Monitoring the immune system response

Inflammatory diseases are common on hospital wards. When patients are suspected of inflammatory disease it is important to rapidly differentiate between various possible causes. It is essential to distinguish between inflammations caused by infections and those that have other underlying causes. In case of an infection it is necessary to determine the responsible pathogen and understand the patient's immune response so treating physicians are able to establish a diagnosis and start appropriate treatment.

The human immune system is able to distinguish between a wide variety of pathogens from bacteria to viruses or parasites. The immune system can be divided into an innate and an adaptive part. The innate immune system is an initial, non-specific line of defence against pathogens. Its main function is to identify and remove foreign substances by specialized white blood cells and further activate the second line of defence, the adaptive immune system. The adaptive immune response is antigen-specific and requires the presentation of the pathogen's antigen to specific cells.

Typically, activated neutrophils (characterized by an increased NEUT-RI and NEUT-GI), immature granulocytes (IG), reactive lymphocytes (RE-LYMP) and antibody-synthesizing cells (AS-LYMP) can be found during different stages of the immune response. Generally, the change in value of these parameters depends on the nature of the inflammatory stimulus, severity and stage of the infection. Several studies showed that RE-LYMP and
AS-LYMP counts were mainly increased in viral infections while an increase in the NEUT-RI and NEUT-GI parameters could predict the appearance of later-stage infection markers, such as the presence of immature granulocytes, suggesting that these structural neutrophil parameters can be used to detect bacterial infections at a very early stage (reviewed in this white paper).

The 'Extended Inflammation Parameters' comprise the above mentioned parameters and can be made available on the Sysmex XN-Series. They can give an insight into the patient's immune status and provide quantitative information about the inflammatory reaction of the patient's immune system to support the differentiation between the diverse causes of an inflammation. In particular, the Extended Inflammation Parameters can help to differentiate between viral and bacterial infections, or between acute and subsiding infections, or whether there is an inflammatory condition without an infection.