Immune Complex-mediated Vasculitis Research Articles

Systemic lupus erythematosus of the urinary tract: focus on lupus cystitis.

Systemic lupus erythematosus (SLE) frequently manifests as urinary tract disease, most commonly in the form of lupus nephritis. Bladder involvement in the disease course takes a subclinical form and may affect both children and adults. Lupus cystitis can precede SLE diagnosis and may present with very unspecific urinary and digestive tract symptoms or no symptoms at all. The exact mechanism of bladder inflammation in lupus is not fully understood; however, histopathological studies suggest a possible role of immune complex-mediated small vessel vasculitis. Lupus cystitis is a rare SLE manifestation, but poses a challenge for physicians, due to its complex diagnostics and treatment.

Direct-acting antiviral agents in the therapy of hepatitis C virus-related mixed cryoglobulinaemia: a single-centre experience

BackgroundThe efficacy and safety of direct-acting antiviral agents (DAAs) were evaluated in a cohort of prospectively enrolled patients with hepatitis C virus (HCV)-related mixed cryoglobulinaemia (MC), an immune complex-mediated vasculitis of small and medium vessels in which the pathogenetic role of HCV has been clearly established.MethodsTwenty-two patients received DAAs. Clinical and laboratory features were recorded at baseline, every 4 weeks until the end of treatment (EoT), and 12 weeks afterwards. Primary efficacy endpoints were (a) sustained virological response 12 weeks after therapy completion (SVR12), (b) regression of symptomatology (clinical response) and (c) cryoglobulin disappearance or cryocrit reduction ≥50% (immunological response). Complete response (CR) was defined as the occurrence of all three primary endpoints; partial response (PR) was defined as the occurrence of SVR12, with or without either immunological or clinical response; and no response was defined as missing the achievement of all three endpoints.ResultsAll patients reached SVR12. Compared with basal values, mean cryocrit values were significantly decreased at EoT and SVR12. A significant reduction of alanine transaminase and a parallel increase of complement component C4 levels were also detected. Rheumatoid factor activity was significantly reduced at EoT but not at SVR12. At SVR12, a CR was established in 14 patients (63.7%) and a PR in 8 patients (36.3%). In one patient with small lymphocytic lymphoma, the tumour progressed despite viral clearance. Mild adverse events were recorded in nine patients (40.9%).ConclusionsThe response rates induced by the use of DAAs in patients with MC were remarkably higher than those previously achieved with pegylated interferon-α/ribavirin, with or without rituximab. A much longer follow-up is desirable to achieve useful information in terms of persistent viral clearance and clinical response.

Hepatitis B virus induced cytoplasmic antineutrophil cytoplasmic antibody-mediated vasculitis causing subarachnoid hemorrhage, acute transverse myelitis, and nephropathy: a case report

BackgroundTransverse myelitis, subarachnoid hemorrhage, and nephropathy are established but rare complications of hepatitis B virus infection that can potentially be triggered by an antibody-mediated vasculitis as a result of a viral infection. The following is a case report detailing a patient presenting with all three of the above presentations who is cytoplasmic antineutrophil cytoplasmic antibody-positive and a chronic carrier of hepatitis B.Case presentationA 33-year-old Nepalese man presented to our hospital with headache, swelling of his body, paraplegia, and back pain that developed over a period of 10 days. Laboratory studies showed proteinuria and elevated levels of serum urea and creatinine. Viral serology was suggestive of chronic inactive hepatitis B carrier state. A computed tomography scan of his head revealed features suggestive of subarachnoid hemorrhage. Magnetic resonance imaging of his dorsal spine showed diffuse T2 high signal intensity within his spinal cord extending from second to 12th thoracic vertebral level which was suggestive of transverse myelitis. The origin of these symptoms was attributed to immune complex-mediated vasculitis after serum analysis for cytoplasmic antineutrophil cytoplasmic antibody came out positive. He was managed with steroids administered orally and intravenously and entecavir administered orally.ConclusionThis case highlights the possibility of a hepatitis B virus-induced vasculitis as the cause of subarachnoid hemorrhage, transverse myelitis, and nephropathy.

Mouse Model of Immune Complex-mediated Vasculitis in Dorsal Skin and Assessment of the Neutrophil-mediated Tissue Damage.

Neutrophils are the most abundant leukocytes in the blood. In the recent decades, their crucial roles in host defense, immune regulation and tissue damage have been studied in a deeper dimension. In this protocol, we described a mouse model of immune complex-mediated vasculitis in the dorsal skin induced by Arthus reaction, and the subsequent analysis of edema, hemorrhage and tissue damage due to neutrophil activation by means of Evans blue area analysis, histology, and immunofluorescence. This protocol could facilitate the investigation of cellular therapy strategy against over-activated neutrophil-mediated tissue damage.

A Rare Case of Adult Acute Ileocecal Ischemia Related to Henoch-Schönlein Purpura: MDCT Findings.

Henoch-Schönlein purpura (HSP) is a form of immune complex-mediated leukocytoclastic vasculitis involving the skin and other organs. It primarily affects children. The occurrence of HSP in adults is rare, and gastrointestinal (GI) involvement is one of its most common clinical manifestations. The GI symptoms are caused by hemorrhage and edema within the bowel and wall mesentery. Complete recovery usually occurs, and life-threatening complications are rare. We report a typical case of GI involvement of the ileocecal area diagnosed with multidetector computed tomography (MDCT) and confirmed by skin biopsy.

Bronchial lesions of mouse model of asthma are preceded by immune complex vasculitis and induced bronchial associated lymphoid tissue (iBALT)

We systematically examined by immune histology the lungs of some widely used mouse models of asthma. These models include sensitization by multiple intraperitoneal injections of soluble ovalbumin (OVA) or of OVA with alum, followed by three intranasal or aerosol challenges 3 days apart. Within 24 h after a single challenge there is fibrinoid necrosis of arterial walls with deposition of immunoglobulin (Ig) and OVA and infiltration of eosinophilic polymorphonuclear cells that lasts for about 3 days followed by peribronchial B-cell infiltration and slight reversible goblet cell hypertrophy (GCHT). After two challenges, severe eosinophilic vasculitis is present at 6 h, increases by 72 h, and then declines; B-cell proliferation and significant GCHT and hyperplasia (GCHTH) and bronchial smooth muscle hypertrophy recur more prominently. After three challenges, there is significantly increased induced bronchus-associated lymphoid tissue (iBALT) formation, GCHTH, and smooth muscle hypertrophy. Elevated levels of Th2 cytokines, IL-4, IL-5, and IL-13, are present in bronchial lavage fluids. Sensitized mice have precipitating antibody and positive Arthus skin reactions but also develop significant levels of IgE antibody to OVA but only 1 week after challenge. We conclude that the asthma like lung lesions induced in these models is preceded by immune complex-mediated eosinophilic vasculitis and iBALT formation. There are elevations of Th2 cytokines that most likely produce bronchial lesions that resemble human asthma. However, it is unlikely that mast cell-activated atopic mechanisms are responsible as we found only a few presumed mast cells by toluidine blue and metachromatic staining limited to the most proximal part of the main stem bronchus, and none in the remaining main stem bronchus or in the lung periphery.

Clinical and biological differences between cryoglobulinaemic and hypergammaglobulinaemic purpura in primary Sjögren's syndrome: results of a large multicentre study

Objectives: To determine the clinical and laboratory differences between cryoglobulinaemic and hypergammaglobulinaemic purpura in primary Sjögren’s syndrome (pSS), in a large Italian multicentre cohort.Method: Patients were selected according to the following criteria: fulfilling the American–European classification criteria for pSS, serum cryoglobulin and gammaglobulin levels evaluated, and lack of hepatitis C virus (HCV) infection. Multinomial analyses were performed by distinguishing three groups of pSS: (i) purpura associated with cryoglobulinaemic vasculitis (CV), (ii) purpura associated with hypergammaglobulinaemic vasculitis (HGV), and (iii) pSS patients without purpura (pSS controls). Patients with purpura but without cryoglobulins or hypergammaglobulinaemia were excluded.Results: A total of 652 patients were enrolled in this study. Group 1/CV comprised 23/652 patients (3.53%), group 2/HGV 40/652 patients (6.13%), and group 3/pSS controls 589/652 (90.34%). The three groups were found to be significantly different from each other (post-estimation test: group 1/CV vs. group 3/pSS controls: p < 0.0001; group 1/CV vs. group 2/HGV: p = 0.0001; group 2/HGV vs. group 3/pSS controls: p = 0.0003), thus confirming the different phenotypes of purpura in pSS.Multivariate analyses revealed that peripheral neuropathy (p < 0.001), low C4 (p < 0.001), leucopaenia (p = 0.01), serum monoclonal component (p = 0.02), and the presence of anti-SSB/La antibodies (p = 0.02) characterized CV whereas rheumatoid factor (p = 0.001), leucopaenia (p = 0.01), serum monoclonal component (p = 0.01), and anti-SSA/Ro antibodies (p = 0.049) were significantly associated with HGV. Lymphoma was associated only with CV.Conclusions: HGV is a cutaneous vasculitis, related to a benign B-cell proliferation, whereas CV is a systemic immune complex-mediated vasculitis with complement activation and a higher risk of lymphoma, thus confirming CV but not HGV as a prelymphomatous condition in pSS.

Blocking Von Willebrand Factor for Treatment of Cutaneous Inflammation

Von Willebrand factor (VWF), a key player in hemostasis, is increasingly recognized as a proinflammatory protein. Here, we found a massive accumulation of VWF in skin biopsies of patients suffering from immune complex (IC)-mediated vasculitis (ICV). To clarify the impact of VWF on cutaneous inflammation, we induced experimental ICV either in mice treated with VWF-blocking antibodies or in VWF(-/-) mice. Interference with VWF led to a significant inhibition of the cutaneous inflammatory response. We confirmed the major findings in irritative contact dermatitis, a second model of cutaneous inflammation. In vivo imaging of cutaneous inflammation in the dorsal skinfold chamber revealed unaffected leukocyte rolling on anti-VWF treatment. However, we identified that reduced leukocyte recruitment is accompanied by reduced vascular permeability. Although VWF-mediated neutrophil recruitment to the peritoneum was described to require the VWF receptor on platelets (glycoprotein Ibα (GPIbα)), the VWF/GPIbα axis was dispensable for cutaneous inflammation. As assessed in tail bleeding assays, we could exclude interference of VWF blockade with hemostasis. Of particular importance, anti-VWF treatment was effective both in prophylactic and therapeutic administration. Thus, VWF represents a promising target for the treatment of cutaneous inflammation, e.g., leukocytoclastic vasculitis.

Molecular imaging reveals time course of matrix metalloproteinase activity in acute cutaneous vasculitis in vivo

Matrix metalloproteinases (MMPs) play a critical role in various pathological conditions including cutaneous inflammation. Thus far, serial assessment of MMP activity in ongoing inflammation is hampered due to technical limitations. Here, we present an innovative method for longitudinal detection of MMP activity by in vivo imaging. First, we analysed skin sections from patients suffering from leucocytoclastic vasculitis (LcV) and detected a significant MMP signal via immunofluorescence staining. Then, we mimicked LcV in mice in a well-studied model of immune complex-mediated vasculitis (ICV). This acute inflammatory process was serially visualized in vivo using the fluorescence-labelled MMP tracer Cy5.5-AF443. The deposition of fluorescence-labelled immune complexes and MMP tracer distribution was visualized repeatedly and non-invasively by fluorescence reflectance imaging. In correlation with the presence of MMP-2 and MMP-9 in immunofluorescence stainings, Cy5.5-AF443 accumulated in ICV spots in the skin of C57BL/6 mice. This tracer accumulation could also be observed in mice equipped with a dorsal skinfold chamber, where microscopic observations revealed an increased recruitment of fluorescence-labelled leucocytes during ICV. The specificity of the MMP tracer was supported by (i) analysis of mice deficient in functional β2 -integrins (CD18(-/-) ) and (ii) subsequent MMP immunofluorescence staining. These findings let us conclude that MMP accumulation in the acute phase of ICV depends on β2 -mediated leucocyte recruitment. In summary, we show that MMPs are involved in ICV as determined by Cy5.5-AF443, a new optical marker to longitudinally and non-invasively follow MMP activity in acute skin inflammation in vivo.

Neuropsychiatric lupus: how much do we know?

Involvement of the nervous system in systemic lupus erythema-tosus (SLE) is associated with a poor prognosis. Patients present with a number of neurological and psychiatric syndromes (NPSLE). In 1999, the American College of Rheumatology ad hoc Committee on Neuropsychiatric Lupus Nomenclature provided case definitions for 19 NPSLE syndromes. Albeit comprehensive, none of the syndromes described are specific to SLE. This is largely due to the variable disease pathogenic mechanisms of NPSLE, ranging from immune-complex mediated vasculitis, antibody directed tissue injuries, thrombosis and non-inflammatory vasculopathy. Indeed, with some of the syndromes, non-SLE causes such as complications of lupus therapy, infection and metabolic dysfunction may contribute to their manifestation. Furthermore, NPSLE may precede the onset or occur at any time during the course of lupus. They may also occur as an isolated complication or as part of a general disease flare, and multiple neurological events may occur in the same individual. As a result, therefore, assessment and management of NPSLE are difficult. Therapeutic options for NPSLE are limited, often comprising high-dose corticosteroids plus an immunosuppres-sive agent but this has not been validated in large scale controlled studies. In patients with psychiatric symptoms, auxiliary treatments such as anti-psychotic and anti-anxiolytic are often required.

Cryoglobulinémie mixte symptomatique au cours de l’hépatite virale C

Cryoglobulins are immunoglobulins that reversibly precipitate in the cold. They may lead to an immune complex-mediated vasculitis, which may sometimes be severe. A wide range of conditions may be related to cryoglobulinaemia, and the most frequent of them is chronic hepatitis C. The purpose of this work was to emphasize the diagnostic and therapeutic characteristics of cryoglobulinaemia associated with hepatitis C. A 55-year-old woman, with a history of arterial hypertension, was admitted with transudative ascites. Clinical investigation revealed purpuric lesions and oedema of the lower limbs with Raynaud phenomenon. Proteinuria and haematuria were detected in the urine test strip. The patient had a positive serology for hepatitis C, but no signs of portal hypertension. Further investigations showed renal failure with nephrotic syndrome. Renal biopsy showed membranous proliferative glomerulonephritis with parietal and mesangial deposits of IgM and IgG antibodies. Skin biopsy showed leucocytoclastic vasculitis. Immunological investigations found type IIb mixed cryoglobulinaemia associated with hepatitis C. The patient was treated by pegylated interferon and ribavirin. She showed a satisfactory clinical and a sustained virological response for 1 year after the withdrawal of therapy. Mixed cryoglobulinaemia is the main extrahepatic manifestation of hepatitis C, but it is rarely symptomatic. The combination of peginterferon-α and ribavirin leads to virological and clinical responses of vasculitis in most patients.

Infectious Serologies and Autoantibodies in Hepatitis C and Autoimmune Disease-Associated Mixed Cryoglobulinemia

Mixed cryoglobulinemia (MC) syndrome is an immune complex-mediated vasculitis characterized by the clinical triad of purpura, weakness, and arthralgias, the morbidity of which is mainly related to kidney and peripheral nervous system dysfunction as well as to the development of a secondary lymphoma (Ferri et al. Autoimmun Rev 7:114-120, 2007, Lidar et al. Ann N Y Acad Sci 1173:649-657, 2009, Trejo et al. Semin Arthritis Rheum 33:19-28, 2003). MC is associated with infectious and systemic disorders, principally autoimmune and lymphoproliferative diseases. Since the 1990s, a striking association (>90%) between MC and hepatitis C virus (HCV) infection has been established (Ferri and Bombardieri 2004; Pascual et al. J Infect Dis 162:569-570, 1990). However, information regarding the etiopathogenesis of HCV-negative MC is scant (Mascia et al. Dig Liver Dis 39:61-64, 2007). We hereby present our findings, as well as previously published data, regarding the presence of antibodies against infectious agents and autoantibodies in patients with MC in an attempt to establish novel associations which may shed light on the etiopathogenesis of this disease.

The clinical implications of adult-onset henoch-schonelin purpura

Henoch-Schonlein Purpura (HSP) is a small vessel vasculitis mediated by IgA-immune complex deposition. It is characterized by the clinical tetrad of non-thrombocytopenic palpable purpura, abdominal pain, arthritis and renal involvement. Pathologically, it can be considered a form of immune complex-mediated leukocytoclastic vasculitis (LCV) involving the skin and other organs. Though it primarily affects children (over 90% of cases), the occurrence in adults has been rarely reported. Management often involves the use of immunomodulatory or immune-suppressive regimens.

Endothelial Damage in All Types of T-Lymphocyte–Mediated Drug-Induced Eruptions

In severe drug-induced eruptions, bullous lesions can be associated with immune complex-mediated vasculitis and/or with T-lymphocyte-mediated keratinocyte apoptosis. We have recently identified endothelial cell apoptosis in severe bullous T-lymphocyte-mediated drug-induced eruptions. We assessed microvessel involvement in the whole spectrum of T-lymphocyte-mediated drug-induced eruptions. Thirty-two patients with T-lymphocyte-mediated drug-induced eruptions in 4 groups (8 cases of toxic epidermal necrolysis/Stevens-Johnson syndrome, 8 cases of drug rash with eosinophilia and systemic symptoms, 8 cases of acute generalized exanthematous pustulosis, 8 cases of drug maculopapular exanthema) and 8 healthy controls were included. On skin biopsy specimens, we performed a systematic ultrastructural study of endothelial cells, vascular walls, and inflammatory cells; a quantification of apoptotic cells, inflammatory infiltrate, and immune complex deposits; and we assessed granzyme-B, tumor necrosis factor, and Fas ligand expression. Correlations of apoptosis with clinical data of skin lesions and systemic involvement in liver, kidney, lung, and lymph nodes were then assessed. Findings from ultrastructural study showed that endothelial cell apoptosis was present in all 32 drug-induced eruptions. No leukocytoclastic vasculitis was associated. Granzyme-B and tumor necrosis factor were expressed around microvessels. In toxic epidermal necrolysis/Stevens-Johnson syndrome and drug rash with eosinophilia and systemic symptoms, the number of apoptotic endothelial cells was related to the extension of skin lesions and the presence of purpura. It was also related to liver and kidney involvement. Endothelial apoptosis occurs in skin microvessels of all types of T-lymphocyte-mediated drug-induced eruptions. This skin endothelial cell damage is related to the severity of skin lesions and systemic involvement.

Nierenbeteiligung bei systemischen Vaskulitiden

The systemic vasculitides are a heterogenous group of autoimmune disorders, characterised by vessel wall inflammation leading to tissue damage and consecutive loss of function in the dependent organ systems. Vasculitides are classified by aetiological, morphological and immunological criteria. Primary and secundary vasculitis are distinguished diseases and they are categorised according to different sizes of the involved vessels into small, medium and large vessel vasculitis. Immunologically important are 2 different types of vasculitis, immune complex-mediated and pauci immune vasculitis. Renal involvement with rapid progressive glomerulonephritis (RPGN) is a life-threatening complication and needs to be diagnosed and treated immediately. Necrotising crescentic glomerulonephritis is histologically characteristic for ANCA-associated vasculitis. There are evidence-based protocols for induction and maintenance therapy. Combined treatment with steroids and cyclophosphamide is mandatory for critical organ involvement. B-cell-depleting therapy with rituximab is an efficient alternative. Azathioprine, methotrexate and leflunomide are recommended for maintaining remission. Infections, related to therapy or disease, are of particular clinical interest, because they are responsible for increased mortality during the early course of disease. Furthermore, gonadal insufficiency after cyclophosphamide therapy and steroid-induced osteoporosis should be prevented. Immune complex-mediated vasculitis could also cause renal involvement, although the course of glomerulonephritis is less agressive. Kryoglobulinaemic vasculitis is often associated with active hepatitis C infection and remission could be achieved by elimination of virus with interferon alpha. Renal involvement in large vessel vasculitis is mainly attributed to ischaemia and consecutive renal hypertension.

P.4.003 Mismatch negativity predicts cognitive impairments induced by ketamine in healthy volunteers

The three major categories of systemic vasculitis are large vessel vasculitis (chronic granulomatous arteritis), medium vessel vasculitis (necrotizing arteritis), and small vessel vasculitis (necrotizing polyangiitis). This chapter will focus on medium vessel vasculitis (necrotizing arteritis) and small vessel vasculitis that are not known to be caused by direct vessel wall invasion by infectious pathogens. These vasculitides are mediated by immunologic mechanisms that, in many if not most, involve autoimmunity.The two major variants of medium vessel vasculitis are polyarteritis nodosa and Kawasaki’s disease. Small vessel vasculitis is divided into immune complex-mediated vasculitis and pauci-immune vasculitis associated with, and probably caused by, anti-neutrophil cytoplasmic autoantibodies (ANCA). Immune complex vasculitis reviewed in this chapter includes IgA vasculitis (Henoch–Schönlein purpura) and cryoglobulinemic vasculitis. ANCA-associated vasculitis reviewed includes microscopic polyangiitis, granulomatosis with polyangiitis (Wegener’s granulomatosis), and eosinophilic granulomatosis with polyangiitis (Churg–Strauss syndrome).

Hypergammaglobulinaemic purpura associated with alcoholic liver cirrhosis

Hypergammaglobulinaemic purpura (HP) is commonly found in Sjögren's syndrome. We report a rare association of HP arising in a patient with alcoholic liver cirrhosis. A 65-year-old man presented with palpable purpura on the legs. Histological examination of a biopsy taken from the purpura found leucocytoclastic vasculitis in the superficial and mid-dermis. The activity of the vasculitic skin lesions correlated with liver dysfunction. Increased IgA and IgG levels, and hypocomplementaemia, may account for the pathogenesis of the hypergammaglobulinaemic immune complex-mediated vasculitis in this case.

Site of Blood Vessel Damage and Relevance of CD18 in a Murine Model of Immune Complex-Mediated Vasculitis

How neutrophils (polymorphonuclear neutrophils, PMNs) damage vessels in leukocytoclastic vasculitis (LcV) mediated by immune complexes (ICs) is unclear. If degradative enzymes and oxygen radicals are released from PMNs while adhering to the inner side of the vessel wall, they could be washed away by the blood stream or neutralized by serum protease inhibitors. We investigated if in LcV PMNs could damage vessels from the tissue side after transmigration. We used CD18-deficient (CD18-/-) mice because the absence of CD18 excludes transmigration of PMNs. When eliciting the Arthus reaction in ears of CD18-/- mice, deposition of ICs was not sufficient to recruit PMNs or to induce IC-mediated LcV. Injection of PMNs intradermally in CD18-/- mice allowed us to investigate if bypassing diapedesis and placing PMNs exclusively on the abluminal side leads to vascular destruction. We found that injected PMNs gathered around perivascular ICs, but did not cause vessel damage. Only intravenous injection of wild-type PMNs could re-establish the Arthus reaction in CD18-/- mice. Thus, PMNs cause vessel damage during diapedesis from the luminal side, but not from the perivascular space. We suggest that in order to shield the cytotoxic products from the blood stream, ICs induce particularly tight interactions between them, PMNs and endothelial cells.

Transient Encephalopathy Complicating Poststreptococcal Glomerulonephritis in an Adult With Diagnostic Findings Consistent With Cerebral Vasculitis

We report the case of a young woman who had transient encephalopathy with nausea, cognitive impairment, 2 generalized seizures accompanied by visual impairment, and stenotic alterations of cerebral vessels lasting for weeks until complete resolution. These findings were associated with an elevated antideoxyribonuclease B level and biopsy-proven poststreptococcal glomerulonephritis. At the time of the encephalopathy, the patient had no electrolyte level disturbances, an only mildly elevated urea level, and moderate arterial hypertension and was on methylprednisolone therapy. For a couple of days, cranial magnetic resonance imaging showed multiple disseminated asymmetric hyperintensities on T(2)-weighted and fluid-attenuated inversion recovery, suggesting vasogenic edema. However, Doppler ultrasound examinations showed stenoses of extracerebral and multiple intracerebral arteries that persisted for several weeks, lasting considerably longer than the cerebral edema. This finding does not fit the context of hypertensive or steroid-induced encephalopathy, but is consistent with diagnosis of an accompanying vasculitis. Treatment with methylprednisolone for several weeks was associated with resolution of arterial stenoses and neurological symptoms, complete reversibility of Doppler sonographic findings, and significant improvement in renal function.

Pulmonary vasculitis.

Pulmonary vasculitis describes a number of distinct disorders that are pathologically characterized by the destruction of blood vessels. The clinical manifestations of each disorder are defined by the size, type, and location of the affected vasculature. The clinical approach to these disorders rests upon an astute clinician considering the diagnosis and identifying the specific patterns of clinical, radiologic, laboratory, and pathologic abnormalities. Lung involvement is most commonly seen with the primary, idiopathic, small-vessel, or antineutrophil cytoplasmic antibody-associated vasculitides; Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. However, primary, idiopathic medium and large-vessel vasculitis, primary immune complex-mediated vasculitis, and secondary vasculitis are all capable of presenting with lung involvement. In this article, we focus on the more common, antineutrophil cytoplasmic antibody-associated disorder, vasculitides.