Biomarkers in peripheral blood from patients with chronic silicosis caused by artificial quartz agglomerates

Background: Silicosis produced by Artificial Quartz Agglomerates (AQA) evolves more aggressively than the classical form in miners. This entity is emerging worldwide and a significant group of cases has been detected in the province of Cadiz (Spain) in recent years. Biomarkers in the blood of silicotic patients are needed as tools for diagnosis, prognosis of the disease and response to treatment. Objective: To evaluate the plasma levels of some biomarkers (MP-1, MMP-2, MMP-7, MMP-9 and MMP-10, TGFβ, IL-1β, TNFα, IL-18 and MIP-1α), in healthy subjects compared with patients with simple (SS) or complicated (CS) silicosis, in order to use them as biomarkers of the disease. Methods: Fifty-seven patients diagnosed with silicosis by AQA and 18 healthy controls were studied. The blood biomarkers were quantified by single or multiplex ELISA. Results: MMP-2 and MMP-7 were increased in patients with silicosis compared to healthy volunteers, but only MMP-7 (not MMP-2) was found significantly augmented when silicotic patients were split in SS and CS according to the ILO classification. No differences were found for MMP-1, MMP-9, MMP-10, IL-18 and TGFβ. However, IL-1β and TNFα were significantly increased in CS group compared to healthy patients, but not compared to SS group. MIP-1α, showed an increasing gradient when healthy, SS and CS groups were compared. Conclusions: Combining the results of some of the biomarkers studied may be useful in the diagnosis of silicosis. Moreover, several biomarkers, such as MIP-1α, should be helpful to improve predictions of the evolution of the disease