diease

Autoimmune Diseases


OVERVIEW OF Autoimmune Diseases :

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.


CAUSES :

Theories of autoimmune disorder:

Altered glycan theory:

According to this theory, the effector function of the immune response is mediated by the glycans displayed in the humoral and cells in the immune system.

Hygiene theory:

The children exposed to the multiple diseases in their childhood activities leads to the increase in the immune system.

Vitamin D immune responses:

Vitamin d is the

Genetics:

The genetic factor play an important role in the etiologic factor of the diseases.

Environmental  factors:

Environmental factors include air pollution,smoke,chemicals that are present in the surrounding.

Reduced oral intolerance

Gut dysbiosis

Enhanced gut permeability

Increased immune system

The pancreas produces the hormone insulin, which helps regulate blood sugar levels. Type 1 diabtes mellitus,.the immune system attacks and destroys insulin-producing cells in the pancreas.

High blood sugar results can lead to damage in the blood vessels, as well as organs like the heart, kidneys, eyes, and nerves.

 

Genetics:

Autoimmune disease occurs when an oen body defence starts against healthy immune system cells.Genomic scanning can clearly says  what is the genetic cause behind  it.for example

  • Diabetetes inspidius or type 1 diabetes:

In this situation beta cells of the pancreas starts to act against one’s immune system.this results in impaired blood glucose level.

  • Rheumatoid arthritis: Although there is no complete genetic mapping for this condition, several genes are thought to play a role in causing RA. The genes that influence the human immune system contain a TNF receptor associated factor 1(TRAF1). 
  • Environmental factors include:

Chemicals

Infection

Diet

Gut dysbiosis

Examples of autoimmune diseases:

Celiac diseases:

Celiac diseases leads to gastrointestinalcancer and also lymphoproloferative disorders.The main mechanism happens here is the body’s loss of immune tolerance to the ingested gluten.

Gluten is found in the barley,wheat,rye.

This might results in smallintestine,duodenal,anal,rectum,gastrointestinal tract,oesophagus cancers.

Inflammatory bowel disease:

Inflammatory bowel disease is associated with gastrointestinal cancers and lymphoproliferative diseases.the main mechanism behind the disease is the immune system of an individual starts to act against the normal gut flora.chronic irritation results in inflammation of the disease.Inflammatory bowel disease can be divided againinto crohns disease and ulcerative colitis.

Multiple sclerosis:

Multiple sclerosis is an autoimmune disease which happens when bodys T- cell starts to act against the mmyelin sheath which is present in the neurons of the brain.in the lonf run it might leads to degenerative process of the brain cells and ultimately it leads to brain cancer

Rheumatoid arthritis

 presents mild, yet significant associations with focal cancers all throughout the body as well as lymphoproliferative cancers. In rheumatoid arthritis, cells that make up the body's joints and cartilages become invasive and induce local inflammation. Additionally, the chronic inflammation and over-activation of the immune system creates an environment that favors further malignant transformation of other cells. This can explain the associations to cancer of the lungs and skin as well as the increased risk of other hematologic cancers none of which are directly affected by the inflammation of joints.

Systemic lupus erythematosus

Systemic lupus erythematosis is associated with focal cancers throughout the body and lymphoproliferative cancers. Systemic lupus erythematosus affects multiple organ systems and is characterized by a widespread loss of immune tolerance. The chronic inflammation throughout the entire body promotes the malignant transformation of other cells which contributes to the increased risk of systemic and lymphoproliferative cancers. Conversely, systemic lupus erythematosus is correlated with a decrease in some cancers. This is best explained by increased immunosurveillance in these areas, however, the mechanism for why these areas experience lower incidence is poorly understood.

Aplastic anemia

In aplastic anaemia the body fails to produce blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside there. Aplastic anaemia causes a deficiency of all blood cell types: red blood cells, white blood cells and platelet


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


COMMON CLINICAL SIGNS AND SYMPTOMS :

Skin rashes

Fatigue

Achy muscles swelling and redness

Low grade fever

Numbness and tingling of the skin

trouble concentrating


DIAGNOSTIC :

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


TREATMENT AND PROGNOSIS :

 inflammation:

Corticosteroids and oral histamines

Adrenaline-Anaphylactic reactions

Immunotherapy-it is indicated in patients who couldnt able to control the allergic reactions.

Decongestants-helps to cure running nose in allergic rhinitis

Duplimab- used in the treatment of dermatitis

Vitamins or hormones which replaces the supplememts for the body which is lacking in the persons.

Blood transfusion if the disease is blood related


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.


Medicines used in the Treatment :

Corticosteroids and oral histamines

Adrenaline-Anaphylactic reactions

Duplimab- used in the treatment of dermatitis

vitamin B12 and other hormones needed to boost the immunity.


REFERENCE :

http://cdc.govt.in

http:://healthline.in

http://who.org.in

http://medlineplus.gov.in