Inflammation (Latin inflammatio) is the body's innate, physiological response to factors that damage its tissues. How exactly is inflammation going? What symptoms may accompany it? When can inflammation develop into other diseases?

Inflammation(Latininflammatio ) triggers an "alarm" that indicates the presence of a threat, then removes the cause via the appropriate cells and signaling molecules. Under normal conditions, inflammation is self-limiting and results in healing and complete tissue repair. Sometimes, however, the inflammation is not fully extinguished and becomes chronic. Chronic inflammation isan undesirable phenomenonthat can lead to the development of various diseases.

Why does inflammation arise?

Inflammation is one of the mechanisms of innate immunity. It is the body's primary response to various types of damage. It is often believed that inflammation only accompanies infections caused by pathogenic microorganisms. Indeed, inflammation may be part of antimicrobial, antiviral, or antifungal immunity, although these are not the only causes of the inflammatory response.

Inflammation can also be caused by other tissue damage: burns, ischemia, or mechanical trauma. A characteristic feature of the mechanisms of innate immunity is the fact that they act quickly and regardless of the type of pathogen.

Inflammation builds in the body as soon as immune cells recognize the threat. An increase in temperature, an increase in local blood flow, and a rapid inflow of inflammatory cells are among the most primal defense mechanisms in our body.

Inflammation - main symptoms

The characteristics of the inflammatory response were first described by the Roman scholar Celsus, who lived at the beginning of our era. These include:

  • calor- warming, associated with a local increase in blood flow. An additional element of the inflammatory response is a generalized increase in body temperature associated with the shift of the brain's thermoregulation center to a higher level
  • rubor-redness caused by the expansion of blood vessels in the vicinity of damaged tissue
  • dolor- pain caused by irritation of the receptors that send pain signals to the brain. The task of pain is also to "spare" damaged organs: for example, pain after a joint injury causes us to minimize its movements, which in turn improves the healing conditions of tissues
  • tumor- swelling as a result of fluid passing from the inside of the blood vessels to the damaged tissues

The addition of a fifth symptom to the above list is attributed to a Greek physician, Galen. It isfunctio laesa,or impairment of the function of an inflamed organ.

Stages in the development of inflammation

Imagine the moment the tissue is damaged by a selected factor, for example a mechanical trauma or an penetrating microorganism. How does our body react to it? Well, the inflammatory response starts almost immediately, thanks to the cells of the immune system, "living" permanently in the tissues and able to recognize the threat.

These cells begin to produce messenger molecules - cytokines, prostaglandins and leukotrienes, which transmit alarming signals throughout the body through the bloodstream. A local response to these signals is vasodilation in the vicinity of the lesion. This, in turn, allows the rapid influx of immune cells as well as other molecules needed to trigger an inflammatory response.

Inflamed tissue becomes red and warmed, which can be seen with the naked eye. In order for all the necessary elements to get where they should be, the blood vessels also become more permeable - a symptom of which is swelling at the site of damage.

The fluid that accumulates at the site of inflammation is called exudate. It contains a high concentration of proteins that allow the destruction of the pathogen, and also facilitate the subsequent repair of tissues.

When the signal of a threat is announced and the transport of the necessary ingredients is accelerated, cells step into action to remove the cause of the inflammation. I am talking about leukocytes, or white blood cells. Leukocytes find the place of damage thanks to special "indicators" placed inside the vessels in the focus of inflammation. Thanks to them, leukocytes reaching the blood are captured in the right place, and then pass from the vessel to the tissue where they can perform their functions.

In acute inflammation, neutrophils are the dominant group of leukocytes. These arecells with, among others the ability to phagocytosis, that is, "eat" harmful microorganisms and the remains of dead cells.

In addition to them, many other cells are involved in the formation and regulation of inflammation: macrophages, mast cells and dendritic cells. They are in constant contact with each other, adjusting the intensity of the inflammatory response to the current needs of the body.

Under proper conditions, inflammation should restore tissue homeostasis, i.e. full balance.

Acute inflammation resembles a battle, after which cells quickly clean up the "mess" created, and the tissues are repaired and healed.

Unfortunately, the process of extinguishing inflammation is not always going as it should. We are talking then about the transition of inflammation into a chronic form.

Chronic inflammation occurs, for example, when, despite a response from the immune system, it is not fully combating a tissue damaging factor.

In chronic inflammation, the immune response is often altered: the body cannot cope with the pathogen and begins to perceive its own tissues as the cause of the problem. Consequently, chronic inflammation is characterized by simultaneous tissue repair and damage.

This is why chronic inflammation often causes autoimmune diseases, i.e. those in which the body begins to attack and destroy its own tissues (more below).

Inflammation - diagnostics

We now know when and why inflammation develops. The question then remains: How do you know if you are actually dealing with inflammation? A clinical examination is available, revealing typical symptoms as well as laboratory markers of inflammation.

Physical examination usually shows several signs of an inflammatory response:

  • pain
  • swelling
  • warming
  • redness
  • dysfunction of the inflamed organ

With more severe inflammation, systemic symptoms such as fever or a feeling of significant weakness may be associated with them.

Laboratory tests to confirm inflammation include:

  • ESR (Biernacki's Reaction) , in the past one of the most important diagnostic tests for inflammation detection. Currently, it has been somewhat superseded by newer indicators, although it is still often marked. The correct ESR value differs depending on age and gender (the norm for menis 3-15 mm / h, for women 1-10 mm / h, while over 65 years of age in both sexes ESR should not exceed 20 mm / h).
  • Leukocyte count in the blood.The body's natural response to inflammation is a sharp increase in white blood cell counts. The normal concentration of leukocytes in the blood is 4-10 thousand / µl. A rise in white blood cells is called leukocytosis.
  • Electrophoresis , i.e. the separation of individual plasma proteins and the measurement of their concentrations. The main place of protein production in our body is the liver. During inflammation, there is a characteristic shift within its products. Proteins used to induce inflammation are significantly increased at the expense of other proteins that are not so much needed at the moment. Hence the division into so-called positive and negative acute phase proteins. The concentration of positive acute phase proteins increases with inflammation. These include, but are not limited to, CRP, haptoglobin, and fibrinogen. At the same time, in inflammation, we observe a decrease in the concentration of the so-called negative acute phase proteins: albumin and transferrin. Among the above-mentioned markers, CRP currently plays the most important role in the diagnosis of inflammation. CRP in a he althy person should not exceed 5 mg / l.

Diseases related to chronic inflammation

As mentioned above, chronic inflammation is considered a negative phenomenon, damaging your own tissues and contributing to the development of other diseases.

Impaired regulation of the immune response in chronic inflammation underlies allergic (e.g., bronchial asthma) and autoimmune diseases (e.g., rheumatoid arthritis, psoriasis, inflammatory bowel disease).

Chronic inflammation also plays an important role in the pathogenesis of atherosclerosis and related cardiovascular complications (e.g. ischemic heart disease).

It is now believed that chronic inflammation may also contribute to the development of neoplastic diseases.

Generalized Inflammatory Response Syndrome - SIRS

Describing the possible causes and consequences of the development of inflammation, one should also mention SIRS (Systemic Inflammatory Response Syndrome) - generalized inflammatory response syndrome.

Behind this complicated name there is a specific form of inflammation that affects the entire body. We deal with it when acute inflammation, instead of extinguishing itself, is constantly intensifying.

The constant production of inflammatory molecules - cytokines - causes changes in many organs. Clinical symptoms of SIRSinclude:

  • significant increase in heart rate
  • breathing rate increase
  • a high fever or a drop in body temperature
  • significantly increased number of white blood cells (or their drastic decrease)

Inflammation of this magnitude requires immediate intervention because it poses a serious threat to organ function.

In the case of SIRS, one should strive to eliminate the factor that caused such an intense inflammatory response.

Failure to control the systemic inflammatory response syndrome may lead to the development of multiple organ failure and, consequently, even death.

How do we treat inflammation?

Treatment of inflammation requires a medical consultation each time. Not every inflammation requires immediate use of drugs. Moreover, it is very important to choose the right type and route of administration (general / local preparations).

Generally speaking, there are two main groups of agents in the treatment of inflammation: non-steroidal anti-inflammatory drugs and steroidal anti-inflammatory drugs.

Non-steroidal anti-inflammatory drugs (NSAIDs for short) include the popular aspirin, ibuprofen and naproxen. This group of drugs works by blocking the action of cyclooxygenase, an enzyme necessary for the production of molecules that cause inflammation.

Non-steroidal anti-inflammatory drugsusually quickly alleviate the unpleasant symptoms of inflammation, however, taking them is associated with the risk of side effects (mainly damage to the gastrointestinal mucosa, which may aggravate peptic ulcer disease, and in extreme cases even lead to bleeding). For this reason, they should always be used in the lowest effective doses, preferably under the supervision of a doctor.

The second group of anti-inflammatory drugs areglucocorticosteroids,most commonly used in the treatment of chronic inflammatory diseases (asthma, autoimmune diseases).

Chronic, oral use of glucocorticosteroids is associated with a number of side effects (electrolyte disturbances, diabetes, osteoporosis), so now topical preparations have gained popularity. These include, for example, glucocorticoid-based ointments for the treatment of inflammatory skin conditions, or inhaled glucocorticosteroids, which are the basis for the treatment of bronchial asthma.

Finally, it is also worth mentioning the newest methods of fighting inflammation, which are mainly used when the methods described above fail. I am talking about yesso-called biological drugs, i.e. antibodies (human or man-made) to specific molecules that cause inflammation (e.g. various types of interleukins).

This type of therapy is reserved primarily for severe autoimmune diseases. Its main disadvantage is - so far - a very high price.

An example of a drug belonging to this group is Infliximab, used, inter alia, in in the treatment of Crohn's disease.

Currently, many biological preparations with anti-inflammatory properties are the subject of ongoing scientific research.

About the authorKrzysztof BialaziteA medical student at Collegium Medicum in Krakow, slowly entering the world of constant challenges of the doctor's work. She is particularly interested in gynecology and obstetrics, paediatrics and lifestyle medicine. A lover of foreign languages, travel and mountain hiking.

Read more articles from this author

Category:

Immune system