Innovative tool determines immune system differences in humans

Published: 2017-08-01


Immune system function varies significantly between individuals, and up to now there has been no effective means of measuring and describing these differences. Now, a study led by Petter Brodin (Karolinska Institutet/SciLifeLab)  shows that white blood cell composition is unique in individuals, and that the composition of these cells may predict immune system responses. The study, which is published in PNAS, paves the way for more individualized treatment of diseases involving the immune system, e.g. autoimmune disorders, allergies and various forms of cancer.

The human immune system comprises a complex network of different white blood cells, which coordinate their efforts in order to combat different external and internal threats. This network varies widely between different individuals, but the dissimilarities have been difficult to measure and comprehend. Furthermore, the composition and reactivity of the immune system is not constant even in the same individual, but varies over time in response to external factors. In previous studies, Petter Brodin and colleagues have shown that, in humans, individual differences in immune defence can be attributed primarily to the many different environmental factors unique to each individual, e.g. diet, infections, vaccines and microflora.

The present study was performed in collaboration with Massachusetts Institute of Technology (MIT) and Stanford University in the USA and describes the development of a tool for characterizing the unique composition of white blood cells in individuals. It  also shows that the test may predict how individuals will respond to a given treatment, e.g. individual response to an influenza vaccine.

“By measuring all populations of white blood cells in the blood at the same time, we can describe the composition of an individual’s immune system and show that this is unique for the individual. We call this measure, the individual’s “immunotype”. We have also found that this immunotype makes the complex immune system more understandable and predictable,” says Petter Brodin, physician and researcher at SciLifeLab and the Department of Medicine, Solna, at Karolinska Institutet.

The study encompassed blood sample analyses from approximately 1,500 healthy individuals and tested in vitro how their white blood cells respond to different stimuli. They have also vaccinated individuals against influenza and studied which antibody protection the individuals developed thereafter. It transpired that all different types of stimulation could be predicted based on the individual’s immunotype, which was surprising, according to Petter Brodin.

“Our technique can be scaled up, and my hope is that eventually it will be used clinically to predict those individuals who may benefit from a particular immunological treatment or a certain vaccine. The technique may also contribute to more individualized drugs to treat autoimmune disease and allergies, as well as immunotherapy to treat cancer, which can be adapted based on the individual’s immune response,” says Petter Brodin.

Press release from Karolinska Institutet