The HLA region in ANCA-associated vasculitis: characterisation of genetic associations in a Scandinavian patient population.

OBJECTIVE: The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are inflammatory disorders with ANCA autoantibodies recognising either proteinase 3 (PR3-AAV) or myeloperoxidase (MPO-AAV). PR3-AAV and MPO-AAV have been associated with distinct loci in the human leucocyte antigen (HLA) region. While the association between MPO-AAV and HLA has been well characterised in East Asian populations where MPO-AAV is more common, studies in populations of European descent are limited. The aim of this study was to thoroughly characterise associations to the HLA region in Scandinavian patients with PR3-AAV as well as MPO-AAV. METHODS: Genotypes of single-nucleotide polymorphisms (SNPs) located in the HLA region were extracted from a targeted exome-sequencing dataset comprising Scandinavian AAV cases and controls. Classical HLA alleles were called using xHLA. After quality control, association analyses were performed of a joint SNP/classical HLA allele dataset for cases with PR3-AAV (n=411) and MPO-AAV (n=162) versus controls (n=1595). Disease-associated genetic variants were analysed for association with organ involvement, age at diagnosis and relapse, respectively. RESULTS: PR3-AAV was significantly associated with both HLA-DPB1*04:01 and rs1042335 at the HLA-DPB1 locus, also after stepwise conditional analysis. MPO-AAV was significantly associated with HLA-DRB1*04:04. Neither carriage of HLA-DPB1*04:01 alleles in PR3-AAV nor of HLA-DRB1*04:04 alleles in MPO-AAV were associated with organ involvement, age at diagnosis or relapse. CONCLUSIONS: The association to the HLA region was distinct in Scandinavian cases with MPO-AAV compared with cases of East Asian descent. In PR3-AAV, the two separate signals of association to the HLD-DPB1 region mediate potentially different functional effects.

Are JAKis more effective among elderly patients with RA, smokers and those with higher cardiovascular risk? A comparative effectiveness study of b/tsDMARDs in Sweden.

OBJECTIVES: To investigate whether the relative effectiveness of janus kinase inhibitors (JAKis) versus tumour necrosis factor inhibitors (TNFi) or other biological disease-modifying antirheumatic drugs in rheumatoid arthritis differ by the presence or absence of risk factors for cardiovascular (CV) disease, age, sex and smoking. METHODS: Through Swedish registers, we identified 13 493 individuals with 3166 JAKi, 5575 non-TNFi and 11 286 TNFi treatment initiations 2016-2022. All lines of therapy were included, with the majority in second line or higher. Treatment response was defined as the proportion reaching European Alliance of Associations for Rheumatology (EULAR) good response and Clinical Disease Activity Index (CDAI) remission, respectively, within 6 months. Crude percentage point differences in these proportions (JAKis, and non-TNFis, vs TNFis) overall and by risk factors were observed, and adjusted for confounders using linear regression models. Predicted probabilities of response and remission were estimated from adjusted Poisson models, and presented across CV risk and age. RESULTS: Overall, adjusted percentage point differences indicated higher response (+5.0%, 95% CI 2.2% to 7.9%) and remission (+5.8%, 95% CI 3.2% to 8.5%) with JAKis versus TNFis. The adjusted percentage point differences for response in those above 65, at elevated CV risk, and smokers were +5.9% (95% CI 2.7% to 9.0%), +8.3% (95% CI 5.3% to 11.4%) and +6.0% (95% CI 3.3% to 8.7%), respectively. The corresponding estimates for remission were +8.0% (95% CI 5.3% to 10.8%), +5.6% (95% CI 3.0% to 8.2%) and +7.6% (95% CI 5.5% to 9.7%). CONCLUSIONS: As used in clinical practice, response and remission at 6 months with JAKis are higher than with TNFi. Among patients with risk factors of concern, effectiveness is similar or numerically further increased. For individualised benefit-to-risk ratios to guide treatment choice, safety and effectiveness in specific patient segments should be considered.

Dupilumab for relapsing or refractory sinonasal and/or asthma manifestations in eosinophilic granulomatosis with polyangiitis: a European retrospective study.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is often associated with glucocorticoid-dependent asthma and/or ear, nose and throat (ENT) manifestations. When immunosuppressants and/or mepolizumab are ineffective, dupilumab could be an option. We describe the safety and efficacy of off-label use of dupilumab in relapsing and/or refractory EGPA. PATIENTS AND METHODS: We conducted an observational multicentre study of EGPA patients treated with dupilumab. Complete response was defined by Birmingham Vasculitis Activity Score (BVAS)=0 and prednisone dose ≤4 mg/day, and partial response by BVAS=0 and prednisone dose >4 mg/day. Eosinophilia was defined as an eosinophil count >500/mm3. RESULTS: Fifty-one patients were included. The primary indication for dupilumab was disabling ENT symptoms in 92%. After a median follow-up of 13.1 months, 18 patients (35%) reported adverse events (AEs), including two serious AEs. Eosinophilia was reported in 34 patients (67%), with a peak of 2195/mm3 (IQR 1268-4501) occurring at 13 weeks (IQR 4-36) and was associated with relapse in 41%. Twenty-one patients (41%) achieved a complete response and 12 (24%) a partial response. Sixteen (31%) patients experienced an EGPA relapse while on dupilumab, which was associated with blood eosinophilia in 14/16 (88%) patients. The median eosinophil count at the start of dupilumab was significantly lower in relapsers than in non-relapsers, as was the median time between stopping anti-IL-5/IL-5R and switching to dupilumab. CONCLUSION: These results suggest that dupilumab may be effective in treating patients with EGPA-related ENT manifestations. However, EGPA flares occurred in one-third of patients and were preceded by eosinophilia in 88%, suggesting that caution is required.

Identification and functional characterization of a novel susceptibility locus for small vessel vasculitis with MPO-ANCA.

OBJECTIVE: To identify and characterize genetic loci associated with the risk of developing ANCA-associated vasculitides (AAV). METHODS: Genetic association analyses were performed after Illumina sequencing of 1853 genes and subsequent replication with genotyping of selected single nucleotide polymorphisms in a total cohort of 1110 Scandinavian cases with granulomatosis with polyangiitis or microscopic polyangiitis, and 1589 controls. A novel AAV-associated single nucleotide polymorphism was analysed for allele-specific effects on gene expression using luciferase reporter assay. RESULTS: PR3-ANCA+ AAV was significantly associated with two independent loci in the HLA-DPB1/HLA-DPA1 region [rs1042335, P = 6.3 × 10-61, odds ratio (OR) 0.10; rs9277341, P = 1.5 × 10-44, OR 0.22] and with rs28929474 in the SERPINA1 gene (P = 2.7 × 10-10, OR 2.9). MPO-ANCA+ AAV was significantly associated with the HLA-DQB1/HLA-DQA2 locus (rs9274619, P = 5.4 × 10-25, OR 3.7) and with a rare variant in the BACH2 gene (rs78275221, P = 7.9 × 10-7, OR 3.0), the latter a novel susceptibility locus for MPO-ANCA+ granulomatosis with polyangiitis/microscopic polyangiitis. The rs78275221-A risk allele reduced luciferase gene expression in endothelial cells, specifically, as compared with the non-risk allele. CONCLUSION: We identified a novel susceptibility locus for MPO-ANCA+ AAV and propose that the associated variant is of mechanistic importance, exerting a regulatory function on gene expression in specific cell types.

Outcomes of COVID-19 in patients with primary systemic vasculitis or polymyalgia rheumatica from the COVID-19 Global Rheumatology Alliance physician registry: a retrospective cohort study.

BACKGROUND: Patients with primary systemic vasculitis or polymyalgia rheumatica might be at a high risk for poor COVID-19 outcomes due to the treatments used, the potential organ damage cause by primary systemic vasculitis, and the demographic factors associated with these conditions. We therefore aimed to investigate factors associated with COVID-19 outcomes in patients with primary systemic vasculitis or polymyalgia rheumatica. METHODS: In this retrospective cohort study, adult patients (aged ≥18 years) diagnosed with COVID-19 between March 12, 2020, and April 12, 2021, who had a history of primary systemic vasculitis (antineutrophil cytoplasmic antibody [ANCA]-associated vasculitis, giant cell arteritis, Behçet's syndrome, or other vasculitis) or polymyalgia rheumatica, and were reported to the COVID-19 Global Rheumatology Alliance registry were included. To assess COVID-19 outcomes in patients, we used an ordinal COVID-19 severity scale, defined as: (1) no hospitalisation; (2) hospitalisation without supplemental oxygen; (3) hospitalisation with any supplemental oxygen or ventilation; or (4) death. Multivariable ordinal logistic regression analyses were used to estimate odds ratios (ORs), adjusting for age, sex, time period, number of comorbidities, smoking status, obesity, glucocorticoid use, disease activity, region, and medication category. Analyses were also stratified by type of rheumatic disease. FINDINGS: Of 1202 eligible patients identified in the registry, 733 (61·0%) were women and 469 (39·0%) were men, and their mean age was 63·8 years (SD 17·1). A total of 374 (31·1%) patients had polymyalgia rheumatica, 353 (29·4%) had ANCA-associated vasculitis, 183 (15·2%) had giant cell arteritis, 112 (9·3%) had Behçet's syndrome, and 180 (15·0%) had other vasculitis. Of 1020 (84·9%) patients with outcome data, 512 (50·2%) were not hospitalised, 114 (11·2%) were hospitalised and did not receive supplemental oxygen, 239 (23·4%) were hospitalised and received ventilation or supplemental oxygen, and 155 (15·2%) died. A higher odds of poor COVID-19 outcomes were observed in patients who were older (per each additional decade of life OR 1·44 [95% CI 1·31-1·57]), were male compared with female (1·38 [1·05-1·80]), had more comorbidities (per each additional comorbidity 1·39 [1·23-1·58]), were taking 10 mg/day or more of prednisolone compared with none (2·14 [1·50-3·04]), or had moderate, or high or severe disease activity compared with those who had disease remission or low disease activity (2·12 [1·49-3·02]). Risk factors varied among different disease subtypes. INTERPRETATION: Among patients with primary systemic vasculitis and polymyalgia rheumatica, severe COVID-19 outcomes were associated with variable and largely unmodifiable risk factors, such as age, sex, and number of comorbidities, as well as treatments, including high-dose glucocorticoids. Our results could be used to inform mitigation strategies for patients with these diseases. FUNDING: American College of Rheumatology and the European Alliance of Associations for Rheumatology.

Are Farming and Animal Exposure Risk Factors for the Development of Granulomatosis With Polyangiitis? Environmental Risk Factors Revisited: A Case-control Study.

OBJECTIVE: To investigate the possible association between animal exposure and risk for granulomatosis with polyangiitis (GPA). METHODS: Patients with GPA at the Department of Rheumatology, Uppsala University Hospital, between January 1, 2011, and December 31, 2018, were consecutively included. All patients filled in a questionnaire on possible environmental exposures: occupation, hobbies, and animal contact. As controls we included 128 patients with rheumatoid arthritis (RA) and 248 population controls collected from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, matched for age, sex, and geographical area of residence. The controls filled out a questionnaire on current and past contact with farming and animals, at the time of the RA patient's diagnosis. RESULTS: A total of 62 patients with GPA, 128 patients with RA, and 248 population controls were included in the study. GPA was significantly associated with horse exposure, with a 2- to 3-fold increased risk compared with RA (OR 3.08, 95% CI 1.34-7.08) and population controls (OR 2.61, 95% CI 1.29-5.29). Borderline increased risks were found for any animal contact, but no association was found when analyzing contact with cats/dogs only. A significant association was found between GPA and farming compared to the population controls (OR 7.60, 95% CI 3.21-17.93). CONCLUSION: This study has identified for the first time, to our knowledge, a significant association between exposure to specific animals, namely horses, and the development of GPA. The results also support previous studies reporting an association between farming and GPA, underscoring the possibility of exogenous factors as initiators in the development of GPA.

Tick-borne encephalitis (TBE) vaccine to medically immunosuppressed patients with rheumatoid arthritis: A prospective, open-label, multi-centre study.

BACKGROUND: Tick-borne Encephalitis (TBE) is endemic in south-eastern Sweden as well as in the Baltic regions, Central Europe and Russia. Ageing and immunosuppressed individuals are more prone to severe disease and neurological complications. We assessed the immunogenicity of TBE-vaccine in rheumatoid arthritis (RA) patients treated with tumor necrosis factor-inhibitors (TNFi) and/or methotrexate (MTX). METHODS: TBE vaccine, FSME-Immune(®) or Encepur(®), was administered to non-immune RA patients as well as age and gender matched healthy controls. Individuals <60 years of age were given three doses at month 0, 1, 12. Individuals ≥ 60 years old were given an additional priming dose at month 3, i.e. a total of four doses. Tick-borne encephalitis neutralizing antibodies were assessed by a rapid fluorescent focus inhibition test. RESULTS: The study population consisted of 66 patients and 56 age and gender matched healthy controls. Median age was 58.5 years. The patients were either treated with TNFi (n=16), TNFi+MTX (n=36) or MTX (n=14). After the last TBE-vaccine dose, given one year after the first, 39% of the patients compared to 79% of the healthy controls had seroprotective levels (p=<0.05). CONCLUSIONS: Standard TBE-vaccine schedule does not confer enough immunogenicity in this group of immunosuppressed patients, who should be carefully informed about a higher risk for vaccination failure and risk of infection when exposed in high-endemic areas.

A multicentre, randomised, controlled, open-label pilot study on the feasibility of discontinuation of adalimumab in established patients with rheumatoid arthritis in stable clinical remission.

OBJECTIVES: Treatment with tumour necrosis factor (TNF) blockers, once started as therapy for rheumatoid arthritis (RA), is usually continued indefinitely. The aim of this trial was to assess the possibility of discontinuing treatment with adalimumab (ADA) while maintaining remission in patients with RA with established disease in stable remission on combination therapy with ADA and methotrexate (MTX). METHODS: In a randomised, controlled, open-label pilot study of patients with RA in stable remission treated with ADA+MTX, patients were randomised in a 1:1 ratio to continue with ADA plus MTX (arm AM) or MTX monotherapy (arm M) for 52 weeks. Flare was defined as Disease Activity Score (DAS28) ≥2.6 or a change in DAS28 (ΔDAS28) of >1.2 from baseline at any time. Patients in arm M with a flare restarted ADA. The primary end point was the proportion of patients in remission at week 28. RESULTS: 31 patients were enrolled in the study and randomised to arm AM (n=16) or arm M (n=15). At 28 weeks, 15/16 patients (94%) and 5/15 patients (33%) in arms AM and M, respectively, were in remission (p=0.001). During the first 28 weeks, 50% (8/16) in the AM arm and 80% (12/15) in the M arm had a flare (p=0.08). The number of patients in the AM and M arms with ≥1 ΔDAS28 >1.2 during the first 28 weeks was 1/16 (6%) and 8/15 (53%), respectively (p=0.005). CONCLUSIONS: In this study, remission was rarely maintained in patients with long-standing disease who discontinued ADA. Discontinuation may be feasible in only a minority of patients with established RA in stable clinical remission. TRIAL REGISTRATION NUMBER: NCT00808509.

Cathepsin S and cathepsin L in serum and synovial fluid in rheumatoid arthritis with and without autoantibodies.

OBJECTIVES: Cathepsin S and cathepsin L are endosomal proteolytic enzymes involved in the degradation of extracellular matrixes, angiogenesis and antigen presentation. Cathepsins could thus play several roles in the disease process of RA. The aim of this study was to examine differences in cathepsin S and cathepsin L levels in serum and SF of RA patients with and without ACPA and RF. METHODS: In this study 121 patients with RA and clinical signs of knee synovitis were recruited. Patient characteristics were collected and matched samples of serum and SF were analysed for cathepsin S, cathepsin L, ACPA, IgA and IgM RF, CRP and MMP3. RESULTS: SF levels of cathepsin L, cathepsin S and MMP3 were significantly higher than in serum. Serum levels of both cathepsins were significantly higher in patients with ACPA, IgM-RF and IgA-RF compared with patients without these antibodies. SF levels of both cathepsins correlated with DAS28 and CRP in ACPA- and RF-positive but not in seronegative patients. CONCLUSION: The differences in cathepsin S and cathepsin L between RA patients with and without autoantibodies indicate that these cathepsins have a specific role in the disease process of seropositive RA. In this phenotype, cathepsin serum levels may reflect the autoimmune activity, whereas the levels in SF may reflect the local inflammatory and matrix degrading process in the joint.

Leukemia and myelodysplastic syndrome in granulomatosis with polyangiitis: subtypes, clinical characteristics, and outcome.

OBJECTIVE: Previous studies have shown that patients with granulomatosis with polyangiitis (GPA) have an increased risk of hematological malignancies, especially leukemia. Our aim was to assess clinical characteristics and treatment of patients with GPA complicated by hematological malignancies with focus on leukemia and to describe these malignancies in more detail. METHODS: From the Swedish population-based patient register, all individuals with a diagnosis of GPA from 1964-2012 were identified (n = 3224). Through linkage with the Swedish Cancer Register, we searched for all cases of leukemia [International Classification of Diseases (ICD) 7: 204-207 and corresponding codes ICD 8-10] registered after the first discharge listing GPA. The GPA diagnosis was evaluated using the European Medical Association classification algorithm. To confirm the hematological malignancy, all diagnostic bone marrow samples were reclassified. Clinical data of both the GPA and hematological malignancy were collected from medical files. RESULTS: Twenty-one cases were identified, all of myeloid origin, including 9 with myelodysplastic syndrome developing to acute myeloid leukemia (MDS-AML), 7 AML, 3 MDS, and 2 chronic myeloid leukemia. The median time from GPA diagnosis to hematological malignancy was 8 years (range 5-21). All patients had severe generalized GPA and had received high doses of cyclophosphamide (CYC; median cumulative dose 96.5 g). Cytopenia occurred in 76% of the patients prior to the hematological malignancy. CONCLUSION: The findings emphasize the longterm risk of leukemia and MDS in CYC-treated, severely ill patients with GPA. Cytopenia during the course of GPA may be a warning sign and warrants a liberal attitude toward bone marrow examination.

Outcome predictors of intra-articular glucocorticoid treatment for knee synovitis in patients with rheumatoid arthritis - a prospective cohort study.

INTRODUCTION: Intra-articular glucocorticoid treatment (IAGC) is widely used for symptom relief in arthritis. However, knowledge of factors predicting treatment outcome is limited. The aim of the present study was to identify response predictors of IAGC for knee synovitis in patients with rheumatoid arthritis (RA). METHODS: In this study 121 RA patients with synovitis of the knee were treated with intra-articular injections of 20 mg triamcinolone hexacetonide. They were followed for six months and the rate of clinical relapse was studied. Non-responders (relapse within 6 months) and responders were compared regarding patient characteristics and knee joint damage as determined by the Larsen-Dale index. In addition, matched samples of serum and synovial fluid were analysed for factors reflecting the inflammatory process (C-reactive protein, interleukin 6, tumour necrosis factor alpha, vascular endothelial growth factor), joint tissue turnover (cartilage oligomeric matrix protein, metalloproteinase 3), and autoimmunity (antinuclear antibodies, antibodies against citrullinated peptides, rheumatoid factor). RESULTS: During the observation period, 48 knees relapsed (40%). Non-responders had more radiographic joint damage than responders (P = 0.002) and the pre-treatment vascular endothelial growth factor (VEGF) level in synovial fluid was significantly higher in non-responders (P = 0.002). CONCLUSIONS: Joint destruction is associated with poor outcome of IAGC for knee synovitis in RA. In addition, higher levels of VEGF in synovial fluid are found in non-responders, suggesting that locally produced VEGF is a biomarker for recurrence of synovial hyperplasia and the risk for arthritis relapse.

Increased risk of autoimmune disease in families with Wegener's granulomatosis.

OBJECTIVE: The etiology of Wegener's granulomatosis (WG) is unknown. Susceptibility genes for WG that also affect the risks of other autoimmune/inflammatory diseases have been identified, indicating the existence of shared interdisease genetic susceptibilities. To determine the effect, on a population level, of shared susceptibility on disease risk, we assessed the occurrence of autoimmune/inflammatory disease in first-degree relatives of patients with WG. METHODS: In the Swedish Hospital Discharge Register we identified 2288 individuals discharged with the diagnosis of WG between 1970 and 2003. Through linkage to the Swedish Multi-generation Register we identified 787 parents, 1212 siblings, and 3650 children of these patients. From the Register of Total Population we identified 10 controls for each patient with WG, and 65,000 of their first-degree relatives. Through linkage to the nationwide Outpatients Register, we identified autoimmune/inflammatory disease among all relatives. Relative risks were estimated as hazard ratio (HR) using Cox regression. The study period was 2001-2006. RESULTS: Biological first-degree relatives of patients with WG were at a moderately increased risk of any autoimmune/inflammatory disease (HR 1.32, 95% CI 1.18-1.49), including specific associations with, for example, multiple sclerosis (HR 1.92, 95% CI 1.16-3.16), Sjögren's syndrome (HR 2.00, 95% CI 1.07-3.73), and seropositive rheumatoid arthritis (HR 1.54, 95% CI 1.09-2.19). CONCLUSION: Relatives of patients with WG are at increased risk of being diagnosed with other autoimmune/inflammatory diseases, indicating shared susceptibility between WG and other auto-immune/inflammatory disease.

Occupational risk factors for Wegener's granulomatosis: a case-control study.

BACKGROUND: Wegener's granulomatosis is a systemic vasculitis of unknown aetiology. Previous studies have presented environmental exposures such as silica and farming as potential risk factors. OBJECTIVE: To investigate the potential risk for Wegener's granulomatosis associated with occupations involving contact with animals and various airway exposures, using a population-based approach. METHODS: In the Swedish Register of inpatient care 2288 cases with Wegener's granulomatosis were identified. Ten matched controls for every case were selected from the Swedish Population Register. By linking the cases and controls to the Swedish population censuses, information on employments before the diagnosis of Wegener's granulomatosis was collected. Relative risks were assessed as odds ratios using conditional logistic regression. RESULTS: Odds ratios for specific occupations ranged from 0.6 to 1.9, and centred symmetrically around 1. No statistically significant increased risk was noted for the investigated occupations.

Risks and relative risks of Wegener's granulomatosis among close relatives of patients with the disease.

OBJECTIVE: The etiology of Wegener's granulomatosis (WG) supposedly involves interplay between genetic susceptibility and environmental triggers. However, little is known about whether WG actually clusters in families. Information on the degree of familial aggregation in WG is of clinical relevance, because patients with WG often want to know whether their diagnosis puts their closest relatives at increased risk of the disease. The aim of this study was to investigate the risk of WG in relatives of patients with WG. METHODS: Using Swedish nationwide registers on morbidity, family structure, and vital status, we compared the occurrence of WG (register-based plus chart review) among 6,670 first-degree relatives and 428 spouses of 1,944 Swedish patients with WG with the occurrence among 68,994 first-degree relatives and 4,812 spouses of 19,655 control subjects from the general population. Relative risks were estimated using the Cox proportional hazards regression model. RESULTS: Two of the 6,670 first-degree relatives of patients with WG and 13 of the 68,994 first-degree relatives of their population controls had WG, resulting in a relative risk of 1.56 (95% confidence interval 0.35-6.90). None of the 428 spouses of patients had WG. CONCLUSION: In absolute terms, the occurrence of WG among close biologic and nonbiologic relatives of patients with WG is low. In terms of relative risk, our results provide strong evidence against a pronounced increase in familial risk such as that noted for systemic lupus erythematosus, irritable bowel disease, and multiple sclerosis but are compatible with familial aggregation of a magnitude similar to that for rheumatoid arthritis.

Increasing incidence of Wegener's granulomatosis in Sweden, 1975-2001.

OBJECTIVE: Studies of Wegener's granulomatosis (WG) since the late 1980s indicate a probable increase in incidence of unknown cause and significance, possibly related to antineutrophil cytoplasmic antibody (ANCA) testing. To extend these observations and to include calendar periods before ANCA was introduced, we assessed time trends in the incidence of WG in Sweden in the period 1975-2001. METHODS: In the population-based Swedish Inpatient Register, we identified 1938 individuals diagnosed with WG in the period 1975-2001, and calculated the annual age and sex adjusted incidences. RESULTS: The incidence increased from 0.33 (95% CI 0.28-0.39) in the period 1975-85 to 0.77 (95% CI 0.69-0.85) in 1986-90, to 1.19 (95% CI 1.12-1.26) in 1991-2001, resulting in a mean incidence of 0.78 (95% CI 0.74-0.82). CONCLUSION: WG displays a strong temporal trend. While the increase coincides to some extent with the implementation of ANCA testing, suggestive of increased disease recognition, ANCA testing remains an incomplete explanation as increasing incidences were noted before as well as after their introduction.

Cancer incidence in a population-based cohort of patients with Wegener's granulomatosis.

Wegener's granulomatosis is necrotizing granulomatous vasculitis of unknown origin, which untreated has a high mortality within the first year of onset. The introduction of corticosteroids and cyclophosphamide in the treatment has considerably improved survival rates, but past studies have indicated an increased cancer risk, including an increased risk for urinary bladder cancer. No large assessment of the general cancer occurrence in Wegener's granulomatosis has been reported. The aim of our study was to assess the general incidence of cancer in patients with Wegener's granulomatosis and to put this in relation to the risk for bladder cancer. We identified a population-based cohort of 1,065 patients with Wegener's granulomatosis in the Swedish In-patient Register. Through linkage with the Swedish Cancer Register, we followed the cohort for cancer occurrence for up to 26 years. Standardized incidence ratios (SIR) between observed and expected numbers of cancers were used as a measure of relative risk. There was a 2-fold overall increased risk for cancer in the cohort. The increase was most pronounced for bladder cancer (SIR = 4.8; 95% CI 2.6-8.1), squamous cell skin cancer (SIR = 7.3; 95% CI 4.4-12), leukemias (SIR = 5.7; 95% CI 2.3-12) and for malignant lymphomas (SIR = 4.2; 95% CI 4.2-8.3). The results confirm previous indications of an increased risk for cancer of the urinary bladder but also points to increased risks for cancer at other sites.