Our white blood cells are our internal army that defended us against invaders.
In our blood, we found 5 different types:
Their average number is constant between individuals. However, the increase of one or more of them may be a sign of an ongoing infection (viral, bacterial or parasitic). Also, a decline of one or more of them, is a sign that our immune system is less efficient, perhaps consecutive to defect in the bone marrow (which produces the blood cells). Also, HIV-positive people may also present low levels of lymphocytes. These cells are a key indicator of our immune state.
These 5 types of cells have different roles or functions. A bit like a football team, which is composed of a goalkeeper, defenders, midfielders and attackers, even if all have a different role, together they share a common objective… to win the game.
Neurotrophils are predominant (about 50 to 70% of leukocytes) and can feel the presence of foreign elements and “eat”, or more scientifically, phagocyte, them. Monocytes have also this role, but they can also activate the lymphocytes when a larger response is needed.
Basophils and eosinophils are involved in the allergic response. In addition, eosinophilis are also implicated in the response against parasites. These immune cells attached to the surface of the parasite and released the contents of their granules. The toxic released molecules attacked and killed the invader.
There are several types of lymphocytes. The B cells produced antibodies that attacked bacteria, viruses, etc.. These molecules are like remote-controlled missiles, but unlike during wars, only recognized and caused the destruction of the enemy. The T cells attacked sick cells such as cells infected by viruses or tumor cells.
Finally, an analysis of free blood proteins can also give many clues about our health. It is a very common examination that can assess the state of certain organs such as the liver or kidneys, and highlight some abnormalities (inflammatory syndrome, autoimmune diseases, lymphoma, etc.).
Without going into very complicated details, there are two families of proteins present in the plasma: albumins and globulins.
Albumin is the most abundant protein in the blood (60%). These are produced by the liver and are essential for the exchange of liquids between the blood and the different organs or tissues. Generally, a low level of albumin is associated to liver or kidney dysfunction and edema.
There are different types and subtypes of Globulins: alpha1, alpha2, beta1 and beta2, and gamma globulins or, also called, antibodies/immunglobulins. There are five classes of immunoglobulins: A, G, D, E and M.
All of the antibody classes are not necessarily produced after an infection and this is why their analysis in patient’s blood may guide a diagnosis. For example, an increase in A, G or M types is a sign of a normal immune response whereas E type is associated with allergies.