Study the relationship of endothelial damage / dysfunction due to occupational exposure to low dose ionizing radiation versus high dose exposure during radiotherapy.

BACKGROUND

Vascular injuries caused by irradiation include acute vasculitis with neutrophil invasion, endothelial cell (EC) swelling, capillary loss, and activation of coagulator mechanisms, along with local ischemia and fibrosis. The circulating endothelial cells (CECs), increase dramatically in diseases with vascular damage.

AIM: The aim of this study is to provide data on the endothelial dysfunction due to occupational exposure to low dose ionizing radiation versus high dose exposure during radiotherapy (RT).

PATIENTS AND

METHODS

This study included 100 subjects divided into three main groups: Group I: High dose exposure group: 50 breast cancer patients treated with post-operative radiotherapy. Group II: Low dose exposure group: 25 hospital radiation workers. Group III: 25 healthy volunteers' age and sex matched as control group who had never worked in radiation-related jobs. TM levels measured by enzyme linked immunosorbent assay (ELISA). Circulating endothelial cells (CEC) enumerated in peripheral blood by flow cytometric analysis of their signature receptor CD146.

RESULTS

% CD146+ cells and plasma TM were significantly increased in radiation workers and after exposure to radiotherapy treatment in breast cancer patients. When comparing patients group with radiation workers group, we found significant elevation in plasma TM in radiation workers while insignificant difference was found in % CD146+ cells.

CONCLUSION

CECs and plasma TM both are increased in radiation workers and patients treated with radiotherapy. They may constitute valuable markers of endothelial injury. Workers exposed to low doses of ionizing radiation may develop significant endothelial dysfunction predisposes them to cardiovascular complications namely thrombosis, mostly due to oxidative stress among other causes.