Occupational silica exposure in an Australian systemic sclerosis cohort

Abstract

Objective To determine the frequency of self-reported occupational exposure to silica in SSc patients enrolled in the Australian Scleroderma Cohort Study, and to compare the disease characteristics of the silica-exposed patients with those of the non-exposed patients. Method Data collected over a 12-year period from 1670 SSc patients were analysed. We compared the demographic and clinical characteristics of those who reported occupational silica exposure with those who did not. A subgroup analysis of male patients was performed, as well as a multivariable analysis of correlates of silica exposure. Results Overall, 126 (7.5%) of the cohort reported occupational silica exposure. These individuals were more likely to be male (73 of 231, i.e. 31.6% males exposed) and to have worked in mining and construction industries. Those who reported silica exposure were younger at the onset of SSc skin involvement [odds ratio (OR) 0.9, P = 0.02], of male gender (OR 14.9, P < 0.001), have joint contractures (OR 1.8, P = 0.05) and have higher physical disability as defined by scleroderma HAQ (OR 1.4, P = 0.01). Conclusion The highest percentage of silica exposure was found in males. These patients were more likely to have the presence of certain clinical manifestations and Scl-70 antibody, which is known to confer a poor prognosis. These findings support the association between occupational silica exposure and the subsequent development of SSc. Further investigation is required to describe the range of clinical manifestations and disease course, including prognosis and treatment response, in those diagnosed with occupationally induced SSc compared with idiopathic SSc.

Clinical features and prognostic factors of systemic sclerosis in Guangxi, China: Retrospective, single‐center study of long‐term survival in 470 patients

“…Considering that SSc may be related to occupation and environmental factors, exposure to dust in these mountainous areas may have affected the prevalence of SSc in our study population. A study in Spain 23 showed that 2.0% of silicosis patients had SSc and a study in Australia 24 showed that 7.5% of SSc patients had occupational dust exposure (which was also more common in men), thus suggesting a relationship of dust exposure with SSc.…”

Nationwide and international registries on scleroderma. Past, present, and future

“…The ASIG registry has contributed to the field of PAH screening 123,124 , GI involvement 125 , overlap syndrome 126 , quality of life 127 , and activity impairment 128 . Furthermore, in the immunological characterization of patients, especially patients with anti-Ku, anti-RNA pol III, and anti-PM75-100 86,[129][130] , also the relation with occupational silica exposure 131 .…”

“…The SPIN uses a novel research design, the Multiple Cohort Randomized clinical trial Design, to collect longitudinal data related to the problems experienced by people living with SSc and as a framework for the development, evaluation, and delivery of psychosocial and rehabilitation interventions. The first step toward the long-term objectives of the SPIN is the establishment of the SPIN Cohort 131 . It does not have an associated biobank.…”

Exposure to silica and systemic sclerosis: A retrospective cohort study based on the Canadian Scleroderma Research Group

“…The prevalence of SSc in Canada in 2003 was estimated to be 74.4/100,000 females and 13.3/100,000 males ( 2 ). While SSc is more common in females, the prognosis has been consistently shown to be worse in male patients including more diffuse cutaneous SSc (dcSSc), more interstitial lung disease (ILD) and higher mortality ( 3 , 4 ). It is not known whether this different SSc phenotype and prognosis seen in males is mediated by biological/hormonal influences or whether exposure/occupation related factors in males contribute to the process.…”