ANCA-associated vasculitis with renal involvement: an outcome analysis.

BACKGROUND: The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are a group of heterogeneous diseases. This study was undertaken to investigate the outcome of Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and renal-limited vasculitis (RLV). Furthermore, we analysed the differences in patients with proteinase 3-ANCA (PR3-ANCA) and those with myeloperoxidase-ANCA (MPO-ANCA), which have not been assessed in a homogeneously treated group of patients with renal involvement. METHODS: In this retrospective analysis, 80 patients with a new diagnosis of WG, MPA or RLV with biopsy-proven renal involvement were followed over a median of 46.7 months (range: 0.8-181.9 months). All patients had induction treatment with cyclophosphamide and oral corticosteroids. RESULTS: At the end of follow-up, 23% were dependent on dialysis. Renal survival was significantly worse in patients with WG compared with patients with MPA or RLV (P = 0.04). A higher rate of end-stage renal disease (ESRD) was noticed in PR3-ANCA- vs MPO-ANCA-positive patients. A total of 21 patients (26%) died. Predictors of patient mortality were development of ESRD, older age and the maximum creatinine in the first month. Mortality was found to be higher in patients with WG and was significantly higher in PR3-ANCA-positive cases (P = 0.02). The relative risk of death was 9.32 times higher in PR3-ANCA- vs MPO-ANCA-positive patients. CONCLUSIONS: Our data underscore the pathogenetic potential of ANCA by demonstrating a more aggressive disease state and a poorer outcome in patients with PR3-ANCA.     

Renal survival and prognostic factors in patients with PR3-ANCA associated vasculitis with renal involvement

BACKGROUND: Severe renal disease is a feature of anti-neutrophil cytoplasmic antibodies (ANCA)-associated small-vessel vasculitis. We evaluated patient and renal survival and prognostic factors in patients with PR3-ANCA associated vasculitis with renal involvement at diagnosis during long-term follow-up. METHODS: Eighty-five patients were diagnosed between 1982 and 1996 and followed until 2001 allowing >or=5 years of follow-up. All patients were treated with prednisolone and cyclophosphamide. Univariate and multivariate analyses with patient and renal survival as dependent variables were performed. RESULTS: Of the 85 patients in this study, 17 (20%) died within one year after diagnosis. Of the 25 patients (29%) who were dialysis dependent at diagnosis, two remained dependent and two again became dialysis dependent after less than one year; nine died early without renal recovery. Risk factors for death occurring within one year in univariate analysis (RR, 95% CI) were age>65 years (6.5, 1.6-13.7) and dialysis dependency at diagnosis (3.6, 1.0-13). Twenty patients died beyond one year during the long-term follow-up. Male gender (4.7, 1.6-10) and developing dialysis dependency during follow-up (4.1, 1.4-12) were associated with poor outcome. Risk factor for renal failure within one year was dialysis dependency at diagnosis (29, 3.6-229). Of 64 patients dialysis independent one year after diagnosis, 12 patients became dialysis dependent during follow-up. A renal relapse was strongly associated with development of renal failure in long-term follow-up (17, 3.5-81). CONCLUSIONS: Early death and failure to recover renal function in PR3-ANCA associated vasculitis is associated with age> 65 years and dialysis dependency at diagnosis. Long-term renal survival is determined by renal relapses during follow-up only. Slow, progressive renal failure without relapses is rarely observed in this group.     

Comparison of anti-PR3 capture and anti-PR3 direct ELISA for detection of antineutrophil cytoplasmic antibodies (ANCA) in long-term clinical follow-up of PR3-ANCA-associated vasculitis patients.

A total of 118 sera from 11 patients with anti-neutrophil cytoplasmic antibodies against proteinase-3- (PR3-ANCA) associated vasculitis were retrospectively screened by anti-PR3 capture and anti-PR3 direct ELISA tests. We studied the relationship between capture and direct ELISA scores and the clinical activity of PR3-ANCA-associated vasculitis patients during follow-up. We also studied the ability of the anti-PR3 capture ELISA to detect positive values of PR3-ANCA in clinical vasculitis relapses. Only capture ELISA presented a significant relationship (p < 0.05) with clinical activity of PR3-ANCA-associated vasculitis patients over time. Capture ELISA appears to be a reliable method for detecting clinical relapses in this group of patients. Our results indicate that the new capture ELISA test is more effective than direct ELISA in the follow-up of patients with PR3-ANCA-associated vasculitis and in the detection of relapses.     

Renal histology in Chinese patients with anti-myeloperoxidase autoantibody-positive Wegener's granulomatosis.

BACKGROUND: Proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) was the serological marker for Wegener's granulomatosis (WG), while myeloperoxidase (MPO)-ANCA was the serological marker for microscopic polyangiitis (MPA). However, our previous study suggested that patients with MPO-ANCA positive WG were common in Chinese. This study aimed to analyse the renal histology of patients with MPO-ANCA positive WG. METHODS: Patients in our centre with WG were selected according to both the Chapel Hill Consensus Conference (CHCC) definition and American College of Rheumatology classification criteria. Patients with MPA were selected according to the CHCC definition. The renal histology was compared between patients with MPO-ANCA positive WG and with PR3-ANCA positive WG as well as patients with MPO-ANCA positive MPA. RESULTS: Sixty-one patients with WG had complete renal histological data, 39/61 with positive MPO-ANCA and 22/61 with positive PR3-ANCA. Among patients with crescents in glomeruli, those with MPO-ANCA had fewer cellular crescents and more fibrous crescents than those with PR3-ANCA (P < 0.01 and P < 0.05, respectively). Interstitial fibrosis and tubular atrophy were more prevalent and severe in patients with MPO-ANCA than in those with PR3-ANCA (P < 0.01 and P < 0.05, respectively). Compared with 44 patients with MPO-ANCA positive MPA, patients with MPO-ANCA positive WG had fewer glomeruli with crescents and more normal glomeruli (P < 0.01 and P < 0.01, respectively). CONCLUSION: Patients with MPO-ANCA positive WG are common in Chinese. In renal histology, chronic lesions were more severe and prevalent in patients with MPO-ANCA positive WG than in patients with PR3-ANCA positive WG. Glomerular lesions were less severe and less prevalent in patients with MPO-ANCA positive WG than in those with MPO-ANCA positive MPA.     

Characteristics of Chinese patients with Wegener's granulomatosis with anti-myeloperoxidase autoantibodies

BACKGROUND: Cytoplasmic antineutrophil cytoplasmic autoantibodies (cANCA)/proteinase-3(PR3)-ANCA was considered the serologic diagnostic marker for Wegener's granulomatosis (WG). However, Chinese patients with MPO-ANCA positive WG were frequently diagnosed. We now analyze the characteristics of patients with MPO-ANCA positive WG and investigate the difference between patients with MPO-ANCA and PR3-ANCA. METHODS: Patients with WG were selected according to both Chapel Hill Consensus Conference definition and American College of Rheumatology (ACR) classification criteria in 500 Chinese patients with ANCA-associated systemic vasculitides. The clinical manifestions were compared between patients with MPO-ANCA and with PR3-ANCA. RESULTS: Eight-nine patients fulfilled the diagnostic criteria of WG: 54/89(60.7%) were MPO-ANCA positive, 34/89(38.2%) were PR3-ANCA positive. Patients with MPO-ANCA were predominantly female compared with patients with PR3-ANCA. Patients with MPO-ANCA also had multisystem involvement. However, the prevalences of arthagia, skin rash, ophthalmic and ear involvement were significantly lower in patients with MPO-ANCA than those in patients with PR3-ANCA (46.3% vs. 70.6%, P < 0.05; 20.4% vs. 44.1%, P < 0.05; 27.8% vs. 58.8%, P < 0.01; 40.7% vs. 67.6%, P < 0.05, respectively). The prevalence of elevated initial serum creatinine was significantly higher in patients with MPO-ANCA than that in patients with PR3-ANCA (81.5% vs. 61.8%, chi(2) = 4.20, P < 0.05). CONCLUSION: Patients with MPO-ANCA positive WG were not rare in Chinese.     

PR3-ANCA-positive crescentic necrotizing glomerulonephritis accompanied by isolated pulmonic valve infective endocarditis, with reference to previous reports of renal pathology

Patients with infective endocarditis (IE) often have renal complications which may include infarcts, abscesses and glomerulonephritis (GN). Furthermore, it is generally accepted that there is an association between IE and anti-neutrophil cytoplasmic antibody (ANCA). Here, we report the case of a 24-year-old man who developed rapidly progressive GN in the course of IE due to infection with alpha-streptococcus. The initial clinical manifestation of the condition was severe sacroiliitis without fever. Sandwich ELISA showed that the patient was positive for PR3-ANCA at low titer, and the classical complement pathway was also activated. Renal biopsy demonstrated several lesions: focal embolic GN, GN with immune deposits and focal and segmental crescentic necrotizing GN. Treatment with antibiotics and steroids led to eradication of the infection, and resolution of the renal disease was accompanied by immediate disappearance of PR3-ANCA and hypocomplementemia. During a 4-year follow-up period, no recurrence was observed. There have only been 7 case reports of GN associated with IE and PR3-ANCA in which the renal pathology has been described, and the current report is the first to document renal pathology in a patient with isolated pulmonic valve IE and PR3-ANCA. Moreover, this report is the first to show a change in renal biopsy findings in response to treatment. A review of the 7 literature cases and that of our patient showed that none involved pauci-immune GN. Hence, further studies are needed to clarify the prevalence of pauci-immune GN in ANCA-positive IE patients.     

抗髓过氧化物酶抗体阳性的韦格纳肉芽肿病的特点

目的 分析抗髓过氧化物酶(MPO)抗体阳性的韦格纳肉芽肿病(WG)患者的临床病理特点及其与传统的抗蛋白酶3(PR3)抗体阳性者之间的差异&#65377;方法 89例WG患者经本院肾内科确诊,分析其临床病理资料并对比抗MPO抗体阳性和抗PR3抗体阳性的两组患者之间的差异&#65377;结果 89例患者中54例抗MPO抗体阳性,34例抗PR3抗体阳性&#65377;抗MPO抗体阳性患者中男性所占的比例显著低于抗PR3抗体阳性者(男:女分别为23:31与24:10, P<0.05)&#65377;抗MPO抗体阳性的WG临床亦呈多器官受累的表现,其中关节痛&#65380;皮疹&#65380;眼&#65380;耳受累的发生率显著低于抗PR3抗体阳性者(分别为46.3%比70.6%,P < 0.05; 20.4%比44.1%,P < 0.05;27.8%比58.8%,P < 0.01和40.7%比67.6%,P < 0.05);伯明翰血管炎活动度积分(BVAS)显著低于抗PR3抗体阳性者(22.2±6.2比24.7±6.9, P < 0.05);而在确诊时Scr增高的发生率则显著高于抗PR3抗体阳性者(81.5%比61.8%, P < 0.05)&#65377;结论 在国人的WG患者中,抗MPO抗体阳性者可能不占少数,它与抗PR3抗体阳性者临床表现有所不同&#65377;     

Neutrophil membrane expression of proteinase 3 (PR3) is related to relapse in PR3-ANCA-associated vasculitis

Wegener granulomatosis (WG) is strongly associated with the presence of antineutrophil cytoplasm autoantibodies (ANCA) with specificity for proteinase 3 (PR3). Relapses of WG are frequently preceded by a rise of autoantibody titer and PR3-ANCA are able to activate primed neutrophils in vitro. Except being stored intracellularly and translocated to the cell surface upon neutrophil stimulation, PR3 can also be detected on the surface of non-stimulated neutrophils (membrane PR3 or mPR3), with an interindividual variability in percentages of mPR3(-)-positive cells and level of mPR3 expression. This study began with the hypothesis that the presence of PR3 on the surface of non-stimulated neutrophils enables interaction with PR3-ANCA and influences clinical manifestations of the disease. It analyzed mPR3 expression on neutrophils of 89 WG patients in complete remission and 72 healthy controls to evaluate whether the presence of PR3 on the surface of resting neutrophils is related to clinical manifestations of WG and/or to the susceptibility to develop relapses. The number of patients with a bimodal mPR3 expression on resting neutrophils did not differ between patients and controls. However, in WG patients, an increased percentage of mPR3(+) neutrophils and an elevated level of mPR3 expression compared with healthy individuals (P = 0.037) were found. Within the group of WG patients, an elevated level of mPR3 expression was significantly associated with an increased risk for relapse (P = 0.021) and with an increased relapse rate (P = 0.011), but not with the disease extent or particular manifestations at diagnosis or at relapse. These data support the hypothesis that PR3 expression on the membrane of neutrophils plays a role in the pathophysiology of PR3-ANCA associated vasculitis.     

Renal histology in ANCA-associated vasculitis: differences between diagnostic and serologic subgroups.

BACKGROUND: Differences in renal histopathology between microscopic polyangiitis (MPA) and Wegener's granulomatosis (WG), and between anti-neutrophil cytoplasm autoantibody (ANCA) test results in patients with ANCA-associated vasculitis may provide insight into the differences in pathogenesis and raise the opportunity of classifying the vasculitides more accurately. The possible differences in histopathology are investigated in this study. METHODS: We report an analysis of 173 patients with renal disease in microscopic polyangiitis or Wegener's granulomatosis. A total of 173 renal biopsies, performed at diagnosis, were scored by two observers separately, using a previously standardized protocol. Consensus on each biopsy was achieved during a central review. RESULTS: Normal glomeruli were more common in WG than in MPA (P < 0.001). Glomerulosclerosis was more prominent in MPA than in WG (P=0.003). Interstitial fibrosis (P < 0.001), tubular atrophy (P < 0.001), and tubular casts (P=0.005) were more frequently present and more severe in MPA than in WG. Presence of glomerulosclerosis was more extensive in patients with myeloperoxidase (MPO)-ANCA than with proteinase 3 (PR3)-ANCA (P=0.022). Interstitial fibrosis (P=0.008), tubular necrosis (P=0.030), tubular atrophy (P=0.013), and intra-epithelial infiltrates (P=0.006) were more frequently present and more severe in MPO-ANCA than in PR3-ANCA. CONCLUSIONS: Glomerulonephritis in relation to MPA has more characteristics of chronic injury at the time of presentation than glomerulonephritis in relation to WG. This difference may be due to a delayed establishment of diagnosis in patients with MPA compared to patients with WG. Both active and chronic lesions are more abundantly present in MPO-ANCA-positive patients than in patients with PR3-ANCA-positivity, which suggests that the pathogenesis of renal disease in these ANCA subsets could be different. Our results also suggest that ANCA test results may be useful in classifying ANCA-associated vasculitides.     

Clinical characteristics and prognosis of ANCA-associated vasculitis in patients with renal injury

Objective To investigate the characteristics and outcome of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in patients with renal injury. Methods AAV patients with renal injury diagnosed in the Department of Nephrology, Renmin Hospital of Wuhan University, from January 2012 to January 2017 were included into this study. Patients were divided into MPO-ANCA positive and PR3-ANCA positive groups for further study. The clinical characteristics, pathological and laboratory indexes, treatment and prognosis were retrospectively analyzed. Results A total of 68 cases were enrolled, among which 52 cases (76.5%) were MPO-ANCA positive and 16 cases (23.5%) were PR3-ANCA positive, and 41 patients (60.3%) were over 65 years old. The incidences of interstitial lung disease, digestive and nervous system damage in PR3-ANCA positive group were significantly higher than those MPO-ANCA positive group (P＜0.05). There were significant differences of hemoglobin, complement C3, complement C1q, IgE, 24 h urinary protein, erythrocyte sedimentation rate, procalcitonin, BVAS score and eGFR in two groups (P＜0.05). 19 cases had done renal biopsy,among them 14 cases were MPO-ANCA positive and 5 cases were PR3-ANCA positive. Incidence of crescentic necrotizing glomerulonephritis in PR3-ANCA positive group was significantly higher than that in MPO-ANCA positive group, and incidence of diffuse global glomerulosclerosis in MPO-ANCA positive group was significantly higher than that in PR3-ANCA positive group (all P＜0.05). At the median follow-up time of 32 months, the relapse rate at 6 month of MPO-ANCA-positive and PR3-ANCA-positive patients were 46.2% and 75.0%, respectively (P＜0.05). Multivariate logistic regression analysis showed that PR3-ANCA positive, age≥65 years old, baseline eGFR＜30 ml?min-1?(1.73 m2)-1, and combined with pulmonary interstitial lesions were all independent risk factors for relapse. And the incidence of ESRD were 42.3% and 75.0% during the follow-up period and 10 patients (14.7%) died. COX regression analysis showed that patients older than 65 years old, BVAS score≥18 points, eGFR＜30 ml?min-1?(1.73 m2)-1 and complicated with pulmonary interstitial disorders at the onset were independent risk factors causing ESRD or death. Conclusion The PR3-ANCA-positive patients had more severe renal injury than those with MPO-ANCA-positive patients, and the injury of extrarenal organs was more serious, recurrence rate was higher, and the prognosis was worse.     

Antineutrophil cytoplasmic antibodies to proteinase 3 in Wegener's granulomatosis: epitope analysis using synthetic peptides

BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCA) to proteinase 3 (PR3) are strongly associated with Wegener's granulomatosis (WG) and are thought to be involved in its pathogenesis. Levels of PR3-ANCA do not always correspond to clinical disease activity nor to functional effects of these antibodies in vitro, suggesting differences in epitope specificity. To define relevant epitopes for PR3-ANCA, sera of WG patients were analyzed on their reactivity to linear peptides of PR3. METHODS: Fifty linear peptides of 15 amino acids in length with an overlap of 10 aa spanning the entire PR3 sequence were synthesized. Sera of 27 WG patients with active disease and 27 age- and sex-matched healthy controls, eight anti-PR3 monoclonal antibodies (mAbs), and a rabbit anti-PR3 serum were tested by enzyme-linked immunosorbent assay for reactivity to PR3 peptides. RESULTS: Rabbit anti-PR3 serum recognized three distinct peptide areas, whereas none of the anti-PR3 mAbs bound PR3 peptides. Sera of both WG patients and healthy controls recognized a restricted number of PR3 peptides. Four of these peptide areas were recognized significantly more strongly by WG sera than by control sera. Sera drawn at the initial presentation of WG mainly recognized these peptides. Two of the recognized peptide areas were located near the active center of PR3. CONCLUSION: A restricted number of epitope areas of PR3 are recognized both by WG patient sera and control sera. Four peptide areas were bound stronger by sera of WG patients at initial presentation than by healthy controls.     

ANCA相关性血管炎肾损害临床特征及早期诊治探讨

目的 分析抗中性粒细胞胞浆抗体(ANCA)相关性血管炎的临床表现和肾脏病理特征,探讨早期诊断和治疗对预后的影响.方法选取本院2000年1月至2009年8月明确诊断的ANCA相关性血管炎共21例,18例行肾活检.总结患者的临床病理资科.分析不同治疗时机对肾功能转归的影响.结果本组21例ANCA相关性血管炎平均年龄(52.5±11.5)岁,显微镜下多血管炎(MPA)16例,韦格纳肉芽肿(WG)3例,变应性肉芽肿性血管炎(CSS)2例.肾外表现主要为发烧17例(80.1%)、下呼吸道症状18例(85.7%)、肺影像学改变21例(100%)、贫血16例(76.2%)、眼耳鼻受累8例(38.1%);肾脏表现血尿21例(100%),蛋白尿19例(90.1%),血肌酐正常6例(28.5%),升高15例(71.4%),8例需透析替代.ANCA检测pANCA和MPO-ANCA阳性16例,cANCA和PR3-ANCA阳性3例.pANCA/MPO-ANCA和cANCA/PR3-ANCA均阳性1例,全阴性1例.肾活检可见节段性小血管壁纤维素样坏死,新月体多见.免疫荧光无或微量免疫复合物沉积.治疗采用糖皮质激素联合环磷酰胺,重症加用血浆置换.7例血肌酐异常但不需透析者5例治疗后血肌酐恢复正常;8例需透析者2例治疗后血肌酐恢复正常,2例脱离透析但血肌酐异常,4例未能脱离透析.结论ANCA相关性小血管炎临床表现多样,肺、肾是最常见的受累器官.ANCA检测和肾活检有助于早期诊断,尽早积极治疗有助于肾功能的恢复.     

Effects of carboxy-terminal modifications of proteinase 3 (PR3) on the recognition by PR3-ANCA

BACKGROUND: Autoantibodies directed against neutrophil proteinase 3 (PR3-ANCA) from patients with Wegener's granulomatosis and microscopic polyangiitis recognize conformational epitopes of PR3. During maturation of neutrophils, PR3 undergoes amino-terminal and carboxy-terminal processing. In contrast to amino-terminal processing, the effects of carboxy-terminal processing on recognition of PR3 by PR3-ANCA remain unknown. Carboxy-terminally modified or tagged recombinant PR3 (rPR3) molecules may be useful for the refinement of diagnostic assays and for the study of biological processes. METHODS: This study was designed to determine whether 293 cells can be used to express specifically designed carboxy-terminal variants of rPR3, and to evaluate the effects of different carboxy-terminal modifications on the recognition by PR3-ANCA in the capture ELISA. RESULTS: The rPR3-variants secreted into the media supernatants of transfected 293 cells escaped proteolytic processing. Furthermore, in contrast to the effects of amino-terminal pro-peptide deletion on PR3-ANCA binding, carboxy-terminal modifications (deletion and additions) did not significantly affect recognition by PR3-ANCA. CONCLUSIONS: This expression system is ideally suited for the expression of custom-designed carboxy-terminal rPR3 variants, and major conformational effects of carboxy-terminal modifications seem unlikely.     

A case of exorbitism in association with Wegener's granulomatosis with renal involvement

Wegener's granulomatosis (WG) is a necrotizing granulomatous vasculitis involving the nose, paranasal sinuses, lungs, and kidneys. Ocular involvement can occur in about 50% of cases. There are very few reports of WG with orbital inflammation and exorbitism. We report a case of a female patient who presented with exorbitism related to orbital inflammation secondary to WG, with renal involvement. A 29-year-old woman with a previous history of recurrent pan-sinusitis presented with bilateral exophthalmos and renal failure with rapidly progressive glomerulonephritis. Computed tomography showed extensive bilateral soft tissue in the retro-orbital area. Immunologic tests showed the presence of type-C anti-neutrophil cytoplasmic antibodies and renal biopsy revealed pauci immune crescentic glomerulonephritis. The patient was treated with corticosteroids and pulses of cyclophosphamide followed by azathioprine and trimethoprim-sulfamethoxazole. After a follow-up of 10 months, the renal outcome was favorable with improvement of renal function but there was persistence of exorbitism and loss of visual function. Our case suggests that WG should be considered in the differential diagnosis of persistent bilateral exophthalmos. Prompt recognition of this early manifestation is important for the institution of early treatment.     

ANCA in haemodialysis patients

The prevalence of positive ANCA as well as the prevalence ofPR-3 and MPO antibodies were examined in a cross-sectional sampleof 1277 haemodialysis patients from 16 German haemodialysiscentres. We found 32 patients positive for c-ANCA (median titre1:40; range 1:20–1:320) and 65 for p-ANCA (1:80; 1:20–1:1280).Twenty-two percent of the c-ANCA-positive and 31% of the p-ANCA-positivepatients had PR-3 and MPO antibodies by ELISA respectively.Clinical evidence of vasculitis was found in 11 of 32 c-ANCA-positiveand 19 of 65 p-ANCA-positive patients. Of the 11 c-ANCA-positive,four had a known diagnosis of Wegener's granulo-matosis (WG);WG was recognized after the test in a further five patientsand two had renal limited RPGN. Of the 19 p-ANCA-positive patients,three had a clinical diagnosis of microscopic polyarteritis(MP), MP was newly diagnosed in a further 12, WG in one andrenal limited RPGN in three. The patients had not received cyclophosphamide(the diagnosis had been non-specified ‘systemic disease’).Thus false-positive ANCA, as defined by absence of vasculitis,was found in 5% of dialysis patients versus 0% in patients withpreterminal renal failure {n=152) or blood donors (n=150). Patientswith vasculitis tended to have higher c-ANCA and p-ANCA titresrespectively, but there was a considerable overlap. Titres werenot higher in patients symptomatic at the time of examination(6 of 11 c-ANCA and 10 of 19 p-ANCA), but PR-3 and MPO ELISAwere positive in all but two. Thus c-ANCA were false positive(i.e. not associated with clinical vasculitis) in 66% and p-ANCAin 71%. In some patients ANCA was positive, but ELISA negative. We conclude that (i) in dialysis patients c-ANCA and p-ANCAare frequently present in the absence of vasculitis; (ii) specificitycan be improved, but sensitivity is lost, by using PR-3 andMPO ELISA respectively; (iii) serology permits the recognitionof WG or MP in cases where the diagnosis has been missed. Itis recommended that all patients with unknown primary renaldisease admitted to renal replacement therapy be examined usingboth ANCA-IF and PR-3/MPO ELISA.     

Human anti-neutrophil cytoplasm autoantibodies to proteinase 3 (PR3-ANCA) bind to neutrophils

BACKGROUND: Recently, the in vivo pathogenic role of anti-neutrophil cytoplasm autoantibodies (ANCA) in ANCA-associated vasculitis has been challenged by Abdel-Salam et al. In their report, they observed that ANCA directed against proteinase 3 (PR3) cannot bind to their target autoantigen PR3 on circulating neutrophils (PMN). Here we present evidence that human PR3-ANCA do specifically bind to PMN that express PR3 on their membrane. METHODS: PMN were isolated from donors showing bimodal membrane PR3 expression on their PMN (N= 3). TNFalpha-primed PMN or PMA-stimulated PMN were incubated with serum or plasma from PR3-ANCA-positive patients with Wegener's granulomatosis (WG) (N= 8) or healthy controls (N= 8). Binding of IgG in serum or plasma samples to PMN was assessed by indirect immunofluorescence. RESULTS: Binding of IgG in undiluted plasma or serum from PR3-ANCA-positive WG-patients to PMN was significantly increased compared to plasma or serum from healthy controls. Dilution of plasma and serum showed concentration-dependent binding of IgG. Double staining for PR3 and IgG demonstrated that IgG in plasma or serum from PR3-ANCA-positive patients only bound to those PMN that expressed PR3, and not to PMN that lacked PR3 expression on their membrane. CONCLUSION: PR3-ANCA in undiluted serum or plasma from PR3-ANCA-positive WG patients bind to TNFalpha- primed and PMA-stimulated PMN that express PR3 on their membrane. Therefore, the hypothesis that PR3-ANCA can bind and activate primed PMN is still the most attractive explanation for the contribution of PR3-ANCA to the pathogenesis of Wegener's granulomatosis.     

Clinical significance of anti-neutrophil cytoplasmic antibodies (ANCA) in collagen diseases associated with vasculitic syndrome in Japan.

The present study was undertaken to determine the anti-neutrophil cytoplasmic antibody (ANCA) levels in 96 patients with various collagen diseases associated with renal vasculitis and vasculitic syndrome in Japan. The results indicated that cytoplasmic(C)-ANCA is an autoantibody highly specific to Wegener's granulomatosis (WG) and that it is also active in renal injury. The relationships between ANCA and focal segmental necrotizing GN, i.e., renal vasculitis as proposed by Balow, were investigated. Perinuclear(P)-ANCA was detected with high sensitivity and specificity in renal vasculitis without WG, and the severity of necrotizing and crescentic nephritis in WG was correlated especially well with the C-ANCA titer. Detection of ANCA is considered clinically useful for the etiological differentiation of renal vasculitis, suggesting the possibility that C-ANCA may be involved in the onset of vasculitis of the glomerular capillary vessels in WG. The presence of C-ANCA and cytokines (IL-1 beta and TNF-alpha) is important in the pathogenesis of vasculitis and GN in WG.     

Cytoplasmic antineutrophil cytoplasmic antibody positive pauci-immune glomerulonephritis associated with infectious endocarditis

Renal deterioration often occurs in cases of infectious endocarditis (IE), but, IE- associated nephritis with rapidly progressive glomerulonephritis (RPGN) is rare. Patients with severe infection (e.g., IE) sometimes show positivity for cytoplasmic antineutrophil cytoplasmic antibodies (C-ANCA). Therefore, diagnosis and treatment are very difficult in cases of RPGN with IE and positivity for C-ANCA. Such cases are rare, only 12 have been reported in the English literature. Herein, we describe the case of a 50-year-old man who presented with RPGN with IE and tested positively for C-ANCA. He was referred to our hospital because of leg edema, purpura and renal dysfunction. Laboratory tests revealed serum creatinine elevation and positivity for C-ANCA and proteinase 3-specific (PR3)-ANCA. RPGN and acute renal failure were diagnosed. Hemodialysis and steroid therapy were started. Streptococcus oralis was isolated by blood culture. Transthoracic echocardiography revealed grade III mitral valve insufficiency with two vegetations. Therefore, IE was diagnosed. The steroid therapy was stopped, and antibiotic therapy was begun. Because there was no improvement, surgical therapy was performed. The operation was successful, but the patient died of brain hemorrhage. Our experience in this case indicates C/PR3-ANCA positive RPGN must be ruled out in patients with infectious disease, particularly IE, together with renal symptoms, and renal biopsy should be performed.     

Clinicopathological analysis of Sjogren's syndrome complicated with ANCA associated vasculitis with renal involvement

Objective To investigate the clinical and pathological features of patients with a combination of Sjogren's syndrome (SS) and antineutrophil cytoplasmic antibody (ANCA) associated vasculitis with renal involvement. Methods By searching the Peking Union Medical College Hospital medical database and literature between January 1990 and June 2017, patients had a combination of SS and ANCA associated vasculitis with renal involvement were included. Data of clinical information, autoimmune antibodies, renal manifestations and renal pathology were retrieved and analyzed. Results Eighteen patients were enrolled: 4 from our hospital and 14 from literature. SS was diagnosed no later than ANCA associated vasculitis in all the patients, among which 83.3%(15/18) of patients had extra-glandular and extra-renal organs involved. All the patients were tested positive for myeloperoxidase (MPO)-ANCA, and only two were protein 3 (PR3)-ANCA positive concurrently. The positivity rates of antinuclear antibody (ANA), rheumatoid factor (RF), anti-SSA antibody, and anti-SSB antibody were 83.3%(15/18), 55.6%(10/18), 77.8%(14/18), and 38.9%(7/18), respectively. The renal manifestations were characterized by renal insufficiency with a median serum creatinine of 174 μmol/L, hematuria, moderate proteinuria with a median 24 hour urine protein of 1.70 g, and necrotizing vasculitis with oligo-immune complex and varying degrees of interstitial damage in pathology. Conclusions A combination of Sjogren's syndrome and ANCA associated vasculitis with renal involvement is rare in clinical setting, and almost all of the patients are MPO-ANCA positive, with high probability of ANA positivity and extra-glandular involvement. Physicians should beware of ANCA associated glomerulonephritis in SS patients with inexplicable renal dysfunction and renal biopsy should be carried out in time.     

Antineutrophil cytoplasmic antibodies (ANCA) in Chinese patients with anti-GBM crescentic glomerulonephritis

OBJECTIVE: To study the prevalence of ANCA and their target antigen in Chinese patients with anti-GBM crescentic glomerulonephritis (CGN), and to evaluate the possible role of ANCA in Chinese anti-GBM CGN patients with coexisting serum ANCA by studying clinicopathologic features of this disease. MATERIAL AND METHODS: Twenty-three sera were collected from 23 renal biopsy-proven anti-GBM CGN patients. According to the standardized procedures, all of the sera were determined by both, indirect immunofluorescence (IIF) ANCA, and enzyme-linked immunosorbent assay (ELISA) MPO-ANCA, PR3-ANCA and BPI-ANCA. The patients were divided into two groups according to serum ANCA positivity (Group A) or negativity (Group B). Thirty-three ANCA-associated pauci-immune CGN patients were regarded as control group (Group C). Their clinicopathologic features were compared to reveal whether ANCA correlated with disease activity. RESULTS: There were 11 (47.8%) cases with positive serum ANCA in 23 anti-GBM glomerulonephritis patients. There were 4/11 MPO-ANCA (one with positive PR3-ANCA and C-ANCA, three with negative IIF-ANCA), 1/11 PR3-ANCA (with positive MPO-ANCA and C-ANCA), 3/11 P-ANCA (with negative ELISA-ANCA) and 5/11 C-ANCA (one with positive PR3-ANCA and MPO-ANCA, and the other four with negative ELISA-ANCA). No BPI-ANCA was detected. No different clinicopathologic features were found between Groups A and B. Both were different from Group C in age, sex ratio, frequence of anuria and ESRD, variety of crescents, glomerular sclerosis, vessel lesion and prognosis. CONCLUSION: Our data demonstrate that ANCA in Chinese patients with anti-GBM CGN is not rare. The major target antigen of ANCA is MPO. ANCA seems not to be correlated with disease activity.