Occupational Exposures and Smoking in Eosinophilic Granulomatosis With Polyangiitis: A Case-Control Study.

OBJECTIVE: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Environmental agents and occupational exposures may confer susceptibility to EGPA, but data are scarce. This study was undertaken to investigate the association between occupational exposures (e.g., silica, farming, asbestos, and organic solvents) and other environmental agents (e.g., smoking) and the risk of EGPA. METHODS: Patients with newly diagnosed EGPA (n = 111) and general population controls (n = 333) who were matched for age, sex, and geographic area of origin were recruited at a national referral center for EGPA. Exposures were assessed using a dedicated questionnaire administered by a specialist in occupational medicine, under blinded conditions. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: Exposures to silica (OR 2.79 [95% CI 1.55-5.01], P = 0.001), organic solvents (OR 3.19 [95% CI 1.91-5.34], P < 0.001), and farming (OR 2.71 [95% CI 1.71-4.29], P < 0.001) were associated with an increased risk of EGPA. Co-exposure to silica and farming yielded an OR of 9.12 (95% CI 3.06-27.19, P < 0.001), suggesting a multiplicative effect between these 2 exposures. Smoking (current and former smokers combined) was significantly less frequent among patients with EGPA compared to controls (OR 0.49 [95% CI 0.29-0.70], P < 0.001). The pack-year index was also lower among patients with EGPA (OR 0.96 [95% CI 0.94-0.98], P < 0.001). The association of silica and farming was primarily aligned with ANCA-positive EGPA, while the association of smoking status and organic solvents was primarily aligned with ANCA-negative EGPA. CONCLUSION: The environment can influence susceptibility to EGPA. Exposure to silica, farming, or organic solvents is associated with an increased risk of EGPA, while smoking is associated with a lower risk. These exposures seem to have distinct effects on different EGPA subsets.

Slowly progressive anti-neutrophil cytoplasmic antibody-associated renal vasculitis: clinico-pathological characterization and outcome.

BACKGROUND: Although rapidly progressive glomerulonephritis is the main renal phenotype of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), slow renal disease progression is sometimes observed. These forms have been rarely discussed; we analysed their prevalence, clinico-pathological characteristics and outcome. METHODS: We screened patients with microscopic  polyangiitis (MPA) and granulomatosis with polyangiitis followed at seven referral centres and selected those with estimated glomerular filtration rate (eGFR) reduction <50% over a 6-month period preceding diagnosis. Data regarding patient features and response to treatment were retrieved. RESULTS: Of 856 patients, 41 (5%) had slowly progressive renal AAV. All had MPA and all but one was P-ANCA/myeloperoxidase (MPO) ANCA-positive. At diagnosis, the median age was 70 years [interquartile range (IQR) 64-78] and extra-renal manifestations were absent or subclinical (interstitial lung lesions in 10, 24%). The median (IQR) eGFR was 23 mL/min/1.73 m2 (15-35); six patients (15%) had started renal replacement therapy (RRT). All had proteinuria (median 1180 mg/24 h, IQR 670-2600) and micro-haematuria. Main histologic findings were extracapillary proliferation at chronic stages and glomerulosclerosis; following Berden's classification, 6/28 biopsies (21%) were 'focal', 1/28 (4%) 'crescentic', 9/28 (32%) 'mixed' and 12/28 (43%) 'sclerotic'. At last follow-up (median 32 months, IQR 12-52), 20/34 patients (59%) treated with immunosuppression had eGFR improvement >25% as compared with diagnosis, while 4/34 (12%) had started RRT. CONCLUSIONS: AAV may present with slow renal disease progression; this subset is hallmarked by advanced age at diagnosis, positive MPO-ANCA, subclinical interstitial lung lesions and chronic damage at kidney biopsy. Partial renal recovery may occur following immunosuppression.

Fibrocytes in Chronic Periaortitis: A Novel Mechanism Linking Inflammation and Fibrosis.

OBJECTIVE: Chronic periaortitis (CP) is a rare disease characterized by periaortic and periiliac fibroinflammatory tissue. The pathogenic mechanisms leading to tissue accumulation and activation of fibroblasts are unclear. This study was undertaken to explore the role of fibrocytes, circulating precursors of tissue fibroblasts, in patients with CP. METHODS: We studied 44 patients with newly diagnosed CP and 30 healthy controls. Circulating fibrocytes were identified as Col1+CD45+ cells using flow cytometry. Retroperitoneal tissue biopsy samples from 9 CP patients were stained with anti-type I procollagen, anti-CXCR4, and anti-CD45 antibodies and analyzed by confocal microscopy to detect tissue-infiltrating fibrocytes. Circulating levels and tissue expression of CXCL12, a CXCR4 ligand that promotes fibrocyte homing, were investigated using enzyme-linked immunosorbent assay and immunohistochemistry, respectively. We also characterized T helper polarization in biopsy samples from CP patients and measured serum levels of a panel of cytokines that are hallmarks of T helper responses and capable of influencing fibrocyte differentiation. RESULTS: The frequency of circulating Col1+CD45+ fibrocytes was higher in patients than in controls (P = 0.0371). CD45+proCol1+ and CXCR4+proCol1+ cells were detected in all examined biopsy samples from CP patients. Serum levels of CXCL12 were also higher in CP patients than controls (P = 0.0056), and tissue-infiltrating inflammatory cells intensely expressed CXCL12. Increased serum levels of Th2 cytokines (e.g., interleukin-13 [IL-13] and IL-10) were found in patients, and immunohistochemistry revealed a dominant infiltration of GATA-3+ cells, also indicating Th2 polarization; Th2-skewed responses are known to promote fibrocyte differentiation. CONCLUSION: Our findings indicate that fibrocytes are enriched in the peripheral blood of CP patients and infiltrate target lesions. The accumulation of fibrocytes in the pathologic tissue might be driven by CXCL12, and Th2-skewed immune responses are likely to facilitate their differentiation.

Rituximab as Maintenance Treatment for Systemic Lupus Erythematosus: A Multicenter Observational Study of 147 Patients.

OBJECTIVE: The efficacy of rituximab (RTX) in systemic lupus erythematosus (SLE) is a subject of debate. This study was undertaken to investigate the outcomes of RTX treatment in a European SLE cohort, with an emphasis on the role of RTX as a maintenance agent. METHODS: All patients with SLE who were receiving RTX as induction therapy in 4 centers were included. Patients who received a single course of RTX and those who received RTX maintenance treatment (RMT) were followed up after treatment. Disease flares during the follow-up period were defined as an increase in disease activity and the number or dose of immunosuppressive drugs. RESULTS: Of 147 patients, 27% experienced treatment failure at 6 months. In a multivariate analysis, a low number of previous immunosuppressive therapies (P = 0.034) and low C4 levels (P = 0.008) reduced the risk of treatment failure. Eighty patients received RMT over a median of 24.5 months during which 85 relapses, mainly musculoskeletal, were recorded (1.06 per patient). At the time of the last RTX course, 84% of the patients were in remission. Twenty-eight (35%) of 80 patients never experienced a flare during RMT and had low damage accrual. Active articular disease at the time of the first RTX administration was associated with a risk of flare during RMT (P = 0.011). After RMT, relapse-free survival was similar to that in patients receiving a single RTX course (P = 0.72). CONCLUSION: RMT is a potential treatment option for patients with difficult-to-treat disease. Relapses occur during RMT and are more likely in those with active articular disease at the time of the first RTX administration. Relapse risk after RMT remains high and apparently comparable to that seen after a single RTX course.

Clinical and Prognostic Significance of Serum IgG4 in Chronic Periaortitis. An Analysis of 113 Patients.

Objective: Chronic periaortitis (CP) is a rare fibro-inflammatory disorder that incorporates idiopathic retroperitoneal fibrosis, inflammatory abdominal aortic aneurysms, and perianeurysmal retroperitoneal fibrosis. CP is included in the spectrum of IgG4-related disease. Since CP patients rarely undergo diagnostic biopsies, serum IgG4 levels are often used to classify CP as IgG4-related. However, the clinical and prognostic significance of serum IgG4 in CP is unknown. Methods: We measured serum IgG4 in active CP patients and compared the clinical characteristics, response to therapy and outcome of patients with high and normal levels. We also tested the diagnostic significance of IgG4 by comparing its levels in CP patients, healthy and disease controls (malignancies, Erdheim-Chester disease, large-, and small-vessel vasculitis). Results: We studied 113 consecutive patients with active CP. Twenty-four (21.2%) had high serum IgG4 (>135 mg/dL). The demographic, laboratory, and clinical characteristics of patients with high and normal IgG4 were similar, and so were the rates of ureteral obstruction and the disease characteristics on CT, MRI, and 18F-FDG-PET. Patients with high IgG4 only had a higher frequency of extra-retroperitoneal fibro-inflammatory lesions (p = 0.005). There were no significant differences in response to therapy and relapses between the two groups. Serum IgG4 levels did not discriminate CP from controls. Conclusions: Serum IgG4 levels are high in a minority of CP patients and do not identify specific clinical or prognostic subgroups; only a higher frequency of extra-retroperitoneal lesions is found in high-IgG4 patients. Serum IgG4 levels do not help in the differential diagnosis between CP and its mimics.

Brief Report: Rituximab for the Treatment of Adult-Onset IgA Vasculitis (Henoch-Schönlein).

OBJECTIVE: Adult-onset IgA vasculitis (Henoch-Schönlein) (IgAV) is a rare systemic vasculitis characterized by IgA1-dominant deposits. The treatment of adult-onset IgAV is controversial and is based on the combination of glucocorticoids and immunosuppressive agents, but many patients have refractory or relapsing disease despite treatment. Rituximab (RTX) is a B cell-depleting antibody of proven efficacy in antineutrophil cytoplasmic antibody-associated vasculitis. We undertook this study to test the efficacy and safety of RTX in a multicenter cohort of patients with adult-onset IgAV. METHODS: In this multicenter observational study, we included patients with adult-onset IgAV who had received RTX either for refractory/relapsing disease or because they had contraindications to conventional glucocorticoid/immunosuppressive therapy. We analyzed the rates of remission (defined on the basis of the Birmingham Vasculitis Activity Score [BVAS]) and relapse as well as the variations over time in estimated glomerular filtration rate (GFR), proteinuria, C-reactive protein (CRP) level, BVAS, and prednisone dose. RESULTS: Twenty-two patients were included; their median duration of follow-up was 24 months (interquartile range 18-48 months). Sixteen patients received RTX as add-on therapy and 6 as monotherapy. Twenty patients (90.9%) achieved remission, and 7 of those 20 patients (35%) had subsequent relapse of disease. There were significant reductions in 24-hour proteinuria (P < 0.0001), CRP level (P = 0.0005), BVAS (P < 0.0001), and prednisone dose (P < 0.0001) from RTX initiation through the last follow-up visit; estimated GFR remained stable. RTX was generally well tolerated. One patient died after 60 months of follow-up. CONCLUSION: Our data suggest that RTX is an effective and safe therapeutic option for adult-onset IgAV.

Methotrexate versus cyclophosphamide for remission maintenance in ANCA-associated vasculitis: A randomised trial.

OBJECTIVES: The treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is based on remission-induction and remission-maintenance. Methotrexate is a widely used immunosuppressant but only a few studies explored its role for maintenance in AAV. This trial investigated the efficacy and safety of methotrexate as maintenance therapy for AAV. METHODS: In this single-centre, open-label, randomised trial we compared methotrexate and cyclophosphamide for maintenance in AAV. We enrolled patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA), the latter with poor-prognosis factors and/or peripheral neuropathy. Remission was induced with cyclophosphamide. At remission, the patients were randomised to receive methotrexate or to continue with cyclophosphamide for 12 months; after treatment, they were followed for another 12 months. The primary end-point was relapse; secondary end-points included renal outcomes and treatment-related toxicity. RESULTS: Of the 94 enrolled patients, 23 were excluded during remission-induction or did not achieve remission; the remaining 71 were randomised to cyclophosphamide (n = 33) or methotrexate (n = 38). Relapse frequencies at months 12 and 24 after randomisation were not different between the two groups (p = 1.00 and 1.00). Relapse-free survival was also comparable (log-rank test p = 0.99). No differences in relapses were detected between the two treatments when GPA+MPA and EGPA were analysed separately. There were no differences in eGFR at months 12 and 24; proteinuria declined significantly (from diagnosis to month 24) only in the cyclophosphamide group (p = 0.0007). No significant differences in adverse event frequencies were observed. CONCLUSIONS: MTX may be effective and safe for remission-maintenance in AAV. TRIAL REGISTRATION: clinicaltrials.gov NCT00751517.

Idiopathic Mediastinal Fibrosis: a Systemic Immune-Mediated Disorder. A Case Series and a Review of the Literature.

Mediastinal fibrosis is a rare disease characterised by fibrous proliferation in the mediastinum. It can be idiopathic or secondary to several conditions such as infections and malignancies. Anecdotal reports have described idiopathic mediastinal fibrosis (IMF) in association with other fibro-inflammatory or autoimmune diseases. We report nine new IMF cases recently seen at our Fibro-Inflammatory Disease Clinic and reviewed the IMF cases reported in the English language literature throughout 2006-2016. The purposes of our literature search were to assess the frequency of the association between IMF and other immune-mediated disorders and to analyse which disorders most often coexist with IMF. Of our nine IMF cases, one was associated with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, one with large-vessel arteritis, three with idiopathic retroperitoneal fibrosis (one of which was IgG4-related), one with pancreatitis and one with IgG4-related seminal vesicle involvement. The remaining two cases, in which IMF was not associated with any other disease, were both classifiable as IgG4-related. The literature review showed that, of the 84 IMF cases identified, 27 (32 %) were associated with other idiopathic autoimmune or fibro-inflammatory disorders, particularly small-vessel vasculitis, Behçet disease, retroperitoneal fibrosis and other conditions belonging to the IgG4-related disease spectrum. Based on our own data and the literature review, we conclude that IMF is often associated with other autoimmune or fibro-inflammatory diseases; therefore, its clinical management requires an accurate screening of associated conditions. Immune-mediated mechanisms may be shared by these disorders.

Association of Serum C3 Concentration and Histologic Signs of Thrombotic Microangiopathy with Outcomes among Patients with ANCA-Associated Renal Vasculitis.

BACKGROUND AND OBJECTIVES: Complement alternative pathway (cAP) activation has recently been recognized as a key pathogenic event in ANCA-associated vasculitis (AAV). cAP dysregulation is also a major determinant of thrombotic microangiopathies (TMA), which can in turn complicate AAV. We explored the prognostic significance of cAP activation and of histologic evidence of TMA in a cohort of patients with renal AAV. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We studied 46 patients with AAV diagnosed between January 1990 and December 2011 at the Nephrology Unit of Parma University Hospital; 30 of them had undergone renal biopsy. We analyzed serum levels of C3 (sC3) and C4 (sC4) and, for 19 patients who had frozen plasma, plasma Bb and C5b-9 levels. We also reviewed all kidney biopsy specimens, specifically searching for histologic signs of TMA, and performed immunofluorescence or immunohistochemistry for C3d, C4d, Bb and C5b-9. RESULTS: sC3 was below the lower limit of normal in 35% of the patients, whereas C4 was low in only 2%. Patients with low sC3 tended to be older (P=0.04) and to have lower eGFR at diagnosis (P=0.06). The median follow-up was 78 months (interquartile range, 18-135 months); 18 patients reached ESRD (10 of 14 and 8 of 26 in the low and normal sC3 groups, respectively). Death-censored renal survival was lower in the low sC3 group than in the normal sC3 group (log-rank test, P=0.01). Eight of the 30 patients who had undergone biopsy (27%) had histologic signs of TMA; these signs were more frequent in patients with low sC3 (5 of 10 versus 3 of 20; P=0.04). Notably, patients with histologic signs of TMA had a dramatically worse death-censored renal survival than patients without TMA (log-rank test, P=0.01), with ESRD occurring in 8 of 8 patients with TMA versus 8 of 22 patients without TMA. CONCLUSIONS: Low sC3 levels and histologic signs of TMA are associated with a poor renal prognosis in patients with AAV.

Chronic periaortitis with thoracic aorta and epiaortic artery involvement: a systemic large vessel vasculitis?

OBJECTIVE: Chronic periaortitis (CP) is a rare disease characterized by fibro-inflammatory tissue surrounding the abdominal aorta and the iliac arteries. Anecdotal reports have shown that CP may also involve other vascular districts, particularly the thoracic aorta. The aim of this study was to investigate the thoracic aorta and epiaortic artery involvement in CP. METHODS: Patients were eligible if they had undergone imaging studies assessing inflammatory involvement of the thoracic aorta and its major branches (e.g. contrast CT, MRI or PET-CT). We explored the patterns of thoracic vessel involvement and compared the clinical characteristics of patients with and without thoracic disease. Where available, we also reviewed the thoracic vascular/perivascular tissue biopsies. RESULTS: Of 153 CP patients seen between 1999 and 2012, 77 were eligible. Of these, 28 (36%) had thoracic involvement: 15 (54%) had thoracic periaortitis, with 7 also showing epiaortic artery involvement; 6 (21%) had periaortitis surrounding a thoracic aortic aneurysm, 2 of them with epiaortic artery involvement; 7 (25%) had a thoracic aortic aneurysm without periaortitis. Patients with thoracic disease were more frequently female (P = 0.01), were older (P = 0.001) and had a higher frequency of pain and constitutional symptoms (P = 0.02). Thoracic (peri)vascular biopsies revealed adventitial and peri-adventitial fibro-inflammatory patterns similar to those observed in abdominal CP. CONCLUSION: In about one-third of patients, CP also involves the thoracic aorta and the epiaortic arteries, which supports the hypothesis of a systemic inflammatory disease of the large arteries.

Association between idiopathic retroperitoneal fibrosis and autoimmune thyroiditis: a case-control study.

BACKGROUND: Idiopathic retroperitoneal fibrosis (IRF) is a rare disease often associated with autoimmune disorders. Whether IRF is associated with Hashimoto's thyroiditis (HT) is poorly understood and only addressed by case-reports. We evaluated the prevalence of HT in a large IRF cohort and in matched controls. METHODS: We studied 73 consecutive patients with new-onset IRF and 71 controls. The association between HT and IRF was cross-sectionally evaluated in a referral center. Longitudinally, thyroid function tests were also performed. Serum concentrations of FT4, TSH, and anti-thyroperoxidase antibodies (AbTPO) were evaluated together with thyroid ultrasound (US). Lymphocytic infiltrates were characterized in thyroid nodule fine needle aspirates (FNAB). In patients undergoing thyroidectomy, thyroid histology was also reviewed. RESULTS: A higher prevalence of AbTPO positivity (P<0.03) and US findings suggestive of autoimmune thyroiditis (US-AIT) (P<0.0001) were found in IRF patients compared to controls. In the logistic regression analysis, the risk of AbTPO-diagnosed HT and that of US-AIT was significantly higher in IRF patients than in controls (ORs, 3.56, 95% CI 1.48-8.59, P=0.004 and 4.74, 95% C.I., 2.34-9.61, P<0.0001 in AbTPO-diagnosed HT and US-AIT, respectively). Thyroid histology in IRF patients showed either classical or the fibrous variant of HT. At the end of the follow-up (median, 45 and 36 months in patients and controls, respectively), 25% of IRF patients and 3% of controls were receiving l-thyroxine. CONCLUSIONS: IRF patients have a higher risk of HT compared to controls. Thyroid function should be monitored in patients with IRF.

Asbestos and smoking as risk factors for idiopathic retroperitoneal fibrosis: a case-control study.

BACKGROUND: Idiopathic retroperitoneal fibrosis (RPF) is a rare disease. Asbestos exposure has been proposed as a risk factor for idiopathic RPF. OBJECTIVE: To investigate the role of asbestos and other occupational agents (such as silica, metals, and organic solvents), as well as environmental agents (such as smoking), and their interactions as potential risk factors for idiopathic RPF. DESIGN: Case-control study. SETTING: National referral hospital for idiopathic RPF. PATIENTS: 90 patients with idiopathic RPF and 270 control participants matched for age, sex, and region of residency. MEASUREMENTS: Occupational history was obtained using structured questionnaires administered by blinded specialists in occupational medicine. Exposure to nonoccupational agents and presence of diseases that were potentially predisposing to idiopathic RPF were assessed through patient interviews and examination of medical records. RESULTS: A history of asbestos exposure was associated with idiopathic RPF (odds ratio [OR], 4.22 [95% CI, 2.14 to 8.33]). Both current smoking (OR, 3.21 [CI, 1.46 to 7.07]) and former smoking (OR, 2.93 [CI, 1.39 to 6.14]) were more prevalent among patients than among those who never smoked. A multiplicative effect was found between tobacco smoke and both occupational asbestos exposure (OR, 12.04 [CI, 4.32 to 38.28]) and extraoccupational asbestos exposure (OR, 8.42 [CI, 2.77 to 30.58]). LIMITATION: Retrospective, questionnaire-based assessment of occupational exposure. CONCLUSION: Exposure to asbestos and tobacco smoke resulted in strong risk factors for idiopathic RPF. Coexposure to asbestos and smoke had a multiplicative effect on risk compared with single exposure. PRIMARY FUNDING SOURCE: None.