Wegener's granulomatosis, systemic vasculitis, and antineutrophil cytoplasmic autoantibodies

Proteinase 3; a potential target in chronic obstructive pulmonary disease and other chronic inflammatory diseases

Chronic Obstructive Pulmonary Disease (COPD) is a common, multifactorial lung disease which results in significant impairment of patients' health and a large impact on society and health care burden. It is believed to be the result of prolonged, destructive neutrophilic inflammation which results in progressive damage to lung structures. During this process, large quantities of neutrophil serine proteinases (NSPs) are released which initiate the damage and contribute towards driving a persistent inflammatory state.Neutrophil elastase has long been considered the key NSP involved in the pathophysiology of COPD. However, in recent years, a significant role for Proteinase 3 (PR3) in disease development has emerged, both in COPD and other chronic inflammatory conditions. Therefore, there is a need to investigate the importance of PR3 in disease development and hence its potential as a therapeutic target. Research into PR3 has largely been confined to its role as an autoantigen, but PR3 is involved in triggering inflammatory pathways, disrupting cellular signalling, degrading key structural proteins, and pathogen response.This review summarises what is presently known about PR3, explores its involvement particularly in the development of COPD, and indicates areas requiring further investigation.

Granulomatosis With Polyangiitis in Otolaryngologist Practice: A Review of Current Knowledge

Granulomatosis with polyangiitis (GPA) is an idiopathic vasculitis of medium and small arteries, characterized by necrotizing granulomatous inflammation. GPA typically affects upper and lower respiratory tract with coexisting glomerulonephritis. This disease is generally characterized by antineutrophil cytoplasm antibodies (ANCA), nevertheless, there are rare cases with negative ANCA. GPA affects people at any age, with predominance of the sixth and seventh decade of life. In 80%-95% of the patients the first symptoms of GPA are otorhinolaryngological manifestations of head and neck including nose/sinuses, ears, eyes, larynx/trachea, oral cavity, and salivary glands. Diagnosis of GPA is based on Criteria of the American College of Rheumatology. In clinical practice diagnosis, the presence of distinctive ANCA antibodies and biopsy of affected organ are crucial. GPA must be differentiated from neoplastic, infectious or inflammatory ulcerative lesions of the head and neck. The standard treatment procedure is divided into two essential phases, induction and maintenance. The induction phase is based on combination of systemic corticosteroid and immunosuppressant therapy, whereas the maintenance phase comprises corticosteroids and azathioprine/methotrexate supplementation. Surgical treatment ought to be considered for patients who are not responding to pharmacotherapy.

Current modalities in the diagnosis of pulmonary vasculitis

INTRODUCTION

This review addresses the pulmonary manifestations of the vasculitides, with a focus on diagnostic modalities. Haemorrhagic presentations (usually associated with nephritis: the pulmonary-renal syndrome) are the most common vasculitic cause of early death.

AREAS COVERED

The diagnostic modalities in the pulmonary vasculitides are reviewed, with a focus on primary systemic vasculitis. A literature search of original research and review articles on pulmonary vasculitides was undertaken using the PubMed database.

EXPERT OPINION

Small-vessel anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, especially granulomatosis with polyangiitis (Wegener's granulomatosis) are the most frequent causes of pulmonary vasculitis and typically present as nodules, alveolar infiltrates (haemorrhagic or not), cavities or tracheobronchial stenosis. Lung involvement is less common in large-vessel vasculitis when pulmonary vascular abnormalities can be seen. No single test is pathogonomonic and diagnosis requires integration of clinical, laboratory, imaging and histological findings. Treatment follows similar regimens to other vasculitic presentations, with glucocorticoids in conjunction with immunosuppressive agents, and management of intercurrent sepsis and the increased risk of cardiovascular and thromboembolic events. Prompt diagnosis and intensive treatment of pulmonary vasculitis is essential to improve early mortality and long-term outcomes.

The Influence of Personality Differences Between Subordinates and Supervisors on Perceptions of LMX

Although the concept of leader—member exchange (LMX) has received a considerable amount of attention since its conception in the early 1970s, very little research has focused on antecedents to the formation of this exchange. To fill this gap, the authors collected data from 195 matched pairs of employees and supervisors from a variety of organizations and investigated the role of personality differences on employees' perceptions of LMX quality. As predicted, differences in emotional stability, intellectual openness, agreeable-ness, and conscientiousness negatively related to perceptions of LMX. Implications, limitations, and directions for future research are discussed.

Anticorpos contra o citoplasma de neutrófilos

A descoberta do marcador sorológico denominado anticorpo anticitoplasma de neutrófilos revolucionou o diagnóstico e o seguimento das vasculites pulmonares, especialmente da granulomatose de Wegener. Seu padrão pode ser citoplasmático e perinuclear. Sua titulação auxilia no diagnóstico e no seguimento das vasculites pulmonares.

Gene expression after vaccination of mice with formulations of diphtheria toxoid or tetanus toxoid and different adjuvants: identification of shared and vaccine-specific genes in spleen lymphocytes

We immunized mice with four different combinations of diphtheria toxoid or tetanus toxoid with aluminum phosphate or Freund's adjuvant and studied the resulting gene expression profiles in spleen lymphocytes. Genes, which are unique for each combination or shared in several combinations, were found activated, with functions in immune response but also in other cellular processes like apoptosis or signal transduction. Using bioinformatic tools we show, that some of the genes may serve as indicators for adverse reactions, while other genes may be new immune response markers. The results also suggest that adjuvant participates in the formation of an immunological memory.

Cloning and functional expression of the murine homologue of proteinase 3: implications for the design of murine models of vasculitis

Anti-neutrophil cytoplasmic autoantibodies recognizing conformational epitopes (c-ANCA) of proteinase 3 (PR3) from azurophil granules are a diagnostic hallmark in Wegener's granulomatosis (WG). Because a functional PR3 homologue has not been identified in rodents, it is difficult to assess immunopathological responses in rats or mice immunized with patients' derived c-ANCA or human PR3. Here we report the full length cDNA cloning and functional expression of murine PR3 in HMC-1 cells. Recombinant murine PR3 shows highly similar substrate specificities towards synthetic peptides and is inhibited by human alpha1-proteinase inhibitor like human PR3. However, neither human c-ANCA, rabbit sera nor mouse monoclonal antibodies to human PR3 recognize the murine homologue. Consequently, it is unlikely that disease observed in mice after immunization with c-ANCA or human PR3 is caused by pathogenic antibodies directed against mouse PR3. Recombinant human-mouse chimaeric variants will be a valuable new tool to localize the disease-specific immunodominant epitopes in human PR3.

Molecular characteristics of anti-self antibody fragments against neutrophil cytoplasmic antigens from human V gene phage display libraries

Recently it has been demonstrated that human antibody fragments with binding activities against self antigens can be isolated from repertoires of rearranged V genes from non-immunized humans. We have applied phage display technology to study the B cell repertoire for antibody activity against neutrophil cytoplasmic antigens. These antibodies may play an important role in Wegener's granulomatosis (WG) and related forms of vasculitides. Autoantibodies in patients with WG are directed against proteinase 3. The immunodominant antigen in other forms of vasculitis is myeloperoxidase, but the B cell response can also be directed against other neutrophil enzymes, e.g. lysozyme, human neutrophil elastase, lactoferrin and cathepsin G. We show here that anti-self reactivity against neutrophil cytoplasmic antigens can be detected in the rearranged V gene repertoire of healthy individuals and that the reactivity can be directed against structural related epitopes which are present on different neutrophil cytoplasmic antigens. The scFv with binding activities were sequenced and the V gene usage, the level of somatic mutations and the immunoserological characteristics of the antibody fragments are discussed. Further evidence is presented that antibody fragments consisting only of a heavy chain variable domain can recognize neutrophil cytoplasmic antigens in a specific manner. These single-domain antibody fragments were used in experiments designed to establish the relative role of the light chain variable domains in antigen binding.

Segregation of pANCA antigenic recognition by DNase treatment of neutrophils: ulcerative colitis, type 1 autoimmune hepatitis, and primary sclerosing cholangitis

Antineutrophil cytoplasmic antibodies (ANCA) have been identified in the serum of 50-80% of ulcerative colitis (UC) patients. UC-associated ANCA yield a perinuclear staining pattern (pANCA) with alcohol-fixed neutrophils. More recently, pANCA have been detected in the serum of patients with primary sclerosing cholangitis (PSC) and other autoimmune liver diseases. Up to 70% of PSC patient sera and up to 92% of sera from patients with well-defined type 1 autoimmune hepatitis (type 1 AIH) were found to express pANCA. Such expression by patients with PSC and type 1 AIH raises questions concerning the relationship of these pANCA to each other and to that of UC. Differences and similarities in pANCA characteristics are found among the three diseases, suggesting the use of pANCA to define specific disease subgroups. Our recent finding that the UC-associated pANCA reactive antigen was localized within the nuclear domain prompted an examination of whether DNase treatment of neutrophils would alter antigenic recognition by the pANCA of UC, PSC, and type 1 AIH. While loss of antigenic recognition after DNase digestion of neutrophils was a dominant feature of the UC-associated pANCA, the majority of PSC and type 1 AIH pANCA recognized cytoplasmic constituents. These results further support the feasibility of defining and/or distinguishing disease subgroups based on the characterization of respective pANCA.

Structure of the azurocidin, proteinase 3, and neutrophil elastase genes. Implications for inflammation and vasculitis

The granule-associated elastase homologues neutrophil elastase (NE), proteinase 3 (PR3), and azurocidin (AZU) are involved in immune defense reactions of neutrophils and monocytes. Proteinase 3 and NE contribute to the destruction and elimination of microorganisms, cleave elastin and other proteins of connective tissues, and generate chemotactic activities by forming alpha 1-proteinase inhibitor (alpha 1-PI) complexes. Azurocidin is cytotoxic to certain microorganisms and chemotactic to monocytes. All three proteins are produced and packaged into azurophil granules in large quantities during neutrophil development. The genes encoding AZU, PR3, and NE are closely clustered in this sequence within 50 kb of genomic DNA and have the same transcriptional orientation. All three genes show the same exon-intron organization as neutrophil cathepsin G, mast cell chymase 1, and the lymphocyte serine proteases, granzymes A, B, and H. The AZU-PR3-NE gene cluster was mapped to the telomeric region on the short arm of human chromosome 19 (19p13.3), whereas cathepsin G, lymphocyte granzymes B and H, and mast cell chymase 1 are organized as a separate gene cluster on chromosome 14q11.2. Neutrophil-derived serine proteases are widely regarded as pathogenic factors in degenerative and inflammatory diseases with abnormal tissue catabolism. Autoantibodies against PR3 are an obligate feature in the pathogenesis of Wegener's granulomatosis, a systemic autoimmune vasculitis. In addition, PR3 appears to regulate growth and terminal differentiation of the myelomonocyte lineage. Future investigations will clarify whether allelic variations in the AZU-PR3-NE locus predispose patients to increased degradation of elastic fibers, as in pulmonary emphysema, and to the formation of autoantibodies against PR3 in patients with Wegener's granulomatosis.

Wegener's granulomatosis presenting with sclerokeratitis diagnosed by antineutrophil cytoplasmic autoantibodies (ANCA)

A 23-year-old male presented with bilateral sclerokeratitis. He reported recent bronchitis, sinusitis, dyspnea on exertion, hemoptysis, arthralgias and myalgias. Wegener's granulomatosis was diagnosed by a positive antineutrophil cytoplasmic autoantibody (ANCA) test and a nasal and subglotic biopsy showing granulomatous inflammation. Treatment with cyclophosphamide, systemic corticosteroids and trimethoprim/sulfamethoxazole resulted in resolution of the sclerokeratitis and remission of the disease.

Wegener's granulomatosis associated with vasculitis of the temporal artery: report of five cases

Between January 1973 and October 1991 at the Mayo Clinic, 5 of 345 patients with Wegener's granulomatosis initially had features suggestive of giant cell arteritis and subsequently were found to have biopsy-proven vasculitis of the temporal artery. All five patients were older than 60 years of age and had jaw claudication, sudden loss of vision, severe headache with or without diplopia, or polymyalgia rheumatica at the time of initial examination. The erythrocyte sedimentation rate was high at the time of onset of symptoms in four patients (and unavailable in one patient). A temporal artery biopsy specimen revealed giant cell arteritis in one patient and non-giant cell arteritis in four patients. All five patients subsequently had pulmonary and renal lesions characteristic of Wegener's granulomatosis, with typical histopathologic features on biopsy or positive cytoplasmic staining antineutrophil cytoplasmic antibodies. Thus, overlapping features of giant cell arteritis and Wegener's granulomatosis do occur in some patients.

Antineutrophil-cytoplasmic-autoantibodies in poststreptococcal nephritis

Sera from 210 patients with APSGN, were tested for the presence of ANCA (IgG-isotype). Indirect immunofluorescence (IF) on ethanol fixed human PMNs was used, and for those positive sera, ELISA kits for PR3 (Proteinase 3) and MPO (Myeloperoxidase) was performed. ANCA were detected in 9% (18 out of 210 cases) in a predominantly diffuse cytoplasmic staining pattern in 14 cases (77%), and in a perinuclear pattern in the remaining 4 cases (22%). Anti-MPO was found in 4 cases (C-ANCA 3; P-ANCA 1) and anti-PR3 was always negative. The presence of ANCA was significantly associated with a more severe glomerular disease as assessed by the serum creatinine value and the crescents formation. Longitudinal studies performed in 11 cases have shown that raised levels of these autoantibodies may persist for at least six months, without relationship with disease activity. Further studies are required to dilucidate the specificity of these autoantibodies, and if its presence is either an epiphenomenon of the heterogeneous humoral immune response in streptococcal infection, or they play some pathogenic role in APSGN.

Propylthiouracil-induced hypersensitivity vasculitis presenting as respiratory failure

Hypersensitivity vasculitis associated with propylthiouracil therapy is a well-documented clinical entity. Although any organ system may be involved, it is most unusual for pulmonary manifestations to be the cardinal presenting features. We report a 72-year-old woman presenting with respiratory failure and hemoptysis following initiation of propylthiouracil therapy for Graves' disease. She had cutaneous stigmata of hypersensitivity vasculitis and diffuse pulmonary infiltrates. The infiltrates improved dramatically after discontinuation of the propylthiouracil therapy and initiation of intravenous corticosteroid therapy.