Expression analysis of tumour necrosis factor alpha (TNF-α) and alkaline phosphatase in occupational workers exposed to low dose of X-radiation: A case-control study.

Objectives: To evaluate liver and inflammatory biomarkers in occupationally exposed radiology workers.

Methods: The descriptive study was conducted at Mufti Mehmood Memorial Teaching Hospital and Gomal Centre of Biochemistry and Biotechnology, Gomal University, Dera Ismail Khan, Pakistan, from September 2017 to May 2018, and comprised X-ray technicians working 48-72 hours per week, and a group of age- and gender-matched unexposed healthy controls. The exposed group was divided into three sub-groups based on their radiation work duration. Liver health status involved estimation of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase GGT and bilirubin through automated chemistry analyser, while serum tumour necrosis factor-alpha and interleukin- 6 levels through enzyme-linked immunosorbent assay technique. Relative gene expression analysis of tumour necrosis factor-alpha and alkaline phosphatase was performed through reverse transcription-polymerase chain reaction. Data was analysed using SPSS 20.

Results: Of the 70 subjects, 50(71.4%) were cases with a mean age of 36.98±8.07 years and 20(28.6%) were controls with a mean age of 36.80±7.78 years. Serum alanine aminotransferase and alkaline phosphatase levels showed significant elevation in the cases compared to the controls (p<0.0001), although alanine aminotransferase levels were within the normal range. The difference in aspartate aminotransferase, gamma-glutamyl transferase and bilirubin levels was not significant (p>0.05). Tumour necrosis factor-alpha concentration was significantly high in the cases compared to the controls (p<0.0001). In contrast with proteomic analysis, relative gene expression analysis revealed reduced level of alkaline phosphatase and tumour necrosis factor-alpha in the cases compared to the controls (p<0.05).

Conclusions: Serum proteomic analysis of X-ray technicians indicated acute inflammatory conditions, while genomic analysis exhibited down-regulation of alkaline phosphatase and tumour necrosis factor-alpha genes.