Association of IgM with IgG ANCA in patients presenting with pulmonary hemorrhage.

ANCA are markers for systemic vasculitis such as Wegener's granulomatosis (WG) and microscopic polyarteritis (MPA) and are usually of the IgG isotype. However, IgM ANCA may rarely occur in isolation, and in these circumstances, we have found that they are associated clinically with a syndrome of pulmonary hemorrhage and systemic vasculitis. How frequently IgM ANCA may occur in conjunction with IgG has not previously been investigated. We report here a study of 24 consecutive patients with IgG ANCA-positive systemic vasculitis (14 WG, 10 MPA) in whom we determined whether IgM ANCA occurred in association with IgG ANCA, and if so, whether this had clinical importance. Eight patients were found to have IgM ANCA as well as IgG ANCA, and of these, seven presented with severe pulmonary hemorrhage. None of the IgM ANCA-negative patients presented with pulmonary hemorrhage. Although the occurrence of pulmonary hemorrhage in ANCA positive vasculitis was closely correlated with the presence of IgM ANCA, the antigen specificity of these IgM autoantibodies was variable, since both myeloperoxidase (4 patients), PR3 (3 patients), and an unknown ANCA antigen (1 patient) were found to be targets. We conclude that knowledge of ANCA isotype may have important clinical and therapeutic implications for the management of patients with systemic vasculitis.     

Serial ANCA titers: useful tool for prevention of relapses in ANCA-associated vasculitis

BACKGROUND: The value of measuring serial antineutrophil cytoplasmic autoantibody (ANCA) titers in guiding therapy among patients with ANCA-associated vasculitis is controversial. METHODS: We measured serial titers of proteinase 3 (PR3)- and myeloperoxidase (MPO)-ANCA by antigen-specific enzyme-linked immunosorbent assays (ELISAs) in 48 patients with ANCA-associated vasculitis who were followed up during remission at the Massachusetts General Hospital from 1990 through 2000 (mean follow-up, 46.2 months). We retrospectively assessed disease activity by Birmingham Vasculitis Activity Score (BVAS). RESULTS: We found 21 episodes of fourfold or greater ANCA titer rises in 17 patients who were in complete remission (BVAS=0). Among eight patients who had 10 such titer rises and were not given increased immunosuppression, (group I), all suffered relapses after each episode (mean interval, 5.8 months), whereas among 11 patients, each with one titer rise, who received preemptive increased immunosuppression, (group II), only two relapses occurred, at 3 and 6 months. The difference in the cumulative incidence of relapses in a 1-year period between the two groups was 82% (P=0.0002). Changes in ANCA titers were also used to help guide therapy in the other 31 patients in the study; patients with slight titer rises often received incremental increases in immunosuppression, whereas those with falling titers received incremental decreases. The overall outcome in the entire group was favorable; 46 patients were alive at the end of the study; two died of unrelated diseases. CONCLUSION: Serial measurements of PR3- and MPO-ANCA titers in patients with ANCA-associated vasculitis during remission can help predict relapses, and preemptive increases in immunosuppression following fourfold titer rises reduces the risk of relapses. Moreover, adjustment of immunosuppression based on lesser titer changes appears to result in a favorable outcome.     

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.     

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)     

Pathogenesis of primary systemic vasculitides (I): ANCA-positive vasculitides

The pathogenesis of different types of systemic vasculitis positive for antineutrophil cytoplasmic antibodies (ANCA) remains incompletely understood. ANCA constitute a heterogeneous group of antibodies that are associated with different types of small-vessel vasculitis, including Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg-Strauss syndrome (CSS). Anti-proteinase 3 ANCA are present in more than 90% of patients with systemic WG, and anti-myeloperoxidase (MPO) ANCA in 50-75% of those with MPA and 40-60 % of those with CSS. The pathogenic role of ANCA has been well documented in vivo: passive transfer of anti-MPO ANCA in an MPO knockout mouse model immunized with MPO is sufficient to induce the disease. In vitro, mouse and human anti-proteinase 3 ANCA can activate neutrophils primed with TNF-a and contribute to vasculitic lesions. T-cells are also involved: type 1 helper cytokines have been detected in tissue lesions of limited forms of WG, while type 2 helper cytokines have been identified in its systemic forms. Eosinophils may play a key role in the development of vasculitic lesions in CSS, although this remains to be proved.     

Clinical features and outcomes of ANCA-associated renal vasculitis

To determine the patterns and outcomes of the pauci-immune vasculitis in the nephrology department at hospital La Conception in Marseille, we conducted a retrospective study including all patients with diagnosis of pauci-immune renal vasculitis between January 1, 2000 and December 31, 2007. Among 33 cases, 25 were diagnosed as Wegener granulomatosis (WG), seven as microscopic polyangitis (MPA) and one as Churg-Strauss syndrome (SCS). The median age of the patients was 57.7 years and the sex-ratio (M/F) was 1.6. The visceral manifestations included kidneys (100% of patients), lungs (75%), ENT (52% of WG), and nervous system (57% of MPA). The mean serum creatinine at admission was 3.3 mg/dL. Renal biopsies revealed a pauci-immune crescentic gromerulonephritis in 96% of the cases. Two patients with WG received plasmapheresis and seven patients required emergency hemodialysis. Induction therapy comprised cyclophosphamide IV and corticosteroids, while maintenance therapy included azathioprine for the majority of patients. Eighty four percent of the patients experienced complete remission after induction therapy. During maintenance therapy relapses were more frequent among patients with MPA (28%) compared to WG cases (12%). After 35 months of follow-up, eight patients ended on chronic hemodialysis, and five patients died. ANCA associated vasculitis are frequent in our patients. Long-term outcomes are relatively good despite a mortality rate of 15% and 25% of the patients entering dialysis after three years of follow-up.     

Remittent non-destructive polysynovitis in P-ANCA-positive vasculitis patients with anti-CCP antibodies

Patients with antineutrophil cytoplasm antibodies (ANCA)-associated vasculitis (AASV) commonly suffer from arthralgias and, sometimes, polyarthritis during disease flares. Although rheumatoid factor (RF) can be detected in up to 37–50% of AASV patients, anti-cyclic citrullinated peptide (anti-CCP) antibodies are rare. Herein, we describe the clinical features of five P-ANCA–positive vasculitis patients, who had persistent and/or high anti-CCP levels and, more importantly, suffered from remittent non-destructive arthralgias and polysynovitis, independently of the vasculitis course and without evidence of RA. Two were initially thought to have RA rather than microscopic polyangiitis and, at AASV diagnosis, all had kidney involvement and three had alveolar hemorrhages. With a median follow-up of 30 months, one suffered vasculitis relapses, preceded by polysynovitis, and others had remittent arthralgias and polysynovitis, while their vasculitides remained in remission. None of these patients had radiological destructive arthritis. We discuss the challenge of diagnosing these patients positive for anti-CCP and ANCA, and with dominant articular manifestations. AASV patients with anti-CCP antibodies may experience relapsing polysynovitis and non-erosive polyarthritis prior to vasculitis flares, but also independently of the vasculitis course, which is uncommon in AASV, and might represent a small subgroup of AASV patients.     

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.     

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.     

IgG subclass distribution, affinity of anti-myeloperoxidase antibodies in sera from patients with Wegener's granulomatosis and microscopic polyangiitis

Aim: Our previous study suggested that patients with MPO-ANCA (myeloperoxidase antineutrophil cytoplasmic autoantibodies)-positive Wegener's granulomatosis (WG) were common in Chinese, indicating that patients with MPO-ANCA could manifest as either WG or microscopic polyangiitis (MPA). The aim of this study was to compare the immunological characteristics of MPO-ANCA in patients with WG and MPA. Methods: Fifteen patients with WG and 21 patients with MPA were enrolled in the current study. Anti-MPO IgG subclasses and their titres were detected by antigen-specific enzyme-linked immunosorbent assays (ELISA); affinity was assessed by antigen-inhibition ELISAs. The sera from all patients were employed to inhibit biotin conjugated affinity-purified human anti-MPO antibodies (Probe-biotin), from plasma exchange of a patient with MPA, in a competitive inhibition ELISAs system. Results: All four anti-MPO subclasses could be detected in sera from patients with WG and MPA. The titres of anti-MPO IgG4 subclass in patients with WG were significantly higher than those with MPA (1:1878 vs 1:218, P < 0.005). The affinity constants of MPO-ANCA were comparable between patients with WG and MPA (0.3–70/M vs 0.3–140/M respectively). Eleven out of the 15 sera and 18 out of the 21 sera could inhibit the binding of the Probe-biotin in patients with WG and MPA respectively. The average inhibition rate was 47.7% ± 11.5% and 61.7% ± 14.5% respectively (P < 0.05). Conclusion: MPO-ANCA IgG4 subclass might play a role in the development of WG. The MPO-ANCA in WG and MPA might recognize overlapping but different epitopes on native MPO molecule. The difference in immunological characteristics of MPO-ANCA might contribute to different disease entities.     

阻断IgG-Fcγ受体结合的短肽对粒细胞与内皮细胞黏附及内皮细胞细胞间黏附分子1表达的影响

目的 观察阻断IgG-FcγR结合的短肽tg19320对粒细胞与内皮细胞黏附以及内皮细胞细胞间黏附分子1（ICAM-1）表达的影响，并探讨其作用机制。 方法 培养人脐静脉内皮细胞（HUVEC）。提纯活动期血管炎患者血清抗中性粒细胞胞质抗体（ANCA） IgG。以多肽固相合成tg19320。分离健康人新鲜外周血中性粒细胞。分别以肿瘤坏死因子α（TNF-α）、健康人IgG、ANCA IgG及ANCA IgG+tg19320处理HUVEC，用细胞直接计数法检测粒细胞与内皮细胞间的黏附率；应用Western印迹及实时定量PCR方法检测HUVEC ICAM-1蛋白和mRNA表达；ELISA检测细胞培养上清液中可溶性ICAM-1（sICAM-1）的水平；Western印迹检测HUVEC磷酸化核因子κB抑制物（p-IκB）的表达。 结果 ANCA IgG显著上调中性粒细胞与内皮细胞间的黏附率（P ＜ 0.05），但ANCA IgG+tg19320组较ANCA IgG组黏附率显著降低（P ＜ 0.05）。ANCA IgG组与健康人IgG组相比，HUVEC ICAM-1 mRNA及蛋白表达显著增加（P ＜ 0.05）。tg19320分别从mRNA和蛋白水平阻断ANCA对ICAM-1的作用（P ＜ 0.05），并显著降低ANCA IgG引起的细胞培养上清液中sICAM水平增高（P ＜ 0.05）。ANCA IgG增加HUVEC p-IκB表达，tg19320显著降低p-IκB的表达。 结论 tg19320通过抑制IκB磷酸化进而干预NF-κB活化；抑制ANCA IgG对内皮细胞与中性粒细胞间黏附的促进作用，并阻断ICAM-1上调表达。短肽tg19320对原发性小血管炎具有体外保护作用。     

Clinical significance of autoantibodies against neutrophil cytoplasmic components in patients with renal disease

The diagnostic significance of anticytoplasmic autoantibodies (ANCA) was studied in 71 renal patients. The ANCA test was positive in 67% of patients with Wegener's granulomatosis (WG), in 35% of those with a simultaneous renal and respiratory tract disease but not diagnosed as WG and in 22% of patients with a renal disease associated with unspecific collagenosis/vasculitis. Among WG patients ANCA positivity clearly correlated with the presence of active renal disease. Interestingly, both ANCA-positive and -negative patients were encountered in the group with acute renal failure and acute extracapillary glomerulonephritis associated with diffuse pulmonary infiltrates. The diagnostic and clinical significance of the ANCA test in these cases remains for the present obscure. In the majority of the ANCA-positive renal patients with respiratory tract abnormalities, the antibodies showed diffuse cytoplasmic staining and were mostly of the IgG class, of both IgG and IgM classes in some cases and of IgG, IgM and IgA classes in 1 patient. In patients with unspecific vasculitis/collagenosis the level of ANCA was rather low, and the distribution of different isotypes resembled that of patients with respiratory symptoms. A certain isotype of ANCA or staining pattern did not mark out any clinicopathologic subgroup among the patients. Our findings indicate that the clinical picture of ANCA-positive patients varies considerably and the ANCA test may not be as specific a marker of WG as previously suggested.     

Mycophenolate mofetil for maintenance therapy of Wegener's granulomatosis and microscopic polyangiitis: a pilot study in 11 patients with renal involvement.

Successful maintenance therapy with mycophenolate mofetil (MMF) 2 g/d and low-dose oral corticosteroids (OCS) over a period of 15 mo was given to patients with Wegener's granulomatosis (WG) (n = 9) and microscopic polyangiitis (MPA) (n = 2). All patients had severe generalized disease with pauci-immune necrotizing glomerulonephritis and received standard induction therapy with oral cyclophosphamide and OCS for a mean of 14 wk until remission was achieved. Of 11 patients, only one WG patient relapsed in the 14th month of maintenance therapy. Maintenance therapy with MMF was able to further reduce grumbling disease activity as measured by the Birmingham vasculitis activity score (BVAS2) and proteinuria that were still present by the end of induction therapy. OCS could be reduced to a median daily dose of 5 mg and discontinued in three patients. Possible drug-related adverse effects were transient and included abdominal pain, respiratory infection, diarrhea, leukopenia, and a cytomegalovirus-colitis in one patient that was successfully treated with ganciclovir. It is concluded that MMF in combination with low-dose OCS is well tolerated and effective for maintenance therapy of WG and MPA. Long-term treatment with MMF in these diseases is attractive because of its low toxicity. MMF will have to be studied further and compared with cyclophosphamide or azathioprine maintenance therapy in randomized trials.     

血管炎患者抗中性粒细胞胞浆抗体及中药的干预作用

目的：研究抗中性粒细胞胞浆抗体（ANCA）的检测对血管炎诊断的意义及中药对其影响。方法：间接免疫荧光法检测ANCA相关小血管炎（AASV）组和其他血管炎组ANCA的水平,并对AASV组患者进行通脉祛风汤治疗干预。结果：AASV组的ANCA检测阳性率明显高于其他血管炎组,通脉祛风汤能显著降低AASV疾病的ANCA的阳性率和复发率。结论：ANCA的检测对AASV的诊断具有较高的特异性,中医药对AASV有良好的干预作用。     

Outcome analysis of patients with vasculitis associated with antineutrophil cytoplasmic antibodies

BACKGROUND: Objective scoring systems of disease activity and disease-associated damage have proven useful in the management of patients with systemic vasculitis. PATIENTS AND METHODS: We used the recently designed Birmingham vasculitis activity score (BVAS; maximum score 63) and vasculitis damage index (VDI; maximum score 59) to assess initial activity and long-term damage, respectively, in ANCA positive patients from one center over a 3-year period. Thirty-two patients with ANCA vasculitis were identified and analyzed as an historic cohort. The median BVAS for all vasculitis patients at first presentation was 19 (range 6 - 36). Patients with Wegener's granulomatosis had a significantly higher total score and respiratory BVAS score compared to the 15 with microscopic polyangiitis. The majority of patients received standard cyclophosphamide/steroid treatment. RESULTS: At the end of follow-up (mean 24.9 months), 4 patients had died; all patients had evidence of permanent organ damage. The median total VDI score at last follow-up was 4.0 (range 0-11), with no differences between patients with Wegener's granulomatosis and microscopic polyangiitis. The VDI was not associated with the number of relapses. A high initial BVAS was found to correlate with a later high vasculitis damage index (r = 0.56). Initial renal or respiratory involvement was also associated with longterm damage in the same organ system. CONCLUSION: Although mortality from ANCA-associated vasculitis has decreased, morbidity remains a common problem. High early-disease activity may identify patients at high risk of long-term organ damage, allowing more effective individualized therapy. This hypothesis requires validation in a prospective, controlled study.     

肾脏有免疫复合物沉积的小血管炎的临床病理特点

目的 回顾性总结分析肾脏有免疫复合物沉积的ANCA相关系统性血管炎(AASV)患者的临床和病理特点。方法 将近5年在北京大学第一医院住院诊断为AASV且肾活检免疫荧光显示系膜区有免疫复合物沉积(免疫球蛋白≥++)的患者与同期少免疫复合物沉积的患者的临床和病理进行比较。结果 肾脏有免疫复合物沉积者8例(IgM沉积5例,IgA沉积2例,IgG沉积1例),肾脏少免疫复合物沉积者32例。2组在性别、年龄、ANCA类型、起病至肾活检的时间、临床表现以及短期肾脏存活率方面差异均无显著性意义,仅前组患者在有前驱感染方面显著多于后组(P<0.05)。结论 肾脏有免疫复合物沉积的AASV的临床与病理特点与普通的AASV基本一致,应引起高度重视,而需要针对AASV的强化免疫抑制治疗。     

A typical Wegeners granulomatosis -- but not pauci-immune!

We present a the case of 58-year old man who was admitted to hospital with typical clinical features (bloody nasal discharge, arthralgia, acute kidney injury with a nephritic syndrome) consisting with Wegeners granulomatosis (WG). CT-scan showed pulmonary nodules and antineutrophil cytoplasmatic antibodies (ANCA) were elevated. A kidney biopsy showed a crescentic glomerulonephritis, but not pauci-immune-immune with a histopathological staining of a mesangioproliferative IgA-glomerulonephritis. The patient was put on prednisolone and i.v. cyclophosphamid (CYCLOPS-protocol (1). The anti-proteinase-3 antibody titer decreased and the CT-scan showed decreased activity of Wegener's granulomatosis (BVAS 26 dropped to 2) and the patient`s serum creatinine level was stable. The exact nosological relation of mesangial IgA-nephropathy to WG is still unclear. This case underlines that knowledge of renal histology is essential in the management of patients with renal disease, especially in patients with hematuria and/or proeinuria with positive ANCA.     

ANCA-associated glomerulonephritis/systemic vasculitis in childhood: clinical features–outcome

Background

Antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and systemic vasculitis (AAGNV) is uncommon in childhood.

Methods

This is a retrospective study of AAGNV cases diagnosed over a 13-year period in a tertiary pediatric nephrology department.

Results

Thirteen cases of AAGNV were identified: seven Wegener granulomatosis (WG) and six microscopic polyangiitis (MPA). Acute renal failure/nephrotic range proteinuria (NRP) was found in 77 % of the patients (4 with WG, all with MPA). Eleven (85 %) patients showed necrotizing glomerulonephritis (NGN), with ≥50 % crescents identified in nine patients (69 %) (4 with WG, 5 with MPA). Treatment with methylprednisolone, cyclophosphamide and plasma exchange resulted in extra-renal remission and antibody reduction in all patients and renal function improvement/stabilization in 77 % of the patients. Three patients, all without oliguria at presentation and few sclerotic lesions, had normal renal function at follow-up. Chronic kidney disease (CKD) stages 2 and 3–4 were observed in four (WG) and three (MPA) patients, respectively. Three patients (23 %) developed end stage renal disease: two were MPA patients with severe presentation (markedly impaired glomerular filtration rate, oliguria, NRP, crescentic NGN, glomerular sclerosis) and one was a WG patient with extensive interstitial fibrosis/tubular atrophy.

Conclusions

Severe renal involvement was more common in children with MPA than WG. Treatment with methylprednisolone, cyclophosphamide and plasma exchange induced extra-renal remission/serological response and renal function improvement/stabilization. Markedly decreased GFR, oliguria, NRP, and chronic glomerular lesions at presentation were predictors of poor outcome.     

Serum levels of soluble interleukin-2 receptor in patients with ANCA-associated vasculitis

Serum soluble interleukin-2 receptor (sIL-2R) concentrations were determined using the ELISA method in 19 cases of ANCA-associated vasculitis. These patients were classified as 7 cases of Wegener's granulomatosis (WG) and 12 cases of microscopic polyangiitis (MPA). Elevated levels of sIL-2R were present in the sera of these patients. Levels of serum sIL-2R were not significantly different in patients with WG and MPA either in the active or inactive phase, so the results were expressed as a unified ANCA associated vasculitis group. Concentrations of serum sIL-2R were significantly higher in ANCA-associated vasculitis during the active phase than during the inactive phase (p<0.05), and serum sIL-2R levels were significantly increased in these patients, in the active or inactive stage, compared with a group of healthy subjects (p<0.05). In patients with vasculitis, serum sIL-2R levels correlated with serum levels of C-reactive protein (p<0.05). In the active phase, concentrations of serum sIL-2R correlated to creatinine concentrations. No correlation was found between sIL-2R and ANCA levels in any of the stages of the disease. These findings suggest cellular immune activation in ANCA associated vasculitis.     

A pilot study using mycophenolate mofetil in relapsing or resistant ANCA small vessel vasculitis.

BACKGROUND: The treatment approaches to antineutrophil cytoplasmic autoantibody (ANCA) small vessel vasculitis expose patients to the risks associated with long-term use of corticosteroids and cytotoxic agents. In an effort to explore approaches to minimize risks, we conducted a pilot efficacy and safety study of mycophenolate mofetil (MMF) in the treatment of subjects with nonlife-threatening recurrent or cyclophosphamide-resistant ANCA-vasculitis. METHODS: MMF was initiated at 500 mg orally twice daily and gradually increased to a target dose of 1000 mg twice daily for a duration of 24 weeks. Concomitant therapy with corticosteroids was allowed. The Birmingham Vasculitis Activity Score (BVAS) was used to assess disease activity and treatment efficacy. ANCA titres, serum creatinine and adverse events were secondary measures of efficacy and/or toxicity. RESULTS: Twelve subjects were enrolled in the study. Treatment with MMF led to an improvement in disease activity as measured by the BVAS at 24 weeks (P = 0.0013) and 52 weeks (P = 0.0044) as compared to baseline. The BVAS decreased from an average of 9.1+/-3.5 at baseline (range, 3-17) to an average of 2.8+/-1.9 (range, 1-6) at 24 weeks and to 2.8+/-4.3 (range, 0-13) at 52 weeks. Early and sustained reductions in BVAS occurred in subjects initially classified as disease relapses vs those with treatment resistance. Side effect profile was consistent with the mechanism of action and pharmacokinetic disposition of MMF. CONCLUSIONS: MMF is a reasonable option in the treatment of non-life-threatening recurrent or resistant vasculitis and may obviate the immediate need for recurrent use of cytotoxic agents.