Introduction: Brick industry workers are exposed to silica dust and they are at risk of developing silicosis. Serum Neopterin is used as indicative of a pro-inflammatory immune status and it could be used as a biological marker for diagnosis of silicosis Aim of Work: To assess the environmental exposure for silica at clay brick industry and evaluate the use of serum Neopterin as an early biomarker for silicosis among silica exposed workers. Materials and Methods: A cross-section study was done on 118 individuals; 58 exposed to silica (28 workers of them were diagnosed to have silicosis) and 60 unexposed workers were used as control. The studied group was subjected to a questionnaire, clinical examination, spirometry, chest radiograph, serum Neopterin, and environmental measurements. Results: Mean values of environmental
free crystalline and respirable silica were higher than the national and international permissible levels. Significantly deteriorated spirometry measurements were observed among exposed workers mostly among the silicotic group. The serum Neopterin median was significantly higher among the silicotic group (23.8nm\l) than the non-silicotic exposed (12.1nm\l) and control groups (3.6nm\l). There were significant positive correlations of Neopterin level with the silica exposure (r = 0.9), the work duration (r =0.8), and radiographic findings (r =0.7). Monitoring of serum Neopterin showed its good diagnostic capacity with cutoff value17nm/L (The area under the curve was 0.88), with sensitivity, 86 % and specificity of 87%. Conclusion: The current study results support the use of serum Neopterin as an early biomarker for silicosis screening amongsilica exposed workers in early stages before developing fibrosis.