Job strain in different types of employment affects the immune response.

The immune system, in cooperation with neuroendocrine functions, defends from cancer and infections mainly by the activity of blood natural killer (NK) cells. Blood NK activity may be influenced by the type of employment since work is the central part of life; moreover, job stress is a situation affecting both neuroendocrine and immune systems. This study examines anxiety (by STAI 1 and 2), job strain (by the Karasek's JCQ) and blood NK activity (by an in vitro radio-isotopic method) of 134 male workers. These men, over 38 years old with stable employment, were working in factories, in construction yards, in offices, as hospital attendants or as self-employed craftsmen. Workers in factories and in construction yards, with high job strain, showed lower NK activity, while office employees, with low job demand, and craftsmen with low anxiety and elevated decision latitude, showed higher NK activity; the level of NK activity of the hospital attendants was between the other groups. In conclusion, this study confirms that the type of employment, related to job stress, affects blood NK activity. Moreover, blood NK activity may be used in the bio-monitoring of workers at high risk.