I. Wichmann et al., ANTIMYELOPEROXIDASE ANTIBODIES IN INDIVIDUALS WITH OCCUPATIONAL EXPOSURE TO SILICA, Annals of the Rheumatic Diseases, 55(3), 1996, pp. 205-207
Objective-To determine the prevalence of autoantibodies to myeloperoxi
dase (MPG) in a series of patients exposed to silica. Methods-The stud
y included 52 patients with occupational exposure to silica (mean expo
sure time seven years) and a control group comprising seven patients w
ith progressive systemic sclerosis (PSS), six patients with systemic l
upus erythematosus (SLE), and 15 healthy individuals. Antibodies to MP
O were detected using commercial enzyme linked immunosorbent assay (EL
ISA) plates coated with MPO. Indirect immunofluorescence studies for a
ntineutrophil cytoplasmic antibodies were performed using ethanol and
formol fixed neutrophils. Clinical and biological data of individuals
exposed to silica were recorded (published previously). Results-Antibo
dies to MPO were detected in 14 individuals exposed to silica (27%). T
here was a statistically significant difference in anti-MPO ELISA unit
s between the healthy subjects and patients (SLE, PSS, silica exposed
individuals) (p < 0.01), but no difference between the different disea
se groups. Conclusions-Individuals chronically exposed to silica, whet
her or not they have a connective tissue disease, have levels of antib
odies to MPO (as detected by ELISA) that are greater than those found
in the normal population, but similar to those in patients with system
ic diseases not induced by silica (SLE/PSS).