Original Article

 

Authors: G. Prakova¹, P. Gidikova², E. Slavov³, G. Sandeva², Zh. Racheva^4
1UMHAT – Stara Zagora EAD,
²Department of Hygiene, Epidemiology and Infectious Diseases, TU – MF Stara Zagora,
³Department of Molecular Biology, Immunology and Medical Genetics, TU – Stara Zagora,
⁴OM – Mini Maritza Iztok EAD

Author for contacts: G. Prakova, UMHAT Stara Zagora EAD

Keywords: inorganic dust, cell-mediated immunity, neopterin

 

Abstract 

Silicosis is the most common pneumoconiosis caused by the inhalation of dust containing free crystalline silica (FCS). The reasons for the fibrogenous effect of free crystalline SiO2 are not yet clearly defined. For an early biomarker of cellular immune response is indicated neopterin, which is a substance with low molecular weight, from the class of pteridines, produced by activated macrophages after stimulation with γ - interferon.
The main objective of this study was to investigate serum neopterin levels in workers exposed to dust containing FCS and to compare them with the corresponding levels in a control group and a group of patients with silicosis.
Materials and Methods: Serum neopterin was examined in 190 workers exposed to dust, 16 – as a control group and 95 – with developed silicosis. With regards to the qualitative characteristics of the inorganic dust, the surveyed workers were divided into three groups: 1st group - exposed to dust containing less than 2% FCS, 2nd group - exposed to dust containing over 2% FCS and 3rd group - exposed to asbestos dust. All tested persons were taken blood samples obtained by venipuncture after completing an informed consent to participate in the study. Serum neopterin was determined by the method ELISA, kit DRG Diagnostics, Germany in ng/mL. The obtained data were processed using software Basic Statistic and Table for Windows.
Results: Higher levels of neopterin were established in workers exposed to dust (3.26 ng/mL) by comparison with the control group (1.56 ng/mL) and patients with silicosis (2.84 ng/mL ). Serum neopterin was reliably higher in workers from the 2nd group (3.32 ng/mL) and the 3rd group (3.20 ng/mL) as compared with that of the first and the control groups. 
Conclusion: These results confirm the involvement of macrophages and cell-mediated immune reactions in the pathogenesis of pulmonary fibrosis in pneumoconiosis.