Analyses of registry data of patients with anti-GBM and antineutrophil cytoplasmatic antibody-associated (ANCA) vasculitis treated with or without therapeutic apheresis.

Therapeutic apheresis (TA) as a treatment for antibody-associated vasculitis (AAV) was questioned by the PEXIVAS although the MEPEX study favored TA. The aim of this study was to evaluate the efficacy of TA to improve renal function in patients consecutively included in the WAA-apheresis registry versus patients not treated with TA. MATERIALS AND METHODS: Included were 192 patients that suffered from anti-glomerular basement membrane disease (anti-GBM, n = 28) and antineutrophil cytoplasmic antibody-associated vasculitis of MPO or PR3 origin. Of these 119 had performed TA and the other 73 had not performed TA for theses diagnoses (CTRL). RESULTS: Elderly had an increased risk to die within 12 months (p = 0.002). All 28 anti-GBM had renal involvement, 21 dialysis dependent. At 3 month nine (36 %) did not need dialysis. Baseline data regarding renal function of AAV patients, subtype MPO and PR3, were worse in the TA groups than in CTRL. Recovery out of dialysis was better for the PR3-TA group compared with 1) the controls of MEPEX (RR 0.59, CI 0.43-0.80) and 2) the MPO-TA patients (RR 0.28, CI 0.12-0.68). The MPO-TA recovered similarly as the MEPEX-CTRL. Renal function improved most for TA-patients from baseline during the first 3 months (MPO-TA and PR3-TA) and stabilized thereafter and less for MPO-CTRL and PR3-CTRL. CONCLUSION: PR3-TA patients seem to have best chances to get out of dialysis. PR3-TA and MPO-TA improved residual renal function better than CTRL. The present study recommends reconsiderations to use TA for AAV especially those with PR3-vasculitis with severe renal vasculitis.

Epidemiology of primary systemic vasculitis in children: a population-based study from southern Sweden.

OBJECTIVES: To estimate the annual incidence rate of paediatric primary systemic vasculitis (PSV) in a defined geographical area in southern Sweden. METHODS: Potential cases of PSV [IgA vasculitis (IgAV, Henoch-Schönlein purpura), Kawasaki disease (KD), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), polyarteritis nodosa (PAN), and Takayasu's arteritis (TAK)] were identified in a comprehensive regional healthcare register. The study area is Skåne, the southernmost county of Sweden (population 1.29 million; 21.4% aged <18 years). Case records for children (0-17 years) assigned a diagnosis code between M300 and M319 and/or D690 were reviewed to ascertain diagnosis. Only patients diagnosed between 2004 and 2014 were included. RESULTS: In total, 556 patients with PSV were identified. The annual incidence rate per million children (95% confidence interval) was estimated to be 200 (183-217) for all PSV, 175.5 for IgAV (160-191), 20.1 for KD (14.9-25.4), 1.4 (0-2.8) for each of GPA and MPA, 0.7 (0-1.7) for PAN, and 0.4 (0-1.1) for each of EGPA and TAK. Among children aged <10 years, 99.5% of cases were either IgAV or KD, both exhibiting a seasonal pattern paralleling infections. There were no deaths, but three cases of end-stage renal disease were noted, all in MPA. CONCLUSIONS: Vasculitis is relatively common during childhood. Mild cases associated with the infection season are most common in the youngest age groups, while during adolescence a substantial proportion has more severe forms of vasculitis.

IgA- and SIgA anti-PR3 antibodies in serum versus organ involvement and disease activity in PR3-ANCA-associated vasculitis.

Circulating immunoglobulin (Ig)A class anti-neutrophil cytoplasm antibodies (ANCA) directed against proteinase 3 (PR3) have been reported in ANCA-associated vasculitis (AAV) with mucosal involvement. However, secretory IgA (SIgA) PR3-ANCA has not been reported previously. In this study we compared serum levels of SIgA PR3-ANCA and IgA PR3-ANCA with IgG PR3-ANCA in relation to disease characteristics. Among 73 patients with AAV and PR3-ANCA at diagnosis, 84% tested positive for IgG PR3-ANCA, 47% for IgA-ANCA and 36% for SIgA PR3-ANCA at the time of sampling for the present study. IgA and IgG PR3-ANCA were represented similarly among patients with different organ manifestations, i.e. upper airway, lung or kidney at time of sampling. However, SIgA PR3-ANCA was significantly less represented among patients with upper airway involvement. During active disease, the proportions of IgA PR3-ANCA and SIgA PR3-ANCA-positive patients were significantly higher compared to inactive disease. Eight patients were sampled prospectively during 24 months from onset of active disease. In these patients, IgA PR3-ANCA and SIgA PR3-ANCA turned negative more often after remission induction compared to IgG PR3-ANCA. Our findings suggest that serum IgA PR3-ANCA and SIgA PR3-ANCA are related more closely to disease activity in AAV compared to IgG PR3-ANCA. Further studies are required to reveal if this has implications for disease activity monitoring. The mean number of PR3-ANCA isotypes increased along with disease activity, suggesting a global B cell activation during active disease.

EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis.

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

Circulating microRNA expression pattern separates patients with anti-neutrophil cytoplasmic antibody associated vasculitis from healthy controls.

OBJECTIVES: Antineutrophil cytoplasmic antibody associated vasculitis (AAV) has an unpredictable course and better biomarkers are needed. Micro-RNAs in body fluids are protected from degradation and might be used as biomarkers for diagnosis and prognosis, here we explore the potential in AAV. METHODS: Plasma samples from two AAV cohorts (n=67 and 38) were compared with samples from healthy controls (n=27 and 45) and disease controls (n=20). A panel of 32 miRNAs was measured using a microfluidic quantitative real-time PCR system, and results were compared with clinical data. RESULTS: Seven individual miRNAs were differently expressed compared to controls in both cohorts; miR-29a, -34a, -142-3p and -383 were up-regulated and miR-20a, -92a and -221 were down-regulated. Cluster analysis as well as principal component analysis (PCA) indicated that patterns of miRNA expression differentiate AAV patients from healthy subjects as well as from renal transplant recipients. Loadings plots indicated similar contribution of the same miRNAs in both cohorts to the PCA. Renal engagement was important for miRNA expression but consistent correlations between estimated glomerular filtration rate and miRNA levels were not found. We found no significant correlation between treatment regimens and circulating miRNA levels. CONCLUSIONS: In this first study ever on circulating miRNA profiles in AAV, we find clear indication of their potential as biomarkers for diagnosis and classification, but more studies are needed to identify the best markers as well as the mechanisms responsible for variations.

A myelopoiesis gene signature during remission in anti-neutrophil cytoplasm antibody-associated vasculitis does not predict relapses but seems to reflect ongoing prednisolone therapy.

A myelopoiesis gene signature in circulating leucocytes, exemplified by increased myeloperoxidase (MPO) and proteinase 3 (PR3) mRNA levels, has been reported in patients with active anti-neutrophil cytoplasm antibody-associated vasculitis (AAV), and to a lesser extent during remission. We hypothesized that this signature could predict disease relapse. mRNA levels of PR3, MPO, selected myelopoiesis transcription factors [CCAAT/enhancer binding protein α (CEBP-α), CCAAT/enhancer binding protein ß (CEBP-ß), SPI1/PU.1-related transcription factor (SPIB), spleen focus forming virus proviral integration oncogene, PU.1 homologue (SPI1)] and microRNAs (miRNAs) from patient and control peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) were analysed and associated with clinical data. Patients in stable remission had higher mRNA levels for PR3 (PBMC, PMN) and MPO (PBMC). PR3 and SPIB mRNA correlated positively in controls but negatively in patient PBMC. Statistically significant correlations existed between PR3 mRNA and several miRNAs in controls, but not in patients. PR3/MPO mRNA levels were not associated with previous or future relapses, but correlated with steroid treatment. Prednisolone doses were negatively linked to SPIB and miR-155-5p, miR-339-5p (PBMC) and to miR-221, miR-361 and miR-505 (PMN). PR3 mRNA in PBMC correlated with time since last flare, blood leucocyte count and estimated glomerular filtration rate. Our results show that elevated leucocyte PR3 mRNA levels in AAV patients in remission do not predict relapse. The origin seems multi-factorial, but to an important extent explainable by prednisolone action. Gene signatures in patients with AAV undergoing steroid treatment should therefore be interpreted accordingly.

Neutrophils from vasculitis patients exhibit an increased propensity for activation by anti-neutrophil cytoplasmic antibodies.

Anti-neutrophil cytoplasmic antibodies (ANCA) are thought to be pathogenic in ANCA-associated vasculitis (AAV) by stimulating polymorphonuclear leucocytes (PMNs) to degranulate and produce reactive oxygen species (ROS). The aim of this study was to investigate if PMNs from AAV patients are stimulated more readily by ANCA compared with PMNs from healthy controls (HCs). Differences in ANCA characteristics that can account for different stimulation potential were also studied. PMNs from five AAV patients and five HCs were stimulated with 10 different immunoglobulins (Ig)Gs, purified from PR3-ANCA-positive patients, and ROS production, degranulation and neutrophil extracellular trap (NET) formation was measured. ANCA levels, affinity and clinical data of the AAV donors were recorded. The results show that PMNs from AAV patients produce more intracellular ROS (P = 0·019), but degranulate to a similar extent as PMNs from HCs. ROS production correlated with NET formation. Factors that may influence the ability of ANCA to activate PMNs include affinity and specificity for N-terminal epitopes. In conclusion, our results indicate that PMNs from AAV patients in remission behave quite similarly to HC PMNs, with the exception of a greater intracellular ROS production. This could contribute to more extensive NET formation and thus an increased exposure of the ANCA autoantigens to the immune system.

Primary systemic vasculitis with severe α1-antitrypsin deficiency revisited.

OBJECTIVES: To study the clinical characteristics and epidemiology of the combination of primary systemic vasculitis (PSV) and severe alpha-1 antitrypsin (α1-AT) deficiency. METHOD: Patients with PSV [granulomatosis with polyangiitis (GPA) (Wegener's), microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss), and polyarteritis nodosa] were identified through diagnosis registries and serological databases. Clinical and laboratory data, including the presence of severe α1-AT deficiency, were collected from the time of diagnosis. During follow-up, data on relapses and permanent organ damage were collected. Using the county of Skåne as the denominator population, we estimated the annual incidence rate and point prevalence of PSV in people with severe α1-AT deficiency. RESULTS: Five patients (three women, median age 49 years) with PSV diagnosed between 1996 and 2008 were found to have α1-AT deficiency, all of them carrying the protease inhibitor ZZ (PiZZ) phenotype. During follow-up (median time 166 months, range 53-208), four patients experienced a total of 13 relapses. The median Vasculitis Damage Index (VDI) score for all patients was 3 (range 1-4) at year 1, and 7 (range 3-9) at the last follow-up. The incidence rate of PSV among PiZZ carriers was estimated to be 397/million [95% confidence interval (CI) 8-787]. The point prevalence on 1 January 2013 was estimated to be 4689/million (95% CI 94-9285). CONCLUSIONS: In this study both the incidence and prevalence of PSV were elevated nearly 10-fold for individuals with severe α1-AT deficiency compared with the general population. Combined with previous publications, this indicates a dose-response relationship for the genetic risk and suggests a causal relationship between the PiZ allele and vasculitis.

Phagocytosis of apoptotic cells by macrophages in anti-neutrophil cytoplasmic antibody-associated systemic vasculitis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune diseases, including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). It is not known why ANCA develop, but it has been shown that they participate in pathogenesis by activating polymorphonuclear neutrophils (PMNs). In this study we hypothesize that dysregulation of phagocytosis in AAV leads to the accumulation of apoptotic neutrophils seen in association with blood vessels in AAV. These cells progress into secondary necrosis, contributing to tissue damage and autoantibody formation. Peripheral blood cells were counted, and phagocytosis was investigated using monocyte-derived macrophages (MØ) and PMNs from healthy blood donors (HBD), AAV patients and systemic lupus erythematosus (SLE) patients. Furthermore, the effect of serum was assessed. Phagocytosis was measured using flow cytometry. The results showed no deviation in monocyte subpopulations for AAV patients compared to HBDs, although there was a decrease in lymphocyte and pDC (plasmacytoid dendritic cell) populations (4·2 × 10(6) cells/l versus 10·4 × 10(6) cells/l, P < 0·001). The number of neutrophils was increased (6·0 × 10(9) cells/l versus 3·8 × 10(9) cells/l, P < 0·001). There were no differences found in the ability of MØs to engulf apoptotic cells, nor when comparing apoptotic PMNs to become engulfed. However, serum from AAV donors tended to decrease the phagocytosis ability of MØs (36%) compared to serum from HBDs (43%). In conclusion, there is no intrinsic dysfunction in the MØs or in the PMNs that have an effect on phagocytic activity, but ANCA may play a role by decreasing phagocytic ability.

Extensive endoscopic image-guided sinus surgery decreases BPI-ANCA in patients with cystic fibrosis.

Antineutrophil cytoplasm autoantibodies (ANCA) directed against bactericidal/permeability-increasing protein (BPI) are common in patients with cystic fibrosis (CF), and serum levels are correlated with lung colonization by Pseudomonas aeruginosa and the severity of lung damage. The production of BPI-ANCA may be due to the costimulation of BPI when mounting an immune response against P. aeruginosa. The effect of surgery aiming to eradicate bacteria and infected tissue on BPI-ANCA levels is sparsely described. A cohort of patients with CF were included: 53 patients having extensive image-guided sinus surgery (EIGSS) with topical postoperative antibiotic treatment, 131 non-operated controls and 36 who had double lung transplantation (LTX). In all 219 patients, serum samples before and after surgery or at similar intervals were analysed for IgG and IgA BPI-ANCA. The EIGSS group showed a highly significant decrease in both IgA and IgG BPI-ANCA levels compared with their own preoperative values and control group values (P < 0.001-0.02). The LTX patients also showed a highly significant decrease in both IgA and IgG BPI-ANCA levels (P < 0.001). EIGSS and LTX decrease IgA and IgG BPI-ANCA levels in patients with CF, indicating that extensive removal of infected tissue influences the pathogenic process of autoantibody production. The results shown herein are in favour of applying EIGSS in selected patients with CF and for using BPI-ANCA as a surrogate marker for guiding further therapeutic interventions.

Association of cigarette smoking with organ damage in primary systemic vasculitis.

OBJECTIVES: To study the association between late organ damage in patients with primary systemic vasculitis (PSV) and cigarette smoking. PSV included Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), Churg-Strauss syndrome (CSS), and polyarteritis nodosa (PAN). METHODS: The pattern and extent of organ damage according to the Vasculitis Damage Index (VDI) were analysed for 86 prevalent cases with PSV retrieved from a geographically defined population in southern Sweden (46 WG, 27 MPA, four CSS, and nine PAN). Data on clinical findings, laboratory tests, and smoking habits were collected from case records from the time of diagnosis. The patients were stratified into two main groups according to their smoking habits: smokers (subdivided into active and ex-smokers) and non-smokers (patients who had never smoked). RESULTS: Data on smoking habits were available for 77 patients (90%). Thirty-three (38%) patients were categorized as smokers and 44 (51%) were non-smokers. Smoking was more common in men (61.5% vs. 23.6% in women, p = 0.001). There were no differences in smoking habits between the main diagnostic groups (WG 40% smokers, MPA 45%). Ear, nose, and throat (ENT) damage was significantly more prevalent in non-smokers (p = 0.001). Myocardial infarction (MI) and end-stage renal disease (ESRD) were more common in the current smokers (p = 0.04) than in the non-smokers. CONCLUSIONS: We found ENT damage to be significantly less prevalent in smokers. This is the first report of a possible modifying effect of cigarette smoking on the development of organ damage in PSV, but more studies are needed before any firm conclusions can be made.

Epitope shift of proteinase-3 anti-neutrophil cytoplasmic antibodies in patients with small vessel vasculitis.

Anti-neutrophil cytoplasmic antibodies against proteinase 3 (PR3-ANCA) are used as diagnostic tools for patients with small vessel vasculitis (AASV). We have produced chimeric mouse/human PR3 molecules and investigate changes in reactivity over time and the possible relationship between epitope specificity and clinical course. Thirty-eight PR3-ANCA-positive patients diagnosed between 1990 and 2003 were followed until December 2005. Plasma was collected at each out-patient visit and older samples were retrieved retrospectively. Patients reacted with multiple epitopes at the time of diagnosis. At subsequent relapses 12 patients shifted reactivity, in 11 cases from epitopes located in the C-terminal towards epitopes in the N-terminal. Patients with reactivity against N-terminal parts of PR3 at diagnosis had a significantly lower relapse rate, 30% compared to 78% in the group with predominantly C-terminal reactivity (P = 0.04). The reactivity pattern did not correlate to outcome measured as death, end-stage renal disease or vasculitis activity index score (VDI) at 5 years. Further research is necessary to conclude if this is a general phenomenon.

Elevated neutrophil membrane expression of proteinase 3 is dependent upon CD177 expression.

Proteinase 3 (PR3) is a major autoantigen in anti-neutrophil cytoplasmic antibodies (ANCA)-associated systemic vasculitis (AASV), and the proportion of neutrophils expressing PR3 on their membrane (mPR3+) is increased in AASV. We have shown recently that mPR3 and CD177 are expressed on the same cells in healthy individuals. In this study we try to elucidate mechanisms behind the increased mPR3 expression in AASV and its relationship to CD177. All neutrophils in all individuals were either double-positive or double-negative for mPR3 and CD177. The proportion of double-positive neutrophils was increased significantly in AASV and systemic lupus erythematosus patients. The proportion of mPR3+/CD177+ cells was not correlated to general inflammation, renal function, age, sex, drug treatment and levels of circulating PR3. AASV patients had normal levels of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. Pro-PR3 was found to constitute 10% of circulating PR3 but none of the mPR3. We found increased mRNA levels of both PR3 and CD177 in AASV, but they did not correlate with the proportion of double-positive cells. In cells sorted based on membrane expression, CD177-mRNA was several-fold higher in mPR3+ cells. When exogenous PR3 was added to CD177-transfected U937 cells, only CD177+ cells bound PR3 to their membrane. In conclusion, the increased membrane expression of PR3 found in AASV is not linked directly to circulating PR3 or PR3 gene transcription, but is dependent upon CD177 expression and correlated with the transcription of the CD177 gene.

The extent and pattern of organ damage in small vessel vasculitis measured by the Vasculitis Damage Index (VDI).

OBJECTIVES: To assess the extent and pattern of irreversible organ damage in patients with Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), polyarteritis nodosa (PAN), and Churg-Strauss syndrome (CSS) by a cross-sectional point prevalence study within a defined geographical area. METHODS: The Vasculitis Damage Index (VDI) was recorded for 86 prevalent cases, classified as 46 patients with WG, 27 with MPA, nine with PAN, and four with CSS from a defined population in southern Sweden, with a median age of 64.8 years and a median disease duration of 9 years. The VDI was determined for all patients at the day of point prevalence (pp), 1 January 2003. RESULTS: The median VDI score was 3 [interquartile range (IQR) 2-5] for all patients: 3 (2-4) for WG, 3 (1.5-4.5) for MPA, 5 (2-6) for PAN, and 1.5 (0.75-2.75) for CSS. Only 9% of patients had not been assigned a single item of damage. The most common damage was cardiovascular, followed by renal, neuropsychiatric, ear nose and throat (ENT), and musculoskeletal. Major vascular and treatment-related damage was associated with advanced age whereas ENT damage was more prevalent in younger patients. There was an almost complete separation between ENT damage and cardiac and renal damage with only two out of the 22 patients assigned ENT damage having experienced renal damage; none had been assigned cardiac damage. Patients with cardiac damage had significantly higher damage rates. CONCLUSIONS: Damage remains an important problem for patients with systemic vasculitis despite effective remission-inducing drugs. Only a small fraction of patients are unmarked by their disease.

Alport syndrome in southern Sweden.

AIM: The aim of the present investigation is to study the epidemiology of Alport syndrome in southern Sweden, to search for mutations in the COL4A5 gene and to estimate the mutation frequency. PATIENTS AND METHODS: Patients with suspected Alport syndrome were identified in an area with a population of 1.45 million. Clinical criteria were used to establish the diagnosis and samples for mutation analysis were collected. Mutation analyses were performed with Single-Stranded Conformation Polymorphism analysis (SSCP) of PCR-amplified genomic DNA. RESULTS: Altogether 25 families with hereditary nephritis were identified. Alport syndrome with X-linked transmission was evident in 14 families, with juvenile (< 31 years) progression to end-stage renal failure (ESRF) in ten, and adult (> or = 31 years) in four families. CONCLUSION: The frequency of males with X-linked disease was calculated to one in 17,000 male births (95% confidence interval (CI) 1/10,500-1/28,600), and the prevalence to one in 40,000. A total of seven females with ESRF were identified, with a median age at ESRF of 45 years. The male to female ratio of cases with ESRF was 4.9 to 1. The risk of developing ESRF among females was from the expected incidence roughly estimated to 12%. Patients with X-linked disease constituted 1.8% of patients with ESRF in the examined area. A mutation was identified positive in 10 of 14 families with X-linked disease, but never in families not fulfilling the clinical criteria for Alport syndrome. In families with juvenile phenotype and positive mutation analysis, the mutation frequency was calculated to between 1/78,000 and 1/198,000 (95% CI 1/42,000-1/177,000) if the effective fertility was estimated to be between 0 and 0.2.

Systemic necrotizing vasculitides in severe alpha1-antitrypsin deficiency.

We describe the clinical presentation and outcome in a series of eight patients with systemic necrotizing vasculitis and severe alpha1-antitrypsin (AAT) deficiency followed up at three Swedish hospitals during 1968-92. We also review six other cases reported in the literature during the same period. Diagnosis of severe AAT deficiency was based on the presence of the PiZZ phenotype, or low plasma total trypsin inhibitory capacity, or a low plasma AAT concentration (10-40% of the normal mean value) and presence of the PiSZ or PiFZ phenotype. The diagnosis of systemic vasculitis was biopsy-verified in all eight patients. Pretreatment laboratory findings, treatment protocol, and outcome were reviewed in each of the 14 patients. Of the eight patients in the Swedish series, six had systemic vasculitis of the microscopic polyangiitis form, one had Wegener's granulomatosis, and another had Henoch-Schönlein purpura. In the series as a whole (n = 14), median age at diagnosis was 48 years (range 44-84), the median number of affected organs was eight, and all 14 patients had skin involvement, and either renal or joint involvement (in most cases both); 71% (10/14) had emphysema; 57% (8/14) had hepatic abnormalities (two having cirrhosis, two fibrosis, and one multiple aneurysms in hepatic arteries); one patient who presented with acute ulcerative colitis developed manifest vasculitic syndrome three years later; and 64% (9/14) died, the major cause of death being renal failure. This syndrome, characterized by multiple organ involvement and fatal outcome, has been underdiagnosed. Physicians should be alert to the presence of the PiZ AAT deficiency gene in patients with systemic vasculitis, especially when the course is progressive or when the patient also has emphysema or cirrhosis. Awareness of those features may aid prompt recognition and enable early treatment.

How and why should we detect ANCA?

Antineutrophil cytoplasmic antibodies (ANCA) have become an established tool for the diagnosis of systemic vasculitis. The major role for ANCA testing is in diagnosing renal insufficiency of unknown origin, where a positive test indicates whether the patient will benefit from immunosuppressive treatment or not. A negative test result almost completely rules out the presence of systemic vasculitis. In this clinical setting the major antigens for ANCA are proteinase 3 and myeloperoxidase, and antibodies to these antigens can best be tested by ELISA. In other clinical settings like inflammatory bowel disease, arthritis and so on, several other ANCA specificities have been described and the IIF test is preferred. However, the clinical value of these somewhat more esoteric specificities is doubtful. New developments in assay techniques and better knowledge of specific epitopes will lead to tools for the improved diagnosis as well as follow up of patients during treatment, as has already been seen with the capture assay for PR3-ANCA.

Pseudomonas-induced lung damage in cystic fibrosis correlates to bactericidal-permeability increasing protein (BPI)-autoantibodies.

OBJECTIVE: Lung damage is the most common cause of death in cystic fibrosis (CF). It is induced by bacterial colonization and inflammatory activity perpetuates its course. Autoantibodies directed against BPI (bactericidal permeability increasing protein), called BPI-ANCA, have recently been associated with cystic fibrosis. Here we confirm this association and evaluate the relation between ANCA and total IgG level as they relate to bacterial colonization, pulmonary function, and musculoskeletal symptoms. METHODS: BPI-ANCA, MPO-ANCA, and PR3-ANCA were measured with ELISA in 46 adult patients with CF. Total IgG was determined by immunoturbidimetry. Results were correlated to bacterial colonization, lung function and musculoskeletal symptoms. RESULTS: BPI-ANCA was found in 33 patients. In the whole group, both BPI-ANCA and total IgG were inversely correlated to lung function, but in patients chronically colonized with Pseudomonas aeruginosa (P. aeruginosa), BPI-ANCA alone was correlated to lung damage (p = 0.01). Median lung function, measured as forced expiratory volume in 1 second, in P. aeruginosa colonized patients with high levels of BPI-ANCA was 43% of the predicted value. In BPI-ANCA negative, the corresponding figure was 83%. In patients not colonized with P. aeruginosa, this relation was less evident. No correlation between ANCA and musculoskeletal symptoms was seen. CONCLUSION: P. aeruginosa induced lung damage in CF patients is associated with the presence of BPI-ANCA. P. aeruginosa colonized patients without BPI-ANCA have almost normal lung function. We suggest that BPI-ANCA discriminate P. aeruginosa colonized CF patients with severe lung damage from those whose disease is less destructive. Vasculitis like symptoms in CF are not ANCA associated.

ANCA and IgG subclasses.

We studied IgG subclass distribution of ANCA in 247 patients with ELISA. We used monoclonal subclass specific antibodies and purified MPO and proteinase 3 as antigen. We found that IgG1 and IgG4 yield high values in both groups. We also found that high IgG2 titers were rare among the anti-proteinase 3 positive, while it was common among anti-MPO sera. In the assays for IgG3 the situation was the opposite.

Prevalence of Wegener's granulomatosis, microscopic polyangiitis, polyarteritis nodosa and Churg-Strauss syndrome within a defined population in southern Sweden.

OBJECTIVES: To estimate the point prevalence (p.p.) of Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), polyarteritis nodosa (PAN) and Churg-Strauss syndrome (CSS) within a defined population in southern Sweden. METHOD: A cross-sectional p.p. study using multiple sources for case identification. The study area, a healthcare district around the city of Lund in southern Sweden (Mellersta Skånes sjukvårdsdistrikt), had, on 31 December 2002, a total population of 287 479 inhabitants. All the identified cases were verified by medical record review. The patients were classified according to an algorithm based on the American College of Rheumatology classification criteria 1990 and the Chapel Hill Consensus Conference definitions 1994. RESULTS: Eighty-six patients (49% female) with a median age of 64.8 yrs (range 15-90.5) fulfilled the study criteria. There were 46 patients with WG; 27 with MPA; nine with PAN; and four with CSS. The p.p. per million inhabitants was estimated on 1 January 2003 to be 160 (95% confidence interval 114-206) for WG, 94 (58-129) for MPA, 31 (11-52) for PAN and 14 (0.3-27) for CSS. Capture-recapture analysis estimated the completeness of the case finding to 96%. CONCLUSIONS: The prevalence of WG, MPA, PAN and CSS in our district is the highest figure reported so far. Explanations for this finding may include high incidence, extensive ANCA-testing, good survival as well as sensitive search methods for case identification.