Wegener's Granulomatosis and the ANCA TestIntroduction:  The history of Wegener's Granulomatosis and the ANCA test: Below is a brief history of this disease with laboratory findings. The information, especially in the box, is a great resource for medical transcription education; it includes not only common abbreviations for commonly heard diseases like IBD (irritable bowel disease), CD (Crohn disease), systemic lupus erythematosus (SLE) - the technical results in chemistry terms are a great resource for medical transcriptionists should you come across these terms. To our medical transcriptionist friends: Wegener granulomatosis is the preferred American Association for Medical transcription (AAMT) way to transcribe this eponym. An eponym is a word that is derived from the proper name of a person or place. AAMT prefers the use of non-possessive Eponyms. Remember, if the author drops the noun, then we keep the possessive apostrophe: "The patient has Wegener's." cANCA - PR3-ANCA - pANCA-negative - MPO-ANCA In 1931, Heinz Klinger of the University of Berlin first reported two patients who died having prolonged sepsis with inflammation of blood vessels scattered throughout the body. Five years later, Friederic Wegener in Breslau described a distinct syndrome in three patients. These patients were found to have necrotizing granulomas involving the upper and lower respiratory tract. In 1954, seven more patients were described. This resulted in the establishment of the definite criteria for the diagnosis of the disease described by Wegener. Dr. Friederic Wegener died in July of 1990 at the age of 83. What causes Wegener's Granulomatosis? The cause of Wegener's Granulomatosis remains unknown. Though the disease resembles an infectious process, no causative agent has been isolated. Anti-Neutrophilic Cytoplasmic Antibody (ANCA) is found in the majority of patients, and its level appears to correlate with the disease activity. The Incidence of Wegener's Granulomatosis General: Wegener's granulomatosis is an uncommon disease, in which the blood vessels are inflamed (vasculitis). This inflammation damages important organs of the body by limiting blood flow to those organs and destroying normal tissue. Although the disease can involve any organ system, Wegener's granulomatosis mainly affects the respiratory tract (sinuses, nose, trachea [windpipe], and lungs) and kidneys. This disorder can affect people at any age and strikes men and women equally. It is rare in African Americans compared with Caucasians. As stated, Wegener's Granulomatosis is a quite rare disease, especially in Europe and in dark people (Africans, South-Americans, Asian people). The exact number of patients is not known, but a very rough estimate is two new cases per million Americans per year, or about 500 new cases diagnosed every year in America.
The symptoms of Wegener's Granulomatosis, and the severity of those symptoms, vary from one patient to another, although most patients first notice symptoms in the upper respiratory tract. A common manifestation of the disease is a persistent rhinorrhea ("runny nose") or other cold-like symptoms that do not respond to standard treatment, and that become progressively worse. Rhinorrhea can result from sinus drainage and can cause upper respiratory obstruction and pain. Complaints include discharge from the nose, sinusitis, nasal membrane ulcerations and crusting, inflammation of the ear with hearing problems, cough, coughing of blood and pleuritis (inflammation of the lining of the lung). Other initial symptoms include fever, fatigue, malaise (feeling ill), loss of appetite, weight loss, joint pain, night sweats, changes in the color of urine, weakness. Be aware that not all Wegener's patients experience all of the above symptoms, and that the severity of the disease is different with each patient. Fever is often present, sometimes resulting from bacterial infection in the sinuses. One third of patients may be without symptoms at the onset of the disease. How do you diagnose Wegener's Granulomatosis? Laboratory tests are not specific for Wegener's Granulomatosis and only suggest that that the patient has an inflammatory disease. Blood tests often show anemia (low red blood cell count) and other changes in the blood. Chest X-rays and kidney biopsy are important tools used in diagnosing Wegener's Granulomatosis. For the most effective treatment, early diagnose is critical. Asymptomatic patients can be diagnosed by ANCA blood tests and CT scans of sinuses and lungs. Background on the ANCA test ANCA stands for anti-neutrophilic cytoplasmic antibodies. These are a class of antibodies identified by immunofluorescence. In general, serologic testing for ANCA is recommended for patients with: Glomerulonephritis Pulmonary hemorrhage, especially Pulmonary-Renal syndrome Cutaneous vasculitis with systemic features Mononeuritis multiplex or other peripheral neuropathy Long standing sinusitis or otitis Subglottic tracheal stenosis Retro-orbital mass It takes 5-15 months, on average, to make a diagnosis of Wegener's Granulomatosis. 40% of all diagnoses are made within less than 3 months, 10% within 5-15 years. Test One: 12 sera, four of which were selected for their potential to cause problems in the detection of various ANCA specificities, were analyzed in the standard indirect immunofluorescence (IIF) test and in ELISAs for ANCA routinely performed in the seven participating laboratories. The IIF methodology differed with respect to the dilution of the serum being screened and the concentration of the conjugate used. Results from sera with high ANCA titers were similar, although the quantitative values could not be compared. In sera containing rheumatoid factor and anti-nuclear antibodies (ANA), ANCA-unrelated staining patterns were observed. Six antigen preparations were used in ELISA for the detection of cANCA. In ELISA with purified proteinase-3 all three cANCA sera were positive, but not anti-myeloperoxidase (MPO) or anti-lactoferrin (LF) positive sera. The other assays were less sensitive or gave inconsistent results. Various preparations of purified MPO and LF used in ELISA were readily recognized by anti-MPO and anti-LF positive sera. From this study it can be concluded that the IIF test, although performed with different methods, shows comparable results using strongly positive sera. In general solid phase assays for cANCA detection are not well standardized and need improvement although the purified proteinase-3 ELISA is possibly an exception. MPO and LF can be used in ELISA procedures for the detection of pANCA-related antibodies. Antineutrophil cytoplasmic antibodies (ANCA) are used as diagnostic markers for systemic vasculitis. However, the specificity and sensitivity of ANCA detection differs from centre to centre due in large part to variations in methodology. Test Two: We compared 8 commercial ELISA kits and an in-house method (HM) for their specificity and sensitivity in detecting ANCA against proteinase 3 (PR3-ANCA, 7 kits) and myeloperoxidase (MPO-ANCA, 8 kits). Sera from 5 patients with systemic lupus erythematosus (SLE), 28 with Wegener's granulomatosis (WG), 22 with microscopic polyangiitis (MPA), 5 with idiopathic rapidly progressive glomerulonephritis (RPGN), and 5 healthy controls were examined by both the indirect immunofluorescence technique (IFT) and the ELISA kits. Sera from healthy controls and patients with SLE or cANCA-negative WG were shown to be PR3-ANCA negative by all 7 PR3-ANCA kits. In 25 cANCA-positive sera from WG patients, PR3-ANCA positivity ranged from 44% to 84%. An absolute concordance among the 7 kits was noted in 56% of the cANCA-positive samples. The PR3-ANCA levels in 5 of the 7 kits correlated with the cANCA titers in IFT. Sera from the healthy controls and 4 out of the 5 SLE and pANCA-negative patients were found to be MPO-ANCA negative in all 8 MPO-ANCA kits. In 20 pANCA-positive sera, MPO-ANCA positivity ranged from 25% to 75%. Thirty-five percent of MPO-ANCA-positive sera were confirmed by capture ELISA, immunoblot and inhibition assay. The concordance rate was only 30% among pANCA-positive sera in the 8 MPO-ANCA kits. No significant correlation was observed between pANCA titers and MPO-ANCA levels. The HM showed that 65% of cANCA-positive sera were PR3-ANCA positive, and 45% of pANCA-positive sera were MPO-ANCA positive. Our results indicate that the sensitivities and specificities for ANCA detection differ significantly among the commercial kits tested and underline the necessity of establishing uniform international standards for ANCA ELISA procedures in order to permit more reliable interpretation and comparison of data. Test Three: In the present study we have used the monoclonal antibody (MoAb) 4A3 for the capture of PR3 in an ELISA, and a clinical evaluation of the diagnostic properties of the new capture ELISA has been made. The sensitivity of the capture PR3-ANCA ELISA was 85% in a material of c-ANCA positive sera. A specificity of 90% was obtained in analyses from patients having various forms of glomerulonephritis. There was a significantly higher diagnostic sensitivity of the capture PR3-ANCA ELISA (85%) compared to c-ANCA by IIF (58%) in patients with Wegener's granulomatosis with renal involvement. Capture PR3-ANCA and direct ELISA for MPO-ANCA together gave a diagnostic sensitivity of 98%, versus 75% using IIF. In conclusion, the capture PR3-ANCA ELISA seems to be a valuable tool in the diagnosis of Wegener's granulomatosis with renal involvement. Preliminary data suggest that the technique may have an advantage over direct ELISA for PR3-ANCA, as well as in the follow-up of c-/PR3-ANCA associated vasculitides. However, further prospective studies are needed to clarify this premise. Anti-neutrophil cytoplasmic antibodies (ANCA) are widely used as diagnostic markers for Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), Churg-Strauss syndrome (CSS) and idiopathic rapidly progressive glomerulonephritis (iRPGN). The objective of this study was to evaluate the diagnostic value of ANCA measurement by the indirect immunofluorescence (IIF) test, and by anti-PR3 and anti-MPO ELISA performed in different locations, in patients with idiopathic small vessel vasculitis. Test Four: Fourteen centers participated in a standardization study of ANCA assays, and entered a total number of 169 newly diagnosed and 189 historical patients with idiopathic systemic vasculitis or iRPGN. Patients were classified according to a pre-defined diagnostic classification system. Results were compared with those of 184 disease controls and 740 healthy controls. The IIF test was performed according to standard methodology; ELISAs had been standardized among the participants in a previous phase of the study. The sensitivities of assays in patients were as follows. The sensitivity in WG was: cANCA 64%, pANCA 21%, anti-PR3 66%, anti-MPO 24%. In MPA the sensitivity was: cANCA 23%, pANCA 58%, anti-PR3 26%, anti-MPO 58%. Sensitivity in iRPGN was: cANCA 36%, pANCA 45%, anti-PR3 50%, anti-MPO 64%. The specificity of assays (related to disease controls) was: cANCA 95%, pANCA 81%, anti-PR3 87%, anti-MPO 91%. When the results of the IIF test were combined with those of the ELISAs (cANCA/anti-PR3 positive, pANCA/anti-MPO positive), the diagnostic specificity increased to 99%. The sensitivity of the combination of cANCA + anti-PR3 or pANCA + anti-MPO for WG, MPA or iRPGN was 73%, 67% and 82%, respectively. From this study we conclude that the value of the IIF test for ANCA detection can be greatly increased by the addition of a well standardized antigen-specific ELISA. In a significant number of patients with idiopathic small vessel vasculitis, however, the ANCA test results (either in IIF or ELISA) are negative. This review intends to highlight important differences between neutrophil-specific autoantibodies (NSA) typically found in chronic inflammatory bowel diseases (CIBD) and anti-neutrophil cytoplasm antibodies (ANCA) associated with primary systemic small vessel vasculitides (SSVV). Indirect immunofluorescence (IF) techniques alone cannot distinguish NSA from ANCA and special measures must be taken to separate these two autoantibody populations. Many autoantigens originating in all cell compartments may be targeted by NSA in CIBD, several of these being constituents of neutrophil nuclei. Apart from the use of NSA in the differential diagnosis between Crohn's disease (CD) and ulcerative colitis (UC), very limited clinical significance is ascribed to these antibodies in CIBD. Laboratory reports on NSA-positivity must be clearly distinguishable from reports on ANCA to help avoid clinical misinterpretation. Perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) of the IgG class have been reported in inflammatory bowel disease, mainly in ulcerative colitis. Since this disease affects the gastrointestinal tract, we determined whether IgA class ANCA were present in inflammatory bowel disease. Test Five: We used an indirect immunofluorescence assay for IgG and IgA ANCA testing. Sera from 34 patients with Crohn's disease and 29 patients with ulcerative colitis were collected together with clinical and laboratory data. We found IgA class ANCA of a perinuclear type in 52% of patients with ulcerative colitis and in 9% of Crohn's disease patients. There was a significant association between the presence of IgA ANCA and the occurrence of blood in the feces in the ulcerative colitis group (P = 0.03). IgG ANCA was found in 56% of patients with ulcerative colitis and in 7% of patients with Crohn's disease. Because of partial overlap between IgG and IgA ANCA positivity, the sensitivity of ANCA testing in ulcerative colitis increased from 56% up to 78% by combining IgG and IgA assays. In conclusion, IgA ANCA occurs with a high prevalence in ulcerative colitis. Moreover there is a possible relationship between IgA ANCA and disease activity in ulcerative colitis. Test Six: To evaluate, in a cohort of 566 patients with systemic lupus erythematosus (SLE) drawn from 11 European centres: (i) the prevalence of ANCAs and their subspecificities in a large series of European SLE patients; (ii) the possible associations of ANCA with the most common clinical manifestations of the disease; and (iii) whether ANCAs correlate with some of the autoantibodies commonly found in SLE. METHODS: ANCA detection was performed by indirect immunofluorescence (IIF), and by ELISA for lactoferrin (LF), myeloperoxidase (MPO), proteinase3 (PR3) and lysozyme (LZ) subspecificities. RESULTS: The prevalence of ANCA was 16.4% (IIF). The prevalence of LF was 14.3%, LZ 4.6%, MPO 9.3%, and PR3 1.7%. Our results show that ANCA is associated with certain clinical manifestations of SLE. In particular, positive correlations were found between IIF ANCA and serositis (p = 0.026), livedo reticularis (p = 0.01), venous thrombosis (p = 0.03) and arthritis (p = 0.04), while anti-LF antibodies were associated with serositis (p = 0.05) and livedo reticularis (p < 10(-3). Nevertheless, multivariate analysis demonstrated that other autoantibodies, such as aCL and SSA/Ro, are more closely correlated than ANCA with some of the aforementioned clinical features. CONCLUSION: Our results demonstrate that ANCA are detectable in SLE sera and that some of them are associated with particular clinical manifestations. Whether ANCA plays a direct pathogenetic role in the vascular damage of SLE or only represents an epiphenomenon or a marker of disease activity remains to be elucidated. RESULTS: Large-scale multi-center testing of patient and normal sera by the European ANCA Assay Standardization Project using immunofluorescence assays and enzyme immunoassays indicate the assays have good sensitivity and specificity, and diagnostic utility for ANCA-associated vasculitis. A few investigations covering basic and clinical research with ANCA remain controversial: whether endothelial cells do or do not express a 29-kd neutral serine protease termed proteinase-3 (PR-3), the target of ANCA in most individuals with Wegener's granulomatosis, and whether anti-myeloperoxidase (MPO) ANCAs recognize a restricted number of epitopes on MPO. This issue has relevance for using monoclonal antibodies to treat patients with vasculitis who have adverse effects from immunosuppressive drugs. The two allelic forms of FcgammaRIIa (H131/R131) and the two of FcgammaRIIlb (NA1/NA2) are discussed as possible inheritable genetic elements for vasculitic disorders and for signaling responses. Stimulatory and co-stimulatory molecules, and cytokine profiles of T lymphocytes are characterized to show that these cells are actively involved in the ANCA-associated vasculitides. The patient described had a de novo ANCA associated small vessel vasculitis which developed after renal transplantation. CONCLUSIONS: There have been significant advances in the development of sensitive and specific ANCA assays. The immunopathogenetic mechanism of ANCA involves the constitutive FcgammaRs, ligands, and signaling responses to activate cytokine-primed neutrophils. This may lead to the generation of reactive oxygen intermediates, degranulation, and secretion of intracellular granule contents, and ultimately inflammation and vasculitis. Other diagnostic tools are as follows:
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