ANCA – Associated Vasculitis

The Discovery of Anti-Neutrophil Cytoplasmic Antibodies (ANCA) First described in 1982 by Davies in 8 patients with necrotizing pauci-immune glomerulonephritis1 Hall and colleagues identified ANCA in four patients with systemic vasculitis2 In 1985, Van der Woude suggested an association between ANCA and Wegener’s granulomatosis3 ANCA subsequently reported in microscopic polyangiitis and in Churg Strauss syndrome4 1. Davies DJ, et al: Br Med J 285:606, 1982 2. Hall JB, et al: Aust NZ J Med 14:277, 1984 3. van der Woude FJ, et al: Lancet 1:425, 1985 4. Jennette CJ, Falk R: New Eng J Med 337:1512, 1997

ANCA-Associated Vasculitis

Shared Features of ANCA-Associated Vasculitides Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), and Churg Strauss syndrome (CSS) Can be considered together in view of a number of shared pathologic, clinical, and laboratory features Preferentially involve small vessels (arterioles, capillaries, venules) Similar glomerular lesions (crescents, focal necrosis, pauci-immune) Propensity to present as lung-renal syndromes Varying prevalence of ANCA positivity

Detection of ANCA ANCAs were originally described based on their immunofluorescence patterns cytoplasmic (c-ANCA) and perinuclear (p-ANCA) The antigens responsible for these patterns have also been identified proteinase 3 (PR3) for c-ANCA myeloperoxidase (MPO) for p-ANCA

Immunofluorescence and Antigenic Specificity In c-ANCA reactivity PR3 is responsible for more than 90% of such reactions Other antigens may occasionally contribute bactericidal permeability-inducing protein (BPI) rarely MPO In p-ANCA reactivity MPO is responsible for ~10% of such reactivity Other antigens include elastase, azurocidin, cathepsin G lysozyme, lactoferrin antinuclear antibodies (ANA) can also have p-anca patterns

ANCA Testing International Consensus Statement for Testing and Reporting ANCA recommends all sera are screened for ANCA by IIF IIF-positivity is confirmed by direct ELISAs Some laboratories test by direct ELISA alone Others screen with direct ELISA and confirm positive sera by IIF A few use capture (“sandwich”) ELISAs

Problems in ANCA Testing Diversity of antineutrophil cytoplasmic antibody target antigens Assay standardization and performance Application of antineutrophil cytoplasmic antibody testing in a clinical setting with a low pretest probability The widespread assumption that antineutrophil cytoplasmic antibody titers alone may closely reflect disease activity and therefore may be used to guide therapy

ANCA Frequencies in Vasculitis Hagen EC, et al: Kidney Int 53(3):743–753, 1998.

ANCA in Other Diseases Connective tissue diseases: Infections: SLE, rheumatoid arthritis, myositis Infections: Endocarditis, HIV Inflammatory bowel disease: Ulcerative colitis > Crohn’s disease Other autoimmune GI diseases Sclerosing cholangitis, autoimmune hepatitis Drug-induced ANCA: Hydralazine, propylthiouracil, D-penicillamine and minocycline

Schematic concept of proinflammatory effects of ANCA leading to vasculitis

ANCA and Disease Activity Pooled analysis studies by Davenport in Am J Nephrol 15(3):201–207, 1995 48% of rises followed by relapse 51% of relapses preceded by rise 100 patients followed serially for 2 years by Boomsma: Arthritis Rheum 43(9):2025–2033, 2000 92% of flares associated with rises in ANCA Predictive value higher with ELISA than with IIF Greatest utility when tests are negative

Wegener’s Granulomatosis: History WG is a granulomatous necrotizing vasculitis characterized by its predilection to affect the upper and lower respiratory tracts and the kidneys First described in 1931 by Heinz Klinger, a German medical student In 1936 and 1939, Dr. Friedrich Wegener provided detailed information about three patients with a similar illness Remained relatively unknown in the American literature until the 1950s, when Godman and Churg published a detailed description of the disorder

WG: Epidemiology WG affects both sexes equally Occurs in patients of all ages (mean age 41 years; range 9 to 78 years) More commonly seen in Caucasian patients (97%) Period prevalence of WG (1986-1990) was estimated to approximate 3 per 100,000 persons It is likely that the prevalence of WG has been underestimated Only since the early 90's has the existence of mild and more indolent forms of disease has been recognized

WG: Clinical Features Classic Triad: Limited WG Upper airway Lower respiratory tract Kidneys Limited WG Relatively mild and indolent without renal involvement

WG: Upper Airway Upper airway disease is the most common presenting feature 70 percent of patients at onset Develops in more than 90 percent of cases Otologic manifestations initial presentation in about 25 percent 60 percent of cases during the course of disease Serous otitis media is the most common ear problem encountered (25 to 44%) Nasal disease is a prominent presenting feature of WG in about one third of cases eventually develops in 64 to 80%

Wegener’s granulomatosis: face This patient with Wegener’s granulomatosis developed a saddle nose deformity with destruction of the dorsal nasal cartilage. Other nasal complications in Wegener’s granulomatosis include perforated nasal septum, mucosal ulceration, epistaxis, and boggy nasal turbinates with purulent nasal discharge. #1102081

WG: Upper Airway Sinusitis Laryngotracheal disease Initial presentation in about one half to two thirds of patients with WG 85 percent of cases during the entire course of disease Laryngotracheal disease asymptomatic subtle hoarseness stridor and life-threatening upper airway obstruction The most characteristic lesion is that of subglottic stenosis (SGS), which occurs in up to 16 percent of patients In pediatric and adolescent patients SGS is dramatically increased, reaching an alarming 48 percent prevalence

WG: Pulmonary Manifestations Pulmonary manifestations occur in 45 percent of cases at presentation 87 percent during the course of disease Cough, hemoptysis, and pleuritis are the most common pulmonary symptoms ~ 1/3 with radiographically demonstrable pulmonary lesions may not have lower airway symptoms The most common radiologic findings include pulmonary infiltrates (67%) nodules (58%) The pulmonary infiltrates in WG may be quite fleeting, appearing and resolving in some cases even before the institution of therapy

WG: Pulmonary Manifestations Persistent diffuse interstitial infiltrates are rare (less than 1%) and should suggest other diagnoses Pulmonary nodules in WG are usually multiple, bilateral, and often cavitate (50%) CT of the chest may reveal infiltrates and nodules that were undetected by conventional radiographs in 43 to 63 percent of cases Less common pulmonary manifestations of WG include pleural effusions, diffuse pulmonary hemorrhage, and mediastinal or hilar lymph node enlargement or mass Diffuse pulmonary hemorrhage has been reported in up to 8 percent of cases, and it carries a high fatality rate (50%)

Wegener’s granulomatosis: lungs (radiograph) These chest radiographs show large cavitary lesions with air-fluid levels from a patient with Wegener’s granulomatosis. #3512031

WG: Renal manifestations Presence or absence of renal disease defines the subsets of generalized and limited WG Frequency of renal involvement in WG is difficult to ascertain Limited WG may go undiagnosed in patients with mild disease By excluding such patients, published series may overestimate the frequency of renal disease in WG Early renal disease may be clinically silent Patients who appear to have limited WG at one time may later develop glomerulonephritis Monitoring of renal status in all patients is important

WG: Renal manifestations Renal disease is estimated to occur in 11 to 18% at presentation 77 to 85% during the course of disease Extrarenal manifestations often precede renal disease Renal disease may progress to fulminant glomerulonephritis within days or weeks, resulting in end-stage renal failure Untreated, mean survival time for this subset is about 5 months Initial and recurrent renal damage may lead to chronic renal insufficiency in up to 42 percent of patients dialysis (11%) renal transplantation (5%)

Early Segmental Fibrinoid Necrosis and Infiltration by Neutrophils in an ANCA Positive Patient with WG

WG: Ocular Manifestations Reported to occur in 28 to 58 percent of patients with WG and may be part of the initial presentation in 8 to 16 percent of cases Any compartment of the eye may be affected Keratitis, conjunctivitis, scleritis, episcleritis, nasolacrimal duct obstruction, uveitis, retroorbital pseudotumor with proptosis, retinal vessel occlusion, and optic neuritis have all been described Most ocular findings are nonspecific proptosis is a diagnostically helpful finding poor prognostic sign for vision

WG: Cutaneous Manifestations Reported in 40 to 50 percent of patients with WG and may be part of the initial presentation in 13 to 25 percent of cases The cutaneous manifestations of WG have included ulcers, palpable purpura, subcutaneous nodules, papules, and vesicles Cutaneous lesions tend to parallel disease activity in other organs The presence of active skin lesions is a reliable clinical marker for active systemic disease

WG: Joint Disease Arthritis is observed in up to 28 percent of patients several patterns can be observed, including monoarticular disease, migratory oligoarthritis, and symmetric or asymmetric polyarthritis of small and large joints. Symmetric polyarthritis of small and large joints may be mistaken for RA A positive test for rheumatoid factor (RF) may be observed in as many as 50 to 60 percent of cases In contrast to RA, the symmetric polyarthritis of WG is generally nonerosive and nondeforming

WG: Neurologic Rarely a presenting feature of WG, may develop during the course of disease in 22-50% Multiple neurologic complications may occur in up to 11 percent of patients Peripheral neuropathy is the most common single neurologic manifestation (10 to 16%) Mononeuritis multiplex (12 to 15%) Distal and symmetric polyneuropathy (2%) Cranial neuropathy occurs in 6 to 9% Cerebrovascular events (4%) cerebral or brain stem infarction, subdural hematoma, and subarachnoid hemorrhage Diffuse meningeal and periventricular white matter disease has been reported

WG: Other Manifestations Gastrointestinal: Abdominal pain, diarrhea, and bleeding are the most frequently reported symptoms Relate to the presence of ulcerations in the bowel Perforation may occur Genitourinary Case-reports of bladder wall, prostate involvement Hemorrhagic cystitis – complication of cyclophosphamide Cardiac Pericarditis Myocarditis Arteritis

WG: Diagnosis Non-specific abnormalities Organ specific Leucocytosis, thrombocytosis, high ESR, anemia Organ specific Urinalysis, sediment, creatinine The sensitivity of PR3-ANCA is about 90 percent in active WG and 40 percent when disease is in remission The specificity of PR3-ANCA in the diagnosis of WG exceeds 95 percent In general, the presence of high-titer ANCA by IFA combined with confirmatory antigen-specific assay for either PR3 or MPO in the setting of a high index of suspicion for vasculitis (i.e., high pretest probability) is sufficient for diagnosis, even in the absence of tissue confirmation

Positive Predictive Value of ANCA 1 100 2 3 4 1. Documented WG 2. Pulmonary-Renal Syndrome 3. Systemic Necrotizing Vasculitis 4. Rapidly Progressive GN 5. GN 6. Hospitalized Patient 5 Positive Predictive Value 50 50 100 6 Disease Prevalence Jennette. Amer J Kidney Dis 18:164, 1991

Diagnostic Yield of Biopsy in WG Inflammatory lesions in WG Necrosis Granulomatous changes Vasculitis Diagnostic yield of a biopsy Nasal, paranasal sinus biopsies Small amount of tissue available in may make it difficult to identify all of the pathologic features Complete diagnostic triad is only seen in 3 to 16% Lung Transbronchial biopsies are rarely diagnostic (less than 7%) Open lung biopsies reveal various combinations of vasculitis, granulomas, and necrosis in 90% Kidney Focal and segmental GN True vasculitis of medium-sized renal arteries is only occasionally noted (3 to 15%), and granulomatous changes are equally rare (3%) The results of kidney biopsies usually not diagnostic of WG

Wegener’s granulomatosis: lung (photomicrographs) Left, The pulmonary parenchyma has been entirely obliterated by a granulomatous inflammatory reaction bordering large necrotic areas. The necrotic areas stain darkly because they contain many fragmented pyknotic nuclei. The inflammatory cells in the lighter staining (viable) areas include several multinucleated giant cells. A large blood vessel forms the center of one necrotic focus. (hematoxylin-eosin; low power) Right, A high-power view of an inflamed blood vessel reveals that most of the wall is necrotic and bordered by palisaded histiocytes. The surrounding tissue is intensely infiltrated by lymphocytes, histiocytes, and a few multinucleated giant cells resembling Langhans' cells. With this stain it is impossible to determine whether the vessel is an artery or a vein. (hematoxylin-eosin; high power) #9412110

WG: Principles of Treatment General: Rapid diagnosis, assessment of extent of disease activity Untreated – high mortality Pharmacotherapy Induction of remission Prevention of relapse Management of drug-toxicity

WG: Induction of Remission Glucocorticoids (GC) Pulse therapy for life threatening disease 1g Solu-Medrol daily for 3 days High dose steroid treatment 1mg/Kg daily Taper after 1 month For classic WG (with renal involvement) Begin concurrent daily oral cyclophosphamide (CTX) 2mg/Kg/day Pulse cyclophosphamide has been studied but not currently recommended Consider methotrexate for less severe or limited disease

WG: NIH experience Hoffman GS, et al: Ann Intern Med 116(6):488–498, 1992. 158 patients with WG followed at the NIH for up to 24 years (mean follow-up period of 8 years) 84% received "standard" therapy with daily CTX and GC Marked improvement in 91% Complete remission in 75% Disease relapse was seen in 50% permanent morbidity from disease occurring in 86% chronic renal insufficiency (42%) hearing loss (35%) nasal deformities (28%) tracheal stenosis (13%) visual loss (8%) Permanent morbidity as a result of treatment with GC and CTX occurred in 42% 46% experienced serious infectious episodes

Summary of Cyclophosphamide Cyclophosphamide induces remission, but Relapses are common, and Cyclophosphamide causes toxicity

WG: Efforts to find less toxic alternatives to cyclophosphamide NIH open label study (Sneller MC, et al Arthritis Rheum 38(5):608–613, 1995) open-label study of weekly low-dose MTX plus GC in 42 patients with biopsy-proven WG Patients with life-threatening disease excluded serum creatinine above 2.5 mg/dl or acute pulmonary hemorrhage 50 percent had active glomerulonephritis remission in 71% after a median of 4.2 months relapses occurred in 36% after a median of 29 months Toxicity: PCP in 4 with 2 deaths

WG: Efforts to find less toxic alternatives to cyclophosphamide EUVAS trial of MTX vs CYC (de Groot, et al Arthritis Rheum; 52:2461–9, 2005) in ANCA associated vasculitis 94% had WG Patients with life-threatening disease excluded serum creatinine above 2.5 mg/dl or acute pulmonary hemorrhage 30% had active glomerulonephritis At 6 months, the remission rate with MTX (89.8%) was not inferior to CYC (93.5%) Relapse rates at 18 months were 69.5% in the MTX group and 46.5% in the CYC group

Summary of Methotrexate as an alternative to Cyclophosphamide for induction MTX, given at a dosage of 20–25 mg per week in combination with glucocorticoids, has emerged as the standard remission induction regimen for WG in patients whose disease is classified as “limited,” “early systemic,” or “non–life or organ threatening.” However relapse remains a problem

WG: Maintaining remission Options Continue cyclophosphamide for 12 months after remission is achieved Switch to methotrexate or azathioprine as soon as remission is achieved (usually 3-6 months) Methotrexate to maintain remission De Groot, et al. Arthritis Rheum 1996; 39:2052 Langford, et al. Arthritis Rheum 1999; 42:2666 Azathioprine to maintain remission Jayne et al.. N Engl J Med 2003; 349:36

WG: New agents Etanercept Rituximab WGET trial (N Engl J Med 2005;352:351-61) Failed to show that etanercept was effective in maintaining remission (no difference when compared with control groups) 6 solid tumors versus none in controls Rituximab 11 refractory patients all responded with remission and decrease in ANCA titers (8/11 became ANCA negative) Arthritis Rheum. 2005 Jan;52(1):262-8

Microscopic Polyangiitis (MPA) MPA was first recognized as a distinct entity by Davson and colleagues in 1948 described as a subgroup of polyarteritis nodosa, distinguished by the presence of segmental necrotizing glomerulonephritis. The Chapel Hill International Consensus Criteria defined MPA as a necrotizing vasculitis (with few or no deposits) affecting small vessels (i.e., capillaries, venules, or arterioles) It was noted that MPA is frequently associated with necrotizing glomerulonephritis and pulmonary capillaritis

MPA: Clinical Features Percentage Constitutional symptoms 76-79 Fever 50-72 Renal Disease 100 Arthralgia 28-65 Purpura 40-44 Pulmonary Disease 50 Neurologic Disease 28 ENT 32

MPA: Renal Disease 100 % occurrence reflects ascertainment bias The renal lesion of MPA is that of necrotizing glomerulonephritis It is indistinguishable from the renal lesion of WG

MPA: Pulmonary Disease Lung involvement is common in MPA and is present in more than half of reported cases in most series Diffuse alveolar hemorrhage (DAH) is the most serious form of lung involvement and has been reported in 12 to 29 percent of patients in several series The clinical manifestations range from mild dyspnea and anemia without any hemoptysis to massive hemorrhage and bleeding with profound hypoxia with acute onset in most patients The radiographic features of DAH are nonspecific, demonstrating patchy or diffuse alveolar infiltration The characteristic histopathology of MPA is that of pulmonary capillaritis

MPA: Diagnosis Problems in diagnosis Variable clinical presentation Histologic findings not specific Imperfect association with p-ANCA (anti-MPO) c-ANCA (anti-PR3) can be positive in MPA Differentiation from WG may at times be difficult granulomas are not always found in WG Prominent involvement of the upper respiratory tract or the presence of PR3-ANCA should seriously raise the possibility of WG

Churg Strauss Syndrome (CSS) The syndrome defined by Churg and Strauss in 1951 has undergone several redefinitions but is still characterized by three histopathologic features: necrotizing vasculitis infiltration by eosinophils extravascular granulomas The 1994, Chapel Hill classification defined the disease as an eosinophil-rich and granulomatous inflammation involving the respiratory tract necrotizing vasculitis involving the medium-sized vessels associated with asthma and eosinophilia

Churg-Strauss syndrome: bowel (photomicrograph) The biopsy of the bowel wall in a patient with with Churg-Strauss syndrome shows a blood vessel with subendothelial fibrin accumulation and non-necrotizing transmural inflammation with lymphocytes and polymorphonuclear leukocytes. Eosinophils and scattered multinucleated giant cells are also present. (hematoxylin-eosin; medium power) #9412091

CSS: Clinical Features CSS is characterized by three distinct phases Prodrome, dominated by allergic features, is common in patients ultimately diagnosed with CSS Allergic rhinitis and asthma may often precede diagnosis of vasculitis by 3 to 7 years Systemic vasculitis

CSS: Organ Involvement Pulmonary Disease Pulmonary infiltrates Pleural effusions (often eosinophilic) Pulmonary hemorrhage Nervous System Involvement Peripheral neurologic involvement often dominates the clinical picture and has been reported in the majority of patients Renal Disease Kidney involvement is less common in CSS than MPA or WG Skin involvement has often led to confusion, for the term Churg-Strauss granuloma may be seen in other disorders Palpable purpura has been observed in nearly 50 percent of CSS patients

Diagnostic Approach to Small Vessel Vasculitis Vasculitis suspected (lung-renal syndrome, purpura, neuropathy) ANCA associated Not ANCA associated Granulomatous IgA deposit Yes No Yes No Asthma/eosinophilia MPA HSP Cryoglobulins Yes No Yes No CSS WG Cryoglobulinemia Other

Summary ANCA-associated vasculitides are still rare but life-threatening disorders ANCA testing is yet to fully standardized ANCA-associated vasculitides may present with lung-renal syndromes often with neurologic, ocular or cutaneous manifestations MPA and WG may be hard to separate when the clinical presentation is incomplete CSS appears to be a more distinctive disorder The treatment approach is similar and largely successful Relapse and long-term morbidity are still serious issues