The analysis of the possible association between the presence of ANCA (antineutrophil cytoplasmic antibodies) and exposure to fibrogenic dusts, containing silicon.
ANCA were determined by indirect immunofluorescence in 188 patients exposed previously to silica (mean length of exposure 20.5 years), in 84 patients exposed previously to asbestos (mean length of exposure 25.0 years), and in the control group of 73 persons. Lung functions and renal functions were measured in all the groups studied.
ANCA positivity was detected significantly more frequently (p<0.05) both in the group of workers exposed to silica (34x, i.e. 18.1%) and workers exposed to asbestos (15x, i.e. 17.9%), than in the control group (5x, i.e. 6.9%). Lung functions impairment was more frequent (p<0.01) both in the silica and asbestos exposed subjects, renal functions impairment only in the silica-exposed subjects (p<0.05), comparing with the controls.CONCLUSIONS: Asbestos, which has not been extensively studied yet, is another occupational factor besides silica, associated with ANCA-positivity. Asbestos’s influence seems even stronger, because ANCA-positivity was found also in subjects with the history of exposure to asbestos, without typical radiographic signs of asbestosis on the chest radiograph.
This finding suggests that asbestos represents another danger, even under conditions of lower exposure, when asbestosis does not develop. ANCA-associated diseases were not more frequent among subjects previously exposed to fibrogenic dusts, but further follow-up of all patients with ANCA positivity is necessary.
D. Pelclová, None.