Antineutrophil Cytoplasmic Antibody Type Research Articles

10.5937/mckg48-3313 = Vasculitides of the small blood vessels of kidney: Etiopathogenesis, diagnosis and treatment

Vasculitis is an inflammation of blood vessel walls. Vasculitides of kidney's small blood vessels include microscopic polyangiitis, Wegener's granulomatosis and Churg-Strauss-syndrome. The main pathohistological characteristics of all three types of vasculitis are the inflammation of small blood vessels, glomeruli, with necrosis and glomerular crescents formation. Anti-neutrophil cytoplasmic antibodies (ANCA) play an important role in the development of vasculitis. Depending on the target antigen and immunofluorescence microscopy findings, there are two types of ANCA: cytoplasmic (cANCA) and perinuclear (pANCA). Immunopathogenesis of ANCA-associated vasculitis involves four main steps: regrouping of neutrophils and their approaching to the endothelial surface, interaction of ANCA with neutrophil antigens, adherence and penetration of neutrophils into the endothelium and, finally, activation of neutrophils and production of mediators that damage endothelial cells. Kidney damage is clinically manifested by appearance of microhematuria with nonnephrotic range proteinuria and development of acute nephritic syndrome. Diffuse alveolar hemorrhage (DAH) often develops, too. Kidney biopsy is the main diagnostic procedure that enables the right choice of treatment regime. The treatment comprises of two phases: the first is the induction of disease remission and the second is the maintenance of remission. The first phase consists of administering high doses of corticosteroids and cyclophosphamide while in the second phase azathioprine or methotrexate are administered instead of cyclophosphamide. Disease relapse is treated with rituximab.

Clinical characteristics and outcome of pauci-immune glomerulonephritis in African Americans

ObjectivesPauci-immune glomerulonephritis is rare in African Americans (AA) and the clinical presentation and treatment outcomes of vasculitis have not been well described. MethodsWe identified patients who were 2–92 years of age between 1983 and 2011 with a diagnosis of biopsy-proven pauci-immune glomerulonephritis (GN) at any point during their disease course. Comparing AA to Caucasian patients, we examined demographics, clinical features at presentation, treatment and outcomes of relapse, end-stage renal disease (ESRD), and death. ResultsOf the 672 patients, 75 were AA with the remainder being Caucasian. Compared to Caucasians, disease onset in AA was at an earlier age (52 vs. 57 years, p = 0.05) and was more often myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) positive (71% vs. 54%, p = 0.01). AA patients had a shorter median time between onset of symptoms and biopsy compared to Caucasians [median (IQR): 0.23 (0.00, 1.22) months vs. 0.66 (0.00, 3.62) months, p = 0.003]. Median [Interquartile range (IQR)] follow-up in months was 28 (5, 52) in AA and 26 (10, 55) in Caucasian patients. Median estimated glomerular filtration rate was similar at presentation (21 vs. 22ml/min/m2). Both groups had similar induction treatment regimens. There was less favorable treatment response among AA compared to Caucasians for initial treatment resistance (28% vs. 18%, p = 0.05) and complete remission (72% vs. 82%, p = 0.05). There were no differences in the number of renal relapses or number of deaths between the 2groups. Overall, in multivariable analyses controlling for age, race, ANCA type, and entry serum creatinine, there were not differences by race in treatment response, renal relapse, ESRD, or death over the entire time of follow-up. ConclusionsAA patients with pauci-immune GN are younger and more often MPO-ANCA positive compared to Caucasians. Despite a shorter time to diagnosis for AA patients, there were no differences compared to Caucasians in treatment response, ESRD, renal relapse, or death rates by race over the entire duration of follow-up.

Reversible cochlear disorders with normal vestibular functions in three cases with Wegener's granulomatosis

Patients with Wegener's granulomatosis (WG) often suffer from hearing loss, but its precise mechanisms have not been well understood. We experienced 3 WG cases whose initial symptoms were bilateral progressive mixed (both conductive and sensorineural) hearing loss, followed by systemic symptoms one year later. They were diagnosed as WG based on positive serology of anti-neutrophil cytoplasmic antibodies (ANCAs) and pathologic findings of affected lesions in addition to systemic symptoms. Although they were different in the type of ANCAs and systemic lesions, all showed considerably reversible cochlear disorders with normal vestibular functions. Moreover, their initial otologic manifestations shared same characteristic features, (1) thick ear drums with pulsatile serous intratympanic effusion, (2) poor speech discrimination ability, and (3) steroid-dependent changes of hearing levels (HLs). They exhibited no significant vestibular abnormalities in chair vestibule-ocular reflex (VOR) testing and cold air caloric tests even when they had severe hearing loss. On the basis of these results, we hypothesized that vasculitis of stria vascularis which generates endocochlear potential might cause these reversible cochlear-specific dysfunctions.

Twenty-eight years with antineutrophil cytoplasmic antibodies (ANCA): how to test for ANCA - evidence-based immunology?

Wegener’s granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and primary pauci-immune crescentic glomerulonephritis are associated with circulating antineutrophil cytoplasmic autoantibodies (ANCA) (collectively called ANCA-associated vasculitides, AAV). Two types of ANCA, one with a cytoplasmic fluorescence pattern (C-ANCA) and specificity for proteinase 3 (PR3-ANCA) and the other with a perinuclear pattern (P-ANCA) and specificity for myeloperoxidase (MPO-ANCA), account for this association and are highly specific markers for these vasculitides. AAV most often require therapy with cytotoxic and antiinflammatory agents, and hence a well-established diagnosis is mandatory to avoid unnecessary and risky treatment. The widespread use of ANCA screening in the past decade has resulted in the occurrence of greater numbers of false-positive results and has led to greater difficulty in test interpretation. Methods for ANCA detection have been standardized internationally in large multicentre studies and an international consensus statement on testing and reporting of ANCA has been pub lished (1999 and 2003). Despite these advances, problems with the extended use of ANCA testing in daily clinical practice remain. They may be summarized as follows: (1) the basic standards for ANCA testing are not uniformly met; (2) there is still controversy over the value of formalin fixation of neutrophils in differentiating P-ANCA from antinuclear antibodies (what is the place of this substrate in ANCA testing?); (3) the new generation of PR3-ANCA and MPO-ANCA ELISAs are more sensitive and specific than immunofluorescence testing (should ELISAs replace the immunofluorescence test?); and (4) should alternative methods for ANCA detection such as image analysis and/or multiplex immunoassays be used for screening? In this paper, we review these issues, identify areas of uncertainty, and provide practical guidelines where possible.

Clinical feature analysis of 190 patients with anti-neutrophil cytoplasmic antibodies associated vasculitis

To explore the clinical features and disease spectrums for ANCA (anti-neutrophil cytoplasmic antibodies)-associated vasculitis (AAV) and to improve its cognition. Clinical features of 190 cases of patients with AAV hospitalized from 1998 to 2008 were reviewed retrospectively. According to the result of ANCA test, the patients were divided into two groups, cytoplasmic ANCA (C-ANCA) positive and perinuclear ANCA (P-ANCA) positive. The authors compared the differences of disease spectrums, clinical manifestations and laboratory tests between two groups. The relative mortality factors were also analyzed. The authors studied 92 males and 98 females with an age range of 8 - 89 (59 +/- 18) years old. There were 156 cases aged 40 - 80 years old (82.1%) and 162 patients (85.3%) were of primary AAV including 146 cases of P-ANCA positive and 16 cases of C-ANCA positive. There were 28 patients with secondary AAV including 18 cases of connective tissue disease, 7 cases of propylthiouracil induction, 1 case each of idiopathic thrombocytopenic purpura, lung cancer and endometrial carcinoma. There were 25 cases of P-ANCA positive and 3 cases of C-ANCA positive in secondary AAV. There were 171 cases (90.0%) in P-ANCA group and 19 cases (10.0%) in C-ANCA group. The number of organ involvement was 2.53 in C-ANCA group and 1.92 in P-ANCA group. Gastrointestinal tract, joint, upper respiratory tract and ocular involvement was more in C-ANCA group than in P-ANCA group. Oral and auricular involvement was more in P-ANCA group than in C-ANCA group. The involvement difference was of statistic significance in upper respiratory tract, joint and eye (all P < 0.05). Renal and pulmonary involvement in P-ANCA group was similar to C-ANCA group. There were 3 mortality cases in C-ANCA group and 22 in P-ANCA group. Respiratory failure and multiple organ dysfunctions were relative mortality factors. AAV is observed in elders with multiple organ involvement. The number of organ involvement in C-ANCA group is more than that in P-ANCA group. P-ANCA positive patients are more than c-ANCA patients. The disease spectrum is different in these two groups. Secondary AAV is more in P-ANCA group than in C-ANCA group. Clinical manifestations, laboratory tests and type of ANCA are helpful for the diagnosis of AAV.

Autoantibodies in vasculitis

Before the mid-1980s the only autoantibody widely used to assist in diagnosing vasculitic disease was IgG antibody to the α3 domain of the noncollagenous part of type IV collagen (anti-glomerular basement membrane). Since that time, antineutrophil cytoplasmic antibodies (ANCAs) directed at the azurophilic granule proteins proteinase-3 and myeloperoxidase have been established as clinically useful autoantibodies to support a diagnosis of Wegener's granulomatosis, microscopic polyangiitis, Churg–Strauss syndrome and limited forms of these primary, small vessel necrotizing and often granulomatous vasculitides. The establishment of standardized methods for identifying those antibodies was needed before they could be used in clinical practice. The levels of both types of ANCAs tend to increase in parallel with the degree of clinical disease activity, and they decrease with successful immunosuppressive therapy. More than one assay may have to be used to discover imminent exacerbations in proteinase-3-ANCA associated syndromes. Although autoantibodies to endothelial cells may be important players in the pathogenesis of several vasculitic conditions, they have not gained clinical popularity because of lack of standardized detection methods.

False-positive myeloperoxidase binding activity due to DNA/anti-DNA antibody complexes: a source for analytical error in serologic evaluation of anti-neutrophil cytoplasmic autoantibodies.

Anti-myeloperoxidase antibodies (anti-MPO) are a major type of anti-neutrophil cytoplasmic antibody (ANCA). While evaluating anti-MPO monoclonal antibodies from SCG/Kj mice, we observed several hybridomas that appeared to react with both MPO and DNA. Sera from some patients with systemic lupus erythematosus (SLE) also react with MPO and DNA. We hypothesized that the MPO binding activity is a false-positive result due to the binding of DNA, contained within the antigen binding site of anti-DNA antibodies, to the cationic MPO. Antibodies from tissue culture supernatants from 'dual reactive' hybridomas were purified under high-salt conditions (3 M NaCl) to remove any antigen bound to antibody. The MPO and DNA binding activity were measured by ELISA. The MPO binding activity was completely abrogated while the DNA binding activity remained. The MPO binding activity was restored, in a dose-dependent manner, by the addition of increasing amount of calf-thymus DNA (CT-DNA) to the purified antibody. Sera from six patients with SLE that reacted with both MPO and DNA were treated with DNase and showed a decrease in MPO binding activity compared with untreated samples. MPO binding activity was observed when CT-DNA was added to sera from SLE patients that initially reacted with DNA but not with MPO. These results suggest that the DNA contained within the antigen binding site of anti-DNA antibodies could bind to the highly cationic MPO used as substrate antigen in immunoassays, resulting in a false-positive test.

Anti-lactoferrin antibodies and other types of anti-neutrophil cytoplasmic antibodies (ANCA) in reactive arthritis and ankylosing spondylitis.

Fifty-five serum samples from patients with reactive arthritis (ReA), 40 from patients with ankylosing spondylitis (AS) and three from patients with chronic sacroiliac joint arthritis were analysed for the presence of ANCA of IgG class by means of enzyme immunosorbent assay using lactoferrin (Lf), myeloperoxidase (MPO) and antigen extracted from azurophil granules ('alpha-antigen') containing proteinase 3 (PR3) as substrate. IgG-ANCA were found in 31 (56%) patients with ReA. Twenty-three (42%) had anti-Lf antibodies, nine (16%) had anti-MPO and eight (15%) had anti-alpha-antigen antibodies, none of which reacted with PR3. Only six (14%) AS or sacroiliac joint arthritis patients had ANCA (P < 0.001). Three (7%) had anti-Lf, two (5%) anti-MPO and two (5%) anti-alpha-antigen antibodies. Yersinia and Salmonella bacteria were separated by SDS-PAGE and blots were incubated with serum from rabbits immunized with human Lf. The hyperimmune serum recognized a band of 78 kD from both bacteria which was not seen when preimmune serum was used. The reaction to the 78-kD antigen could be completely inhibited when anti-Lf antibodies were absorbed on Lf coupled to cyanogen bromide-activated Sepharose, possibly indicating cross-reacting epitopes in Lf and enterobacterial antigen.

Three-diaengional radiation therapy treatment planning and delivery

Anti-neutrophil cytoplasmic antibodies (ANCA) are antibodies directed against enzymes that are found mainly within the azurophil or primary granules of neutrophils. There are 3 types of ANCA that can be distinguished by the patterns they produce by indirect immunofluorescence when tested on normal ethanol-fixed neutrophils. Diffuse fine granular cytoplasmic fluorescence (cANCA) is typically found in Wegener’s granufomatosis, in some cases of microscopic polyarteritis and Churg Strauss syndrome, and in some cases of crescentic and segmental necrotising glomerulonephritis, but it is rare in other conditions. The target antigen is usually proteinase 3. Perinuclear fluorescence (pANCA) is found in many cases of microscopic polyarteritis and in other cases of crescentic and segmental necrotising glomerulonephritis. These antibodies are often directed against myeloperoxidase but other targets include elastase, cathepsin G, lactoferrin, lysozyme and beta-glucuronidase. The third group designated “atypical” ANCA includes neutrophil nuclear fluorescence and some unusual cytoplasmic patterns, and while a few of the target antigens are shared with pANCA, the others have not been identified. Sera that produce a pANCA or atypical ANCA pattern on alcohol-fixed neutrophils result in cytoplasmic fluorescence when formalin acetone fixation is used. pANCA or atypical ANCA occur in about 2/3 of all individuals with ulcerative colitis or primary sclerosing cholangitis, and they are found in a third of patients with Crohn’s disease. The reported incidence of ANCA in rheumatoid arthritis and SLE varies considerably but the patterns are predominantly pANCA and atypical ANCA. Where ANCA are associated with a small vessel vasculitis, such as Wegener’s granulomatosis and microscopic polyarteritis, antibody titres may parallel disease activity and have been used to monitor the response to treatment. In other non-vasculitic conditions ANCA levels do not necessarily reflect disease activity or the presence of a vasculitis. ANCA are also common in HIV infections where all fluorescence patterns are found, but the presence of these antibodies has no clinical significance. There have been many reports of ANCA occurring occasionally in other diseases.ANCA have not yet been demonstrated to be pathogenetic in the small vessel vasculitides. However there is in vitro evidence for 2 mechanisms, one of which focuses on neutrophil activation as the primary event and the other on antibody binding to *An update from the recent International and Australian Workshops. This paper is based on contemporary published data and observations presented at the 4th International Workshop on ANCA (Lubeck, May 1992) and 1st Australian Workshop on ANCA (Melbourne, October, 1992). vascular endothelium. Both mechanisms assume increased levels of circulating tumor necrosis factor or another cytokine that might result from the infections that often precede the onset of Wegener’s granulomatosis and microscopic polyarteritis. Successful new regimens in the treatment of Wegener’s granulomatosis and microscopic polyarteritis include the use of pooled immunoglobulin, and cyclosporin in combination with low dose prednisolone, but one report of 3-weekly pulse cyclophosphamide as a single agent indicated that it was effective in only 42% of patients.

Antineutrophil cytoplasmic autoantibodies in patients with systemic sclerosis

Perinuclear type of antineutrophil cytoplasmic antibodies (p-ANCA) have been found in patients with periarteritis nodosa, Churg-Strauss arteritis, or pauci-immune idiopathic crescentic glomerulonephritis. Recently, the association of p-ANCA and normotensive renal failure, in patients with systemic sclerosis (SSc), was reported. We have studied the incidence of p-ANCA in patients with SSc and have investigated its relationship to clinical and laboratory findings. Sera from 77 patients with SSc were examined by the indirect immunofluorescence (IIF) test, employing an ethanol-fixed human neutrophil and enzyme-linked immunosorbent assay, using purified myeloperoxidase (MPO) as an antigen (MPO-ELISA). The sera from seven patients (9.1%) were p-ANCA positive, by both IIF and MPO-ELISA. One patient died from systemic necrotizing angiitis but the remaining six patients have shown no symptoms of systemic vasculitis or of renal involvement. There was a tendency for patients positive for p-ANCA (anti-MPO antibody) to also be positive for other autoantibodies, such as anti-Sc1-70 antibody, anti-centromere antibody, anti-microsome antibody, anti-thyroglobulin antibody and rheumatoid factor. Although the incidence of p-ANCA (anti-MPO antibody) is low in patients with SSc, and its clinical significance in SSc needs further investigations, this could be a serological marker for certain symptoms in SSc.

The Syndrome of Lung Hemorrhage and Nephritis Is Usually an ANCA-Associated Condition

In the absence of evidence of arteritis or Wegener's granulomatosis, the syndrome of lung hemorrhage and nephritis has been commonly associated with anti-glomerular basement membrane (GBM) antibodies. However, it has been increasingly recognized that many cases are associated with antineutrophil cytoplasmic antibodies (ANCAs). To review available clinical and pathologic findings to determine the diseases accounting for lung hemorrhage and nephritis. We studied the records of 750 patients from whom serum samples were sent to our laboratory for anti-GBM antibody assays between 1981 and 1993 and found 88 patients with evidence of lung hemorrhage and nephritis. Serum samples were retested, using current methods, for anti-GBM antibodies (against noncollagenous 1 domain of the alpha 3 chain of type IV collagen) and for antibodies to proteinase 3 and myeloperoxidase--the two types of ANCA of diagnostic value. Of 88 patients with evidence of lung hemorrhage and nephritis, 48 had ANCAs, six had anti-GBM antibodies, and seven had both. In 48 patients with ANCAs, the pathologic findings that accounted for the pulmonary renal syndrome were pauci-immune necrotizing and crescentic glomerulonephritis and pulmonary capillaritis. Only eight had convincing evidence (during life) of Wegener's granulomatosis and only one other had documented arteritis. In 27 patients without ANCAs or anti-GBM antibodies, a variety of unrelated renal and pulmonary diseases were found. The largest group of patients who present with the syndrome of lung hemorrhage and nephritis have ANCAs and not anti-GMB antibodies. Appropriate tests for antibodies to proteinase 3, antibodies to myeloperoxidase, and anti-GBM antibodies provide reliable guides for making a diagnosis in patients with this pulmonary renal syndrome.

Antineutrophil cytoplasmic antibodies in the classification of vasculitis.

Two important types of antineutrophil cytoplasmic antibodies (ANCA) have been identified: anti-proteinase 3 and anti-myeloperoxidase antibodies. In the appropriate clinical setting, the presence of either is virtually diagnostic of the subset of vasculitis that includes Wegener's granulomatosis, microscopic polyangiitis (microscopic polyarteritis), the Churg-Strauss syndrome, idiopathic pauci-immune necrotizing and crescentic glomerulonephritis, and related and overlapping forms of these vasculitidies. The finding of ANCA throughout this group identifies these syndromes as belonging to a single category or spectrum of disease.

Anti–neutrophil cytoplasmic antibodies (ANCA): their detection and significance: report from workshops

Anti-neutrophil cytoplasmic antibodies (ANCA) are antibodies directed against enzymes that are found mainly within the azurophil or primary granules of neutrophils. There are 3 types of ANCA that can be distinguished by the patterns they produce by indirect immunofluorescence when tested on normal ethanol-fixed neutrophils. Diffuse fine granular cytoplasmic fluorescence (cANCA) is typically found in Wegener's granulomatosis, in some cases of microscopic polyarteritis and Churg Strauss syndrome, and in some cases of crescentic and segmental necrotising glomerulonephritis, but it is rare in other conditions. The target antigen is usually proteinase 3. Perinuclear fluorescence (pANCA) is found in many cases of microscopic polyarteritis and in other cases of crescentic and segmental necrotising glomerulonephritis. These antibodies are often directed against myeloperoxidase but other targets include elastase, cathepsin G, lactoferrin, lysozyme and beta-glucuronidase. The third group designated "atypical" ANCA includes neutrophil nuclear fluorescence and some unusual cytoplasmic patterns, and while a few of the target antigens are shared with pANCA, the others have not been identified. Sera that produce a pANCA or atypical ANCA pattern on alcohol-fixed neutrophils result in cytoplasmic fluorescence when formalin acetone fixation is used. pANCA or atypical ANCA occur in about 2/3 of all individuals with ulcerative colitis or primary sclerosing cholangitis, and they are found in a third of patients with Crohn's disease. The reported incidence of ANCA in rheumatoid arthritis and SLE varies considerably but the patterns are predominantly pANCA and atypical ANCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of antineutrophil cytoplasmic antibodies with the extrarenal histopathology of Wegener's (pathergic) granulomatosis and related forms of vasculitis

We studied the histologic findings from extrarenal biopsies (especially of the lung or upper respiratory tract) or autopsies of 68 patients who were tested for serum antineutrophil cytoplasmic antibodies (ANCAs). We used antigen-specific assays to detect antibodies against proteinase 3 (PR3) and myeloperoxidase (MPO), the two types of ANCAs of proven diagnostic value for the spectrum of diseases that includes Wegener's (pathergic) granulomatosis, microscopic polyarteritis (microscopic polyangiitis), Chung-Strauss syndrome, idiopathic necrotizing and crescentic glomerulonephritis, and their variants. Twenty-eight patients had antibodies to PR3 and 16 had antibodies to MPO; no patient had antibodies to both. All 44 patients with ANCAs had histologic evidence of this spectrum of diseases. Thirteen patients without histologic evidence of this spectrum of diseases had negative tests for ANCAs. There were no pathologic features that reliably identified patients with one or the other type of ANCA. Eighteen of 31 patients with lesions of Wegener's granulomatosis had antibodies to PR3, seven had antibodies to MPO, and six had neither. Three of four patients with necrotizing arteritis without granulomas had anti-MPO antibodies, but similar lesions were seen, together with extravascular granulomas, in three patients with anti-PR3 antibodies. Of 16 patients with alveolar hemorrhage, nine had anti-PR3 and five had anti-MPO antibodies. Two patients diagnosed clinically as having Churg-Strauss syndrome had anti-MPO antibodies. In 16 of the 25 patients with ANCAs and a histologic diagnosis of Wegener's granulomatosis the diagnosis was made on the basis of extravascular granulomatous lesions alone, which argues against the requirement for vasculitis. Of six patients with negative tests for ANCAs and histologically diagnosed Wegener's granulomatosis, none had evidence of renal involvement. We conclude that in the appropriate clinical setting the presence of anti-PR3 or anti-MPO antibodies provides reliable evidence of the above spectrum of diseases, but that subclassification (to the extent this is possible) depends on the presence of distinctive clinical or pathologic features. In patients with negative tests for ANCAs, interpretation of clinical and histologic findings remains the only definitive method of diagnosis.

Value of tests for antineutrophil cytoplasmic autoantibodies in the diagnosis and treatment of vasculitis.

The diagnosis and classification of vasculitis has been revolutionized by the discovery and characterization of serum antineutrophil cytoplasmic autoantibodies. These autoantibodies are highly specific, objective markers for the major subset of vasculitis that includes Wegener's granulomatosis, polyarteritis nodosa (microscopic polyangiitis), Churg-Strauss syndrome, primary or idiopathic pauciimmune necrotizing and crescentic glomerulonephritis with or without pulmonary hemorrhage, as well as some poorly characterized and overlapping forms of these vasculitides. The finding of antineutrophil cytoplasmic antibodies throughout this group identifies these syndromes as a single category or spectrum of disease. The sensitivity of antineutrophil cytoplasmic antibodies for this group of conditions is high when there is systemic involvement, as defined by the presence of renal involvement. However, the antibodies are only moderately sensitive markers in limited or localized cases of these vasculitides (without renal involvement), and hence diagnosis of these conditions based on histologic and clinical criteria remains important. Two significant types of antineutrophil cytoplasmic antibodies have been identified: anti-proteinase 3 and antimyeloperoxidase antibodies. Both have proven to be of diagnostic value for the spectrum of vasculitis listed above. Remarkably, patients with this spectrum of vasculitis have only one or the other of these two types of antibodies.

HLA class II specificities in vasculitis with antibodies to neutrophil cytoplasmic antigens

HLA class II genes were examined in patients with small vessel vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCA) using restriction fragment length polymorphism and allele specific oligonucleotide typing. Fifty-nine patients were studied, 34 with Wegener's granulomatosis and 25 with microscopic polyarteritis, and their results were compared with those from 1103 British Caucasoid controls. The frequency of HLA-DQw7 was significantly increased in patients with vasculitis (patients 53%; controls 27.8%, chi 2 17.8, Pc less than 0.0025, relative risk 2.9), and all the DQw7 bearing haplotypes commonly found in Caucasoid populations contributed to the increase. By contrast, the frequency of HLA-DR3 bearing haplotypes was decreased in the patients (patients 6.8%; controls 21.6%, chi 2 6.7, P less than 0.01). HLA specificities were similar in the groups of patients presenting with Wegener's granulomatosis and microscopic polyarteritis and with different types of ANCA assessed by indirect immunofluorescence. However, patients with the DQw7, DR4 haplotype were significantly more likely to have transiently positive tests for ANCA than patients with other DQw7 bearing haplotypes, whereas patients with DR2 bearing haplotypes were more likely to have persistently positive ANCA. These results show that HLA class II genes are associated with small vessel vasculitis and may influence the duration of the associated autoimmune response.

Anticorps anti-cytoplasme des polynucléaires: un nouvel outil diagnostique

Two main types of antineutrophil cytoplasmic antibodies (ANCA) have been recognized by indirect immunofluorescence. ANCA-D are defined by diffuse fluorescence and are directed against proteinase 3. They are highly specific for Wegener's granulomatosis, and their titre varies with disease activity. ANCA-P are responsible for perinuclear fluorescence and are principally found in other types of vasculitis and in idiopathic crescentic glomerulonephritis. In patients with suggestive clinical signs, ANCA are of considerable diagnostic value when specific histology is difficult to obtain. Therapeutic monitoring and prevention of Wegener's disease relapses could rely on regular measurements of ANCA titres. Moreover, studies on the pathogenetic role of ANCA may transform current physiopathological concepts and nosology of vasculitis.

Clinical investigation of anti-myeloperoxidase antibodies in patients with glomerulonephritis with crescent formation

Anti-neutrophil cytoplasmic antibodies (ANCA) have been found in patients with systemic vasculitis and crescentic glomerulonephritis. Recently two types of ANCA were identified, one is anti-myeloperoxidase antibodies (Anti-MPO Ab) stained perinuclear pattern of alcohol-fixed neutrophils by immunofluorescence test, and the other is autoantibodies with no reactivity with myeloperoxidase stained diffuse cytoplasmic pattern (C-ANCA). We investigated 59 patients with various glomerulonephritis with or without crescent to detect anti-MPO Ab and C-ANCA by an enzyme-linked immunosorbent assay. The results were as follows: 1) Anti-MPO Ab were detected only in patients with various glomerulonephritis with crescent. 2) Titers of anti-MPO Ab were high related to percentage of crescent in some cases of glomerulonephritis. 3) Titers of anti-MPO Ab were elevated at stage of cellular and fibro-cellular crescent. 4) C-ANCA were detected only in patients with Wegener's granulomatosis. These data suggested that anti-MPO Ab may play important roles in crescent formation and may be a marker of crescent formation in various glomerulonephritis.