Antineutrophil Cytoplasmic Antibodies Determination Research Articles

What is the meaning of ANCA positivity in IgG4-related disease?

To evaluate the prevalence and meaning of antineutrophil cytoplasmic antibodies (ANCA) positivity in a cohort of IgG4-related disease (IgG4-RD). We identified patients with ANCA determination from a retrospective cohort of 69 patients with IgG4-RD. ANCA were measured by indirect immunofluorescence microscopy (IIF) and/or proteinase 3 (PR3)-ANCA and MPO-ANCA by ELISA. IIF patterns were classified as perinuclear (P-ANCA), cytoplasmic (C-ANCA) and atypical (X-ANCA). We compared the ANCA-positive vs the ANCA-negative IgG4-RD group. Out of 69 patients, 31 IgG4-RD patients had an ANCA determination. Four patients with concomitant systemic autoimmune diseases were excluded. We found positive ANCA by IIF in 14 (56%) of 25 patients tested. The most common IIF pattern was C-ANCA in eight (57.1%), followed by dual C-ANCA/X-ANCA in four (28.6%) and P-ANCA and dual C-ANCA/P-ANCA in one each (7.1%). Of the 20 patients with ANCA determination by both IIF and ELISA, four have positive ANCA by ELISA (three for MPO-ANCA and one for PR3-ANCA). Of the two patients with only ELISA determination, one was positive for MPO-ANCA. The prevalence of ANCA positivity by ELISA was 22.7% (5 out of 22 patients). ANCA was more frequent in the Mikulizc/systemic phenotype (42.9%) compared with other phenotypes (P=0.04). ANCA-positive IgG4-RD patients had more frequently lymph node and kidney involvement, high IgG1 levels and erythrocyte sedimentation rate, and positive antinuclear antibodies. ANCA are found in a significant number of patients with IgG4-RD and differed from the ANCA-negative group in terms of clinical and serological features.

The diagnostic and prognostic value of serological markers of inflammatory bowel diseases (a literature review)

The diagnosis of inflammatory bowel disease (IBD) is based on a combination of clinical, endoscopic, histological, radiological and laboratory methods. However, conventional diagnostic methods are not always sufficiently informative in IBD, especially in the case of unclassified colitis, which necessitates the extension of standard diagnostic approaches. Currently, there is an actively search for non-invasive serological markers for early and differential diagnosis of IBD and for the assessment of activity and prognosis of Crohn's disease (CD) and ulcerative colitis (UC). Among the most interesting serological markers are anti-Saccharomyces cerevisiae antibodies (ASCA), anti-neutrophil cytoplasmic antibodies (ANCA), goblet cells antibodies (GAB) and pancreatic autoantibodies (PAB). The aim of this review is to assess the diagnostic and prognostic significance of ASCA, ANCA, GAB, PAB in CD and UC. The paper presents the summary of the data on the role of ASCA, ANCA, GAB and PAB in abnormalities of the immunological tolerance mechanisms to intestinal microflora and intestinal permeability in IBD. We discuss the results of the studies on the associations of ASCA with a complicated CD phenotype, its response to genetically engineered biological therapies, and the need for surgical intervention. The article describes the data on the association of ANCA to the risk of progression of left-sided UC to widespread (total) colon lesions resistant to hormonal therapy, and that of antibodies to DNA-lactoferrin complexes and proteinase 3 to primary sclerosing cholangitis. It has been noted that PAB may be a prognostic marker for ileocolitis, perianal lesions, extraintestinal manifestations and complicated CD, and GAB a predictor of total UC with chronic persistent course. It should be emphasized that combined determination of ASCA, ANCA, GAB and PAB is highly informative, compared to the isolated detection of autoantibodies, for the differential diagnosis and prognosis of CD and UC.

ANCA diagnostics in vasculitis

The cornerstone of the laboratory diagnostics of small vessel vasculitis is the detection of antineutrophil cytoplasmic antibodies (ANCA). The current international consensus recommendations suggest that proteinase 3 (PR3) and myeloperoxidase (MPO) ANCA immunoassays should be used as afirst-line test if there is a justified suspicion of ANCA-associated vasculitis (AAV). A second method is only recommendable when the immunoassay shows a negative or borderline result. The precise identification of all patients with active AAV and avoidance of misdiagnoses due to false positive ANCA measurements is achieved when the ANCA determination is limited to defined clinical situations, which are indicative for AAV. There is increasing evidence that the specificity of ANCA to define homogeneous groups of patients could be better with respect to the prognosis than the clinical subtype.

A fully automated IIF system for the detection of antinuclear antibodies and antineutrophil cytoplasmic antibodies

Indirect immunofluorescence (IIF) is the main technique for the detection of antinuclear antibodies (ANA) and antineutrophil cytoplasmic antibodies (ANCA). The fully automated IIF processor HELIOS(®) is the first IIF processor that is able to automatically prepare slides and perform automatic reading. The objective of the present study was to determine the diagnostic performance of this system for ANA and ANCA IIF interpretation, in comparison with visual IIF. ANA detection by visual IIF or HELIOS(®) was performed on 425 sera samples including: 218 consecutive samples submitted to a reference laboratory for routine ANA testing, 137 samples from healthy subjects and 70 ANA/ENA positive samples. For ANCA determination, 170 sera samples were collected: 40 samples for routine testing, 90 samples from healthy blood donors and 40 anti-PR3/anti-MPO positive subjects. Good correlation was found for the visual and automated ANA IIF approach regarding positive/negative discrimination of these samples (kappa = 0.633 for ANA positive samples and kappa = 0.657 for ANA negative samples, respectively). Positive/negative IIF ANCA discrimination by HELIOS(®) and visual IIF revealed a complete agreement of 100% in sera from healthy patients and PR3/MPO positive samples (kappa = 1.00). There was 95% agreement between the ANCA IIF performed by automated and visual IIF on the investigation of routine samples. Based on these results, HELIOS(®) demonstrated a high diagnostic performance for the automated ANA and ANCA IIF interpretation that was similar to a visual reading in all groups of samples.

Antineutrophil Cytoplasm Antibody: Positivity and Clinical Correlation

ObjectiveTo determine positivity and clinical correlation of anti-neutrophil cytoplasmic antibodies (ANCA), taking into account the interference of antinuclear antibodies (ANA). Material and methodsA prospective study was conducted in the Laboratory of Immunology of the National Cuban Center of Medical Genetic during one year. Two hounded sixty-seven patients with indication for ANCA determination were included. ANCA and ANA determinations with different cut off points and assays were determined by indirect immunofluorescense. Anti proteinase 3 and antimyeloperoxidase antibodies were determined by ELISA. ResultsMost positivity for ANCA was seen in patients with ANCA associated, primary small-vessel vasculitides, rheumatoid arthritis and systemic lupus erythematosus. Presence of ANCA without positivity for proteinase 3 and myeloperoxidase was higher in patients with ANA and little relation was observed between the perinuclear pattern confirmed in formalin and specificity by myeloperoxidase. Highest sensibility and specificity values for vasculitides diagnostic were achieved by ANCA determination using indirect immunofluorescense with a cut off 1/80 and confirming antigenic specificities with ELISA. ConclusionANCA can be present in a great number of chronic inflammatory or autoimmune disorders in the population studied. This determination using indirect immunofluorescence and following by ELISA had a great value for vasculitis diagnosis. Anti mieloperoxidasa assay has a higher utility than the formalin assay when ANA is present.

Anticuerpos contra el citoplasma del neutrófilo: positividad y correlación clínica

ObjectiveTo determine positivity and clinical correlation of anti-neutrophil cytoplasmic antibodies (ANCA), taking into account the interference of antinuclear antibodies (ANA). Material and methodsA prospective study was conducted in the Laboratory of Immunology of the National Cuban Center of Medical Genetic during one year. Two hounded sixty-seven patients with indication for ANCA determination were included. ANCA and ANA determinations with different cut off points and assays were determined by indirect immunofluorescense. Anti proteinase 3 and antimyeloperoxidase antibodies were determined by ELISA. ResultsMost positivity for ANCA was seen in patients with ANCA associated, primary small-vessel vasculitides, rheumatoid arthritis and systemic lupus erythematosus. Presence of ANCA without positivity for proteinase 3 and myeloperoxidase was higher in patients with ANA and little relation was observed between the perinuclear pattern confirmed in formalin and specificity by myeloperoxidase. Highest sensibility and specificity values for vasculitides diagnostic were achieved by ANCA determination using indirect immunofluorescense with a cut off 1/80 and confirming antigenic specificities with ELISA. ConclusionANCA can be present in a great number of chronic inflammatory or autoimmune disorders in the population studied. This determination using indirect immunofluorescence and following by ELISA had a great value for vasculitis diagnosis. Anti mieloperoxidasa assay has a higher utility than the formalin assay when ANA is present.

Determination of anti-neutrophil cytoplasmic antibodies in small vessel vasculitis: Comparative analysis of different strategies

Background Anti-neutrophil cytoplasmic antibodies (ANCA) are associated with primary small vessel vasculitis (SVV). Proteinase-3 (PR3)-ANCA are primarily associated with Wegener granulomatosis, whereas myeloperoxidase (MPO)-ANCA are primarily associated with microscopic polyangiitis (MPA) and vasculitic Churg–Strauss syndrome. We evaluated whether a strategy that is based on screening with ELISA or fluoroenzymeimmunoassay (FEIA) is an accurate alternative to screening with indirect immunofluorescence (IIF). Methods C-ANCA and P-ANCA were determined by IIF and PR3-ANCA and MPO-ANCA were determined by ELISA (Inova) or FEIA (Phadia) on 326 patients (38 with newly diagnosed SVV and 288 diseased controls). Results Specificity and positive likelihood ratios were higher for ELISA and FEIA than for IIF. Post-test probability for SVV of a positive test result was higher for ELISA and FEIA than for IIF. Decision tree analysis in which several testing strategies were compared revealed that a testing strategy that is based on screening with ELISA or FEIA had an expected clinical utility that was comparable to screening with IIF and confirming with ELISA or FEIA. The highest expected clinical utility was found when both IIF and ELISA or FEIA were performed on all samples. Conclusions A strategy based on screening for ANCA with ELISA or FEIA (without prior IIF) is a valuable alternative to screening with IIF and confirming with ELISA or FEIA.

Antineutrophil cytoplasmic antibodies, anti-Saccharomyces cerevisiae antibodies, and specific IgE to food allergens in children with inflammatory bowel diseases.

Differential diagnosis between ulcerative colitis (UC) and Crohn's disease (CD) is difficult in the initial phases in pediatric patients with inflammatory bowel diseases (IBD). This study was performed to determine the significance of anti-neutrophil cytoplasmic antibodies (ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) in IBD. ANCA were specified with regard to their antigenic specifity, significance to the diagnosis, and correlation of titer with the disease activity. The occurrence of food allergy was questioned, too. Serum samples from 44 children with UC (n = 23) or CD (n = 21) and from disease-control children (coeliac disease, n = 21) were analyzed for IgG ANCA, ANCA target antigens, IgA and IgG ASCA, and IgE to food allergens. Results show that ANCA occur more frequently in UC than in CD and disease-control (74, 24, and 10%, respectively). The presence of ANCA does not reflect disease activity. Antigenic specificity does not differ in any group. IgA-ASCA are found more often in patients with CD (76% versus 17% in UC). The testing for both ANCA and ASCA enabled clear-cut differential diagnosis between UC and CD based on the high specificity (ANCA+ ASCA- 92.5% for UC, ANCA- ASCA+ 93.2% for CD). Specific IgE to food allergens were found in 8.7, 14.3, and 23.8% of patients with UC, CD, and coeliac disease, respectively. We conclude that combined testing of ANCA and ASCA represents a valuable tool in the differential diagnosis between UC and CD in pediatric patients, minimizing invasive diagnostic procedures. Monitoring of ANCA, its specificity, and titer determination does not bring more information. Testing for specific IgE to food allergens may be considered in individual patients.

Antineutrophil cytoplasmic antibodies in patients with early rheumatoid arthritis: an early marker of progressive erosive disease.

To evaluate the clinical associations of antineutrophil cytoplasmic antibodies (ANCA) in patients with early rheumatoid arthritis (RA), as well as the possible predictive role of ANCA. We also assessed the overlap of ANCA with other specific serologic markers of RA. Eighty-two RA patients with symptoms for < or = 12 months were studied for the presence of ANCA by immunofluorescence and specific enzyme immunoassays. ANCA were determined and clinical, radiographic, and laboratory data were collected at study entry and later at 12, 36, 60, and 84 months. In 2 patients, the first serum samples (obtained at study entry) were no longer available for the determination of ANCA. Perinuclear ANCA (pANCA) were found in 40 patients (50%), and atypical cytoplasmic ANCA were found in 3 patients (4%) at study entry. Perinuclear ANCA-positive patients were significantly more frequently positive for rheumatoid factor (78%) than were ANCA-negative patients (54%) (P = 0.0297). Fifty-five percent of pANCA-positive patients and 22% of ANCA-negative patients were positive for antiperinuclear factor (P = 0.0044). Similarly, pANCA-positive patients had antikeratin antibodies more frequently than did ANCA-negative patients (35% versus 20%). During a 7-year followup, the progress of radiographic joint destruction, assessed with Larsen scores, was significantly more rapid in patients who were pANCA positive at study entry than in those who were ANCA negative (P = 0.0015). Also, the mean titer of pANCA at study entry was significantly higher in those patients who subsequently had advanced radiographic joint destruction at 60 and 84 months. The association of pANCA with rapid radiographic destruction in patients with early RA was further corroborated by a logistic regression analysis that selected pANCA positivity as an independent and statistically significant predictor of rapid radiographic joint destruction. In patients with early RA, pANCA are associated with specific serologic markers of RA and predict rapid radiographic joint destruction.

Pitfalls of formalin fixation for determination of antineutrophil cytoplasmic antibodies.

Sera can produce nuclear or perinuclear immunofluorescence staining in neutrophils which may be caused by antibodies with differing antigenic specificities. These include perinuclear antineutrophil cytoplasmic antibodies (P-ANCA), granulocyte specific antinuclear...

Comparative evaluation of unfixed and fixed human neutrophils for determination of antineutrophil cytoplasmic antibodies by indirect immunofluorescence.

BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCAs) are found in the sera of patients with vasculitides and ulcerative colitis. Using indirect immunofluorescence on ethanol fixed neutrophils, ANCAs can be divided into two...

Antineutrophil cytoplasmic antibodies (ANCA) in chronic graft-versus-host disease after allogeneic bone marrow transplantation.

We studied the usefulness of monitoring antineutrophil cytoplasmic antibodies (ANCA) in chronic graft-versus-host disease (cGVHD), a major complication of allogeneic bone marrow transplantation. Antigen-specific ELISA and indirect immunofluorescence (IIF) were used to search for ANCA in 47 allogeneic bone marrow graft recipients who developed cGVHD and in 43 who did not (controls). Eight patients exhibited ANCA IIF positivity in the cGVHD group, but none in the controls. Specificity was confirmed in antigen-specific assays in only two cGVHD patients, both showing antilactoferrin (anti-LF) activity. One of these patients was followed-up, and the antilactoferrin antibodies were found only at the time of active but limited cGVHD. Among three ANCA IIF-positive patients, two had antinuclear autoantibodies and three antineutrophil alloantibodies secondary to blood transfusion, which may have been responsible for false ANCA IIF positivity. It is concluded that ANCA determination is not useful in patients with cGVHD. Polyclonal activation of B lymphocytes could result in ANCA activity during cGVHD. False-positive ANCA could be due to allo-immunization following blood transfusion. Rare patients may present antilactoferrin antibodies of unknown clinical significance.

Occurrence of autoantibodies to human leucocyte elastase in Wegener's granulomatosis and other inflammatory disorders.

Antineutrophil cytoplasmic antibodies (ANCAs) constitute a new class of autoantibodies that seem to recognise myeloid lysosomal enzymes. The occurrence of ANCAs with specificity for human leucocyte elastase (HLE) was assessed in serum samples that were routinely submitted for ANCA determination. During a study period of more than six years anti-HLE was found in only six out of 1102 serum samples that produced a perinuclear or an atypical cytoplasmic staining pattern on ethanol fixed granulocytes. These six serum samples were from four patients with a clinical diagnosis of Wegener's granulomatosis but without a definite histological diagnosis, one patient with systemic vasculitis, and one patient with Cogan's syndrome. To further evaluate the prevalence of anti-HLE we tested 315 serum samples from patients with different forms of vasculitis and related disorders. Anti-HLE was detected in two patients only. Thus autoantibodies to HLE are rarely found in serum samples from patients with vasculitic or related disorders.

Intérêt du dosage des anticorps anticytoplasme des polynucléaires neutrophiles. Étude clinique de 256 patients

We examined clinical, biological and anatomical findings of 256 patients who were tested for the presence of antineutrophil cytoplasmic antibodies (ANCA) during last 3 years in the immunopathology laboratory. We found 37 patients with positive ANCA: Wegener granulomatosis 16, periarteritis nodosa 2, glomerulopathies and 7 other nephropathies or systemis diseases. ANCA determination was useful for diagnostic procedure in some cases but not all.

Detection of autoantibodies against myeloid lysosomal enzymes: A useful adjunct to classification of patients with biopsy-proven necrotizing arteritis

purpose: Assessment of the value of determination of antineutrophil cytoplasmic antibodies (ANCA) and its specificities for classification of patients with biopsy-proven necrotizing arteritis. patients and methods: The serum samples of 28 consecutive patients with biopsy-proven vasculitis involving medium- and/or small-sized arteries were tested for ANCA by an indirect immunofluorescence technique, by neutrophil extract enzyme-linked immunosorbent assay (ELISA), and by catching ELISA. results: Eight patients had Churg-Strauss syndrome, six had myeloperoxidase (MPO) antibodies, and in the other two patients, ANCA were not detected. Six patients had polyarteritis nodosa (PAN) limited to the skin and the musculoskeletal system; ANCA were not detected in these patients. Two patients had systemic PAN and both had MPO antibodies. The remaining 12 patients had overlapping clinical features of the different forms of vasculitis. Five patients had polyarteritis in combination with chronic nasal inflammation and glomerulonephritis compatible with Wegener's granulomatosis (WG) but without granulomas in the respiratory tract. All five patients had 29-kd serine protease antibodies. Two patients had polyarteritis in combination with nasal polyposis and asthma compatible with Churg-Strauss syndrome, but eosinophilia was not detected. Both patients had MPO antibodies. Three patients with unclassified granulomatous arteritis had either elastase antibodies or ANCA of unknown specificity. One patient with unclassified systemic vasculitis had 29-kd serine protease antibodies, and one patient with necrotizing arteritis of the bowel in combination with Schönlein-Henoch purpura was negative for ANCA. conclusion: Determination of ANCA and its specificities is a useful adjunct to the classification of patients with biopsy-proven necrotizing arteritis. Within the spectrum of idiopathic vasculitides, 29-kd serine protease antibodies are associated with WG, MPO antibodies are associated with Churg-Strauss syndrome and systemic PAN, and PAN limited to the skin and the musculoskeletal system is not associated with ANCA.