the patient's treatment. In contrast, the exacerbation and even new occurrence of several autoimmune diseases have been reported as a result of immunomodulatory treatment of MS. To simplify treatment and avoid disease exacerbation, knowledge of the beneficial and adverse effects of DMT in other autoimmune disorders is critical. Therefore, we conducted a literature search and described the beneficial and adverse effects of approved and currently studied DMT in a large number of comorbid autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, cutaneous disorders including psoriasis, Sjögren´s syndrome, systemic lupus erythematosus, systemic vasculitis, autoimmune hepatitis, and ocular autoimmune disorders. Our review aims to facilitate the selection of an appropriate DMT in patients with MS and comorbid autoimmune diseases.

Alveolar Hemorrhage

Alveolar hemorrhage (AH) is a clinical syndrome with diverse etiologies both immune and nonimmune. The defining pathological feature of AH is the presence or absence of pulmonary capillaritis. The antineutrophil cytoplasmic antibody (ANCA) related vasculitis and systemic lupus erythematosus are the commonest causes of immune AH with pulmonary capillaritis, whereas Goodpasture's syndrome and idiopathic pulmonary hemosiderosis are common causes of immune AH without pulmonary capillaritis. The major nonimmune causes of AH are primarily drug induced, or due to hematological malignancy and disorders of coagulation. Clinical features of AH include: dyspnea, fever, hemotypsis, bilateral crackles and pallor. Hypoxemia and bilateral diffuse airspace disease on the chest radiograph with relative sparing of the bases and apices which most often clears within 48 hours after its onset further characterize this syndrome. The major clinical implications of this syndrome are its potential to cause respiratory failure in severe cases and its sequelae of pulmonary fibrosis with associated morbidity and disability. In addition, AH may be the initial manifestation of a systemic immune disorder which can be managed optimally if recognized early. The diagnosis of AH is confirmed by bronchoalveolar lavage by demonstrating a progressively bloody return on successive aliquots of instilled saline or hemosiderin laden macrophages in the bronchoalveolar lavage fluid. The open lung biopsy remains the gold standard for the diagnosis of AH but is reserved for inapparent cases in whom corticosteroids and immunosuppressive therapy may be life saving. Serologic testing and examination of the urine sediment are useful adjuncts to the diagnosis. The treatment of AH is primarily supportive while an attempt is made to determine its etiology and initiate specific therapy. Glucocorticoids and cyclophosphamide are the cornerstones of therapy in immune AH with adjunctive plasmapheresis in life-threatening cases.

Biologics for the treatment of autoimmune renal diseases

Biological therapeutics (biologics) that target autoimmune responses and inflammatory injury pathways have a marked beneficial impact on the management of many chronic diseases, including rheumatoid arthritis, psoriasis, inflammatory bowel disease, and ankylosing spondylitis. Accumulating data suggest that a growing number of renal diseases result from autoimmune injury - including lupus nephritis, IgA nephropathy, anti-neutrophil cytoplasmic antibody-associated glomerulonephritis, autoimmune (formerly idiopathic) membranous nephropathy, anti-glomerular basement membrane glomerulonephritis, and C3 nephropathy - and one can speculate that biologics might also be applicable to these diseases. As many autoimmune renal diseases are relatively uncommon, with long natural histories and diverse outcomes, clinical trials that aim to validate potentially useful biologics are difficult to design and/or perform. Some excellent consortia are undertaking cohort studies and clinical trials, but more multicentre international collaborations are needed to advance the introduction of new biologics to patients with autoimmune renal disorders. This Review discusses the key molecules that direct injurious inflammation and the biologics that are available to modulate them. The opportunities and challenges for the introduction of relevant biologics into treatment protocols for autoimmune renal diseases are also discussed.

Biotherapies targeting T and B cells: from immune suppression to immune tolerance

The field of immunotherapy has undergone a major rejuvenation with the development of monoclonal antibodies and fusion proteins targeting specialized receptors of T and B lymphocytes or cytokines relevant for the differentiation of these cells. This review will focus on autoimmunity, probably the field that benefited most from these new biological therapies that very significantly impacted the modalities of patient's care. The aim is to present the agents which constitute major disease modifying drugs for the treatment of chronic invalidating autoimmune diseases. In doing so, we shall distinguish between agents that globally depress immune responses and those that may selectively target the harmful autoimmune response over long-term while preserving the capacity of the host to react normally to exogenous antigens, in other words, agents promoting 'operational tolerance'.

Alemtuzumab in the treatment of multiple sclerosis

Alemtuzumab (formerly known as Campath-1H) has recently been approved by the European Medicines Agency for highly-active, relapsing-remitting multiple sclerosis (MS). The molecule targets the CD52 surface glycoprotein on certain T cells and B cells and is thought to exert its effect in MS through a “resetting” of the lymphocyte population. Approval was granted on the strength of two pivotal studies, Comparison of Alemtuzumab and Rebif® Efficacy in Multiple Sclerosis (CARE-MS)-1 in the first-line setting and CARE-MS-2 in patients who had failed first-line therapy. In both studies, alemtuzumab significantly reduced the relapse rate compared to the comparator, interferon beta-1a (44 μg) given subcutaneously three-times per week (Rebif®). In the first-line study, alemtuzumab was also found to significantly reduce the number of patients with sustained progression compared to interferon beta-1a therapy. Autoimmune disorders represent the major side effect of alemtuzumab therapy although they can be managed by careful monitoring and early treatment. Overall, alemtuzumab is likely to be a valuable addition to the neurologist’s armamentarium for the treatment of relapsing-remitting MS.

The outlook for alemtuzumab in multiple sclerosis

Alemtuzumab is a humanized anti-CD52 monoclonal antibody. Treatment in humans results in a rapid, profound, and prolonged B- and T-cell lymphopenia. Subsequently, lymphocyte reconstitution by homeostatic mechanisms alters the composition, phenotype, and function of T-cell subsets, thus allowing the immune system to be 'reset'. One phase II and two phase III randomized, multicenter, single-blinded (outcomes assessor) clinical trials of alemtuzumab in relapsing-remitting multiple sclerosis have now been completed. Against an active comparator and the current first-line therapy for relapsing-remitting multiple sclerosis (interferon-beta), alemtuzumab showed a significant reduction in annualized relapse rate as well as a significant reduction in the accumulation of disability. These outcomes are sustained over at least 5 years following treatment. The most common adverse effects are mild infusion reactions, an increased incidence of mild-to-moderate severity infections and secondary autoimmunity. The latter is observed in a third of treated patients, commonly thyroid disease but other target cells have been described including cytopenias. Marketing authorization applications have been submitted for the use of alemtuzumab in multiple sclerosis to the Food and Drug Administration and the European Medicines Agency, with licensing expected in 2013. Here, we discuss the outlook for alemtuzumab in multiple sclerosis in light of the currently available therapies, outcomes of and lessons learnt from clinical trials, and the overall position of monoclonal antibodies in modern treatment strategies.

A review of Campath in autoimmune disease: Biologic therapy in the gray zone between immunosuppression and immunoablation

Campath, the subject of this review, is an example of a broadly targeted biologic agent, approved for patients with B-CLL, which may combine immunosuppressive as well as immunoablative properties. For many years Campath has been in clinical use as an immunosuppressive agent for various autoimmune diseases and as part of the preparative regimes for allogeneic HSCT, successfully preventing graft-versus-host-disease (GVHD). This review summarizes the experience of 24 studies including a total of 323 patients treated with Campath for various autoimmune diseases such as arthritis, MS, vasculitis, autoimmune cytopenias and others. The results demonstrate that Campath is fairly safe and 75% of the patients experienced clinical improvement and 15% of the patients were reported in clinical remission even though improvements were often transient.While other biologic drugs may have to narrow targets, Campath, is able to bridge the gap between immunosuppression and immunoablation and may offer an alternative to human stem cell transplantation avoiding the risks of chemotherapy and radiation.

Biological therapy for systemic vasculitis: a systematic review

OBJECTIVE

Relapses and failure are frequent in systemic vasculitis (SV) patients. Biological agents have been prescribed as rescue therapies. The aim of this systematic review is to analyze the current evidence on the therapeutic use of biological agents for SV.

METHODS

MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched up to the end of April 2013. Systematic reviews and meta-analysis, clinical trials, cohort studies, and case series with >3 patients were included. Independent article review and study quality assessment was done by 2 investigators with consensus resolution of discrepancies.

RESULTS

Of 3447 citations, abstracts, and hand-searched studies screened, 90 were included. Most of the studies included ANCA-associated vasculitis (AAV) patients and only a few included large vessel vasculitis (LVV) patients. Rituximab was the most used agent, having demonstrated efficacy for remission induction in patients with AAV. A number of studies used different anti-TNFα agents with contrasting results. A few uncontrolled studies on the use of abatacept, alemtuzumab, mepolizumab, and tocilizumab were found.

CONCLUSION

Current evidence on the use of biological therapies for SV is mainly based on uncontrolled, observational data. Rituximab is not inferior to cyclophosphamide for remission induction in AAV and might be superior in relapsing disease. Infliximab and adalimumab are effective as steroid-sparing agents. Etanercept is not effective to maintain remission in patients with granulomatosis with polyangiitis, and serious adverse events have been reported. For LVV, both infliximab and etanercept had a role as steroid-sparing agents, and tocilizumab might be effective also for remission induction in LVV.

Alemtuzumab: evidence for its potential in relapsing-remitting multiple sclerosis

Alemtuzumab (previously known as Campath^®) is a humanized monoclonal antibody directed against the CD52 antigen on mature lymphocytes that results in lymphopenia and subsequent modification of the immune repertoire. Here we explore evidence for its efficacy and safety in relapsing–remitting multiple sclerosis. One Phase II and two Phase III trials of alemtuzumab versus active comparator (interferon beta-1a) have been reported. Two of these rater-blinded randomized studies assessed clinical and radiological outcomes in treatment-naïve patients; one explored patients who had relapsed despite first-line therapy. Compared to interferon beta-1a, alemtuzumab reduced the relapse rate by 49%–74% (P < 0.0001), and in two studies it reduced the risk of sustained disability accumulation by 42%–71% (P < 0.01). In one study (Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis; CARE-MS1), there was no significant difference compared to interferon, perhaps reflecting the surprisingly low frequency of disability events in the comparator group. After alemtuzumab, the Expanded Disability Status Scale score improved by 0.14–1.2 points, culminating in a net advantage with alemtuzumab of 0.41–0.77 points over interferon in the CAMMS223 and CARE-MS2 trials (both P < 0.001). Radiological markers of new lesion formation and brain atrophy following alemtuzumab were significantly improved when compared to interferon in all studies. Adverse events were more common following alemtuzumab than interferon beta-1a (7.2–8.66 versus 4.9–5.7 events per person-year). While infusion reactions are the most common, autoimmunity is the most concerning; within Phase III studies, thyroid disorders (17%–18% versus 5%–6%) and immune thrombocytopenic purpura (1% versus 0%) were reported in patients taking alemtuzumab and interferon beta-1a, respectively. All patients responded to conventional therapy. One patient taking alemtuzumab in the Phase II study suffered a fatal intracranial hemorrhage following immune thrombocytopenic purpura, heralding assiduous monitoring of all patients thereafter. Alemtuzumab has been submitted for licensing in relapsing–remitting multiple sclerosis in the United States and Europe.

Prospects for the application of antibodies in medicine

Prospects for the Application of Antibodies in Medicine.

[Alemtuzumab: a further option for treatment of multiple sclerosis]

Alemtuzumab is a humanized monoclonal therapeutic antibody that targets the CD52 antigen which s expressed on most cells of the lymphoid lineage, exclusive of precursors. Alemtuzumab rapidly depletes CD52(+) cells from the peripheral blood. This depletion is long-lasting, and cells repopulate in a specific pattern with B cells and regulatory T cells peaking first. Alemtuzumab was examined for clinical utility in two open-labelled intervention trials in multiple sclerosis (MS). Because of very promising results its clinical efficacy was further explored in a clinical phase-II trial using s.c. interferon beta-1a as the active comparator. Severe or opportunistic infections were surprisingly rare given the long-term lymphopenia. However, up to 30% of patients developed some antibody-mediated autoimmunity. The thyroid gland was the most frequently affected organ. Immune-mediated thrombocytopenic purpura and Goodpasture's syndrome were additionally observed. This review summarizes the pre-clinical and clinical development of alemtuzumab and discusses potential modes of action as well as the pathogenetic link to the treatment emergent autoimmune phenomena.

Immunological Aspects of Systemic Vasculitis

Primary vasculitis are commonly multifactorial disorders involving environmental, genetic and immunological factors. Several immune-based effector mechanisms are implicated in the vascular wall damage. These effector mechanisms commonly imply auto-antibodies or immune complexes - mediated cytotoxicity but the contribution of a T-cell mediated immune response has also been described, particularly in large vascular vasculitis. Despite advances in understanding the pathophysiological mechanisms of vasculitis, the triggering events initiating the disease remain largely undefined in most cases. This review highlights the recent advances in the etiopathogenesis of primary vasculitis. A better understanding of the immunological aspects of these disorders may provide insight into the development of novel therapeutical strategies.

Management of ANCA-associated vasculitis: Current trends and future prospects

The antineutrophil cytoplasm antibody (ANCA)-associated vasculitides are a spectrum of heterogeneous autoimmune diseases characterized by necrotizing small vessel vasculitis and the presence of ANCA. These chronic multisystem disorders may be life-threatening if there is major organ involvement, such as acute renal failure or pulmonary hemorrhage, and require significant initial immunosuppression and long-term maintenance treatment. Long-established protocols using cyclophosphamide and prednisolone have resulted in dramatically improved outcomes for patients since the 1970s. Subsequently, international collaboration has contributed to a growing evidence base and consensus in the management of these rare disorders. Modifications to traditional treatment protocols by the use of azathioprine or methotrexate rather than cyclophosphamide, and the introduction of newer agents, such as rituximab, has maintained outcomes whilst decreasing toxicity. However, the treatment limitations of incomplete efficacy, infection, and cumulative toxicity persist. These issues have continued to drive the search for safer and more effective modulation of the immune system using targeted immunotherapy. This review will explore the current evidence base for management of ANCA-associated vasculitis and future treatment prospects.

Urinary CD4+ effector memory T cells reflect renal disease activity in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

Numbers of circulating CD4+ effector memory T cells are proportionally increased in patients with proteinase 3 antineutrophil cytoplasmic antibody-associated vasculitis (AAV) whose disease is in remission and are decreased during active disease, which presumably reflects their migration toward sites of inflammation. Since renal infiltrating cells may appear in urine, we investigated the presence of CD4+ effector memory T cells in urinary sediment as a reflection of renal disease activity in AAV.

METHODS

CD4+ effector memory (CD45RO+CCR7-CD3+CD4+) T cells were quantitated in the urine and peripheral blood of patients with AAV with renal involvement (n = 33), patients with AAV without renal involvement (n = 18), patients with AAV whose disease was in remission (n = 29), and patients with active disease (n = 22), using 4-color flow cytometric analysis. Numbers and percentages of urine CD4+ effector memory T cells in 12 patients with AAV with active renal disease were obtained over several weeks of followup during remission induction.

RESULTS

A notable increase in urine CD4+ effector memory T cell numbers was observed in patients with active renal AAV compared with patients whose disease was in remission and patients with active disease without renal involvement. The increase in these cells in the urine of patients with active renal AAV was accompanied by a reciprocal decrease in these cells in peripheral blood. Results from followup analysis showed a clear reduction in urine CD4+ effector memory T cells following treatment. Moreover, a negative correlation was observed between percentages of circulating and urine CD4+ effector memory T cells, consistent with their migration toward sites of inflammation.

CONCLUSION

Our findings indicate that the presence of CD4+ effector memory T cells in urine reflects renal involvement in AAV. Flow cytometric analysis of these cells in urine may contribute to assessing renal disease activity in patients with AAV.

Pulmonary Renal Syndrome Due to Anti-GBM and IgM C-ANCA Disease Requiring the Use of Novel Therapeutic Agents

There are several known causes for the clinical syndrome of pulmonary hemorrhage and acute renal failure. Here, we report a unique case of a 50-year-old man presenting in this manner. The initial diagnosis was one of antiglomerular basement membrane (anti-GBM) disease that responded well to steroids, cyclophosphamide, and plasma exchange (PE). The pulmonary hemorrhage resolved, but he remained dialysis dependent. However, despite falling anti-GBM titers, the symptoms relapsed and standard therapy was reinitiated with limited success. The anti-GBM antibody titer fell to zero despite clinical deterioration, prompting a search for an alternative diagnosis. He was found to be IgM anti-proteinase-3 antineutrophil cytoplasmic antibody (C-ANCA) positive. The pulmonary hemorrhage responded successfully to the use of intravenous immunoglobulin and the antilymphocyte monoclonal antibody CD52. To our knowledge, this is the first known case of IgM C-ANCA in association with anti-GBM disease. As such, it highlights the predominance of pulmonary hemorrhage in this condition, as well as the need to consider alternative therapies in refractory cases.

[Possibilities and risks of the monoclonal antibody alemtuzumab as a new treatment option for multiple sclerosis]

Monoclonal antibodies are of growing interest as treatment options for immune-mediated diseases in neurology. As our knowledge of immunological principals increases, we learn to modulate specifically mechanisms of pathogenesis by the use of monoclonal antibodies. It is clearly desirable to improve efficacy in disease treatment without increasing toxicity by using drugs with more specific modes of action. Natalizumab was the first monoclonal antibody approved in the field of neurology for treatment of relapsing remitting multiple sclerosis (MS). Several other monoclonal antibodies are currently under investigation. Alemtuzumab, a monoclonal antibody targeting CD52, is a highly promising agent currently being studied in two phase III clinical trials. In this review, data from the recently published phase II clinical trial in the treatment of early relapsing remitting MS is summarized and analyzed in light of the development of alemtuzumab for MS and its potential role in treating this disease is discussed.

Targeted biologic approaches to the treatment of systemic vasculitis

The introduction of biological agents in the treatment of systemic vasculitis offers the promise of targeted therapy with greater efficacy and fewer side effects than conventional treatments. In this paper, we review the rationale for biological strategies in vasculitis and discuss the results of clinical studies to date. The biotherapies discussed include immune-cell-depleting agents, both B- and T-cell targeted; costimulatory blockade; and cytokine blockade. Although most of these agents remain unproven until ongoing randomized clinical trials are complete, their introduction heralds a new era of vasculitis treatment and has provided novel insights into disease pathogenesis.

CD4-Positive Effector Memory T Cells Participate in Disease Expression in ANCA-Associated Vasculitis

Although the cause of ANCA-associated vasculitis (AAV) remains undetermined, the presence of lymphocytic infiltrates in inflammatory lesions of patients suggests that vascular damage is immune mediated. Studies over the past decade have implicated a role for T cells in the pathogenesis of AAV as altered T cell phenotype has been observed in this disorder. The distribution of T cell subpopulations has been analyzed most intensely in Wegener's granulomatosis (WG), where an expanded population of circulating CD4(+) effector memory T cells (CD4(+)T(EM)) was demonstrated. CD4(+)T(EM) cells play a major role in the pathogenesis of several autoimmune diseases. Specific suppression of CD4(+)T(EM) cells inhibits delayed-type hypersensitivity (DTH) and has therapeutic potential in autoimmune disease. Thus, CD4(+)T(EM) cells may act as inducers of tissue injury and participate in the development of AAV. Therapies that target CD4(+)T(EM), without impairing the activity of other lymphocyte subsets, may hold therapeutic promise for AAV.

ANCA-associated vasculitis: new options beyond steroids and cytotoxic drugs

Small vessel vasculitic syndromes--Wegener's granulomatosis, microscopic polyangiitis and renal limited vasculitis (which are associated with circulating antineutrophil cytoplasmic autoantibodies)--are an important cause of renal failure. Present immunosuppressive regimens that are based on cyclophosphamide have significantly increased survival rates. However, these treatments are toxic, increase the risk of infection and do not cure disease. Therefore, newer approaches are required. Understanding disease pathogenesis has allowed rational use for newer therapies such as rituximab, which depletes B cells. Unfortunately, blockade of promising targets such as TNF-alpha, which was thought to be a pivotal cytokine in inflammation, has not shown benefit in a randomised controlled trial. Better understanding of the pathogenesis of the disease is the key to the development of novel targeted therapies, which are urgently required to improve patient prognosis. Gene therapy with targeted delivery of specific proteins is an exciting future prospect.

Pharmacological therapy for Wegener's granulomatosis

Wegener's granulomatosis (WG) is the most common pulmonary granulomatous vasculitis and was a uniformly fatal disease prior to the identification of efficacious pharmacological regimens. The pathogenesis of WG remains elusive but proteinase 3-specific anti-neutrophil cytoplasmic antibodies may be involved. Histologically, WG is defined by the triad of small vessel necrotising vasculitis, 'geographic' necrosis and granulomatous inflammation. Organ involvement characteristically includes the upper and lower respiratory tracts and kidney, but virtually any organ can be involved. The severity of the disease varies, ranging from asymptomatic disease to fulminant, fatal vasculitis. Similarly, the degree of organ involvement is highly variable; WG may be limited to a single organ (typically the lungs or upper respiratory tract), or may be systemic. Currently, a regimen consisting of daily cyclophosphamide and corticosteroids, which induces complete remission in the majority of patients, is considered standard therapy. Since approximately 50% of patients experience a relapse following discontinuation of therapy, alternative regimens designed to maintain remissions after using cyclophosphamide and corticosteroids are usually necessary. This 'induction maintenance' approach to treatment has emerged as a central premise in planning therapy for patients with WG.A number of trials have evaluated the efficacy of less toxic immunosuppressants (e.g. methotrexate, azathioprine, mycophenolate mofetil) and antibacterials (i.e. cotrimoxazole [trimethoprim/sulfamethoxazole]) for treating patients with WG, resulting in the identification of effective alternative regimens to induce or maintain remissions in certain sub-populations of patients. Given the efficacy of methotrexate (for early systemic WG) and cotrimoxazole (in WG limited solely to the upper airways) to induce remissions, and the relatively decreased associated morbidity compared with cyclophosphamide, these alternative regimens are preferred in appropriate patients. Similarly, therapeutic options to maintain disease remission that are less toxic than cyclophosphamide should be offered following induction of remission unless a specific contraindication exists. By following this premise, the development of cyclophosphamide-induced morbidities (e.g. haemorrhagic cystitis, uroepithelial cancers and prolonged myelosuppression) may be minimised. Recent investigation has focussed on other immunomodulatory agents (tumour necrosis factor-alpha inhibitors [infliximab and etanercept] and anti-CD20 antibodies [rituximab]) for treating patients with WG. However, the current data are conflicting and difficult to interpret. As a result, these newer agents cannot be recommended for routine use until vigorous clinical study confirms their efficacy.

Persistent expansion of CD4+ effector memory T cells in Wegener's granulomatosis

In order to test the hypothesis that Wegener's granulomatosis (WG) is associated with an ongoing immune effector response, even in remission, we examined the distribution of peripheral naive and memory T-lymphocytes in this disease, and analyzed the function-related phenotypes of the memory T-cell population. Peripheral blood mononuclear cells (PBMCs) were freshly isolated from WG-patients in remission (R-WG, n=40), active WG-patients (A-WG, n=17), and age-matched healthy controls (HCs, n=21). Expression of CD4, CD8, CD45RO, CCR7, interleukin (IL)-18Ralpha, ST2L, and FoxP3 were determined by four-color flow cytometric analysis. CD45RO and CCR7 were used for distinction between naive and memory T cells, IL-18Ralpha, ST2L, and FoxP3 for the assessment of Type1, Type2, and regulatory T-cells, respectively. In R-WG, the CD4+CD45RO+CCR7- effector memory T-cell subpopulation (TEM) was relatively increased, whereas the CD4+CD45RO-CCR7+ naive T-cell population (TNaive) was decreased as compared to HC. The distribution of naive and memory CD8+T cells did not differ between R-WG, A-WG, and HC, nor did CD4+CD45RO+CCR7+ central memory T cells (TCM). In contrast to HC, the percentage of CD4+TNaive cells in R-WG correlated negatively with age, whereas CD4+TEM cells showed a positive correlation. In R-WG, a skewing towards Type2 T cells was observed in CD4+TEM cells. No differences were detected in FoxP3+CD4+TEM cells between R-WG and A-WG, whereas the FoxP3-CD4+TEM cells were increased in R-WG and decreased in A-WG as compared to HC. Collectively, peripheral blood homeostasis of CD4+T cells is disturbed in R-WG with the persistent expansion of non-regulatory CD4+TEM cells. These cells might be involved in relapse and may constitute a target for therapy.

Vasculitis treatment - new therapeutic approaches

In childhood, vasculitis carries with it a not inconsequential morbidity and mortality. Current therapy is usually effective in inducing remission, but there is a penalty in terms of significant and serious side effects as well as concerns about long-term maintenance regimens. Additionally, some patients are recalcitrant to treatment and options have, hitherto, been limited in relation to alternative therapy. In view of this, novel therapeutic approaches are being explored that include the better use of long-established agents as well as the utilization of newer immunosuppressive and immunomodulatory strategies. Blockade of circulating mediators and surface receptors as well as lymphocyte depletion and immunoablation are being introduced predominantly in adults but increasingly also in children. With greater understanding of the pathogenetic mechanisms involved in the disease processes it is becoming possible to utilize much more focussed therapy for these serious and life-threatening disorders with, hopefully, a decrease in long-term morbidity and mortality as well as a diminution of drug-induced adverse effects.

Anti-neutrophil cytoplasm-associated glomerulonephritis

Wegener's granulomatosis, microscopic polyangiitis, and renal limited vasculitis are associated with circulating anti-neutrophil cytoplasm antibodies and are an important cause of rapidly progressive glomerulonephritis. This review gives an account of recent advances in the understanding of the pathogenesis underlying these conditions and how these may lead to future treatments. Consideration is given to recent clinical trials in the management of anti-neutrophil cytoplasm antibodies (ANCA)-associated vasculitides.

Wegener's granulomatosis: a rare, chronic and multisystem disease

Wegener's granulomatosis (WG) is an autoimmune disease which has a clinical predilection for the upper airways, lungs and kidneys. It is a necrotising granulomatous vasculitis which is associated with a distinct autoantibody--the antineutrophil cytoplasmic antibody (ANCA). A heightened index of suspicion by clinicians is needed in the diagnosis of this complex and rare condition. A multidisciplinary approach should then be used to treat this chronic multisystem disease. Treatment involves the use of various regimens of corticosteroids and immunosuppressive medication. Mortality due to WG has been significantly decreased by this therapy. In this article, we focus on clinical manifestations and review the salient histologic, laboratory and serologic features and treatment.

CAMPATH: from concept to clinic

Lymphocyte depletion has a long history in the area of therapeutic immunosuppression. CAMPATH-1H (alemtuzumab) was generated in an attempt to replace anti-lymphocyte globulins in the transplant arena. Its efficacy in killing lymphocytes has established it as a licensed drug for the management of chronic lymphocyte leukaemia. Short-term therapy with alemtuzumab has demonstrated long-term benefit in a number of autoimmune conditions. This drug has the potential to facilitate recruitment of tolerance processes so enabling drug minimization in transplantation, autoimmune and hypersensitivity diseases.

Glomerulonephritis due to antineutrophil cytoplasm antibody-associated vasculitis: an update on approaches to management

A patient with antineutrophil cytoplasm antibody-associated vasculitis frequently has multisystem disease and might present to a range of medical specialities. The manifestations that result in the greatest burden of morbidity and mortality are renal and pulmonary disease. In this review we will focus on rapidly progressive glomerulonephritis due to vasculitis, with specific reference to recent advances in our understanding of pathogenesis. The current standard of care for managing renal vasculitis, be it mild, moderate or severe, has largely been established in clinical trials of prednisolone, cyclophosphamide, methotrexate, azathioprine and plasma exchange. In addition to these, newer therapies such as mycophenolate mofetil and infliximab are being used more frequently. We will review the role of each of these approaches to management of small vessel vasculitis in 2005.

Systemic Vasculitis: Still a Challenging Disease

The efficacy of current therapeutic regimens in patients with systemic vasculitis is high, at the expense of considerable treatment toxicity. Optimal therapy for patients with these potentially life-threatening diseases is still debated. Our increased understanding of the pathogenetic mechanisms of systemic vasculitis has led to the development of new therapeutic alternatives, with better potential specificity for both the inflammation and immunologic causes of vasculitis: new immunosuppressive drugs (mycophenolate), monoclonal antibody modulators of lymphocyte function (rituximab), and cytokine-directed therapies (infliximab and eternacept). The safety and efficacy of such agents increasingly are being investigated in patients with systemic vasculitis. Additionally, many randomized prospective clinical trials have been completed to determine the precise roles for more conventional treatments (cyclophosphamide, azathioprine, and plasma exchange), providing an expanding evidence base to guide therapy in these challenging diseases. There now is clear evidence that duration of cyclophosphamide therapy can be relatively short (3 months), long-term maintenance therapy is needed to avoid relapse (often azathioprine), and patients at relatively greater risk for relapse can be identified. We review the most recent data on the current management of systemic antineutrophil cytoplasmic antibody-associated vasculitis, with emphasis on strategies to improve long-term outcome and reduce treatment toxicity while minimizing the risk for relapse.

The window of therapeutic opportunity in multiple sclerosis: evidence from monoclonal antibody therapy

From 1991-2002, we treated 58 patients with multiple sclerosis (MS) using the humanised monoclonal antibody, Campath-1H, which causes prolonged T lymphocyte depletion. Clinical and surrogate markers of inflammation were suppressed. In both the relapsing-remitting (RR) and secondary progressive (SP) stages of the illness, Campath-1H reduced the annual relapse rate (from 2.2 to 0.19 and from 0.7 to 0.001 respectively; both p < 0.001). Remarkably, MRI scans of patients with SP disease, treated with Campath-1H 7 years previously, showed no new lesion formation. However, despite these effects on inflammation, disability was differently affected depending on the phase of the disease. Patients with SPMS showed sustained accumulation of disability due to uncontrolled progression marked by unrelenting cerebral atrophy, attributable to ongoing axonal loss. The rate of cerebral atrophy was greatest in patients with established cerebral atrophy and highest inflammatory lesion burden before treatment (2.3 versus 0.7 ml/year; p = 0.04). In contrast, patients with RR disease showed an impressive reduction in disability at 6 months after Campath-1H (by a mean of 1.2 EDSS points) perhaps owing to a suppression of on-going inflammation in these patients with unusually active disease. In addition, there was a further significant, albeit smaller, mean improvement in disability up to 36 months after treatment. We speculate that this represents the beneficial effects of early rescue of neurons and axons from a toxic inflammatory environment, and that prevention of demyelination will prevent long-term axonal degeneration. These concepts are currently being tested in a controlled trial comparing Campath-1H and IFN-beta in the treatment of drug-naïve patients with early, active RR MS.

Unresolved issues and current concepts in management of primary glomerulonephritis

The successful treatment of primary glomerulonephritis (GN) presenting with nephrotic syndrome in adults depends heavily on an accurate diagnosis. A successful diagnosis depends on a correct approach, combining light microscopy, immunofluorescence, and other special staining of renal biopsy material examined by a trained nephropathologist. A good clinical history and serological tests easily rule out possible secondary causes (for example, infection, autoimmune, metabolic or toxic) in most cases. Unfortunately, these procedures are not put into practice in most cases in developing countries, resulting in missed diagnosis and unnecessary steroid and immunosuppressant therapy with its inherent morbidity. Following the emergence of IgA and IgM nephropathies as very common forms of glomerular disorders in some countries, immunofluorescence has become absolutely necessary for their diagnosis. Moreover, a recent meta-analysis has defined different treatment protocols for minimal change nephropathy, focal segmental glomerulosclerosis, membranous nephropathy, and IgA nephropathy for a better outcome. This article emphasizes and elaborates on these issues for proper management of primary GN.

Alemtuzumab: validation of a sensitive and simple enzyme-linked immunosorbent assay

Alemtuzumab (MabCampath) is a humanized rat monoclonal antibody that targets the CD52 antigen. It has been approved for the treatment of patients with resistant chronic lymphocytic leukaemia (CLL). Measuring plasma/serum levels of alemtuzumab is important for optimizing the dosing and scheduling of therapy; however, current assays in serum or plasma, based on the capture of alemtuzumab using CD52, are complicated and difficult to adapt for high throughput testing. We developed a simple sandwich enzyme-linked immunosorbent assay (ELISA) to measure alemtuzumab that takes advantage of the remaining rat sequence in alemtuzumab. Using specific anti-rat immunoglobulin (Ig) antibodies (absorbed against human Ig), alemtuzumab levels were measured in the serum and plasma of patients treated with alemtuzumab. Levels were similar between plasma and serum samples, in fresh samples and samples stored at 4 degrees C for 24 h, but were significantly lower in samples stored at room temperature for 24h. The assay was successfully used to determine serum alemtuzumab pre- and post-treatment. This assay is simple and adaptable for high throughput testing, with a limit of detection of 0.05 microg/ml and a coefficient of variation of +/-12.5%. No false positivity was observed in >200 samples tested. This validated assay should help optimize the dosing and scheduling of alemtuzumab therapy. The underlying principles are also applicable to the measurement of other humanized antibodies using an appropriate anti-Ig.

Blood concentrations of alemtuzumab and antiglobulin responses in patients with chronic lymphocytic leukemia following intravenous or subcutaneous routes of administration

Alemtuzumab is a humanized anti-CD52 antibody licensed for refractory B-cell chronic lymphocytic leukemia (B-CLL), when given intravenously at 30 mg thrice weekly. However, the intravenous route is associated with infusion-related reactions and is inconvenient. We measured blood concentrations in 30 relapsed patients treated with intravenous alemtuzumab and in 20 patients from a previously untreated group who received similar doses subcutaneously. Highest trough samples in the intravenous group were less than 0.5 microg/mL to 18.3 microg/mL (mean 5.4 microg/mL). The cumulative dose required to reach 1.0 microg/mL was 13 mg to 316 mg (mean 90 mg). Higher blood concentrations correlated with the achievement of better clinical responses and minimal residual disease. The highest measured concentrations in the subcutaneous group were similar (0.6 microg/mL to 24.8 microg/mL, mean 5.4 microg/mL). However, the cumulative dose to reach 1.0 microg/mL was higher: 146 mg to 1106 mg (mean 551 mg). No antiglobulin responses were detected in 30 patients given intravenous alemtuzumab whereas 2 of 32 patients given subcutaneous alemtuzumab made substantial anti-idiotype responses. Thus, subcutaneous alemtuzumab achieved concentrations similar to those for intravenous alemtuzumab, although with slightly higher cumulative doses. Subcutaneous alemtuzumab is more convenient and better tolerated but may be associated with some patients forming anti-alemtuzumab antibodies, particularly those patients who were previously untreated.

Present experience with Campath-1H in organ transplantation and its potential use in pediatric recipients

Campath-1H is a humanized monoclonal antibody directed at CD52 expressed on lymphocytes and other cells of the immune system. It has been tested extensively in lymphoid malignancies, autoimmune diseases including rheumatoid arthritis, multiple sclerosis, and organ transplantation. Although its use in children has been limited to date, so far it appears to be well tolerated in children. Currently, studies are being implemented to further assess its safety and efficacy in pediatric organ transplantation. Immune cell depletion using Campath-1H appears to be particularly useful in organ transplantation in that lower doses of maintenance immunosuppressive drugs are needed. This feature is particularly attractive in children.

Plasma Exchange Treatment Improves Prognosis of Antineutrophil Cytoplasmic Antibody-associated Crescentic Glomerulonephritis: A Case-Control Study in 26 Patients from a Single Center

Twenty-six patients with Antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis (GN) were divided into two groups according to the acute phase treatment: drug therapy consisting of steroids and oral cyclophosphamide plus a plasma exchange (PE) course (group A, 13 patients) or drug therapy alone (group B, 13 patients). Group A patients had a more severe clinical picture and higher serum creatinine than group B (12.7 +/- 6.9 vs. 8.5 +/- 5.3 mg%); nine patients from group A (69%) and five from group B (38%) required dialysis. At follow up (mean 35 months) all patients treated with PE were alive: four of them were in end-stage renal disease. Among group B patients, three (23%) died in the acute phase; 6 (46%) needed renal replacement therapy at follow up. Of the dialysis-dependent patients, five out of nine from group A were free of dialysis, while in group B two out of five patients had died, two had entered a regular dialysis treatment and one had received a cadaver graft. These data suggest that PE may significantly improve the prognosis of patients with ANCA-associated crescentic GN even if they are not dialysis-dependent at the time of diagnosis.

Vasculitides with predominantly renal involvement: influence of age on the mode of presentation

Vasculitis with predominant renal involvement are increasingly observed in elderly patients. It predominantly involves patients with microscopic polyangiitis, Wegener's granulomatosis, renal limited vasculitis and, in a smaller proportion, Churg Strauss syndrome. The elderly patients present very few obvious symptoms or signs of vasculitis such as hemoptysis and pulmonary infiltrates, and they are often submitted to: 1/renal biopsy when renal failure is already advanced; 2/ have more severe renal disease than do young and middle-aged patients (81% of acute and/or rapidly progressive renal failure versus 62%, and 30% of oliguria versus 6%); and 3/ a worse prognosis compared with younger individuals (probability of survival at 3 months, 1 year and 5 years of 93%, 93% and 92% in patients under 65, versus 67%, 62% and 46% in the elderly). Management of all patients with vasculitis and predominant renal involvement requires a quick diagnosis and immunosuppressive treatment aimed at controlling the disease. Treatment is mantained for 18 to 24 months. Nevertheless, relapses do occur (between 20% to 52%) of all patients with microscopic polyangiitis and Wegener's granulomatosis.

The pulmonary physician in critical care * illustrative case 3: pulmonary vasculitis

The case history of a patient admitted to the ICU with severe hypoxic respiratory failure later diagnosed as Wegener's granulomatosis is presented. The diagnosis and management of patients with suspected pulmonary vasculitis is discussed.

Cutaneous vasculitis

Vasculitis can range in severity from a self-limited single-organ disorder to a life-threatening disease with the prospect of multiple-organ failure. This condition presents many challenges to the physician, including classification and diagnosis, appropriate laboratory workup, treatment, and the need for careful follow-up. The physician must not only be able to recognize vasculitis but also be able to provide a specific diagnosis (if possible) as well as recognize and treat any underlying etiologic condition. Most diagnostic criteria are based on the size of vessel involvement, which often correlates with specific dermatologic findings. This may allow the dermatologist to provide an initial diagnosis and direct the medical evaluation. This article reviews the classification and diagnosis of cutaneous vasculitic syndromes and current treatment options; it also presents a comprehensive approach to diagnosing and treating the patient with suspected cutaneous vasculitis. (J Am Acad Dermatol 2003;48:311-40.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the classification and clinical features of the various forms of cutaneous vasculitis. They should also have a rational approach to diagnosing and treating a patient with vasculitis.

Biologic therapies in the vasculitides

Monoclonal antibody and recombinant DNA technologies have led to the development of biologic therapies capable of directly targeting selected components of the immune response. With the steady expansion of knowledge regarding the mechanisms of vascular inflammation, the safety and efficacy of biologic agents in the vasculitic diseases are being increasingly investigated. By targeting specific effector mechanisms involved in the pathogenesis of vasculitis, these agents may provide a less toxic means of inducing remission and lessening relapse. However, the study of biologic therapies in the vasculitides must be approached with caution, as unanticipated effects on disease activity and disease-specific toxicities can occur. Studies to examine these agents must recognize the potential for active vasculitis to be organ- or life-threatening as well as the current existence of effective therapies. In the research setting, investigation of biologic agents in the treatment of vasculitic diseases may also provide important insights into pathogenesis of these syndromes.

Wegener's granulomatosis: current and upcoming therapies

Wegener's granulomatosis is a complex multisystem disease that can be associated with morbidity and mortality. The introduction of cyclophosphamide and glucocorticoids brought about the potential for long-term survival and provided the opportunity and impetus to explore treatment options that can reduce the toxicity of therapy and lessen the likelihood of relapse. With the growth of knowledge regarding disease pathophysiology and the increasing ability to selectively target the immune system, the potential options for therapeutic investigation have continued to expand. Careful study of new agents through rigorously designed trials is essential to answering questions of safety and efficacy in Wegener's granulomatosis.

Control of a relapse and induction of long-term remission of Wegener's granulomatosis by cyclosporine

We report a case of severe Wegener's granulomatosis that caused end-stage renal failure and recurrent flares of sinusitis and pulmonary manifestations. To avoid the cumulative toxicity of iterative treatments with cyclophosphamide pulses and glucocorticoids, treatment with cyclosporine as a single agent was instituted in the early phase of the third relapse, before any pulmonary involvement. Cyclosporine enabled rapid control of the disease and induced a complete remission of more than 30 months.

Peripheral blood and granuloma CD4(+)CD28(-) T cells are a major source of interferon-gamma and tumor necrosis factor-alpha in Wegener's granulomatosis

To elucidate whether the fraction of CD28(-) T cells within the CD4(+) T-cell population is a major source of Th1-like and proinflammatory cytokine production driving Wegener's granulomatosis (WG) granuloma formation, we analyzed the phenotype and functional characteristics of peripheral blood CD4(+)CD28(-) T cells and of T cells in granulomatous lesions of 12 patients with active WG. Surface markers and intracytoplasmic cytokine and perforin expression were assessed by flow cytometry. Cytokine secretion was measured by enzyme-linked immunosorbent assay. Immunohistological studies demonstrated interferon-gamma and tumor necrosis factor-alpha cytokine positivity attributable to CD4(+)CD28(-) T cells in granulomatous lesions. Peripheral blood CD4(+)CD28(-) T cells expressed CD57, also found on natural killer cells, and intracytoplasmic perforin. They were generally CD25 (interleukin-2 receptor)-negative. CD18 (adhesion molecule beta(2)-integrin) was strongly up-regulated on CD4(+)CD28(-) T cells, whereas only a minority of CD4(+)CD28(+) T cells expressed CD18. CD4(+)CD28(-) T cells appeared as a major source of interferon-gamma and tumor necrosis factor-alpha. In contrast, CD4(+)CD28(+) T cells were able to produce and secrete a wider variety of cytokines including interleukin-2. One-quarter of CD4(+)CD28(+) T cells expressed the activation marker CD25, but they lacked perforin. Thus, CD4(+)CD28(-) T cells appeared more differentiated than CD4(+)CD28(+) T cells. They displayed Th1-like cytokine production and features suggestive of the capability of CD4(+) T-cell-mediated cytotoxicity. CD4(+)CD28(-) T cells may be recruited into granulomatous lesions from the blood via CD18 interaction, and may subsequently promote monocyte accumulation and granuloma formation through their cytokine secretion in WG.