嗜酸细胞肉芽肿性血管炎抗中性粒细胞胞浆抗体阳性与阴性患者临床特征

嗜酸细胞肉芽肿性血管炎(EGPA)是以外周血和受累脏器组织中嗜酸性粒细胞增高并伴有坏死性肉芽肿为特征的系统性血管炎,依据血清抗中性粒细胞胞浆抗体(ANCA)检测结果可分为ANCA阳性及ANCA阴性表型,ANCA阳性患者更易出现神经系统、肾脏、皮肤紫癜和肺泡出血;心脏和肺受累在ANCA阴性患者中更常见。本文就ANCA阳性与阴性患者的临床表现及受累脏器特征进行文献复习,并综述如下。     

Renal Involvement as Rare Acute Tubulointerstitial Nephritis in a Patient with Eosinophilic Disorder Treated with Early Add-on Administration of Mepolizumab

A 39-year-old man presented with peripheral eosinophilia, pulmonary eosinophilic infiltrate, and renal failure due to acute tubulointerstitial nephritis (TIN). He had experienced childhood asthma and was negative for anti-neutrophil cytoplasmic antibody (ANCA). He was tentatively diagnosed with ANCA-negative eosinophilic granulomatous polyangiitis (EGPA) or idiopathic hypereosinophilic syndrome (HES). Renal involvement of isolated TIN with eosinophil infiltration is rare in EGPA and HES and does not seem to have a good prognosis in the literature. However, his condition improved well with corticosteroids and mepolizumab. The revised classification of EGPA based on the etiology should dictate the proper treatment in suspected EGPA patients with nonsystemic vasculitis.     

Are antineutrophil cytoplasmic antibodies a marker predictive of relapse in Wegener's granulomatosis? A prospective study

OBJECTIVES: To investigate the predictive value of testing for antineutrophil cytoplasmic antibodies (ANCA) in 55 patients with systemic Wegener's granulomatosis (WG) included in a randomized, prospective trial comparing corticosteroids and oral or pulse cyclophosphamide. METHODS: All 55 patients received corticosteroids. A cyclophosphamide pulse of 0.7 g/m2 was given at the time of diagnosis. After the first pulse, the patients were assigned at random to receive either pulse or oral cyclophosphamide (2 mg/kg/day), independently of ANCA results. ANCA were sought using an immunofluorescence assay and an attempt was made to correlate them with relapse of WG. ANCA were monitored throughout the study. RESULTS: At the time of diagnosis, ANCA were detected in 48 (87%) patients, with a cytoplasmic labelling pattern in 44 and a perinuclear pattern in four. ANCA follow-up was available for 50 patients. ANCA disappeared in 34 patients and persisted in nine. For 79% of the patients, the clinical course improved with the disappearance of ANCA and deteriorated with their persistence or increased titre. Among the patients who were initially ANCA-positive, 23 relapses occurred. Relapses were more frequent when ANCA remained positive or reappeared [13/19 ANCA-positive patients vs 3/29 ANCA-negative patients (P<0.01)]. Nine relapses (39%) occurred in patients with persistent ANCA, and ANCA reappearance preceded relapse in eight (35%). The mean time between inclusion and relapse did not differ between the patients who became ANCA-negative and those who were persistently ANCA-positive (14.6+/-13.2 vs 14.4+/-8.2 months). The mean time to ANCA disappearance was similar for the patients who relapsed and those who did not. Corticosteroids and pulse or oral cyclophosphamide did not significantly modify the time to ANCA disappearance. Throughout the study, seven patients were ANCA-negative. CONCLUSION: Although ANCA positivity was associated with relapse, discordance between cytoplasmic ANCA and disease activity was not unusual. In the absence of clinical manifestations, ANCA titres alone can serve as a warning signal but not indicate whether to adjust or initiate treatment.     

Characteristics and Diagnostic Challenge of Antineutrophil Cytoplasmic Antibody Positive Infective Endocarditis

ObjectiveAntineutrophil cytoplasmic antibody (ANCA) has been reported in patients with infective endocarditis. Whether ANCA is associated with certain characteristics of infective endocarditis is unclear. The principal aim of this study is to investigate the clinical implications of ANCA in infective endocarditis and highlight the diagnostic challenge in ANCA-positive patients with infective endocarditis.MethodsA retrospective study was conducted in a tertiary hospital in China from August 2012 to December 2021. Patients with a diagnosis of infective endocarditis and available ANCA results were included in the study. The clinical and pathological characteristics were compared between ANCA-positive and ANCA-negative patients.ResultsA total of 237 patients were included. Forty three (18.1%) were ANCA-positive, predominantly c-ANCA/anti-PR3. Compared to ANCA-negative patients, ANCA-positive patients had longer disease duration (P = .004), more frequent purpura (P = .015), macrohematuria (P = .002), proteinuria (P = .043), acute kidney injury (P = .004), and rapidly progressive glomerulonephritis (P = .010). Histologic findings of 8 patients with infective endocarditis-associated glomerulonephritis were reviewed. Two ANCA-positive patients with infective endocarditis presented with pauci-immune necrotizing and crescentic glomerulonephritis. A total of 18.6% of ANCA-positive patients with infective endocarditis were misdiagnosed as ANCA-associated vasculitis.ConclusionsANCA is detected in a substantial proportion of patients with infective endocarditis. The presence of ANCA in infective endocarditis is associated with longer disease duration, more frequent purpura, and kidney involvement. ANCA-positive infective endocarditis may mimic ANCA-associated vasculitis, and the differential diagnosis is challenging. Whether ANCA is pathogenic in infective endocarditis-associated small vessel vasculitis requires further study.     

A historical study of American patients with anti-neutrophil cytoplasmic antibody negative pauci-immune glomerulonephritis

Anti-neutrophil cytoplasmic antibodies (ANCA) play an important role in the pathogenesis of ANCA-associated vasculitis. The lack of ANCA antibodies may indicate a variation in clinical presentation and outcomes of this disease. We identified 74 adult patients between 1995 and 2009 with the diagnosis of pauci-immune glomerulonephritis. Demographics, histological features, and treatment outcomes were compared between ANCA-positive and ANCA-negative patients. These factors were correlated with renal function at presentation and follow-up. Of the 74 patients, 57 were ANCA-positive, and 17 were ANCA-negative. Demographics and mean Birmingham Vasculitis Activity Score were similar between ANCA-negative and ANCA-positive patients at presentation. Renal function was significantly worse at presentation in the ANCA-negative patients (eGFR 16.59 vs. 31.89 ml/min/1.73 m², p?=?0.03). Patients in the ANCA-negative group had a significantly higher interstitial fibrosis score compared to the ANCA-positive group (2.1 vs.1.6, p?=?0.04). The median time to remission was shorter in the ANCA-negative patients (51 vs. 78 days, p?=?0.01). Long-term renal function and 1-year patient and renal survival were similar between ANCA-negative and ANCA-positive patients. Baseline eGFR, percentage of normal glomeruli, glomerular sclerosis, and tubulointerstitial scarring predicted eGFR at 1 year in both groups similarly. This is the first historical review of American patients with pauci-immune glomerulonephritis, comparing patients with ANCA-negative and ANCA-positive serology. Although ANCA-negative patients present with lower eGFR and more interstitial fibrosis, 1-year and long-term outcomes in both groups are similar.     

Prevalence of rheumatic manifestations and antineutrophil cytoplasmic antibodies in haematological malignancies. A prospective study

OBJECTIVE: To evaluate the prevalence of antineutrophil cytoplasmic antibodies (ANCA) and rheumatic manifestations associated with chronic haematological malignancies. METHODS: Two groups of patients were prospectively studied (group I: 60 patients with myelodysplastic syndromes and group II: 140 patients with lymphoid malignancies) for clinical 'immune' manifestations and ANCA. RESULTS: In the myelodysplastic group, six patients had ANCA-negative systemic medium-size vasculitis, one had systemic vasculitis with cytoplasmic ANCA, one relapsing polychondritis, one giant cell arteritis, one polymyalgia rheumatica, one polyarthritis and two fasciitis. In group II, two patients had ANCA-negative systemic vasculitis, two had leucocytoclastic vasculitis associated with tuberculosis, two had polyarthritis, one polymyalgia rheumatica and one giant cell arteritis. Six sera were ANCA-positive with perinuclear pattern in four cases, atypical pattern in one and cytoplasmic pattern in one. Two sera had anti-myeloperoxidase (MPO) specificity, and others had no known specificity; none had anti-proteinase 3 (PR3) specificity. Global prevalence of ANCA in our cohort was 3%, similar to the French general population. CONCLUSION: Polyarteritis nodosa-type systemic vasculitis and polymyalgia rheumatica were the most frequent findings (18%) in myelodysplastic syndromes and particularly in chronic myelomonocytic leukaemia. ANCA were not helpful for the diagnosis of vasculitis. Vasculitis associated with infection, in particular tuberculosis, must be ruled out.     

Antineutrophil cytoplasmatic antibodies in patients with premature atherosclerosis: prevalence and association with risk factors

OBJECTIVES: Autoimmunity is suggested to play a role in premature atherosclerosis. Antineutrophil cytoplasmatic antibodies (ANCA) are a group of autoantibodies found in several inflammatory disorders in which they supposedly amplify the inflammatory process. In this study the hypothesis is tested that ANCA play a role in premature atherosclerosis. DESIGN: Cross-sectional study followed by nested case-control study. In a total of 286 consecutive patients with premature atherosclerosis (age < 55 years) ANCA were tested. Within the same cohort, a nested case-control study in 16 ANCA-positive patients and 32 ANCA-negative controls matched for sex, and site of atherosclerosis, was executed. SETTING: University hospital outpatient clinic for lipids and premature atherosclerosis. SUBJECTS: A total of 286 consecutive patients with premature atherosclerosis (age < 55 years). RESULTS: Prevalence of ANCA was 5.6% (16 of 286). All cases had perinuclear ANCA (pANCA); no cytoplasmatic ANCA was found. Mean age was 42 +/- 7 in the ANCA-positive vs. 42 +/- 9 years in the ANCA-negative group (P=ns). More female parents were ANCA-positive (8M/8F vs. 200M/70F, P=0.03). Patients with ANCA had more often peripheral vascular disease (37.5 vs. 15.2%, P=0.03). In the case-control study levels of Lp(a) were higher (43.8 vs. 15.6% >300 mg x L(-1), P=0.05), whereas levels of HDL-c were lower in ANCA-positive patients (0.84 +/- 0.26 vs. 1.06 +/- 0.27 mmol x L(-1), P=0.01). Markers of inflammation, C-reactive protein (CRP) and serum amyloid A (SAA), did not differ, nor did antibodies against oxidized-LDL and malondialdehyde (MDA)-LDL, markers for the extent of atherosclerosis. CONCLUSIONS: Our results suggest that ANCA do not appear to play a major role in premature atherosclerosis as there was no increased prevalence of the autoantibody. Moreover, no differences in the incidence of classical cardiovascular risk factors nor in serum levels of markers of inflammation were found between the ANCA-positive group as compared with the ANCA-negative group.     

Severe cardiomyopathy revealing antineutrophil cytoplasmic antibodies‐negative eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of systemic vasculitis in which cardiac involvement is frequent and severe, and accounts for half of EGPA‐related deaths. ANCA‐positive EGPA differs from ANCA‐negative EGPA in that the former is significantly associated with renal involvement, peripheral neuropathy and biopsy proven vasculitis, whereas the latter is associated with cardiac involvement. Herein, we report a case of EGPA with myocarditis in a woman, who was successfully treated with steroids and cyclophosphamide. This report highlights the importance of diagnosing cardiac involvement in EGPA early, especially in ANCA‐negative patients.     

嗜酸性肉芽肿性多血管炎146例患者临床特征分析

目的:分析和总结嗜酸性肉芽肿性多血管炎(EGPA)的临床特征。方法:收集2000年至2019年北京协和医院确诊的146例EGPA住院患者资料,回顾性分析其临床表现、实验室检查、辅助检查、治疗、并发症及转归。结果:146例患者中男93例,女53例,年龄(41.7±16.1)岁,发病至确诊时间为0.5~450个月,中位时间18(6,60)个月。以肺部[121例(82.9%)]、鼻与鼻窦[119例(81.5%)]受累最多见;血清抗中性粒细胞胞质抗体(ANCA)阳性者36例(24.7%),以核周型或髓过氧化物酶ANCA为主。ANCA阳性者肾脏(66.7%比20.9%,P<0.001)、神经系统受累比例(80.6%比51.8%,P<0.001)明显高于ANCA阴性者,更易出现发热(66.7%比40.9%,P<0.05)及视神经病变(8.3%比0,P<0.05),疾病活动度更高[中位伯明翰血管炎活动度评分25(18,30)比19(14,24),P=0.001],红细胞沉降率[40.5(20.5,82.8)mm/1 h比25.0(13.3,50.8)mm/1 h,P=0.006]和超敏C反应蛋白[37.1(11.8,72.9)mg/L比13.5(3.4,66.1)mg/L,P=0.036]显著升高;而ANCA阴性者胸腔积液比例高于ANCA阳性者(20.9%比5.6%,P=0.04)。治疗以糖皮质激素和环磷酰胺为主。12例(8.2%)患者病情缓解,6例(4.1%)患者死亡或放弃治疗。并发症以肺部感染最多见。结论:EGPA是一种少见的血管炎,临床表现与转归异质性强,病死率高。     

抗中性粒细胞胞浆抗体阴性的少免疫沉积型新月体性肾小球肾炎15例分析

目的　了解抗中性粒细胞胞浆抗体 (ANCA)阴性的少免疫沉积型新月体肾炎的临床病理特点。方法　对近 10年来诊断为少免疫沉积型新月体肾炎患者进行ANCA检测 ,并对其中ANCA阴性患者进行临床病理分析。结果　 33例少免疫沉积型新月体肾炎中 ,ANCA阴性患者 15例 ,占 4 5 % ,为同期所有新月体肾炎的15 %。其中 9例伴多系统受累 ,6例仅累及肾脏。 2例患者病理可见小血管炎。经积极治疗 ,1/13例临床痊愈 ,6 /13例临床缓解 ,6 /13例无效。结论　ANCA阴性少免疫沉积型新月体肾炎在临床、病理上与ANCA阳性病人相似 ,但好发年龄偏低 ,预后相对较差     

Two subtypes of Churg–Strauss syndrome with neuropathy: the roles of eosinophils and ANCA

The aim of this study was to clarify the differences in the pathogenesis of neuropathy between myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive and -negative patients with Churg–Strauss syndrome (CSS). Eight MPO-ANCA-positive and 14 MPO-ANCA-negative patients were included. In addition to the standard histology, nerve biopsies were examined, employing immunohistochemistry for eosinophil major basic protein and electron microscopy. The groups did not differ significantly in clinical profiles, including the peak disability score and number of blood eosinophils. In nerve biopsies, necrotizing vasculitis was found in 63% (5/8) of the ANCA-positive and 21% (3/14) of the ANCA-negative patients. Fibrinoid necrosis of vessel walls was noted in 4 ANCA-positive patients (50%), and in one ANCA-negative patient (p = 0039). In contrast, a large number of eosinophilic infiltrations in the epineurium was shown in 36% (5/14) of the ANCA-negative patients, with no eosinophilic infiltrations shown in ANCA-positive patients. In 3 ANCA-negative patients, endoneurial eosinophils were seen where focal axonal loss and capillary dilatation were occasionally noted. There may be 2 pathogenetic mechanisms of neuropathy with CSS: ANCA-related vascular fibrinoid necrosis, and a toxic eosinophilic effect on nerve fibers which is independent of ANCA. Therapy targeting activated eosinophils may be a possible treatment for intractable neuropathy of CSS.     

Plasma levels of soluble interleukin 2 receptor, soluble CD30, interleukin 10 and B cell activator of the tumour necrosis factor family during follow-up in vasculitis associated with proteinase 3-antineutrophil cytoplasmic antibodies: associations with disease activity and relapse

OBJECTIVES: To evaluate whether T cell activation, as reflected by levels of soluble interleukin 2 receptor (sIL2R), soluble CD30 (sCD30), IL-10 and B cell activator of the tumour necrosis factor family (BAFF) at diagnosis and during initial follow-up, is predictive for persistent or renewed antineutrophil cytoplasmic antibody (ANCA) positivity and clinical relapse in patients with vasculitis associated with proteinase 3-antineutrophil cytoplasmic antibodies (PR3-ANCA). METHODS: 87 Patients with PR3-ANCA-associated vasculitis and at least 2 years of follow-up were included in the study. At diagnosis, and at 3, 6, 12, 18 and 24 months after diagnosis, cytoplasmic ANCA titres were detected by indirect immunofluorescence (IIF), and PR3-ANCA, sIL2R, sCD30, IL-10 and BAFF levels were assessed by ELISA. 31 healthy volunteers provided plasma samples for comparison. Levels of immune markers were related to ANCA positivity and relapse during follow-up. RESULTS: Plasma levels of sIL2R, sCD30 and BAFF were higher in patients than in controls at all time points. Plasma levels of sIL2R, sCD30 and IL-10 were higher at diagnosis and relapse than during remission. At 18 months, sCD30 (p<0.001) and sIL2R levels (p = 0.01) were significantly higher in PR3-ANCA-positive patients (detected by ELISA) than in PR3-ANCA-negative patients. ANCA-positive patients detected by ELISA or IIF at 24 months had significantly higher plasma sCD30 levels (p = 0.02 and p = 0.03, respectively) than ANCA-negative patients. CONCLUSION: Increased T cell activation in patients with ANCA-associated vasculitis in remission during and after immunosuppressive treatment is associated with persistent or renewed ANCA positivity.     

Severe eosinophilic granulomatosis with polyangiitis responding to a combination of rituximab and mepolizumab

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss Syndrome, is a multisystem antineutrophil cytoplasmic antibody (ANCA) positive vasculitis, characterized by the presence of chronic rhinosinusitis, asthma and prominent peripheral blood eosinophilia. Although the most commonly involved organ is the lung, followed by the skin, EGPA can affect any organ system. Herein, we present the complicated case of an 18-year-old male patient with severe life-threatening EGPA, with central nervous system, cardiac and gasterointestinal involvement, which was resistant to initial treatment with glucocorticoids and cyclophosphamide. The patient responded well, achieving complete remission after the addition of rituximab and mepolizumab to glucocorticoids and cyclophosphamide.     

Antineutrophil cytoplasmic antibodies reacting with human neutrophil elastase as a diagnostic marker for cocaine-induced midline destructive lesions but not autoimmune vasculitis

OBJECTIVE: Human neutrophil elastase (HNE) and proteinase 3 (PR3) are structurally and functionally related. PR3 is the prominent target antigen for antineutrophil cytoplasmic antibodies (ANCAs) in Wegener's granulomatosis (WG). Reported frequencies of HNE ANCAs in WG and other autoimmune diseases range from 0% to 20%. We previously detected HNE ANCAs in patients with cocaine-induced midline destructive lesions (CIMDL). We tested the hypothesis that discrepancies in the reported frequencies of HNE ANCAs in patients with vasculitis may be related to differences in detection methods, and that HNE ANCA may be a marker for CIMDL. METHODS: HNE ANCA reactivity in 25 patients with CIMDL was characterized and compared with that in a control cohort of 604 consecutive patients (64 with WG, 14 with microscopic polyangiitis [MPA], and 526 others) and 45 healthy volunteers. HNE ANCAs were measured by indirect immunofluorescence using a previously undescribed expression system for recombinant HNE and by direct and capture enzyme-linked immunosorbent assays using purified native HNE as target antigen. RESULTS: Among patients with CIMDL, HNE ANCAs were detectable by 1 assay in 84%, by 2 assays in 68%, and by all 3 assays in 36%. Fifty-seven percent of HNE ANCA-positive CIMDL sera were also PR3 ANCA-positive by at least 1 assay. In contrast, only 8 (1.3%) of 604 control sera reacted with HNE in at least 1 assay, 3 (0.5%) reacted in 2 assays, and only 1 serum sample (0.16%) reacted in all 3 assays. Sera obtained from patients with WG or MPA were universally HNE ANCA-negative, as were sera obtained from healthy controls. CONCLUSION: Optimal sensitivity for HNE ANCA requires multimodality testing. HNE ANCAs are frequent in CIMDL but not in other autoimmune diseases, including classic ANCA-associated vasculitis. HNE ANCAs may discriminate between CIMDL and WG, whereas a positive test result for PR3 ANCA may not.     

Polymorphisms in tumour necrosis factor and adhesion molecule genes in patients with inflammatory bowel disease: associations with HLA-DR and -DQ alleles and subclinical markers

BACKGROUND: When investigating susceptibility to inflammatory bowel disease (IBD), a multifactorial disorder with a genetic predisposition, polymorphisms of molecules with immunoregulatory function are of potential interest. This is the first time that the polymorphisms of HLA-DR and -DQ, tumour necrosis factor (TNF), E-selectin (CD62E), L-selectin (CD62L), and intercellular adhesion molecule 1 (ICAM-1, CD54) were determined in Estonians, a population with a low IBD incidence rate, and their occurrence investigated in subgroups of a total of 53 IBD patients. METHODS: The reverse hybridization principle and sequence specific primers were used for HLA genotyping. To analyse the TNF and adhesion molecule polymorphisms, the polymerase chain reaction with subsequent restriction fragment length polymorphism or single-strand conformation polymorphism method was used. RESULTS: In the subgroup of antineutrophil cytoplasmic antibody (ANCA)-positive ulcerative colitis (UC) patients we found a higher frequency of the TNF2 (20.8% versus 0.0% in ANCA-negative UC patients, P = 0.051) and HLA-DRB1*15 allele (35.4% versus 15.7% in controls; P = 0.004). Of ANCA-positive UC patients 87.5% were carriers of one of these alleles (22.2% among ANCA-negative UC patients (P<0.001, Pc = 0.039) and 51.4% among controls (P = 0.002). Specific typing of HLA-DRB1*15 alleles showed that the HLA-DRB1*1501 allele was responsible for the HLA-DRB1*15 association with ANCA-positive UC. Associations of ICAM-1, E-selectin, or L-selectin polymorphisms with IBD were not found. CONCLUSIONS: TNF2 and HLA-DRB1*15 alleles were associated with ANCA-positive UC in the investigated population. ANCA might be a useful marker, at least in some ethnic groups, for dividing IBD patients into genetically more homogeneous subgroups.     

Relationship between anti-neutrophil cytoplasmic antibody determined with conventional binding and the capture assay, and long-term clinical course in vasculitis

OBJECTIVES: To evaluate the relationship between anti-neutrophil cytoplasmic antibody (ANCA) measured with two different methods and long-term clinical course in vasculitis. DESIGN: Retrospective determination of ANCA with two different assays for detection of PR3-ANCA, conventional direct binding ELISA and capture ELISA using monoclonal antibodies against PR3. The 245 ANCA determinations were performed from frozen blood samples collected three to four times a year in each patient. SETTING: Department of Nephrology at a Swedish University Hospital. SUBJECTS: A total of 10 ANCA-positive patients with vasculitis caused by Wegener's granulomatosis (WG) or microscopic polyarteritis (MPA) and a very long follow-up time (mean 9 years, range 5-15.5 years). RESULTS: The total number of episodes with active vasculitis was 29 and all of them (100%) were detected by the capture technique whilst the conventional technique detected 23 (79%). The mean number of episodes with active disease requiring treatment with steroids and cytotoxic drugs was three per patient (range 1-6). At the time of clinical relapse of the vasculitis disease, the ANCA titre using the capture technique was either increasing or showed a very high value in all cases. The pattern of capture ANCA response could be subdivided into three categories: a close (four patients), an intermediate (three patients), and no (three patients) relationship between capture ANCA level and long-term clinical course. CONCLUSION: Detection of PR3-ANCA by the capture ELISA showed a higher sensitivity than that obtained by the direct ELISA in diagnosing relapse during follow-up of patients with vasculitis. The specificity of the capture ANCA was, however, low, as high levels occurred in patients without clinical disease activity.     

Anti-neutrophil cytoplasmic antibodies and their clinical significance

Anti-neutrophil cytoplasmic antibodies (ANCA) are a group of autoantibodies that cause systemic vascular inflammation by binding to target antigens of neutrophils. These autoantibodies can be found in serum from patients with systemic small-vessel vasculitis and they are considered as a biomarker for ANCA-associated vasculitis (AAV). A conventional screening test to detect ANCA in the serum is indirect immunofluorescence study, and subsequently confirmed by enzyme-linked immunosorbent assay. A positive staining of ANCA can be classified into three main categories based on the staining patterns: cytoplasmic, perinuclear, and atypical. Patients with granulomatosis with polyangiitis (GPA) mostly have a positive cytoplasmic staining pattern (c-ANCA) whilst a perinuclear pattern (p-ANCA) is more common in microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA) patients. Atypical pattern (a-ANCA) is rarely seen in patients with systemic small-vessel vasculitis but it can be found in other conditions. Here, techniques for ANCA detection, ANCA staining patterns and their clinical significances are reviewed.     

Clinical value of antineutrophil cytoplasmic antibodies

This article presents a brief review of the clinical value of antineutrophil cytoplasmic antibodies (ANCA) in the diagnosis and management of patients with various forms of vasculitis. ANCA assay methodology and testing recommendations are reviewed. The patterns of reactivity of ANCA observed by indirect immunofluorescence, the antigens recognized by ANCA, and the sensitivity, specificity, and positive predictive value of ANCA for diagnosis of different vasculitides are described. In addition, the spectrum of drugs and nonvasculitic diseases that are associated with ANCA and need to be differentiated from true ANCA-positive vasculitides are reviewed. When properly utilized and cautiously interpreted, ANCA are a useful, noninvasive diagnostic tool in the differential diagnosis of vasculitis.     

Alternating antineutrophil cytoplasmic antibody specificity: drug-induced vasculitis in a patient with Wegener's granulomatosis

We describe a patient who presented with Wegener's granulomatosis associated with antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) with a cytoplasmic immunofluorescence pattern (cANCA), whose ANCA type changed to antimyeloperoxidase antibodies with a perinuclear immunofluorescence pattern (pANCA) when treated with propylthiouracil, and changed back to anti-PR3 antibodies with cANCA after the medication was discontinued. The patient developed flares of vasculitis symptoms associated with rises in either type of ANCA. Tests for antimyeloperoxidase ANCA were repeatedly negative before the drug was started, strongly implicating the drug as the cause of the episode. This case demonstrates that patients with idiopathic ANCA-positive vasculitis may quickly develop a superimposed drug-associated ANCA-positive vasculitis. Iatrogenic vasculitis should be suspected when a patient with idiopathic vasculitis with one type of ANCA develops the other type of ANCA.     

A diagnostic score for eosinophilic granulomatosis with polyangiitis among eosinophilic disorders

BackgroundEosinophilic granulomatosis with polyangiitis (EGPA) is a form of systemic vasculitis with eosinophilic inflammation. However, existing classification criteria are all designed to classify EGPA among vasculitis and there is no established method distinguishing EGPA from other eosinophilic disorders. The aim of the present study was to propose a scoring system to differentiate EGPA among eosinophilic disorders.MethodsNon-supervised hierarchical clustering using Ward's method and principal component analysis (PCA) were performed for 19 clinical parameters of 58 patients with eosinophilia-related diseases at a tertiary university hospital. The newly proposed scoring system was externally validated in 40 patients at another tertiary institution.ResultsTwo distinct clusters were identified, and clinical features including peripheral neuropathy, asthma, skin involvement, lung involvement, rheumatoid factor (RF) positivity, myeloperoxidase (MPO)–anti-neutrophil cytoplasmic antibody (ANCA) positivity, IgE elevation, C-reactive protein (CRP) elevation, and vasculitis pathological findings were predominantly observed in one of these clusters (p < 0.05). Ten features defining the cluster with a high rate of vasculitis were weighted by PCA to create the E-CASE (EGPA classification among systemic eosinophilia) scoring system, on a 16-point scale. Based on the distribution of scores in the primary cohort, we defined an E-CASE score ≥12 as positive, ≤ 8 as negative, and 9–11 as undeterminable. The sensitivity and specificity of the E-CASE score in the validation cohort were 93.3% and 100%, respectively.ConclusionsWe developed and verified a novel scoring system for differentiating EGPA from other types of eosinophilic disorders.