The role of tumour necrosis factor-alpha (TNF-α)‎, interleukin-6 (IL-6)‎ and caspase-3 in lung diseases of cement factory workers in Assiut

Abstract EN

Respiratory tract disease represents the most important group of occupational • J-''' disease in the cement industry.

Inhalation of silica dust leads to silicosis, the alveolar \v macrophage plays a key role in the onset and development of inflammatory and $ fibrogenic lung disease through their ability to release potent inflammatory and r"' fibrogenic mediators.

Y The present study aimed to measure the levels of TNF-a and IL-6, in order to f determine a possible relationship between the presence of silica particles, cytokine ":t production, and pulmonary dysfunction in workers exposed to cement dust for less and - more than 10 years.

Also, to test the hypothesis that silica-induced apoptosis of human AM may involve the activation of ICE, we determine the activity of caspase-3 in these workers.

The correlations between these previously mentioned bioindices and pulmonary function tests were investigated.

The study consisted of forty male patients workers engaged in cement production and a control group of 40 normal healthy males.

The exposed workers were divided according to the duration of the exposure time into two groups: 22 workers were exposed to cement dusts for less than 10 years and 18 workers for more than 10 years.

Determination of TNF-a and IL-6 in plasma of exposed workers enzyme linked immunosorbant assay (ELISA) and caspase-3 activity in white blood cells of exposed workers by colorimetric methods.

The results of the current study showed that pulmonary function tests were significantly lower in exposed workers for more than 10 years than those with less than 10 years.

Moreover; in exposed workers for more than 10 years, the plasma levels of TNF- a, and IL-6 were significantly increased compared to those levels in exposed workers to cement dusts for less than 10 years (P < 0.001 for each).

Besides, in this group of workers, caspase-3 activity levels were significantly higher than that of controls (P < 0.001).

However, there was no significant difference in caspase-3 activity levels between both groups of workers.

Significant correlations were also found between TNF-a, IL-6[ caspase-3 activity levels and pulmonaryfunction tests.

In conclusion, the results of the present study showed that prolonged exposure to silica stimulates AM to produce significant increased levels of TNF a and IL-6 compared to those of controls.

Moreover, increased caspase-3 activity was also observed in exposed workers.

These changes were associated with a significant reduction in pulmonary functions of these workers.