Detection rate and antigenic specificities of antineutrophil cytoplasmic antibodies in chinese patients with clinically suspected vasculitis

Clinical features and outcomes of anti-neutrophil cytoplasmic autoantibody-associated vasculitis in Chinese childhood-onset patients

Data on anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) are limited in children. This study is to determine the clinical features and outcomes of childhood-onset AAV. A retrospective study was performed on patients who were diagnosed with AAV before 18 years old in Xiangya Hospital. Their medical records were analyzed by retrospective review. Sixteen patients were diagnosed with AAV before 18 years old in the past 9 years, with an average age of 13.3 ± 3.3 years and 13 of them were female. There were 15 patients with microscopic polyangiitis (MPA) and 1 with Wegener's granulomatosis. The interval between onset of disease and diagnosis of AAV was 2 (1.5-3) months. Most patients (15/16, 93.8%) had multi-organ involvement, and all patients had renal involvement with 7 (43.8%) patients requiring dialysis at presentation. Eleven patients underwent a renal biopsy, of which mixed class and sclerotic class were the most two common histological types. All patients received immunosuppressive therapy for induction therapy including intravenous administrations of methylprednisolone (MP) pulse therapy for 8 patients. 8 patients (50%) achieved remission after induction therapy. After a median follow-up of 46.3 ± 36.1 months, nine (56.3%) patients progressed to end-stage renal disease (ESRD) and 5 (31.3%) patients died. Childhood-onset AAV showed similar clinical and pathological features compared to those of adults, except that it usually occurs in girls. The most commonly involved organ was the kidney, and it had a high risk of progression to ESRD. Early diagnosis and initiation of appropriate immunomodulatory therapy would be important to improve outcomes.

Epidemiology of Glomerular Disease in Southern Arizona: Review of 10-Year Renal Biopsy Data

Glomerulonephritis stands third in terms of the etiologies for end-stage kidney disease in the USA. The aim of this study was to look at the patterns of biopsy-proven glomerulonephritis based on data from a single center.Kidney biopsy specimens of all patients above the age of 18 years, over a 10-year period, who had diagnosis of nondiabetic glomerular disease, were selected for the study.The most common histopathological diagnosis was focal and segmental glomerulosclerosis (FSGS) (22.25%, 158/710) followed by membranous nephropathy (20.28%, 144/710) and immunoglobulin (Ig)A nephropathy (19.71%, 140/710). There was male preponderance in all histological variants except IgA nephropathy, lupus nephritis, and pauci-immune glomerulonephritis. The race distribution was uneven, and all histological variants, except minimal change disease and lupus nephritis, were more commonly seen in whites. In a separate analysis of the histological pattern in Hispanics, lupus nephritis was the most common pathology (28.70%, 62/216) followed by FSGS (18.05%, 39/216). In American Indian population, the most common pathology was IgA nephropathy (33.33%, 8/24) followed by FSGS (16.67%, 4/24).This study highlights the histopathological patterns of glomerular disease in southern Arizona. The data suggest regional and ethnic variations in glomerular disease that may point towards genetic or environmental influence in the pathogenesis of glomerular diseases.

The predictive value of kidney biopsy in renal vasculitis: a multicenter cohort study

The histopathologic classification of antineutrophil cytoplasmic antibody-associated vasculitis has been demonstrated to have prognostic value in small cohorts of patients with pauci-immune extracapillary glomerulonephritis. We aimed to validate this histologic subgrouping system in a large cohort of patients with renal vasculitis from 3 Spanish centers. The additional value of several histologic parameters for predicting renal outcome was investigated. A total of 151 biopsies of patients with renal vasculitis were reviewed and classified as follows: 41% crescentic, 24% mixed, 21% focal, and 14% sclerotic. The cumulative proportions of renal survival at 5 years were 83.2%, 81.2%, 60.5%, and 50.7% for the focal, mixed, crescentic, and sclerotic categories, respectively (P < .05). In the crescentic category, patients with less than 75% of glomeruli showing crescents had better survival at 1 and 5 years compared with those having greater than or equal to 75% of crescents (77.9% and 70.6% versus 51.3% and 45.6%; P = .02). When adjusted by renal function and other histologic parameters, the percentage of extracapillary proliferation and glomerulosclerosis remained as significant predictors for renal survival (hazard ratio, 1.03; 95% confidence interval, 1.01-1.05; P = .001, and hazard ratio, 1.03; 95% confidence interval, 1.01-1.05; P = .002, respectively). In conclusion, patients with pauci-immune crescentic glomerulonephritis experienced different outcomes depending on the percentage of crescents observed, so that extensive extracapillary proliferation was associated with the poorest renal survival. These findings validate the prognostic utility of the histologic classification scheme in antineutrophil cytoplasmic antibody positive and negative patients and suggest a subdivision of crescentic category (<75% and ≥75% of crescents) based on the different survival rates observed among these subgroups.

Circulating Level of Neutrophil Extracellular Traps Is Not a Useful Biomarker for Assessing Disease Activity in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening disorders, and frequently affects the kidneys. This study investigated whether the circulating neutrophil extracellular traps (NETs) levels were associated with disease activity of AAV. We collected serum samples from 34 patients with AAV in active stage and 62 patients with AAV in remission. Cell free DNA in serum was quantified using the Quant-iT PicoGreen assay. NETs associated MPO-DNA complexes, citrullinated-histone H3-DNA (cit-H3-DNA) complexes and the concentration of deoxyribonuclease I (DNase I) were quantified using ELISA. The activity of DNase I was quantified using radial enzyme-diffusion method. Associations between circulating levels of NETs with clinico-pathological parameters were analyzed. Serum levels of NETs in active AAV patients were significantly higher than those in healthy controls, and the level of cell free DNA correlated with C-reactive protein (CRP). However, no correlation was found between MPO-DNA complexes or cit-H3-DNA complexes level and CRP. Also there was no significant correlation between NETs level and initial serum creatinine, estimated glomerular filtration rate (eGFR), crescents formation or Birmingham Vasculitis Activity Score (BVAS). Furthermore, there was no significant difference of serum levels of cell free DNA or MPO-DNA complexes between active stage and remission of AAV. In conclusion, circulating levels of NETs cannot be used as a biomarker to assess disease activity in AAV patients.

Clinicopathological characteristics and outcomes of Chinese patients with scanty immune deposits lupus nephritis: a large cohort study from a single center

Objective. To assess clinicopathological characteristics of lupus nephritis patients with scanty immune deposits. Methods. The data of patients with scanty immune deposits lupus nephritis were retrospectively analyzed. Plasma ANCA and complement components were detected. Results. Among 316 cases with renal biopsy-proven lupus nephritis, 40 cases were diagnosed as scanty immune deposits. There were significantly higher value of serum creatinine (P = 0.002) and lower hemoglobin level (P = 0.009) and higher score of cellular crescents (P = 0.015) in scanty immune deposits group compared with immune complex deposits group. The frequency of positive plasma ANCA was significantly higher in scanty immune deposits group than that in immune complex deposits group (52.5% versus 10.1%, P < 0.001). As for comparisons of plasma complement components, there were significantly higher levels of C1q (P = 0.005) and Bb (P = 0.02) and lower level of factor H (P = 0.003) in scanty immune deposits group. The ratio of treatment failure was significantly higher in scanty immune deposits group than that in immune deposits group (42.5% versus 19.20%, P = 0.001). The renal outcomes were similar between the two groups. Conclusions. Patients with scanty immune deposits lupus nephritis had more severe kidney damage. ANCA and activation of complement alternative pathway might be involved in the pathogenesis of the disease.

Predictors for outcomes in patients with severe ANCA-associated glomerulonephritis who were dialysis-dependent at presentation: a study of 89 cases in a single Chinese center

OBJECTIVE

Anti-neutrophilcytoplasmic autoantibody (ANCA)-associated vasculitis may cause rapid deterioration of renal function, resulting in high prevalence of end-stage renal disease and mortality. The current study investigated factors associated with restoration of renal function and early mortality in patients with severe ANCA-associated glomerulonephritis, i.e. dialysis-dependent at presentation, in a single Chinese cohort.

METHODS

Eighty-nine Chinese patients with ANCA-associated glomerulonephritis who were on dialysis at the time of diagnosis were included in this study. All these patients received immunosuppressive therapy plus intravenous methylprednisolone, plasma exchange, or both. The predictive value of the clinical and histological parameters for renal and patient outcome was analyzed.

RESULT

On the sixth month, 25 (28.1%) patients achieved dialysis independence, 45 (50.6%) patients progressed to end stage renal disease, and 19 (21.3%) patients died. Nine out of the 19 deaths were therapy-related. Factors independently associated with renal function restoration were percentages of normal glomeruli (P<0.05), extent of tubular atrophy (P<0.05) and extent of interstitial fibrosis (P<0.05) in the renal specimens. Age and pulmonary hemorrhage were independently associated with all-cause death (P=0.003 and P=0.007, respectively) and therapy-related death (P=0.037 and P=0.043, respectively).

CONCLUSIONS

Among patients with severe ANCA-associated glomerulonephritis who were dialysis-dependent at presentation, those with a higher percentage of normal glomeruli and less extent of tubular atrophy/interstitial fibrosis have more chance of restoration of renal function. Increased risk for all-cause death and therapy-related death appears to be older age and pulmonary hemorrhage.

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.

Re-evaluation of the histopathologic classification of ANCA-associated glomerulonephritis: a study of 121 patients in a single center

BACKGROUND

The recently published histopathologic classification of antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis might greatly aid in the prognostication of patients at the time of diagnosis. This study aims to re-evaluate the new classification for its prognostic capacity in an independent Chinese series.

METHODS

One hundred and twenty-one consecutive patients with ANCA-associated glomerulonephritis, diagnosed in our center from 1997 to 2010, were included in this retrospective study. The renal specimens were reviewed according to the proposed histopathologic classification. The predictive value of the classification for renal outcome and renal response to treatment was analyzed.

RESULTS

Thirty-three (27.3%), 24 (19.8%), 53 (43.8%) and 11 (9.1%) patients were classified as focal, mixed, crescentic and sclerotic ANCA-associated glomerulonephritis, respectively. The renal biopsy categories correlated with initial serum creatinine and the renal response to treatment (P < 0.001, P < 0.01, respectively). The probability of progressing to end-stage renal disease (ESRD) increased with ascending categories of focal, mixed, crescentic and sclerotic glomerulonephritis (P < 0.01). The patients with focal, mixed and crescentic ANCA-associated glomerulonephritis were all at decreased risk for developing ESRD compared with the patients with in the sclerotic category (P < 0.05).

CONCLUSIONS

The proposed classification system was re-evaluated for the first time in a relatively large and independent series of patients. This system reflects the severity of the initial renal impairment and can predict, at least to some extent, the renal response to treatment. More importantly, it can independently predict renal outcome, in particular development of ESRD.

Class IV-G and IV-S lupus nephritis in Chinese patients: a large cohort study from a single center

This study is to assess the difference between IV-G and IV-S in a large cohort of Chinese patients with lupus nephritis. The detailed data of patients with subclass IV-G and IV-S were retrospectively analyzed. Serum ANCA and anti-C1q antibodies were detected. A total of 172 cases were classified as class IV, including 152 cases with IV-G and 20 cases with IV-S. In IV-S, the level of haemoglobin was significantly higher (P = 0.024), proteinuria was milder (P = 0.003), serum creatinine was lower (P = 0.021), serum C3 was higher (P = 0.045) and the ratio of positive serum anti-cardiolipin antibodies was higher (P = 0.014). On pathological evaluation, the ratio of glomerular fibrinoid necrosis was significantly higher (P = 0.006) and the score of endocapillary hypercellualrity, interstitial inflammation and total activity indices was significantly lower (P < 0.001, P = 0.01, P = 0.006, respectively) in IV-S. The frequency of serum ANCA was significantly higher in IV-S than that in IV-G (20 vs 4.6%, P = 0.008). The frequencies of anti-C1q IgG1 and IgG3 subclass were significantly higher in IV-G (P = 0.006, P = 0.011, respectively). There are significant differences in clinical and pathological manifestations between IV-S and IV-G lupus nephritis which need further investigation.

The role of HLA-DRB1 alleles on susceptibility of Chinese patients with anti-GBM disease

Anti-glomerular basement membrane (GBM) disease, a rare autoimmune disorder, is associated with HLA-DR15 genotype in Caucasian and Japanese populations. But the distribution of HLA-DRB1 alleles in Chinese patients with anti-GBM disease and their association with clinical characteristics of anti-GBM disease are to be determined. The present study analyzed the HLA-DRB1 alleles by sequence based typing in 44 Chinese patients with anti-GBM disease and 200 healthy controls. The effects of DRB1 alleles on susceptibility to anti-GBM disease were examined by a relative predispositional effects (RPEs) method. The clinical and pathological data of the patients were collected and analyzed. The DRB1*1501 allele was significantly associated with anti-GBM disease (p=1.597 x 10(-7)). The RPEs test also showed a significant increased frequency of DRB1*0404 in anti-GBM disease (p=0.037). Interestingly, the patients with DRB1*1501 or 0404 had more crescent formation in glomeruli than those without the two alleles (p=0.021). But the DRB1*0404 was rare in both patients and control groups, which indicates that the importance of the *0404 allele is limited in anti-GBM disease. We conclude that the HLA-DRB1*1501 allele is a genetic marker for susceptibility to anti-GBM disease.

Clinicopathological characteristics and outcomes of patients with crescentic lupus nephritis

There are few clinicopathologic and outcome data on patients with crescentic lupus nephritis, therefore, we determined factors of the disease by retrospectively reviewing the records of 327 patients diagnosed with lupus nephritis. Of these, 152 cases were regrouped as class IV-G, including 33 patients with crescentic glomerulonephritis. Significantly, all patients with crescentic glomerulonephritis had acute kidney injury as compared with only about a quarter of the patients without the disease. On pathological evaluation, activity scores, chronicity indexes, relapse rates, and the frequency of positive serum anti-neutrophil cytoplasmic antibody (ANCA) were each significantly higher, whereas complete remission rates and renal outcomes, over a mean follow-up of 4 years, were significantly poorer in patients with crescentic glomerulonephritis. Our study shows that crescentic glomerulonephritis was not rare in patients with lupus nephritis and that their long-term outcome was poor. The precise role of ANCA in the pathologic course of crescentic lupus nephritis remains to be determined.

Pauci-immune crescentic glomerulonephritis associated with ANCA of IgA class

Pauci-immune renal vasculitis is associated strongly with antineutrophil cytoplasmic antibodies (ANCAs) of the immunoglobulin G (IgG) class, which are detected in 80% to 90% of affected patients. IgA ANCAs have been reported in association with various conditions, but never in the setting of pauci-immune vasculitis. A 28-year-old man with unexplained polyclonal hyper-IgA1 diagnosed in childhood presented with decreased kidney function, nephrotic syndrome, and microscopic hematuria. Kidney biopsy showed pauci-immune crescentic glomerulonephritis. Serum test results were negative for IgG ANCA by means of both indirect immunofluorescence and enzyme-linked immunosorbent assay techniques. Conversely, indirect immunofluorescence performed using anti-IgA antibody was strongly positive with a cytoplasmic ANCA pattern, and an enzyme-linked immunosorbent assay test had positive results for both antimyeloperoxidase and anti-proteinase 3 IgA. IgA ANCAs were not detected in 2 control serum samples from 1 patient with polyclonal hyper-IgA and 1 patient with monoclonal hyper-IgA. The patient received corticosteroids and 4 weekly perfusions of rituximab (375 mg/m2). After a 6-month follow-up, decreased kidney function and nephrotic syndrome persisted and IgA ANCA titers were unchanged. However, a control kidney biopsy showed a decrease in vasculitis activity. This first case of pauci-immune vasculitis associated with ANCA of the IgA class suggests the potential pathogenetic role of these peculiar antibodies. Additional studies are needed to determine whether IgA ANCAs, which are not routinely screened for, can be detected in patients with pauci-immune vasculitis either alone or in association with IgG ANCA.

Hypotheses on the etiology of antineutrophil cytoplasmic autoantibody associated vasculitis: the cause is hidden, but the result is known

The first description of what is now known as antineutrophil cytoplasmic autoantibody-associated necrotizing vasculitis appeared more than 140 yr ago. Since then, many aspects of the pathogenic pathway have been elucidated, indicating the involvement of antineutrophil cytoplasmic autoantibodies, but why antineutrophil cytoplasmic autoantibodies are produced in the first place remains unknown. Over the years, many hypotheses have emerged addressing the etiology of antineutrophil cytoplasmic antibody production, but no exclusive factor or set of factors can so far be held responsible. Herein is reviewed the most influential hypotheses regarding the causes of antineutrophil cytoplasmic antibody-associated vasculitis with the aim of placing in an epidemiologic background the different hypotheses that are centered on environmental and genetic influences.

Characteristics and Outcome of Chinese Patients with Both Antineutrophil Cytoplasmic Antibody and Antiglomerular Basement Membrane Antibodies

BACKGROUND

Antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis (AASV) is a systemic autoimmune disease. A number of cases have been found to have antiglomerular basement membrane (GBM) antibody-positive serum. The purpose of the current article is to investigate the prevalence of anti-GBM antibodies in sera from a large cohort of Chinese patients with AASV and to characterize the clinical and pathological features of the 'double positive' patients.

METHODS

Sera from 652 patients with AASV were screened by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot analysis using purified human alpha(IV)NC1 as antigen. Antigen specificity of anti-GBM antibodies was determined by ELISA using recombinant human alpha 3(IV)NC1 as solid phase ligand. Clinical and pathological data of patients with both ANCA and anti-GBM antibodies were analyzed retrospectively.

RESULTS

61/652 (9.36%) sera from patients with AASV were serum anti-GBM antibody positive and all recognized recombinant human alpha 3(IV)NC1. All the cases had renal involvement, 37/48 (77.1%) cases had pulmonary involvement, non-specific symptoms and other multisystem involvements were common. The renal survival was 14.6% (7/48) and patient survival was 37.5% (18/48) respectively at the end of 1 year. The following factors predicted poor prognosis: (1) serum creatinine >700 micromol/l (p = 0.034); (2) oliguria or anuria on diagnosis (p = 0.001); (3) high percentage (>85%) of glomeruli with crescents (p = 0.011); (4) high titer anti-GBM antibodies (p = 0.003), and (5) hemoptysis (p = 0.049).

CONCLUSION

Patients with double antibodies were not rare in AASV. They had multisystem involvement but poor short-term prognosis.Anti-GBM antibodies should be detected on diagnosis of AASV, especially for old ages.

Clinical and Pathological Features of Renal Involvement in Propylthiouracil-Associated ANCA-Positive Vasculitis

BACKGROUND

The kidney is one of the organs affected in patients with propylthiouracil (PTU)-associated antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. We present a series of Chinese patients with renal involvement in PTU-associated ANCA-positive vasculitis and describe their clinical and pathological characteristics.

METHODS

Clinical and pathological data from patients with PTU-associated ANCA-positive vasculitis with renal involvement, diagnosed in Peking University First Hospital, were collected and analyzed retrospectively.

RESULTS

Nineteen patients with PTU-associated ANCA-positive vasculitis were treated at Peking University First Hospital between December 1999 and December 2005, and 15 of them had renal involvement. Of the 15 patients, 13 were female and 2 were male, with an average age of 26.3 +/- 11.8 years. All 15 patients were perinuclear ANCA positive with specificities to myeloperoxidase (15 of 15), cathepsin G (9 of 15), human leukocyte elastase (8 of 15), lactoferrin (7 of 15), azurocidin (5 of 15), and proteinase 3 (4 of 15). Duration of PTU administration was 43.0 +/- 31.2 months. All 15 patients had clinical markers of renal involvement, including hematuria (100%), proteinuria (100%), and renal function abnormality (47%). All 15 patients underwent percutaneous renal biopsy. Ten patients had necrotizing crescentic glomerulonephritis, and 7 of these 10 patients had immune complex deposition. Three patients had minimal involvement, 2 patients had immunoglobulin A nephropathy, and 2 patients had membranous nephropathy. PTU treatment was discontinued in all 15 patients. All except 2 patients with minimal renal involvement received immunosuppressive treatment. Eleven of 15 patients achieved complete clinical remission.

CONCLUSION

Renal involvement in our case series of patients with PTU-associated ANCA-positive vasculitis was heterogeneous, and nearly half our patients had renal immune complex deposition.

Follow-up of avidity and titre of anti-myeloperoxidase antibodies in sera from patients with propylthiouracil-induced vasculitis

OBJECTIVE

Propylthiouracil (PTU) has been known to induce myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positive vasculitis. Our previous study indicated that the increase of avidity of MPO-ANCA might be associated with the occurrence of clinical vasculitis in patients with PTU-induced ANCA. The current study aimed to follow-up the avidity and titre of anti-MPO antibodies in sequential sera from patients with PTU-induced ANCA-associated systemic vasculitis (AASV).

METHODS

Six patients with PTU-induced vasculitis were enrolled in the current study. Serial sera in both active phase and in remission were collected. MPO-ANCA avidity was assessed by antigen-inhibition enzyme-linked immunosorbent assays (ELISAs), and avidity constant (aK) was determined as the reciprocal value of the MPO molar concentration in the liquid phase resulting in 50% inhibition of anti-MPO antibody binding to MPO in solid phase ELISA. Titres of MPO-ANCA were determined by using serial serum dilutions in MPO-ELISA.

RESULTS

After cessation of PTU and initiation of immunosuppressive therapy, the avidity and titre of MPO-ANCA decreased significantly during follow-up in sera from all the patients, and the avidity decreased much more quickly than the titres.

CONCLUSION

Our study indicates that avidity of anti-MPO antibodies might be more closely associated with clinical vasculitis than titre.

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.

The clinical features of anti-neutrophil cytoplasmic antibody-associated systemic vasculitis in Chinese children

Anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis is reported mainly in adults. Studies in children are limited. The current study retrospectively analyzed the clinical characteristics and pathology of ANCA-associated systemic vasculitis in children in our hospital during the past 7 years. Twenty-four pediatric patients were diagnosed as having ANCA-associated systemic vasculitis, including 19 patients with microscopic polyangiitis (MPA), one with Wegener's granulomatosis (WG), three with propylthiouracil (PTU)-induced ANCA-positive vasculitis and one with anti-glomerular basement membrane (GBM) disease. Of patients with primary ANCA-associated systemic vasculitis (MPA and WG), with an average age of 10.8+/-2.8 (6-14) years, 18 patients (90%) were female and two (10%) were male. Nineteen patients (95%) were p-ANCA/MPO-ANCA positive and one (5%) was c-ANCA/PR3-ANCA positive. The interval between onset and diagnosis was 8.5+/-24.3 (0.2-108) months. The majority of the patients (85%) had multi-organ involvement. All patients had clinical evidence of renal involvement and presented with hematuria and proteinuria. Of 20 patients, 16 (80%) also had acute renal failure, and five patients were dialysis dependent. Nine patients underwent renal biopsy and were diagnosed with necrotizing and crescentic glomerulonephritis. However, six biopsies showed immune complex deposition. All patients received immunosuppressive therapy including prednisone and cyclophosphamide, and ten patients also received intravenous administration of methylprednisone pulse therapy according to their clinical situation and renal pathology. Sixteen patients achieved clinical remission, and four patients presented as treatment failure. Patients were followed up for 12.3+/-5.1 months (median 12 months; range 1 to 91 months). Ten patients maintained their clinical remission, and ten progressed to renal failure requiring dialysis. Our study showed that the clinical features and pathology of primary ANCA-associated systemic vasculitis in children were similar to those of adults, but there were a predominance of female patients and late diagnoses. We suggest that early recognition and prompt aggressive treatment might improve outcome.

Clinical [corrected] and pathological characteristics of Chinese patients with antineutrophil cytoplasmic autoantibody associated systemic vasculitides: a study of 426 patients from a single centre

BACKGROUND

Antineutrophil cytoplasmic autoantibodies (ANCA) are serological markers of ANCA associated systemic vasculitides (AASV), which is one of the most common multisystem autoimmune diseases. Features of Chinese patients with AASV have not been fully investigated.

OBJECTIVE

To analyse the clinical and pathological characteristics of Chinese patients with AASV.

METHODS

426 Chinese patients with AASV diagnosed in the past eight years were retrospectively studied and their clinical and pathological data were analysed.

RESULTS

Of the 426 patients, 87 (20.4%) were Wegener's granulomatosis, 337 (79.1%) were microscopic polyangiitis and two (0.5%) were Churg-Strauss syndrome. Only 201 of 426 (47.2%) patients were diagnosed within three months. Clinically, the patients had multisystem involvement. Altogether 371 of 426 (87.1%) had kidney involvement and 260 of 426 (61.0%) had lung involvement. The prevalences of renal involvement and fatigue were significantly higher in patients with MPO-ANCA than that in patients with PR3-ANCA; the prevalences of ophthalmic, nasal involvement, rash, and arthragia were significantly higher in patients with PR3-ANCA than those in patients with MPO-ANCA. The one and five year death rates were 13.1% and 22.4%, respectively. The percentage of patients progressing to end stage renal disease at one and five years was 15.9% and 27.1%, respectively.

CONCLUSIONS

AASV is not a rare autoimmune disease in Chinese people. Kidney and lung were the most vulnerable organs. For patients with multiorgan damage, an ANCA test should be performed to make an early diagnosis and to start treatment in time.

Epidemiology of systemic vasculitis

The systemic vasculitides are heterogeneous conditions of unknown etiology characterized by inflammation and necrosis of different sized blood vessels. Wegener's Granulomatosis, microscopic polyangiitis, and Churg Strauss syndrome are associated with anti-neutrophil cytoplasmic antibodies and affect small and medium blood vessels. They are very rare in childhood and peak in the 65 to 70 year old age group. Wegener's Granulomatosis appears to be more common in the North of Europe compared with the South. All are more common in whites compared with other populations. Genetic and environmental factors, including infection, drugs, and silica, are important in etiology. Giant cell arteritis is predominantly a disease of whites over the age of 50. It appears more common in individuals with Nordic descent. Incidence may be increasing over time and cyclical variation in disease may reflect an infectious etiology. Takayasu arteritis is a disease of the aorta and its branches, however pulmonary and cardiac arteries may be involved. Patients are usually under 40-years of age at presentation and there are no apparent differences in incidence or clinical characteristics/aortic involvement across the globe. Kawasaki disease (KD) and Henoch-Schonlein purpura are diseases of children and rarely affect adults. Both have been reported to be more common in Asians than whites. The incidence of KD is higher in Japan and China compared with other regions. No definite trigger factors have been found, but KD has been linked to infection, house dust mite and chemicals, and Henoch-Schonlein purpura to a pesticide and drugs.

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.

Anti-myeloperoxidase IgG subclass distribution and avidity in sera from patients with propylthiouracil-induced antineutrophil cytoplasmic antibodies associated vasculitis

OBJECTIVE

Propylthiouracil (PTU) could induce MPO-ANCA-positive vasculitis. The aim of this study was to compare the IgG subclass distribution and avidity of MPO-ANCA in sera from patients with primary ANCA-associated vasculitis (AASV) and PTU-induced vasculitis.

METHODS

Nineteen patients with primary AASV with MPO-ANCA and thirteen patients with PTU-induced vasculitis were enrolled in the current study. Sera in both active phase and remission were collected. Anti-MPO IgG subclasses were detected by antigen specific ELISAs using specific monoclonal antibodies as second antibodies, and MPO-ANCA avidity was assessed by antigen-inhibition ELISAs.

RESULTS

In primary AASV, all four anti-MPO IgG subclasses could be detected in active phase with IgG1 (100%), IgG2 (73.7%), IgG3 (63.2%) and IgG4 (94.7%), and in remission, IgG1 and IgG4 subclasses in most patients remained positive. However, in PTU-induced vasculitis, anti-MPO IgG3 subclass could not be detected, the anti-MPO IgG subclasses in active phase were IgG1 (100%), IgG2 (61.5%) and IgG4 (46.2%). Furthermore, five out of the six patients (88.8%) with PTU-induced vasculitis with positive IgG4 subclass in active phase turned to negative in remission, however, only eight out of the fourteen patients (57.1%) with primary AASV turned to negative. The median avidity constant of MPO-ANCA was 56 (8.96 to >140) x 10(7) mol/l for patients with primary AASV and 0.7 (<0.28 to >140) x 10(7) mol/l for patients with PTU-induced vasculitis respectively. Furthermore, the relative levels of MPO-ANCA avidity were associated with elevation of ESR in primary AASV and were associated with BVAS scores in patients with PTU-induced vasculitis, respectively.

CONCLUSION

MPO-ANCA IgG subclass distribution and avidity were different between patients with primary AASV and PTU-induced vasculitis. It was suggested that the mechanism of ANCA production in PTU-induced vasculitis was different from that in primary AASV, and the avidity of MPO-ANCA might be associated with disease activity.

The clinical and pathological characteristics of Chinese elderly patients with anti-neutrophil cytoplasmic autoantibodies associated small vessel vasculitis

BACKGROUND

Anti-neutrophil cytoplasmic autoantibodies (ANCA) are serological markers of ANCA-associated small vessel vasculitis (AASV) which is one of common autoimmune diseases in Caucasian elderly population.

OBJECTIVE

To analyze the clinical and pathological characteristics of Chinese elderly patients with AASV.

METHODS

One-hundred forty one Chinese patients with AASV over 65 years old, diagnosed between 1997 and 2001 in the Institute of Nephrology of Peking University First Hospital, were retrospectively studied and their clinical and pathological data were analyzed.

RESULTS

Patients diagnosed with AASV patient increased chronologically with the yearly ratio in 2000 and 2001 significantly (P < 0.05) higher than that in 1998 and before. Of the 141 patients, 72 were male and 69 were female with an average age of 68.2 years. 13 of the 141 were cytoplasmic ANCA (cANCA) positive and all recognized proteinase 3 (PR3). The other 128 were perinuclear ANCA (pANCA) positive and 120/128 recognized MPO, 8/128 recognized both PR3 and MPO. Less than 50% of the patients were correctly diagnosed within 3 months. Clinically, 78% of the patients had fever and fatigue, 52.5% had body weight loss, 96.4% had kidney involvement, of which 75% had elevated serum creatinine and 30.8% had acute renal failure. 76.6% had lung involvement, over half of them had hemoptysis or lung infiltrates. Other clinical manifestations included arthralgia (48.2%), muscle pain (39.7%), gastrointestinal symptoms (39.7%), eye involvement (28.3%) and ENT involvement (31.2%). In laboratory examinations, 94.4% of the patients had anemia, 62.4% had increased WBC count, 93.6% had increased ESR and 55.1% had increased CRP.

CONCLUSIONS

More and more patients with AASV were diagnosed in Chinese elderly. Kidney was the most vulnerable organ to be involved and lung was the most important extra-renal organ to be affected. For elderly patients with multi-organ damage, an ANCA test should be performed in order to make an early diagnosis and start therapy in time.