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Autoimmune Diseases


Autoimmune Diseases overview and Definition

Autoimmune diseases occurs due to hyperactivity of the immune system.The indivduals immune system starts to fight against its own cell resulting in autoimmune disease.


Pathophysiology

The immune system of the body mainly focus on the body’s two subsets of T-lymphocytes, known as T helper cells TH1 and TH2. In the normal immune response, TH1 cells releases the mediators which aids the body to defend against invasion from parasites, bacteria and viruses.

In atoimmune disorder, TH2 cells and their mediators encourage the immune system to recognise allergens as an invader, and produce a response against the foreign bodies.Some states that the people living in sterile environment free of exposure to antigen develops reduced immune response to fight against them.

For an autoimmune disorder to take place,the allergen must be come into contact with the body.. Antigen-presenting CELLS SUCH as the macrophages and dentritic cells which are present in the mucosal surface of the cells sensitize the antigen.. the triggering factors enters into the immune system in many ways such as through inhalation,through skin contact, and antigen presenting cells sensitize these allergens and provoke an immune response and this allergen is processed and displayed on the surface of the antigen presenting cells. These cells then migrate to the T lymphocytes and presents the antigen to them which in turn activates B cells to secerete IgE antibodies. This IgE antibodies which is specific to the allergen comes into contact with mast cells on the mucosal surface and basophils on the blood.

After the period of sensitisation described above there is a period of latency, and on subsequent re-exposure to the allergen the allergic response is triggered: allergen cross-links with the IgE on the surfaces of the mast cell or basophil, causing the cell to ‘degranulate’ or release inflammatory mediators. These include largely histamine and other mediators, including cysteinyl leukotrienes, prostaglandins and kinins. They have different actions in terms of symptoms in different organs


Clinical signs & symptoms

Skin rashes

Fatigue

Achy muscles swelling and redness

Low grade fever

Numbness and tingling of the skin

trouble concentrating


Differential Diagnosis

For an disease to be considered as an autoimmune disease it should comes under whitebyski’s criteria:

  • Direct evidence from transfer of disease-causing antibody or disease-causing T lymphocyte white blood cells.
  • The disease should  be capable of replicating the same autoimmune conditions in experimental animals.
  • Circumstantial evidence from clinical clues

Symptoms of the autoimmune disease in early stages include common illness, fatigue,fever,malaise,joint pain and rashes. Due to the fact symptoms vary for affected location, disease causing agents, and individuals, it is difficult for proper diagnosis.

Antinuclear antibody:

It is an disease use to identify certain types of proteins.the protein produced  are against the own tissue in autoimmune diseases.It is the first line of investigation in Lupus erythematosus as it provides 95% of the accuracyin them.

Complete blood count:

it looks  after the total red blood cell count,white blood cell,haematocrit,platelets ,hemoglobin level.For example in leucopenia the white blood cell count is decreased.

Complement

A test used to measure levels of a protein group of the immune system called complement within blood. If complement is found in low levels, this may be an indication of disease.

C reactive protein

C reactive protein, a protein made in the liver generally increases with inflammation, and may be high in autoimmune disease.

Erythrocyte sedimentation rate:

This test measures the rate at which a patient's blood cells descend in a test tube. More rapid descents may indicate inflammation, a common symptom of autoimmune disease.

If these tests are indicative antibody abnormalities and inflammation, further tests will be conducted to identify the autoimmune disease present


Prevention

controls the autoimmune processes

make the body to fight against the diseases and improves the immune function of the body.

stay away from the allergens.


Reference

http://cdc.govt.in

http:://healthline.in

http://who.org.in

http://medlineplus.gov.in