Farm Exposure as a Differential Risk Factor in ANCA-Associated Vasculitis

Abstract

ObjectiveTo investigate the association of farm exposure and the development of ANCA-associated vasculitis (AAV).MethodsOne hundred eighty-nine well defined patients with AAV (n = 119 with granulomatosis with polyangiitis [GPA], n = 48 with microscopic polyangiitis [MPA], n = 22 patients with eosinophilic granulomatosis with polyangiitis [EGPA]) and 190 controls (n = 119 patients with rheumatoid arthritis, n = 71 with large vessel vasculitis) were interrogated using a structured questionnaire. Factors investigated were occupation, farm exposure, contact to different livestock, participation in harvesting, residence next to a farm, MRSA status, and contact to domestic pets at disease onset or ever before. The odds ratio (OR) and 95% confidence interval [95%CI] were calculated for each item.ResultsUnivariate analysis revealed a strong association of AAV with regular farm exposure; OR 3.44 [95%CI 1.43–8.27]. AAV was also associated with regular contact to cattle 4.30 (1.43–8.27), pigs 2.75 (1.12–6.75) and MRSA carriage 3.38 (1.11–10.3). This association was stronger in the subgroup of GPA patients. OR in this group for farm exposure was 4.97; [2.02–12.2], for cattle 6.71 [95% CI 2.19–20.7], for pigs 4.34 [1.75–10.9], and MRSA carriage 5.06 [1.62–15.8]). There was no significant association of MPA or EGPA with these parameters.ConclusionA significant association between farm exposure or farm animal exposure and AAV especially in the subgroup of patients with GPA has been identified. This suggests that these entities are distinct and have different triggers for the immune process.

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

“…In addition the clinical picture varies to some extent with increased involvement of upper airways and presence of granulomas in GPA patients mainly associated with auto-antibodies against PR3 [22,23]. Also environmental and genetic studies propose that GPA and MPA are distinct diseases with different etiological mechanisms [24][25][26]. This would motivate separate analyses of these groups in future studies.…”

Disease-specific incident glomerulonephritis displays geographic clustering in under-serviced rural areas of British Columbia, Canada

“…Several studies have demonstrated an association of ANCA-associated vasculitis and lupus with occupational risk factors such as agricultural and livestock farming, and carbon monoxide and silica exposure. [32][33][34][35] Consistent with these observations, the rural regions of BC with prominent clusters of glomerular disease have common industries known to generate environmental pollutants, including agriculture, farming, forestry, and mining. 36 These hypotheses require further study, and our results can inform future research seeking to explore the potential role of such environmental exposures in the pathogenesis of glomerular diseases.…”

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

“…In our study, farming also showed a strong association with EGPA. Two previous studies on farming and AAV included EGPA patients, but again the numbers were too small (6,11). Given the structure of our questionnaire, we were unable to distinguish between the various farming exposures and could only exclude an association between EGPA and pesticides.…”

“…In AAV, particularly granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), some occupational exposures or activities (e.g., silica and farming) have been found to be associated with an increased risk of disease. However, most of these studies were underpowered and included very few, if any, patients with EGPA (6–11).…”