Demographic, exposure and clinical characteristics in a multinational registry of engineered stone workers with silicosis.

OBJECTIVES: To investigate differences in workplace exposure, demographic and clinical findings in engineered stone (ES) workers from a multinational consortium using the Engineered Stone Silicosis Investigators (ESSI) Global Silicosis Registry. METHODS: With ethics board approval in Israel, Spain, Australia and the USA, ES workers ages 18+ with a physician diagnosis of work-related silicosis were enrolled. Demographic, occupational, radiologic, pulmonary function and silica-related comorbidity data were compared cross-sectionally among countries using analysis of variance, Fisher's exact tests and logistic regression. RESULTS: Among 169 ES workers with silicosis, most were men, with mean age 51.7 (±11.4) years. Mean work tenure in stone fabrication or masonry was 19.9 (±9.8) years. Different methods of case ascertainment explained some inter-country differences, for example, workers in Queensland, Australia with a state-based surveillance program were likely to be identified earlier and with shorter work tenure. Overall, 32.5% of workers had progressive massive fibrosis, the most severe form of dust-related pneumoconiosis, of whom 18.5% reported ≤10 years of work tenure. Lung function impairment including restriction, reduced diffusion capacity and hypoxaemia was common, as was autoimmunity. CONCLUSIONS: Findings from a multinational registry represent a unique effort to compare demographic, exposure and clinical information from ES workers with silicosis, and suggest a substantial emerging population of workers worldwide with severe and irreversible silica-associated diseases. This younger worker population is at high risk for disease progression, multiple comorbidities and severe disability. The ESSI registry provides an ongoing framework for investigating epidemiological trends and developing prospective studies for prevention and treatment of these workers.

Alveolar crystal burden in stone workers with artificial stone silicosis.

BACKGROUND AND OBJECTIVE: An epidemic of silicosis has emerged due to a failure to control risks associated with exposure to high-silica content respirable dust generated while working with artificial stone products. Methods for quantification of alveolar crystal burden are needed to advance our understanding of the pathobiology of silica-related lung injury as well as assisting in the diagnosis, clinical management and prognostication of affected workers. The objective of this study was to develop and validate novel methods to quantify alveolar crystal burden in bronchoalveolar lavage (BAL) fluid from patients with artificial stone silicosis. METHODS: New methods to quantify and analyse alveolar crystal in BAL from patients with artificial stone silicosis were developed. Crystals were isolated and counted by microscopy and alveolar crystal burden was calculated using a standard curve generated by titration of respirable α-Quartz. The utility of the assay was then assessed in 23 patients with artificial stone silicosis. RESULTS: Alveolar crystal burden was greater in patients with silicosis (0.44 picograms [pg]/cell [0.08-3.49]) compared to patients with other respiratory diagnoses (0.057 pg/cell [0.01-0.34]; p < 0.001). Alveolar crystal burden was positively correlated with years of silica exposure (ρ = 0.49, p = 0.02) and with decline in diffusing capacity of the lungs for carbon monoxide (ρ = -0.50, p = 0.02). CONCLUSION: Alveolar crystal burden quantification differentiates patients with silicosis from patients with other respiratory disorders. Furthermore, crystal burden is correlated with the rate of decline in lung function in patients with artificial stone silicosis.

Hot tub lung machine.

Hot tub lung (HTL) is a pulmonary disease where a hypersensitivity pneumonitis is caused by exposure and inhalation of aerosolized non-tuberculous mycobacteria (NTM) traditionally from hot water steam. HTL can affect both immunocompromised and healthy individuals, and diagnosis is dependent on high clinical suspicion in conjunction with high-resolution computed tomography (HRCT) and microbiological evidence. We present, to our knowledge, the only case of HTL occurring from an indoor swimming pool affecting five members of a family, in which one member was not a resident of the household.

Diffuse pulmonary lymphangiomatosis treated with bevacizumab.

Diffuse pulmonary lymphangiomatosis (DPL) is a rare disease caused by uncontrolled lymphatic vessel proliferation resulting in respiratory dysfunction. Lymphatic vessel growth is influenced by vascular endothelial growth factor (VEGF). It has been shown that bevacizumab, a monoclonal antibody to VEGF type A, may be helpful in treating diseases characterized by excessive vessel proliferation. We report the case of a 51-year-old man with DPL treated with 1 mg/kg bevacizumab every three weeks for 6 months. A significant improvement in lung infiltrates was seen on post-treatment computed tomography (CT) chest with a 17.5% improvement in forced expiratory volume in one second (FEV1). The patient reported improved respiratory symptoms, and no significant adverse drug side effects were reported. The authors believe this is the first case of DPL to report lung function improvement [FEV1, forced vital capacity (FVC), and Diffusion Capacity for Carbon Monoxide (DLCO)] following bevacizumab therapy.