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Vasculitic lesions are defined by necrosis of the vascular wall with perivascular inflammatory infiltrates. Secondary forms of vasculitis are observed in some systemic diseases, after infections, secondary to drugs or to malignancies. Usually, these secondary forms are characterised by the presence of immunoglobulin and complement deposits and thus probably caused by immune complex deposits. Conversely, necrotizing vasculitis occurring without known causal factor are named primary vasculitis, are not associated with immune deposits. Wegener's granulomatosis, microscopic polyangitis, Churg and Strauss syndrome and the isolated form of necrotizing and crescent glomerulonephritis are closely associated with the anti-neutrophil cytoplasm auto-antibodies (ANCA). The two main auto-antigen targets recognised by ANCA are lysosomal enzymes, proteinase 3 and myeloperoxidase, both contained in azurophilic granules of polymorphonuclear neutrophils and in primary lysosomes of monocytes. It has been demonstrated that ANCA antigens are expressed at the neutrophil (and monocyte) membrane after preactivation and are accessible to antibodies. Thus, ANCA may amplify neutrophils and monocyte activation. However, the causal or induced nature of anti-neutrophil auto-immunity in vasculitis remains unknown.

The association of lung emphysema with severe systemic antineutrophil cytoplasm antibodies (ANCA)-positive vasculitis, such as Wegener's granulomatosis is unusual since only four cases have been described previously. We report the first case of a 30 year-old smoker man presenting with biopsy-proven Wegener's granulomatosis, who developed a bullous emphysema during severe active lung vasculitis, in association with positive ANCA disclosing an anti-myeloperoxydase pattern. Alpha 1-antitrypsin deficiency, a known risk factor of lung emphysema recently found to be associated with anti-proteinase 3-positive vasculitis, was not present in this patient. Cigarette smoking, in association with severe lung vasculitis, might have contributed to the development of this emphysematous lesion.

The alphav integrins present on the membrane of numerous cells, mediate attachment to matrix proteins, cell proliferation, migration and survival. We studied the expression of alphav integrinis and CD47 (a beta3 chain integrin associated protein) in various forms of glomerulonephritis (GN) characterized by mesangial proliferation and/or increased mesangial matrix. In normal glomeruli, epithelial cells expressed alphavbeta3, alphavbeta5 and CD47; endothelial cells expressed alpha5beta1 and CD47; mesangial cells expressed alphavbeta5, CD47, and to a less extent alphavbeta3. In acute post infectious GN (APIGN), membrano-proliferative GN (MPGN) and diabetic nephropathy(DN), we observed that the beta3 chain, normally expressed by mesangial cells, was not detectable in the mesangium while its expression by epithelial cells was not modified. Parallel to the disappearance of alphavbeta3, the CD47 expression was decreased on the mesangial cells in MPGN, APIGN and DN. The expression of alphavbeta5 was clearly increased on podocytes and on proliferating mesangial cells in APIGN. By contrast, the mesangial expression of alphavbeta was normal or decreased in DN. The alpha5 chain of integrin, absent on normal mesangial cell, was expressed on proliferating mesangial cells in MPGN and APIGN. Thus, we observed modifications of alphavbeta3 and alphavbeta5 expression during human GN. The modulations of alphavbeta3 and alphavbeta5 expression differed according to the different glomerular cell types and were not parallel in glomerular cells: alphavbeta3 was decreased (and alphavbeta5 unchanged) on proliferating mesangial cells and alphavbeta5 was increased (and alphavbeta3 unchanged) in podocytes. This may reflect the existence of two distinct regulatory pathways.

It has been shown previously that proteinase 3 (PR3), a neutrophil intracellular protease that is the main antigen of antineutrophil cytoplasm (ANCA) autoantibodies, is present on the plasma membrane of a subset of freshly isolated neutrophils. This study shows that the size of this subset of membrane PR3-positive (mPR3+) neutrophils is a stable feature of a given individual, most likely genetically controlled. It ranges from 0 to 100% of neutrophils and allows us to define a new polymorphism in the healthy population, with three discrete phenotypes corresponding respectively to less than 20% mPR3 + neutrophils (mPR3low) or to a mean percentage of 47% (mPR3intermediate) and 71.5% (mPR3high) mPR3+ neutrophils. The frequency of the mPR3high phenotype was significantly increased in patients with ANCA-associated vasculitis (85% versus 55% in healthy subjects). The percentage of mPR3+ neutrophils was not affected by disease activity, relapses, or therapy, and did not reflect in vivo cell activation. In addition, mPR3+ phenotypes were normally distributed in cystic fibrosis patients, indicating that infection and/or inflammation per se do not lead to a high percentage of mPR3+ neutrophils. The frequency of the mPR3high phenotype was not related to anti-PR3 autoimmunization, since it was increased in vasculitic patients regardless of the ANCA specificity (anti-PR3, anti-myeloperoxidase, or unknown). Interestingly, the frequency of the mPR3high phenotype was also increased in patients with rheumatoid arthritis. It was normal in type I-diabetes, a T cell-dependent autoimmune disease. It is proposed here that a high proportion of membrane PR3-positive neutrophils could favor the occurrence or the progression of chronic inflammatory diseases.

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. 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.

Objective: To investigate the effectiveness and side effects of oral versus pulse cyclophosphamide (CYC) in combination with corticosteroids (CS) in the treatment of systemic Wegener's granulomatosis (WG)., Methods: Patients with newly diagnosed systemic WG were enrolled in a prospective, randomized trial. At the time of diagnosis, prior to randomization, every patient received a daily injection of methylprednisolone for 3 days, followed by daily oral prednisone (1 mg/kg/day) and a 0.7-gm/m2 pulse of CYC. Patients were then randomly assigned to receive either prednisone plus intravenous pulse CYC (group A) or prednisone plus oral CYC (group B) as first-line treatment. CYC was given for at least 1 year and was then progressively tapered and discontinued., Results: Fifty patients were included in the study: 27 in group A and 23 in group B. At 6 months, 24 group A patients (88.9%) were in remission, versus 18 group B patients (78.3%). At the end of the trial, 18 group A patients (66.7%) and 13 group B patients (56.5%) were in remission. In group A, 66.7% of the patients experienced side effects, versus 69.6% in group B. Infectious side effects were significantly more frequent in group B (69.6%) than in group A (40.7%) (P < 0.05). The incidence of Pneumocystis carinii pneumonia was higher in oral CYC-treated patients (30.4%) than in pulse CYC-treated patients (11.1%). Nine group A patients (33.3%) and 10 group B patients (43.5%) died. Actuarial curves showed that relapses were significantly more frequent in group A (59.2%) than in group B (13%) (P = 0.02)., Conclusion: Our results indicate that pulse CYC is as effective as oral CYC in achieving initial remission of WG and is associated with fewer side effects and lower mortality. However, in the long term, treatment with pulse CYC does not maintain remission or prevent relapses as well as oral CYC.

This study demonstrates (by flow cytometry and immunoprecipitation after cell surface radiolabeling and by using monoclonal antibodies to alpha v, beta 3, and alpha v beta 3 and alpha v beta 5 complexes) that alpha v beta 3, the vitronectin receptor, and alpha v beta 5 are expressed in vitro on cultured human mesangial cells (HMC) of the 5th to 8th passages. Antibodies to alpha v, beta 3 and alpha v beta 3 respectively precipitated an alpha beta heterodimer with molecular weights of 140 and 97 kDa. We analyzed the role of the various integrins in HMC interactions with vitronectin, and with fibronectin and von Willebrand factor (vWf), which are synthetized respectively by mesangial and endothelial cells. Cell adhesion increased in a dose dependent manner with the concentration of plastic-coated matrix protein and vWf. Inhibition of cell attachment with monoclonal antibodies to integrins indicated that HMC adhesion to vWf primarily involves alpha v beta 3, and that alpha v beta 5 may also contribute to cell binding to vWf. Adhesion to vitronectin involves both alpha v beta 3 and alpha v beta 5 complexes. In contrast, adhesion to fibronectin was not affected by monoclonal antibodies to alpha v beta 3 and alpha v beta 5 complexes. We propose that integrins alpha v beta 3 and alpha v beta 5, present on HMC, could mediate an interaction between mesangial and endothelial cells by binding to vWf, released at the basal site of endothelial cells.

Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.

The role of immunoglobulin (Ig) isotype and affinity of antimyeloperoxidase (MPO) antibodies in the clinical expression of vasculitis (organ involvement, severity and evolution) remains incompletely defined. We have determined the anti-MPO antibody isotypes, as well as the apparent affinity constant (aK) of anti-MPO IgG by using fluid phase MPO inhibition of IgG binding in an MPO specific ELISA. Twenty-eight patients with anti-MPO antibodies and necrotic and crescentic glomerulonephritis, either isolated or associated to various other organ localizations, were analyzed. Serum samples were obtained before treatment and during follow-up. No association was observed between the isotype, the level or apparent affinity of anti-MPO antibodies and the clinical symptoms, severity, and organ distribution of vasculitis, including alveolar hemorrhage. No significant correlation was found between the apparent affinity and the level of anti-MPO IgG. However, the presence of anti-MPO IgM was clearly associated with low affinity anti-MPO IgG and vice versa. Furthermore, in a longitudinal study, high levels of anti-MPO IgM, when present, were observed early in the course of the disease and in some cases preceded the reappearance of anti-MPO IgG during relapses. High affinity anti-MPO IgG were usually present before treatment. Immunosuppressive therapy resulted in decreased apparent affinity and level of anti-MPO IgG. Importantly, anti-MPO IgG level increased during relapses but the affinity of these IgG autoantibodies remained low.(ABSTRACT TRUNCATED AT 250 WORDS)

We evaluated on serial sections the distribution of a large number of integrin alpha and beta chains in normal adult human kidney: 1) the beta 1 chain and its corresponding alpha subunits (alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, alpha 6), 2) alpha v and beta 3 chains, 3) the beta 2 chain and its corresponding alpha chains (alpha X, alpha M, alpha L), and 4) the beta 4 chain. We also evaluated ICAM-1, VCAM and ELAM and the major extracellular matrix components (ECM). A three step immunoperoxidase technique was used on frozen sections. Each cell of the kidney shows a specific distribution of these molecules. The relation with ECM and some of their ligands was evaluated. This immunohistochemical study shows that there is no strict colocalisation of a given ECM component with its specific receptor.

Purified proteinase 3 (PR3) devoid of any elastase (HLE) and cathepsin G (Cat.G) contaminants, was prepared from azurophilic granules of human polymorphonuclear neutrophils by using a novel procedure. Although unable to induce platelet activation (up to 25 micrograms/ml) by itself, PR3 at a concentration as low as 2.5 micrograms/ml enhanced the platelet response to a concomitantly added threshold concentration of Cat.G, a recognized platelet agonist. In the presence of 10 micrograms/ml PR3, aggregation and degranulation of platelets induced by Cat.G were 43.2 +/- 5.9% and 27.1 +/- 1.9% as compared with 5.5 +/- 2.9% and 4.2 +/- 1.5% (n = 4) for Cat.G alone. This enhancing effect by PR3 was also observed with collagen and a cyclic endoperoxide analogue, and was inhibited by eglin C and elafin, two PR3 inhibitors. Associated with the removal of activity by a anti-PR3 mAb and the lack of effect of the secretory leukocyte proteinase inhibitor, these data demonstrated that the effect is specifically related to the enzymatic activity of PR3. It is hypothesized that this mechanism could play a role in the polymorphonuclear neutrophil-mediated platelet activation, an event already known to be dependent on Cat.G and HLE. This is supported by the fact that the association of PR3 and HLE, at concentrations ineffective by themselves, was able to potentiate Cat.G-induced platelet activation.

Objective: Antibodies directed against components of neutrophil cytoplasm have been detected in various systemic vasculitides and especially in Wegener's granulomatosis. In polyarteritis nodosa (PAN) and Churg-Strauss syndrome, few data are available and correlation between clinical manifestations and antineutrophil cytoplasm antibodies (ANCA) has not been established. Therefore, we tested, before treatment of vasculitis, 62 consecutive patients suffering from PAN with hepatitis B virus (HBV) markers, PAN of unknown etiology or Churg-Strauss syndrome., Methods: Only patients with PAN and Churg-Strauss syndrome were included in the study. The diseases were histologically and/or angiographically proven. Every patient's serum was tested by an indirect immunofluorescence assay (IFA) and, in 37 cases, by an enzyme linked immunosorbent assay (ELISA)., Results: ANCA detected by IFA were observed in 10.7% of the patients with PAN with HBV markers, in 27.3% of the patients with PAN without HBV markers and in 66.7% of the patients with Churg-Strauss syndrome. When ELISA was performed, 11.1% of the patients with PAN associated with HBV infection, 20% of the patients with PAN without HBV markers and 55.6% of the patients with Churg-Strauss syndrome were positive. ANCA were positively correlated with asthma and purpura and negatively correlated with HBV markers., Conclusion: Regardless of the technique used, Churg-Strauss syndrome was associated with ANCA in about 60% of the cases while, in PAN of unknown etiology, ANCA were found in about 25% of cases. In contrast, IFA and ELISA only detected ANCA in a limited number of cases of PAN related to HBV infection. ELISA positivity in patients with PAN and Churg-Strauss syndrome was usually associated with antimyeloperoxidase antibodies. In our cases of PAN, ANCA and purpura were significantly correlated, suggesting that, in these cases, small vessels are involved and therefore macroscopic and microscopic PAN coexist. Thus it seems that ANCA are essentially present in the cases of small vessel vasculitis, as has been described, and are not a marker of pure macroscopic PAN, at least at our present level of understanding of these antibodies.

Alpha 1-antitrypsin (alpha 1-AT) is the major inhibitor of proteinase 3 (PR3), the main target antigen of antineutrophil cytoplasm antibodies (ANCA) in Wegener's granulomatosis. alpha 1-AT is encoded by a polymorphic gene, with over 75 alleles, defining severely, medium and non-deficient protease inhibitor (PI) phenotypes. We describe the association of severely and medium deficient PI phenotypes with anti-PR3 positive systemic vasculitis, and postulate a pathogenetic role for alpha 1-AT deficiency and the occurrence of ANCA, with specificity for PR3 in a subgroup of patients with Wegener's granulomatosis.

The expression of non-beta 2 integrins on polymorphonuclear neutrophils (PMNs) was analyzed by immunoprecipitation and flow cytometry using platelet-free PMN preparations and anti-Fc gamma R blocking mAbs. No beta 3 integrin was detected with six anti-beta 3 mAbs. Conversely, integrin beta 1 chain was present on PMNs, although at low level, and could be distinguished from platelet beta 1 by SDS-PAGE. The MW differences disappeared after N-glycanase treatment. PMNs express only 2500 molecules of beta 1 per cell and this expression is not modulated by agonists such as phorbol myristate acetate, formylmethionyl-leucyl-phenylalanine, granulocyte-macrophage colony-stimulating factor, or tumor necrosis factor alpha, which enhance CD11b expression, or by interferon-gamma or transforming growth factor beta. PMNs were found to express alpha 6 associated with beta 1, and no reactivity was observed with various anti-alpha 1, anti-alpha 2, anti-alpha 3, anti-alpha 4, anti-alpha 5 or anti-alpha V mAbs. In conclusion, although other leukocytes express various beta 1 integrins, which mediate cell interactions with ECM proteins, PMNs appear to express only the laminin receptor alpha 6 beta 1. PMN interactions with non-laminin ECM ligands thus seem to be mediated either exclusively by beta 2 integrins or by nonintegrin molecules.

Atypical antineutrophil cytoplasm antibodies (A-ANCA) are defined here as ANCA detected by IIF and not directed against the predominant ANCA antigens, proteinase 3 (PR3) and myeloperoxidase (MPO). A-ANCA are found in a variety of clinical conditions, namely rheumatoid arthritis, inflammatory bowel diseases, chronic hepatic diseases and several infections including HIV infection. They are directed against a variety of still ill-defined neutrophil antigens and most frequently yield a perinuclear pattern (P-ANCA) of binding by indirect immunofluorescence on ethanol fixed neutrophils. This paper reviews the literature on A-ANCA and our recent data suggesting that, among others, cathepsin G is one of the predominant antigen targets of A-ANCA. From a clinical point of view, the distinction between MPO-ANCA and A-ANCA is not possible by indirect immunofluorescence (IIF). The determination of ANCA antigens by specific ELISA is therefore necessary to differentiate P-ANCA with MPO specificity from those with undefined specificity. This is of importance because the clinical value of MPO-ANCA is clearly established while the presence of A-ANCA is difficult to interpret given their occurrence in a large variety of clinical conditions.

Unlabelled: From 1987 to 1991, 2500 sera were tested for presence of anti-neutrophil cytoplasmic antibodies (ANCA) by standard indirect immunofluorescence (IIF) and specific proteinase 3 (PR3) and myeloperoxydase (MPO) ELISA. Clinical and histological data leading to precise diagnosis were retrospectively obtained in 98 patients with ANCA positivity by IIF and then a comparative study based on ANCA specificity was performed. Vasculitis was present in all cases. Among patients with anti-PR3 (n = 38), 19 had Wegener's granulomatosis (WG), 15 microscopic polyarteritis (mPA), 2 idiopathic necrotizing and crescentic glomerulonephritis (NCGN) and 2 relapsing polychondritis (RP). Among patients with anti-MPO (n = 45), 26 had mPA, 3 classical polyarteritis nodosa (PAN), 5 WG, 8 NCGN, 2 systemic lupus erythematosus (SLE) and one Churg-Strauss syndrome (CSS). Negative MPO and PR3 specific ELISA despite positive IIF were observed in 15 patients (13 WG, 1 mPA, 1 PAN). In the PR3 group, males predominated (66%) and the mean age was 49 years (range 13-85); in the MPO group, females predominated (62%) and the mean age was 57 years (range 13-85). These differences were statistically significant (p < 0.05). Renal involvement was present in 92% of patients and renal biopsy showed pauci-immune necrotizing and crescentic glomerulonephritis in nearly all cases. PR3 specificity was associated with frequent eye involvement (32%) and presence of granulomas (45%), but was not associated with other autoantibodies. MPO specificity was associated with a higher prevalence of pulmonary hemorrhage (40%) and various autoimmune disorders, especially antinuclear antibodies. Cholestasis was observed in 50% of WG with negative MPO and PR3 ELISA. Renal and patient survival at the 75th percentile was 15 months with MPO-ANCA and 16 months with PR3, and was similar for patients with WG and mPA. Relapses occurred in 20% of patients with anti-MPO and 36% of patients with anti-PR3. Serological follow-up was obtained in 44 patients. With immunosuppressive treatment, ANCA disappeared in 66% of cases and this disappearance was always associated with absence of disease activity., In Conclusion: 1. This study confirms that the presence of ANCA is a good marker of vasculitis. 2. Despite some clinical differences, MPO and PR3-associated vasculitis have a similar prognosis. 3. The titer of ANCA determined by ELISA is not correlated with the severity of vasculitis but disappearance of ANCA is always associated with absence of disease activity.

To determine the spectrum of systemic diseases potentially associated with pauci-immune rapidly progressive glomerulonephritis (GN), most of which being considered as idiopathic, we have analyzed extra-renal manifestations, occurrence of extra-glomerular vasculitis and incidence and specificity of ANCAs in 40 patients selected only on histological criteria. Extra-renal symptoms were unexpectedly observed in all patients but one, and were suggestive of vasculitis in 24 of them. Extra-glomerular vasculitis was evidenced in 18 kidney biopsies and four biopsies from other organs. Among the 33 patients with suspected or established vasculitis, 13 had presumed or biopsy-proven Wegener's granulomatosis (WG), three had a macroscopic form of polyarteritis nodosa and 17 had a clinical presentation compatible with the so-called microscopic polyarteritis previously described in the british literature. An additional patient had clinical signs of WG without clinical and histological evidence of vasculitis. ANCAs were detected in 28/33 and 25/34 sera tested by IF and ELISA, respectively: 19 contained anti-myeloperoxidase (MPO) antibodies and 6 had anti-proteinase 3 (Pr3) activity. Anti-MPO and anti-Pr3 antibodies were present in all clinical subgroups but with various incidences: anti-MPO antibodies were surprisingly more often detected (6/12) than anti-Pr3 (4/12) in patients with suspected or histologically proven WG but anti-Pr3 antibodies were nonetheless 3- to 4-fold more frequent in WG than in non-WG systemic vasculitis (1/12) and necrotizing CGN without evidence of extra-renal vasculitis (1/10). These results strongly suggest that pauci-immune necrotizing CGNs belong to the broad spectrum of necrotizing vasculitides affecting glomerular capillaries. This hypothesis is also supported by the good response of patients to immunosuppressive treatments known for their efficacy in vasculitides, whereas these treatments are usually less successful in severe forms of extra-capillary GN with immune deposits.

This study describes the results of phase I of an international effort to develop and standardize assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). 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.

Clinical and histological data leading to precise diagnosis were retrospectively obtained in 98 patients with antineutrophil cytoplasmic antibodies (ANCA) detected by indirect immunofluorescence (IIF). Specificity was determined by myeloperoxidase (MPO) and proteinase 3 (PR3) specific ELISA in all and a comparative study based on ANCA specificity was performed. Vasculitis was present in all cases. PR3-ANCA occurred predominantly in males (25/38) with WG (19/38). MPO-ANCA occurred predominantly in older women and were often associated with various autoimmune disorders. There was a high prevalence of lung hemorrhage (18/45) and mPA (26/45) in this group. Patients with negative MPO and PR3 specific ELISA despite positive IIF (n = 15) were almost exclusively WG (13/15) and were characterized by a high prevalence of hepatic and digestive manifestations. Renal and patient survival at the 75th percentile was 15 months with MPO-ANCA and 16 months with PR3, and was similar for patients with WG and mPA. With immunosuppressive treatment, ANCA disappeared in 66% of cases and this disappearance was always associated with absence of disease activity.

To determine the spectrum of systemic diseases associated with pauci-immune necrotizing crescentic glomerulonephritis, we have analysed extra-renal manifestations, occurrence of extra-glomerular vasculitis and incidence and specificity of antinuclear cytoplasmic antibodies (ANCA) in 40 patients selected only on renal histological criteria. Extra-renal symptoms were unexpectedly observed in all patients but one, and were suggestive of vasculitis in 24. Extra-glomerular vasculitis was seen in 18 kidney biopsies and four biopsies from other organs. Among the 33 patients with suspected or established vasculitis, 13 had presumed or biopsy-proven Wegener's granulomatosis, three had a macroscopic form of polyarteritis nodosa and 17 could not be adequately classified. An additional patient had clinical signs of Wegener's granulomatosis without clinical and histological evidence of vasculitis. ANCAs were detected in 28 of 33 and 25 of 34 sera tested by immunofluorescence and enzyme-linked immunoassay, respectively: 19 contained anti-myeloperoxidase antibodies and six had anti-proteinase 3 activity. Anti-myeloperoxidase and anti-proteinase 3 antibodies were present in all clinical subgroups but with various frequencies: anti-myeloperoxidase antibodies were more common (six of 12) than anti-proteinase 3 (four of 12) in patients with suspected or histologically proven Wegener's granulomatosis. Anti-proteinase 3 antibodies were 3- to 4-fold more common in patients with Wegener's granulomatosis than in those with systemic vasculitis of other causes (one of 12) or necrotizing crescentic glomerulonephritis without evidence of extra-renal vasculitis (one of 10). These results strongly suggest that pauci-immune necrotizing crescentic glomerulonephritis belongs to the broad spectrum of necrotizing vasculitides affecting glomerular capillaries. This study shows substantial improvement in renal prognosis and life expectancy with aggressive immunosuppressive therapy despite the older age of the patients, dissemination of the vasculitic process and often delayed diagnosis.

Anti-cathepsin G antibodies have been detected by using three different methods. i) Binding to azurophilic granules constituents after separation of purified alpha-granules on Matrex gel Orange A chromatography according to Kao. ii) Binding to azurophilic granules freezed and thawed after coating on ELISA plates. iii) Binding to purified cathepsin G in ELISA assay. Anti-cathepsin G antibodies were observed patient's sera with ulcerative colitis, primary sclerosing cholangitis, primary biliary cirrhosis and autoimmune hepatitis but not in controls or patients with chronic viral hepatitis or vasculitis.

In order to appreciate the frequency of hepatitis B virus (HBV) infection in patients with glomerular diseases in France, a low endemic country, we reviewed the series of patients biopsied in the years 1983-1989 in 2 departments of nephrology differing by the characteristics of the population. In Saint-Brieuc, where the population is almost exclusively Caucasian, with nearly no immigrant, HBsAg was not detected in any of the 86 patients. In Paris, a large number of patients come from highly or intermediately endemic regions. HBsAg was detected in 3 of 209 patients, 2 of the 75 patients with membranous nephropathy and 1 of the 32 patients with minimal-change nephrotic syndrome. These patients came from Africa and Asia. Therefore, in low endemic countries, the role of HBV infection in the etiology of glomerulonephritis is minimal. But, because of the late severity of the disease, screening remains essential in patients belonging to the high-risk groups.

Leukosialin (CD43) is a sialic acid-rich molecule with a relative molecular mass (M(r)) of 140,000 highly represented on polymorphonuclear neutrophils (PMN) and on most leukocytes. One of its functions may be to prevent nonspecific cell-to-cell interactions through negative charge repulsions. As tested by immunofluorescence, neutrophil CD43 membrane expression was shown to decrease by up to 80% upon cell activation by phorbol myristate acetate (10 ng/ml) or by N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP; 10(-6) M) in the presence of cytochalasin B. The kinetic of this decrease paralleled that of CD11b up-regulation. FMLP alone, tumor necrosis factor (TNF-alpha), lipopolysaccharide and granulocyte macrophage colony-stimulating factor had moderate or insignificant effects, while inducing striking CD11b up-regulation. Cell priming with TNF-alpha followed by FMLP stimulation resulted in up to 40% decrease of CD43 expression. Anti-CD43 mAb immunoprecipitated three fragments of M(r) 130,000, 49,000 and 34,000 from the cell-free supernatant of activated neutrophils, suggesting that CD43 is released from the membrane by proteolysis. Indeed, the decrease in CD43 expression was inhibited by phenylmethanesulfonylfluoride (PMSF). Homotypic aggregation of activated PMN was also inhibited by PMSF and could result, at least in part, from the shedding of CD43. The shedding of such a strongly anionic and major membrane protein should drastically modify PMN surface charge and may allow previously hindered interactions by exposing new adhesion molecules.

Autoantibodies directed against polymorphonuclear neutrophils (PMN) have been observed in serum from patients with ulcerative colitis (UC), Crohn's disease (CD) and primary sclerosing cholangitis (PSC) using indirect immunofluorescence and fixed granulocyte ELISA. Our study demonstrates the presence in the serum of these patients of autoantibodies which bind to an azurophilic granule component distinct from proteinase 3, elastase and myeloperoxidase. These autoantibodies thus belong to the ANCA family, but their antigen specificity differs from the already characterized ANCA antigens. We have found that the same ANCA antigen target, named UC-antigen, was recognized by serum IgG from patients with UC, CD and PSC. It was purified by Matrex Gel Orange A dye affinity chromatography and subsequent immunoabsorption of contaminant proteinase 3 with immobilized anti-proteinase 3 MoAb. The identity between this UC antigen and cathepsin G was demonstrated by their coelution from Matrex Gel Orange A column and the parallel titration of cathepsin G-specific enzymatic activity and UC-ANCA binding, both in partially purified UC antigen and in highly pure cathepsin G. Furthermore, the use of cathepsin G ELISA confirmed that UC, CD and PSC patients' IgG did indeed bind to cathepsin G. Comparison of the results obtained with azurophilic granule- and cathepsin G-ELISA as well as inhibition of ANCA binding by anti-cathepsin G polyclonal antibodies, revealed that in some patients cathepsin G is the main azurophilic granule target of ANCA while others have other ANCA specificities. The fact that UC, CD and PSC are frequently associated with cathepsin G ANCA, while rarely occurring in other types of vasculitis, is intriguing but suggests that these diseases may have a common pathogenetic mechanism.

ANCA positive sera, detected by the standard immunofluorescence method, derived from 37 patients with vasculitis were studied using formalin-acetone fixed chronic myelocytic leukemia cells (CML). All 37 sera were positive on CML cell smears. Furthermore formalin-actone fixation selectively impaired antinuclear antibody binding without reducing ANCA staining and thus facilitated differentiation of these autoantibodies which is often difficult with the standard immunofluorescence method. Two unequivocal and mutually exclusive ANCA binding patterns were identified using the CML smears: (1) type I with diffuse granular binding confined to the polymorphonuclear (PMN) cell lineage and preferentially staining immature cells; (2) type II with similar binding to the PMN cell lineage and, in addition, granular staining of the basophils. All type I antibodies were associated with a c-ANCA pattern suggesting that the major antigen recognized by these antibodies, recently identified as proteinase 3, is not detectable in basophils. The type II pattern was detected in both p-ANCA (84%) and c-ANCA (16%) positive sera. The type I sera remained positive on PMN cells from a myeloperoxidase (MPO) deficient subject and anti-MPO antibodies could not be detected in this group by ELISA. Conversely the type II pattern occurred in the presence of anti-MPO antibodies identified by immunofluorescence, ELISA and dot-blot with the exception of a single serum with antilactoferrin antibody. Type I binding only was observed in Wegener's granulomatosis (WG) but both patterns were found in microscopic polyarteritis (MPA) and rapidly progressive glomerulonephritis (RPGN).

The frequency, isotype, and specificity of antineutrophil cytoplasmic antibodies were investigated in a cross-sectional study of 100 patients with IgA nephropathy and 30 children with Henoch-Schönlein purpura. Two of the patients with IgA nephropathy had high titres of antineutrophil cytoplasmic antibodies which were of IgG isotype and confirmed as antimyeloperoxidase antibodies in solid-phase ELISA and inhibition experiments. Antineutrophil cytoplasmic antibodies were not detected in the children with Henoch-Schönlein purpura and none of the patients in either group had IgA antineutrophil cytoplasmic antibodies. A further 20 IgA nephropathy and 10 Henoch-Schönlein purpura patients were studied longitudinally in different clinical phases at 4-monthly intervals over a 2-year period. None of these patients had or developed antineutrophil cytoplasmic antibodies. We conclude that IgA antineutrophil cytoplasmic antibodies are not involved in the vasculitis of Henoch-Schönlein purpura or in the pathogenesis of glomerular injury in IgA nephropathy. The detection of IgG antimyeloperoxidase antibodies in a small minority of IgA nephropathy patients extends the spectrum of diseases associated with autoimmunity to this antigen but is of uncertain significance.

Necrotizing and crescentic glomerulonephritis without immunoglobulin deposits (also called pauci-immune glomerulonephritis) is the cause of approximately 50 percent of acute renal failures of glomerular origin. Our study, based on 40 case-records selected on histological criteria, and on data from the literature, shows that in most cases, if not all, this type of glomerulonephritis is part of a wider systemic vasculitis which predominantly affects the glomerular capillaries. Anti-neutrophil cytoplasm antibodies are detected in three-quarters of the cases, with a specific distribution that varies according to the clinical features. In spite of the patients' age (mean: 62 years), the severity of glomerular lesions and the extra-renal diffusion of the disease, 60 percent of these patients can be cured and recover a normal, or at least acceptable renal function, provided the corticosteroid and sometimes immunosuppressive therapy is initiated at an early stage.

The antigenic specificity and clinical distribution of the antineutrophil cytoplasmic antibodies (ANCA) in kidney diseases have recently been extensively studied. In patients with systemic vasculitis, the great predominance of two major ANCA antigens, proteinase 3 (PR3) and myeloperoxidase (MPO), is now established. PR3 and MPO are colocalized in the azurophilic granules of neutrophils and translocated to the cell surface during activation, and thus are able to interact with autoantibodies after neutrophil preactivation. Furthermore, by comparison of amino acid and DNA sequences, it has been shown that PR3 is identical to myeloblastin, which has been described independently and is involved in the control of growth and differentiation of leukemic cells. Aside from the two major ANCA antigens, a number of neutrophil cytoplasmic antigens recognized by ANCA have been identified, including human leukocyte elastase, lactoferrin, CAP57, and cathepsin G. These rare ANCA specificities occur in a limited number of patients. The variety of ANCA antigen specificities contrasts, however, with the fact that the vast majority of ANCA-positive sera are monospecific for one single ANCA antigen. With regard to clinical distribution, ANCA have major diagnostic significance in the four conditions in which they are frequently detected: Wegener's granulomatosis (WG), Churg and Strauss Syndrome (CSS), microscopic periarteritis (MPA), and necrotic and crescentic glomerulonephritis (NCGN). However, the initial dichotomy between MPO-associated vasculitis (NCGN, MPA) and that associated with anti-PR3 antibodies (WG) appears far from absolute.

The results presented during the Third International ANCA Workshop, Washington, DC, 1990, allowed a better definition of the antigenic specificity of the antineutrophil cytoplasmic autoantibodies (ANCA). The large predominance of two major antigen specificities for proteinase 3 (PR3) and myeloperoxidase (MPO), in the group of vasculitic patients, was confirmed. PR3 and MPO are colocalized in the azurophilic granules of neutrophils and translocated to the cell surface during activation and thus are able to interact with ANCA after neutrophil preactivation. Furthermore, by comparison of amino acid and DNA sequences, the agreement was reached that PR3 was identical to AGP7, p29, and myeloblastin, described independently and involved in the control of growth and differentiation of leukemic cells. In addition to the two major ANCA antigens, a number of neutrophil cytoplasmic antigens recognized by ANCA have been previously identified (human leukocyte elastase [HLE], lactoferrin). It was established during the Third Workshop that these rare ANCA specificities, occurring in a limited number of patients, include a cationic antimicrobial protein (CAP57) and cathepsin G. However, the variety of ANCA antigen specificities contrasts with the fact that the vast majority of ANCA-positive sera are monospecific for a single ANCA antigen. Finally, the fine specificity of granulocyte-specific antinuclear antibodies (GS-ANA) occurring in rheumatoid arthritis and ulcerative colitis is still unknown, but clearly a substantial proportion of GS-ANA belongs to the ANCA family.

A predominant expression of IgA1 in mesangial deposits, serum, and bone marrow culture supernatants has been shown in IgA nephropathy (IgAN). Furthermore an excess of lambda light chains in both mesangial deposits and serum IgA has been observed. However, the origin of mesangial IgA remains controversial. In the present study, we have examined the IgA1 light chain type in IgAN. Total IgA1, IgA1 kappa and IgA1 lambda were measured by ELISA in serum and culture supernatants from spontaneous and pokeweed-mitogen (PWM)-stimulated peripheral blood mononuclear cells (PBMC). We observed an increase in IgA and IgA1 serum concentrations in IgA nephropathy patients, with a ratio of serum IgA1 to total serum IgA identical between patients and controls. The concentration of serum IgA kappa did not differ between patients and controls but patients had a significantly higher concentration of serum IgA lambda. The IgA1 kappa to IgA1 lambda ratio was 1.06 +/- 0.42 in IgAN patients versus 1.55 +/- 0.36 in controls (P less than 0.01). By contrast, the concentrations of IgA1 kappa and IgA1 lambda in PBMC culture supernatants, both spontaneous and PWM-stimulated, were identical in patients and controls. Therefore, there is a specific increase in IgA1 lambda in patients' sera. This contrasts with the normal IgA1 production by PBMC, which are derived from mucosal-associated lymphoid tissues. This suggests that IgA isotypic deregulation is confined to the bone marrow compartment and is not a generalised defect of the IgA system.

We report on an unusual association between partial IgA deficiency and acute lymphoblastic leukemia in a young man. We also report results of the family study of immunoglobulin levels, sIgA B cells, in vitro IgA synthesis and molecular analysis of the structural C alpha genes. The IgA deficiency was present at diagnosis of leukemia prior to any therapy. The indirect arguments for a preexisting IgA deficiency are the absence of improvement of the IgA level during complete remission and especially the finding of a similar partial IgA deficiency in a sister who shared the same HLA haplotype, had a low percentage of sIgA B cells and decreased in vitro IgA production. The mother, who had a normal IgA serum level also had decreased in vitro IgA synthesis. No major structural C alpha gene defect was found. The relationship between acute lymphoblastic leukemia and IgA deficiency remains to be elucidated.

A factor, functionally characterized by its capacity to stabilize the normally labile classical pathway C3-converting complex of the classical pathway of complement, has been isolated from the serum of one patient with a case of acute glomerulonephritis, subsequent to a cutaneous infection. The factor confers long-lived stabilization of classical pathway C3 convertase complexes formed both in the solid (sensitized sheep erythrocytes bearing activated C1 and the classical pathway C3 convertase) and fluid phase. The half-life of such stabilized C3-cleaving enzymes extended beyond several hours at 37 degrees C. The stabilizing activity was associated with a protein fraction immunochemically identified as immunoglobulin (Ig)G, a sizeable population of which exhibited a gamma chain of 60,000 daltons. The IgG-associated stabilizing activity was found to bind to the classical pathway C3 convertase enzyme via a fragment bearing the antigen-binding site of the molecule [F(ab)(2) and F(ab)]. Such binding was demonstrable for classical pathway and not for alternative pathway C3 convertase. Thus, the stabilizing factor behaves like an autoantibody to the C3-converting complex of the classical pathway of complement. The binding of the antibody to the enzyme affords protection of the latter against decay-degradation. By analogy with the nephritic factor of the alternative pathway situation where IgG autoantibodies specifically bind to alternative pathway C3 convertase enzymes and protect them from degradation, the functionally unusual IgG in our patient was designated as the nephritic factor of the classical pathway. Indirect evidence suggests that nephritic factor of the classical pathway-IgG might be of the IgG3 subclass.

A woman with isolated juvenile Sjögren's syndrome gave birth, at 3 years' interval, to two children with complete atrio-ventricular heart block (AVB). This is the first published case of AVB in children of mothers with Sjögren's syndrome without any clinical and laboratory evidence of connective tissue disease, notably lupus. Ultrasonography showed that the AVB was acquired in utero and occurred during the 23rd week of gestation. In both children the AVB was isolated, without any symptom of congenital malformation of the heart; there were no abnormalities of conduction in the mother. Early corticosteroid treatment of the mother's disease had no beneficial effect on AVB in the foetuses. Attempts to reproduce the condition experimentally met with failure.

Approximately 67% of peripheral blood lymphocytes in a case of nonmycosis fungoides-type cutaneous T-cell lymphoma, exhibited Sézary-like changes. Immunotyping showed a helper phenotype with an abnormally faint expression of the T3 membrane antigen, while quantitative electron microscopic study was suggestive of neoplasia. However, T-cell receptor gene study did not show any DNA rearrangement in Ficoll-separated blood lymphocytes, whereas clonal T-cell proliferation was simultaneously evidenced in cutaneous (non-Sézary-like) tumor cells. It is concluded that reactive nonneoplastic Sézary-like cells may be present not only in various benign conditions, as previously known, but also in T-cell lymphomas. This study provides further evidence for the nonspecificity of Sézary-like changes, and stresses the utility of T-cell receptor gene rearrangement study for diagnostic and prognostic procedures during the course of T-cell lymphoproliferative disorders.

A rare form of plasma cell dyscrasia characterized by the various association of polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes has been termed POEMS syndrome. The pathogenesis of the multisystemic features of this syndrome remains unclear. Herein is reported a case of POEMS syndrome with striking clinical similarities with scleroderma, and microangiopathic glomerular lesions, as well as diffuse perivascular non-amyloid deposits, which could explain certain features of the syndrome, including peripheral nerve demyelination. It is proposed that a pathogenic role might be played by a non-immunoglobulin vasculotoxic component.

Since harmful effects of estrogens in murine lupus are well established, we studied the influence of oral contraceptive therapy on systemic lupus erythematosus activity in 26 female patients with lupus nephropathy. Combined preparations containing either 50 micrograms (14 patients) or 30 micrograms (7 patients) of ethinyl-estradiol were used in 21 courses in 20 patients. Initial manifestations or exacerbations of systemic lupus activity appeared within 3 months of beginning hormonal therapy in 9 patients, an overall incidence of lupus flare-up of 43%; there was major renal involvement in 4 patients. Conversely, evidence of lupus exacerbation did not develop in any of 11 patients who received pure progestogen oral contraceptive therapy with either continuous low-dose norsteroids (6 patients) or discontinuous progestogens at normal dosage (5 patients). These patients were followed for 5--30 months. Our data indicated that oral contraceptive therapy that used estrogens, even at low doses, often induced exacerbation of systemic lupus erythematosus activity. Pure progestogens, which were effective and devoid of such unfavorable effects, may be preferred in these patients.