The study of immunity, the protective mechanism involving a variety of means aimed at preventing the invasion and colonisation of the body by foreign organisms.
The human immune system also plays a role in removing damaged and mutated cells from the body. The tests performed by medical scientists working in the immunology laboratory enable the immune response of an individual to disease to be assessed and monitored. More specifically, those disorders affecting the immune system itself may also be investigated.
These include deficiencies of the immune system, such as A.I.D.S., as well as those attributed to overactivity or uncontrolled immune function, such as multiple myeloma or rheumatoid arthritis.
The demonstration of an immune response is important in the diagnosis of diseases such as hepatitis.
Here, it may not be possible to isolate the causative organism by microbiological means, but its presence can be detected immunologically due to the production of antibodies by an affected individual.