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.     

Antineutrophil-cytoplasmic antibodies and antiglomerular basement membrane antibodies in Goodpasture's syndrome and in Wegener's granulomatosis.

Antiglomerular basement membrane (anti-GBM) diseases-including Goodpasture's (GP) syndrome-and Wegener's granulomatosis (WG) are systemic diseases, which may be diagnosed by means of circulating autoantibodies. Possible overlap syndromes may exist; however, they remain imperfectly defined. We analyzed sera from 31 patients with WG and from 23 patients with anti-GBM disease. All underwent biopsy. Anti-cytoplasmic antibodies (ANCA) were demonstrated by indirect immunofluorescence (IIF); a perinuclear (P-ANCA) or diffuse-cytoplasmic (C-ANCA) staining was discerned. In addition, myeloperoxidase (MPO) antibodies (P-ANCA) and protein 3 (SP3) antibodies (C-ANCA) were analyzed by specific ELISA systems. Anti-GBM antibodies (anti-NC1 antibodies) were detected by ELISA and immunoblotting; the globular domain NC1 of collagen IV was employed as antigen. All 31 WG patients, as defined by clinical and histological criteria, showed ANCA by IIF. Twenty-nine of 31 showed a C-ANCA pattern; all were also positive for SP3 antibodies by ELISA. Three of 31 WG patients were P-ANCA positive by IIF and also had anti-MPO antibodies by ELISA. In one of these patients, SP3 antibodies were additionally found by IIF and by ELISA (double positive). No patient with WG had anti-NC1 antibodies. All 23 serum samples from patients with GP syndrome (N = 19) or anti-GBM glomerulonephritis (N = 4) had anti-NC1 antibodies. In seven of these patients, low titers of anti-MPO antibodies were detected by ELISA; however, the IIF for ANCA was negative. None of these seven patients had extraglomerular vasculities. In addition, the clinical prognosis of these patients was similar to that of those patients who lacked these antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of clinical features and prognosis of anti-glomerular basement membrane antibody positive patients with anti-neutrophil cytoplasmic antibodies

Objective To investigate the characteristics and outcome of glomerulonephritis in patients with both antineutrophil cytoplasmic antibody and anti-glomerular basement membrane antibody. Methods The sera of 23 anti-GBM glomerulonephritis patients were collected and were tested for ANCA respectively. Characteristics and outcome of patients with coexisting anti-GBM antibody and ANCA were analyzed, and were compared with anti-GBM glomerulonephritis patients without coexisting ANCA. Results Among the 23 sera with anti-GBM antibody, 7 sera had coexisting ANCA (7 MPO-ANCA, 1 PR3-ANCA), which represented 30.4% of the anti-GBM glomerulonephritis patients. The incidence of hemoptysis and hematuria in ANCA+-anti-GBM glomerulonephritis group was significantly higher than that in ANCA--anti-GBM glomerulonephritis group (P＜0.05). No significant difference in age, sex, other clinical manifestations and pathological features were found between patients with and without coexisting serum ANCA. Conclusion The incidence of hemoptysis and hematuria in ANCA+-anti-GBM glomerulonephritis group is significantly higher than that in ANCA--anti-GBM glomerulonephritis group, but the prognoses of the two groups were poor.     

100例新月体肾炎的免疫病理分型及临床病理分析

目的：了解新月体性肾炎的免疫病理分型及其临床病理特点。方法：对我科近10年来经肾活检确诊的100例新月体性肾炎进行回顾性分析,对患者血清进行抗中性粒细胞胞浆抗体（ANCA）和抗肾小球基底膜（GBM）抗体的检测。结果：100例患者中21％为抗GBM抗体型,其中6／21例同时合并ANCA阳性;47％为免疫复合物型,其中9／47型ANCA阳性;32％为少免疫沉积型,其中17／32例为ANCA阳性小血管炎。3种类型相比,抗GBM抗体型以青年男性为主,多有少尿或无尿（P＜0．05）,肾小球受累受为广泛（P＜0．001）,预后差（P＜0．001）。免疫复合物型以中青年为主,多表现为肾病综合征（P＜0．01）,强化免疫抑制治疗有效。少免疫沉积型以中老年为主,有多系统受累（P＜0．05）,治疗效果相对较好。结论：我国新月体肾炎中虽仍以免疫复合物型为主,但抗GBM抗体型和ANCA阳性小血管炎并不少见。肾活检免疫病理和血清自身抗体的联合应用对新月体肾炎进行分类更接近病因学诊断。     

The role of flow cytometric ANCA detection in screening for acute pauci-immune crescentic glomerulonephritis.

BACKGROUND: Most cases of pauci-immune crescentic glomerulonephritis (PICGN) are associated with serum anti-neutrophil cytoplasmic antibodies (ANCA). This article studied the sensitivity and specificity of serum ANCA, determined by flow cytometry and indirect immunofluorescence (IIF), to identify patients with acute PICGN. METHODS: 577 adults presenting for first biopsy of their native kidneys with serum taken for ANCA (flow cytometry and IIF) determination were studied. A positive ANCA was defined using a flow cytometric ANCA assay as a screening test, followed by a slide-based indirect IIF technique. Pathological confirmation of acute PICGN was used to assess the sensitivity and specificity of this combined approach and its positive predictive value (PPV) and negative predictive value (NPV) in patients presenting for renal biopsy due to abnormal urinary sediment. RESULTS: Forty-nine patients were found to have acute PICGN on renal biopsy. Of these 47 were ANCA positive (sensitivity 95.9%). Overall 93 of the renal biopsy patients were ANCA positive, (specificity 91.3%). A further seven patients (two ANCA positive) had advanced sclerosing disease consistent with PICGN but without evidence of current disease activity. The PPV and NPV of ANCA, assessed by flow cytometry and slide IIF, in predicting that patients presenting with undifferentiated renal disease would have acute PICGN was 50.5 and 99.8%, respectively. CONCLUSIONS: Flow cytometric screening of serum for ANCA in patients undergoing renal biopsy has a high NPV for determining those with acute PICGN. It may provide a rapid, simple screening test for this lesion in laboratories using diagnostic flow cytometry and may complement IIF/ELISA in evaluating ANCA positive patients.     

The level and clinical significance of serum anti-lysosomal associated membrane protein-2 antibody in patients with ANCA-associated glomerulonephritis

Objective To investigate the relationship of the serum anti-lysosome associated membrane protein 2 (LAMP-2) antibody levels and anti-neutrophil cytoplasmic antibodies (ANCA)-associated glomerulonephritis. Methods Thirty-three patients with new onset ANCA-associated glomerulonephritis and thirty healthy controls were enrolled. ANCA detection was performed using indirect immunofluorescence (IIF). Enzyme-linked immunosorbent assay (ELISA) was used to detect myeloperoxidase (MPO), proteinase-3 (PR3) and other ANCA-associated antibodies including LAMP-2. The cut-off value of the serum anti-LAMP-2 antibody was determined by a receiver operating characteristic (ROC) curve. Results The serum levels of anti-LAMP-2 antibody in new onset ANCA-associated glomerulonephritis patients were significantly higher than remission stage ANCA-associated glomerulonephritis patients and healthy controls (P＜0.05). The serum levels of anti-LAMP-2 antibody showed no visible difference between the remissionANCA-associated glomerulonephritis patients and healthy controls (P＞0.05). The levels of anti-LAMP-2 antibody showed a strong positive correlation with ESR, Scr, BUN, proteinuria, crescent proportion and Birmingham vasculitis activity score (BVAS) and a negative correlation with Ccr, Hb and Alb. Conclusions Anti-LAMP-2 antibody is correlated with the activity of ANCA-associated glomerulonephritis and the severity of renal damage. It may be a useful indicator on the activity ofANCA-associated glomerulonephritis.     

A case of MPO ANCA associated glomerulonephritis with interstitial pneumonitis complicated with lung tuberculosis and pericarditis

The main target organs of myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA)-related disease are the kidney and lung. This report describes a 71-year-old man with rapidly progressive glomerulonephritis (RPGN) and interstitial pneumonitis associated with MPO ANCA. The patient was admitted to our hospital because of bloody sputum, low grade fever and appetite loss on October, 1998. He was diagnosed as having interstitial pneumonitis from the findings of chest X-ray and CT examinations. Moderate proteinuria and hematuria, renal dysfunction(serum creatinine: 5.6 mg/dl, BUN: 58.0 mg/dl) and positivity for MPO ANCA were noted. He was negative for anti-glomerular antibody and PR3-ANCA. Renal biopsy was performed and revealed crescentic glomerulonephritis without deposition of immunoglobulins. Therefore, the diagnosis of pauci immune type RPGN was made. Pulse therapy with methylprednisolone(1.0 g/day x 3 days) following oral administration of prednisolone (60 mg/day) found marked improvement of renal function maintenance and interstitial pneumonitis, respectively. However, he died because of lung tuberculosis and acute tuberculous pericarditis during treatment with prednisolone. In this case, MPO ANCA might have been directly associated with both RPGN and interstitial pneumonitis. Furthermore, chronic lung disease, such as interstitial pneumonitis, is important as a preceding disease of RPGN. MPO ANCA-related disease is more frequent in aged persons, therefore particular attention should be paid during their treatment with an immunosuppressant.     

Case of scleroderma with rapid progressive glomerulonephritis associated with both MPO-ANCA and anti-GBM antibodies

A 66-year-old male with scleroderma developed rapidly progressive glomerulonephritis (RPGN). Renal pathology revealed crescentic glomerulonephritis with interstitial inflammation and fibrosis. Immunofluorescent micrography showed linear deposition of IgG along the glomerular capillary wall. Both anti-glomerular basement membrane antibody (anti-GBM Ab), and myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) were detected by an enzyme-linked immunosorbent assay (ELISA). These findings were compatible with ANCA-related vasculitis and anti-GBM Ab nephritis. Laboratory findings showed rapid elevation of the serum creatinine level (5.9 mg/dL), and a high titer of MPO-ANCA (530 EU) and anti-GBM Ab (21 EU). He was started on methylprednisolone pulse therapy and temporary hemodialysis. Since the immunosuppressive therapy lowered both antibody titers steadily and improved renal function, hemodialysis was discontinued 4 weeks after the therapy. It has been reported that some scleroderma patients developed rapid progressive glomerulonephritis due to ANCA-associated vasculitis in addition to the typical scleroderma renal crisis. There have been few reports of a scleroderma patient associated with RPGN, in whom both MPO-ANCA and anti GBM antibodies were detected.     

Glomerular lesions in patients with Churg-Strauss syndrome and the anti-myeloperoxidase antibody.

We report here 4 patients with Churg-Strauss syndrome (CSS) who had classic symptoms including a history of bronchial asthma, severe eosinophilia and necrotizing vasculitis. The antineutrophil antibody (ANCA) against myeloperoxidase (MPO) titers was elevated (44-877 ELISA units), but the ANCA against proteinase-3 (PR3) was negative in all patients. One case was complicated with systemic inflammatory response syndrome (SIRS) and required plasmapheresis and continuous hemodiafiltration. One other patient clinically showed rapidly progressive glomerulonephritis and had hemodialysis 24 times. Two of 4 patients showed good responses with corticosteroid therapy alone, while 2 patients required the addition of cyclophosphamide. Urinary abnormalities such as proteinuria or microscopic hematuria were found in all patients. Three patients had a decreased glomerular filtration rate (GFR) and renal biopsy specimens obtained from these patients showed crescentic glomerulonephritis. One patient had mild to moderate mesangial-proliferative glomerulonephritis with interstitial eosinophilic infiltration. These findings suggest that renal involvements in CSS may not be as uncommon a disorder as previously considered, especially when MPO-ANCA is positive. MPO-ANCA may be associated with the onset of glomerular disorders in CSS.     

Diagnostic significance and antigen specificity of antineutrophil cytoplasmic antibodies in renal diseases. A prospective multicentre study

In a prospective multicentre study on the clinical significanceof ANCA in renal diseases, sera from 920 patients with rapidlyprogressive renal failure and/or renal disease in associationwith extrarenal signs suggestive of a systemic vasculitis weretested for the presence of ANCA by indirect immunofluorescence(IIF) and ELISA. 193 of 920 cases (20.9%) were positive by IIFand 180 (19.5%) by ELISA, using a ‘crude’ cytoplasmicextract as substrate. The sensitivity and specificity of IIFfor ‘pauci-immune’ crescentic necrotizing GN (CNGN),in association or not with systemic vasculitis, was 87.5 and95.6% respectively. The IIF pattern and antigen specificity (alpha granules andMPO) correlated well with the clinical features: a cANCA pattern(alpha granules) was associated with ENT involvement (probableWegener's granulomatosis); a pANCA pattern (MPO) with ‘idiopathic’CNGN and small-vessel vasculitis without respiratory tract disease(microscopic polyarteritis); patients with a pulmonary-renalsyndrome had either c or pANCA in a similar proportion. Our study confirms a high sensitivity and specificity of ANCAfor patients with CNGN. ANCA should be considered an important diagnostic test in patientswith renal diseases, especially in the presence of rapidly progressiverenal failure.     

A 25-year experience with pediatric anti-glomerular basement membrane disease

Anti-glomerular basement membrane (anti-GBM) disease, which is extremely uncommon in children, is characterized by rapidly progressive glomerulonephritis (RPGN) and autoantibodies against GBM collagen. Pulmonary hemorrhage is the third component in Goodpasture Syndrome. Cigarette smoking and exposure to hydrocarbons have been linked to anti-GBM disease in adults, but such an association has not been established in children. We reviewed renal biopsy and autopsy specimens over 25 years from a major tertiary care U.S. children's hospital, diagnosing anti-GBM by clinical RPGN, crescentic glomerulonephritis, and linear immunofluorescence (IF) immunoglobulin G staining in patients under 18 years of age. We identified four patients, with and without pulmonary manifestations. The sole autopsy case showed diagnostic IF despite undetectable serum anti-GBM antibodies and positive testing for serum anti-neutrophil cytoplasmic antibodies (ANCA). Three patients have survived 1–18 years following diagnosis, one of whom is recovering renal function. One adolescent had a history of smoking cigarettes and one had a probable hydrocarbon exposure. Anti-GBM disease is unusual in children, and the relationship to inhaled agents is incompletely understood. Serum anti-GBM antibodies are typically present, but cases with undetectable levels can occur. Some patients are anti-GBM and ANCA positive, with a small subset ANCA-positive, anti-GBM-negative. Ours is the first such described pediatric case.     

Anti-glomerular basement membrane antibody disease in Japan: part of the nationwide rapidly progressive glomerulonephritis survey in Japan

Anti-glomerular basement membrane (anti-GBM) antibody disease is a rare, but well characterized cause of glomerulonephritis. It is defined by the presence of autoantibodies directed at specific antigenic targets within the glomerular basement membrane. This pattern of rapidly progressive glomerulonephritis and alveolar hemorrhage is often referred to as Goodpasture’s syndrome. The prognosis for patients with anti-GBM antibody disease is poor. In Japan, to improve the prognosis of patients with rapidly progressive glomerulonephritis (RPGN), we conducted a nationwide survey of patients with RPGN and investigated the initial symptoms, laboratory findings including renal biopsy findings, treatment methods, and outcomes. Among patients with RPGN, patients with anti-GBM antibody disease were rare: 6.6% (47/715). Alveolar hemorrhage (Goodpasture’s syndrome) was observed in 23.4% of patients with anti-GBM antibody disease. Most patients with anti-GBM antibody disease had renal failure at the time of diagnosis. The mean serum creatinine level of patients with renal-limited anti-GBM antibody disease was 7.07 ± 4.21 mg/dl and that of patients with Goodpasture’s syndrome was 7.99 ± 4.31 mg/dl. The mean level of crescent formation was 78.99 ± 23.54% in patients with anti-GBM antibody disease, and a cellular crescent form was observed in 63.2% of those patients. The prognosis for patients with anti-GBM antibody disease is poor; the renal survival rate at 6 months after onset was 20.9%, and the mortality at 6 months after onset was 23.3%. To improve the prognosis for anti-GBM antibody disease, it may be necessary to detect this disease in the early stages and to treat it without delay. Presented at the 36th Eastern Regional Meeting of the Japanese Society of Nephrology.     

The Diagnostic and Prognostic Significance of ANCA

Antineutrophil cytoplasmic antibodies (ANCA) constitute a family of autoantibodies directed against various components of the neutrophil cytoplasm. Their identification and association with vasculitis and rapidly progressive glomerulonephritis has led to considering these diseases as possible autoimmune disorders. In addition, ANCAs constitute a diagnostic tool and a guideline for therapy during follow-up. Originally identified by Davies et al. in 1982 in 8 patients who had necrotizing glomerulonephritis but no immune deposits or systemic vasculitis (1), ANCA are now regarded as a serological marker for active pauci-immune necrotizing and crescentic glomerulonephritis, either in their renal-limited form or associated with systemic vasculitis such as Wegener's granulomatosis (WG), microscopic polyangütis (mPA), and Churg-Strauss syndrome (CSS) (2-9). The usefulness of ANCA detection for the diagnosis of these forms of vasculitis is now established but its usefulness on follow-up remains disputed (10-13). Two major ANCA antigens have already been identified. Proteinase 3 (PR3) in a serine protease of 29 kDa initially identified by Kao and producing a cytoplasmic staining pattern termed cANCA by indirect immunofluorescence (IIF) (14,15). Myeloperoxidase (MPO) is another myeloid lysosomal enzyme producing an artefactual perinuclear staining of ethanol-fixed neutrophils termed pANCA (2,16). Both are localized in the azurophilic granules of neutrophils and monocytes, are translocated to the cell surface during cell activation (17), and are able to interact directly with ANCA. Despite this common location, MPO and PR3 are associated with a broad spectrum of clinical conditions.     

Retrospective study of 97 ANCA-positive patients: epidemiologic and clinical spectrum

We analysed the clinical profile of antineutrophil cytoplasmic antibodies (ANCA) positive patients in a retrospective study including all cases of ANCA positivity (determined by ELISA) from the Nephrology Clinic, Parhon University Hospital Iasi during the interval 1998-2003. There were 97 ANCA positive patients (mean age 43.7 ?18-75? years, female/male ratio 1.55), of whom almost two thirds had c-ANCA, almost one third p-ANCA, while 9 patients had both types of antibodies. The incidence was 22.5/pmp for the North-Eastern province of Romania. Just 19.3% from the suspected cases with ANCA-associated disease were positive for these antibodies. 47.7% had systemic vasculitis (10 with microscopic polyangiitis--MA, 6 with Wegener's granulomatosis--WG, 1 with Churg-Strauss angiitis, 29 with non-specific vasculitis--NSV). Twenty-seven (27.8%) had connective tissue disease--CTD (systemic lupus erythematosus, rheumatoid arthritis, polymyositis, systemic sclerosis, mixed connective tissue disease, and sarcoidosis), while in 5 cases ANCA were associated with other diseases. Nine cases presented with rapid progressive glomerulonephritis (RPGN) without signs of systemic involvement, and other ten with advanced chronic renal failure (CRF). The most frequent clinical manifestations involved the kidney (71%), the skin, the muscles and joints, and the cardiovascular system. CONCLUSIONS: ANCA positivity is associated with a wide spectrum of diseases, mostly with CTD and NSV. c-ANCA was predominantly seen in WG and advanced CRF, while p-ANCA was associated with MA. In nonspecific vasculitis and connective tissue diseases, both patterns were present. We recommend ANCA determination as a screening method in all cases with renal dysfunction and nephritic syndrome and/or with signs of systemic vasculitis and/or collagenosis.     

Analysis of anti-neutrophil cytoplasmic antibodies (ANCA): frequency and specificity in a sample of 191 homozygous (PiZZ) alpha1-antitrypsin-deficient subjects.

BACKGROUND: ANCA are autoantibodies directed against polymorphonuclear cell antigens, mainly proteinase 3 (PR3) and myeloperoxidase (MPO), which are implicated in the pathogenesis of small-vessel necrotizing vasculitis. Alpha1-antitrypsin is the main inhibitor of neutral serine proteinase [i.e. human leukocyte elastase (HLE) and PR3] present in PMN alpha-granules (alphaGr). An association first reported by us between PR3 ANCA and the deficient PiZZ phenotype in ANCA-positive systemic vasculitis, now widely confirmed by others, led us to study the incidence and specificity of ANCA among PiZZ subjects. METHODS: We tested a population of 191 PiZZ (273 sera) for ANCA activity versus 272 PiMM matched control subjects using alphaGr or antigen-specific ELISA [PR3, HLE, MPO, lactoferin (LF) and bactericidal/ permeability increasing protein (BPI)]. RESULTS: The incidence of antibodies directed against alphaGr and HLE but not PR3, MPO, LF or BPI was increased in the PiZZ as compared to the PiMM group (Fisher probability respectively P < 0.0001 and P < 0.05). CONCLUSIONS: ANCA not directed against classical antigens (MPO and PR3) may be found in PiZZ patients. However, these patients do not develop systemic vasculitis features. Therefore, alpha1-antitrypsin deficiency is not sufficient to induce ANCA positive vasculitides, and may only act as a second hit amplifying factor.     

Anti-glomerular basement membrane (anti-GBM) disease accompanied by vasculitis that was not positive for antineutrophil cytoplasmic antibodies to myeloperoxidase and proteinase 3: a report of two cases and the incidence of anti-GBM disease at one institution

Background

Anti-glomerular basement membrane (anti-GBM) disease is thought to be distinct from vasculitis. In contrast, there have been several papers suggesting the presence of angiitis in cases that were positive for anti-GBM antibody (Ab), as well as for either myeloperoxidase (MPO)- or proteinase 3 (PR3)-anti-neutrophil cytoplasmic antibody (ANCA) (Group I). We experienced four patients who had anti-GBM Abs, but not MPO- and PR3-ANCA (Group II), and two of these patients were found to have vasculitis. Therefore, we performed an in-depth study on these two patients.

Methods

The patients with anti-GBM disease were isolated from 578 cases whose renal tissues were examined, and they were categorized into two groups. We have already published the data about Group I. We then proceeded to study two vasculitic patients in Group II clinically, pathologically, and serologically. The anti-GBM Ab and ANCA levels were detected by enzyme-linked immunosorbent assays. Renal specimens were studied by routine staining as well as immunohistochemical investigations of CD31 and type IV collagen.

Results

The total number of patients with anti-GBM disease was 7 (7/578?=?1.2%), with 3 patients belonging to Group I and 4 patients belonging to Group II. Two patients in Group II were diagnosed to have vasculitis, but the remaining 2 patients did not. One vasculitic patient was complicated by pulmonary hemorrhage, while the other vasculitic patient displayed peripheral neuropathy as well as a small cavity lesion in the lung. The latter patient was found to be positive for perinuclear (p)-ANCA, but not for any other ANCA subsets. The renal pathology in the two vasculitic patients showed crescentic glomerulonephritis (CSGN) and immunoglobulin (Ig) G linear deposits along the glomerular capillary loops. The former patient showed fibrinoid angiitis in an afferent arteriole as well as peritubular capillaritis. The latter patient demonstrated peritubular capillaritis. These peritubular capillaritides were diagnosed by the loss of CD31 and type IV collagen staining, the blurred appearance of peritubular capillary walls by periodic acid-Schiff staining, and the pericapillary infiltration of inflammatory cells.

Conclusion

The incidence of anti-GBM disease was very low, and our patients were categorized into two groups (Groups I and II) based on whether or not they were positive for MPO- or PR3-ANCA. Two patients in Group II were found to have vasculitis. According to our results, we concluded that the anti-GBM disease of Group II could also be associated with vasculitis.     

Antigen and epitope specificity of anti-glomerular basement membrane antibodies in patients with goodpasture disease with or without anti-neutrophil cytoplasmic antibodies

Goodpasture disease (GP) is defined by the presence of anti-glomerular basement membrane (anti-GBM) antibodies and rapidly progressive glomerulonephritis. Besides anti-GBM, many patients with GP produce anti-neutrophil cytoplasmic antibodies (ANCA). For elucidation of the pathophysiologic significance of ANCA in this setting, epitope and antigen specificity of the anti-GBM antibodies and antigen specificity of ANCA were studied. Bovine testis alpha(IV)NC1 (tNC1); recombinant human alpha1, alpha3, alpha4, and alpha5(IV)NC1 (ralpha1 through ralpha5); and three chimeric proteins that contain previously defined epitope regions designated E(A), E(B), and S2 were used to examine the anti-GBM antibodies by ELISA in 205 Chinese patients with GP with or without ANCA. In the 205 anti-GBM antibody-positive sera, 63 (30.7%) were also ANCA positive (61 myeloperoxidase-ANCA and six proteinase 3-ANCA, four being triple positive). All 205 sera recognized tNC1 and ralpha3(IV)NC1. In the double-positive group, 54.0, 66.7, 71.4% of the sera could recognize ralpha1, ralpha4, and ralpha5, respectively, compared with 49.3, 60.6, and 55.6% for patients with anti-GBM antibodies alone. The levels of the antibodies to ralpha3, tNC1, and the alpha3/alpha1 ratio were lower in the double-positive group than that in patients with anti-GBM antibody alone (P < 0.05). Most of the sera could recognize the epitope regions E(A), E(B), and S2, but the absorbance values to E(A), E(B), and S2 were lower in double-positive group (P < 0.05). Double-positive patients had a broader spectrum of anti-GBM antibodies and lower levels of antibodies against alpha3(IV)NC1 compared with that of patients with anti-GBM antibodies alone.     

MPO-ANCA-positive anti-glomerular basement membrane antibody disease successfully treated by plasma exchange and immunosuppressive therapy

Anti-glomerular basement membrane (GBM) antibody disease is clinically manifested as rapidly progressive glomerulonephritis (RPGN) with crescentic changes. The renal prognosis is poor. We report here the case of a 61-year-old woman with myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive anti-GBM antibody disease. This patient was referred to our hospital because of RPGN. Anti-GBM antibody was positive with a titer of 38 EU. The MPO-ANCA titer was 65 EU. Chest imaging examination revealed pulmonary multiple nodules. ANCA-associated vasculitis was suspected. Renal pathology revealed cellular crescents in 13 out of 17 glomeruli. Immunofluorescence with anti-IgG antibody, anti-C3 antibody, and anti-fibrin antibody showed linear staining along the glomerular capillary walls. Based on these findings, the patient was diagnosed with anti-GBM antibody disease. Hemodialysis was started because of uremic syndrome with elevated serum creatinine (6.84 mg/dL). In addition, treatment with plasma exchange using 3.6 L (90 mL/kg) of fresh frozen plasma combined with an oral dose of 40 mg of prednisolone was initiated. Within 3 weeks, both types of autoantibodies became undetectable. Subsequently, this patient achieved dialysis independence and remission of glomerulonephritis. No adverse effects were observed. In patients with MPO-ANCA-positive anti-GBM antibody disease, intensive therapy predominantly with plasma exchange might be operative, even though renal function is less likely to recover.     

Classic and perinuclear anti-neutrophil cytoplasm antibodies and antimyeloperoxidase antibodies in rapidly progressive glomerulonephritis.

Classic anti-neutrophil cytoplasm antibodies (cANCA), perinuclear ANCA (pANCA) and antibodies directed against myeloperoxidase (MPO-Ab) were evaluated in 25 patients with either idiopathic or secondary rapidly progressive glomerulonephritis (RPGN). While cANCA were found almost exclusively in Wegener's granulomatosis, pANCA were detectable in several disorders, including microscopic polyarteritis (mPA), but also idiopathic RPGN. MPO-Ab were frequently found in sera from patients with all types of idiopathic but not of secondary RPGN. These results support the hypothesis that some cases of RPGN are early or limited forms of systematic vasculitis. We then looked for the presence of IgA-ANCA in Henoch-Schoenlein purpura (HSP): we found IgA-ANCA with immunoenzymatic assay but not with immunofluorescence in HSP, in primary IgA-GN and in membranous GN as well, thus suggesting the poor specificity of this type of ANCA. The possible pathologic implications of ANCA were examined in vitro. Serum samples from several patients with ANCA were assessed for their capacity to enhance chemiluminescence generation from resting or PMA-stimulated macrophages. Sera from RPGN and mPA patients displaying anti-MPO activity induced granulocytes to enhance the production of oxygen free radicals, thus suggesting a phlogistic effect of MPO-Ab positive sera.     

抗肾小球基底膜抗体伴抗中性粒细胞胞浆抗体阳性肾炎(四例报告及文献复习)

目的　了解抗肾小球基底膜抗体（ Ａｎｔｉ Ｇ Ｂ Ｍ） 伴抗中性粒细胞胞浆抗体（ Ａ Ｎ Ｃ Ａ） 阳性患者的临床病理特点。方法　对我科近４ 年来６８ 例 Ａｎｔｉ Ｇ Ｂ Ｍ 和（ 或） Ａ Ｎ Ｃ Ａ 阳性患者进行 Ａｎｔｉ Ｇ Ｂ Ｍ 及 Ａ Ｎ Ｃ Ａ 检测,对其中４ 例两者均阳性患者进行临床病理分析。结果　６８ 例患者中４ 例两者均阳性,占全部 Ａｎｔｉ Ｇ Ｂ Ｍ 阳性患者的２４ ％ ,占全部 Ａ Ｎ Ｃ Ａ 阳性患者的７ ％ 。该４ 例患者 Ａｎｔｉ Ｇ Ｂ Ｍ 的百分结合率较单纯 Ａｎｔｉ Ｇ Ｂ Ｍ 阳性患者低。４ 例中３ 例髓过氧化物酶 Ａ Ｎ Ｃ Ａ（ Ｍ Ｐ Ｏ Ａ Ｎ Ｃ Ａ） 阳性,１ 例蛋白酶３ Ａ Ｎ Ｃ Ａ（ Ｐ Ｒ３ Ａ Ｎ Ｃ Ａ） 阳性,全身系统表现较多,与单纯性 Ａ Ｎ Ｃ Ａ 阳性患者相似。所检病例肾脏病理多为新月体肾炎,免疫荧光检查多为 Ｉｇ Ｇ、 Ｃ３ 呈细颗粒样分布于 Ｇ Ｂ Ｍ。虽经积极治疗,多数患者预后较差,类似单纯 Ａｎｔｉ Ｇ Ｂ Ｍ 肾炎。结论　 Ａｎｔｉ Ｇ Ｂ Ｍ 伴 Ａ Ｎ Ｃ Ａ 阳性患者全身表现类似单纯 Ａ Ｎ Ｃ Ａ 相关小血管炎患者,但治疗效果及预后相对较差又类似于 Ａｎｔｉ Ｇ Ｂ Ｍ 肾炎患者