Antinuclear Antibody and Rheumatoid Factor in Silica-Exposed Workers

Abstract

A lot of workers in industries such as foundry, stonecutting, and sandblasting are exposed to higher than permissible levels of crystalline silica. Various alterations in humoral immune function have been reported in silicosis patients and workers exposed to silica dust. The aim of this study was to measure antinuclear antibody (ANA) and rheumatoid factor (RF) levels in foundry workers exposed to silica and to compare them with a control group without such exposure. ANA and RF were measured in 78 exposed and 73 non-exposed workers, and standard statistical methods were used to compare them. The two groups did not signifi cantly differ in age and smoking. Mean work duration of the exposed and non-exposed workers was (14.9±4.72) years and (12.41±6.3) years, respectively. Ten exposed workers had silicosis. ANA was negative in all workers in either group. Its mean titer did not differ signifi cantly between the exposed and control workers [(0.39±0.15) IU mL -1 vs. (0.36±0.17) IU mL -1 , respectively]. RF was positive in two workers of each group. Other studies have reported an increase in ANA and RF associated with exposure to silica dust and silicosis. In contrast, our study suggests that exposure to silica dust does not increase the level of ANA and RF in exposed workers.

T Cell Dysregulation in Non-silicotic Silica Exposed Workers: A Step Toward Immune Tolerance Breakdown

“…However, it is unclear whether autoantibody production in silica-exposed workers is predictive for the development of further AID. In opposition to some studies, our results and another study (68) did not detect RF nor ACPA in CS exposed workers. We suggest that these discrepancies may be related to physical particularities of CS microparticles in our cohort.…”

Serum autoantibodies in silicosis and non‐silicosis cement workers

“…The ANA — though non‐specific — was negative in our silicosis workers, as they all had small round radiographic opacities. Agreeing with the present study, Aminian et al [] found that ANA was negative in all studied silica‐exposed foundry workers, including workers with silicosis. Similarly, Zaghi et al [] found that silica‐exposed workers (61) were also negative for ANA — except only one silica‐exposed patient with ANA titer 1:80, centromeric pattern — which did not differ from their healthy controls.…”

Pesticides, chemical and industrial exposures in relation to systemic lupus erythematosus

“…Silica appears to be a non-specific risk factor for SLE and other systemic autoimmune diseases, and it is not known why some individuals may develop lupus instead of another autoimmune disease. Studies have shown elevated antinuclear autoantibody levels associated with silica exposure (reviewed by Parks and Cooper, 2006) (9), though not consistently (15, 16). While a minority of those with autoantibodies go on to develop SLE, specific factors that may determine progression to SLE remain unexplored.…”