New approaches to treatment in systemic vasculitis: biological therapies

Targeting immune checkpoints in anti-neutrophil cytoplasmic antibodies associated vasculitis: the potential therapeutic targets in the future

Anti-neutrophil cytoplasmic autoantibodies (ANCA) associated vasculitis (AAV) is a necrotizing vasculitis mainly involving small blood vessels. It is demonstrated that T cells are important in the pathogenesis of AAV, including regulatory T cells (Treg) and helper T cells (Th), especially Th2, Th17, and follicular Th cells (Tfh). In addition, the exhaustion of T cells predicted the favorable prognosis of AAV. The immune checkpoints (ICs) consist of a group of co-stimulatory and co-inhibitory molecules expressed on the surface of T cells, which maintains a balance between the activation and exhaustion of T cells. CD28, inducible T-cell co-stimulator (ICOS), OX40, CD40L, glucocorticoid induced tumor necrosis factor receptor (GITR), and CD137 are the common co-stimulatory molecules, while the programmed cell death 1 (PD-1), cytotoxic T lymphocyte-associated molecule 4 (CTLA-4), T cell immunoglobulin (Ig) and mucin domain-containing protein 3 (TIM-3), B and T lymphocyte attenuator (BTLA), V-domain Ig suppressor of T cell activation (VISTA), T-cell Ig and ITIM domain (TIGIT), CD200, and lymphocyte activation gene 3 (LAG-3) belong to co-inhibitory molecules. If this balance was disrupted and the activation of T cells was increased, autoimmune diseases (AIDs) might be induced. Even in the treatment of malignant tumors, activation of T cells by immune checkpoint inhibitors (ICIs) may result in AIDs known as rheumatic immune-related adverse events (Rh-irAEs), suggesting the importance of ICs in AIDs. In this review, we summarized the features of AAV induced by immunotherapy using ICIs in patients with malignant tumors, and then reviewed the biological characteristics of different ICs. Our aim was to explore potential targets in ICs for future treatment of AAV.

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.

Screening of serum samples from Wegener's granulomatosis patients using antibody microarrays

Wegener's Granulomatosis (WG) is an idiopathic granulomatosis autoimmune vasculitis that primarily affects small vessels and is associated with glomerulonephritis and pulmonary granulomatous vasculitis. Anti-neutrophil cytoplasmic auto-antibodies (cANCA) against proteinase-3 are used to identify WG, but ANCA titers are not present in some patients with the localized disease. The objective of this study was to develop an antibody array to help identify protein expression patterns in serum from patients with WG as compared to normals. The arrays were tested for limits of detection, background, and cross reactivity using standard proteins. The arrays were hybridized with either normal patient serum (n = 30) or with serum samples from a population of WG patients (n = 26) that were age and sex matched. Data analysis and curve fitting of the standard dilution series calculated r(2) values and determined a sensitivity of <50 pg/mL for the majority of proteins. A total of 24 proteins were assessed. Several statistically significant increases (p<0.05) were seen in the expression of: angiotensin converting enzyme-I, IFN-γ, IL-8, s-ICAM-1 and s-VCAM in WG patients as compared to controls. Utilizing the antibody microarray technology has led to the identification of potential biomarkers of vascular injury in the serum of WG patients.

Vasculitis and Biologic Infusion Therapies

Vasculitis is a heterogeneous group of uncommon, complex rheumatologic diseases. These diseases are known for their high mortality and morbidity rates due to the underlying disorders themselves, as well as complications of their conventional treatments. Oral and intravenous glucocorticosteroids and other immunosuppressive agents such as cyclophosphamide, methotrexate, and azathioprine are used to manage these diseases. These therapies are effective, but they have a global impact (often negative) on patients' immune systems and cause a number of nonimmunologic toxicities. They also are ineffective in inducing long-term remissions. Novel biologic infusion agents such as rituximab and infliximab are being prescribed off-label for some patients with vasculitis who have failed to respond to conventional therapy or because there are contraindications to standard-of-care treatments. This article provides an orientation to vasculitis, its standard of care, infusion biologics under investigation in these diseases, and the nursing implications for infusion professionals.

TNF-alpha is necessary for induction of coronary artery inflammation and aneurysm formation in an animal model of Kawasaki disease

Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The resultant coronary artery lesions make Kawasaki disease the leading cause of acquired heart disease in children in the developed world. TNF-alpha is a pleiotropic inflammatory cytokine elevated during the acute phase of Kawasaki disease. In this study, we report rapid production of TNF-alpha in the peripheral immune system after disease induction in a murine model of Kawasaki disease. This immune response becomes site directed, with migration to the coronary arteries dependent on TNF-alpha-mediated events. Production of TNF-alpha in the heart is coincident with the presence of inflammatory infiltrate at the coronary arteries, which persists during development of aneurysms. More importantly, inflammation and elastin breakdown in the coronary vessels are completely eliminated in the absence of TNF-alpha effector functions. Mice treated with the TNF-alpha-blocking agent etanercept, as well as TNFRI knockout mice, are resistant to development of both coronary arteritis and coronary aneurysm formation. Taken together, TNF-alpha is necessary for the development of coronary artery lesions in an animal model of Kawasaki disease. These findings have important implications for potential new therapeutic interventions in children with Kawasaki disease.

Successful Treatment of Childhood Onset Refractory Polyarteritis Nodosa With Tumor Necrosis Factor Alpha Blockade

Polyarteritis nodosa is a rare systemic necrotizing vasculitis of small- and medium-sized arteries that affects patients of all ages. Its incidence ranges from 2 to 9 per million people. The 5-year survival rate is 13% in untreated patients and 77.6% with modern therapy. Standard treatment includes corticosteroids and cyclophosphamide. Despite aggressive medical management, 22.4% of patients die within 5 years, and of the survivors, medication-induced morbidity is frequent. There is great need for better treatment modalities in terms of safety and efficacy. We report the case of a 5-year-old boy with polyarteritis nodosa refractory to all known standard treatments. After 9 years of persistently active disease, at the age of 14, he was successfully managed with the tumor necrosis factor alpha antagonist, etanercept.

Primary cutaneous small vessel vasculitis

Disorders associated with cutaneous vasculitis include numerous well-described etiologies. Primary cutaneous vasculitis limits discussion to primary leukocytoclastic vasculitis, essential mixed cryoglobulinemia, urticarial vasculitis, Henoch-Schönlein purpura, and erythema elevatum diutinum. Although the therapeutics for these disorders are based on limited data, we attempt to construct a consensus opinion on the management of primary cutaneous vasculitis. Therapy of primary cutaneous vasculitis is indicated for symptomatic or systemic involvement, because cutaneous small vessel vasculitis is frequently a self-limited, single episodic disease. Conservative, symptomatic treatment includes leg elevation, warming, antihistamines, and nonsteroidal anti-inflammatory drugs. For mild recurrent disease, colchicine, dapsone, and prednisone are first-choice agents. Systemic or severe cutaneous disease requires more potent immunosuppression (eg, prednisone, azathioprine, or mycophenolate mofetil). Plasmapheresis/plasma exchange and intravenous immunoglobulin are viable considerations for refractory disease, but are cumbersome and expensive modalities. There is insufficient evidence to advocate the use of new biological or monoclonal antibody therapies in primary cutaneous vasculitis.

Treatment of Wegener's granulomatosis

The two principal aims in the treatment of Wegener's granulomatosis (WG) are to limit the extent and severity of permanent organ damage by controlling the disease promptly and to minimize the short- and long-term morbidity that often results from therapy. Remission is considered to be the absence of disease activity in any organ system. Once the disease has been controlled by the initial treatment regimen, which is dictated by the degree of disease severity, the focus of therapy shifts to maintaining disease remission, often with medications less toxic than those used to induce remission. The description of WG treatments in terms analogous to cancer chemotherapy (i.e., those designed to induce remissions and those intended to maintain them) is useful in the formulation of current disease management strategies and in the investigation of new therapies for WG.