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Autoimmune disorders


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what i know about autoimmune disorders..

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Autoimmune disorders

  1. 1. By: Safana Sadiq
  2. 2.  What is autoimmunity Causes of autoimmune disorders Classification of autoimmune disorders Examples of autoimmune disorders: Graves’ disease Hashimoto’s thyroiditis Addison’s disease Myasthenia gravis Diabetes mellitus type 1Outline:
  3. 3.  Auto or self antigens Are antigens that presents in ones own cells Are altered by the action of bacteria, viruses, chemicalsor other drugs Auto antibodies Altered cell (Auto Ag) - elicits the productions ofAntibody
  4. 4.  Autoimmunity is defined as the presence of immuneresponse of auto Ab against self Ag. It can be a humoral or cell mediated immuneresponse against the constitutents of the body’s owntissues.What is autoimmunity?
  5. 5.  Autoimmunity is the failure of an organism inrecognizing its own constituent parts as non self,which allows an immune response against its owncells and tissues. Any disease that results from suchan aberrant immune response is termed anautoimmune disease.Autoimmune disease
  6. 6. 1. Sequestered or Hidden antigens Ag in the secluded places - are not accessible to theimmune system. E.g. Lens Ag, Sperm Ag, etc.2. Neo antigens Altered or Modified Antigens – by physical(irradiation), chemical (drugs) or microbial agents (intracellular viruses)3. Cessation of Tolerance It may result when tolerance to the self-Ag isabrogated.Causes of autoimmunediseases
  7. 7. 4. Cross reacting Antigens A foreign Ag which resembles self a 2nd Ag Many species share organ specific Ags. E.g. Ag of Human brain & Ag of sheep brain,Streptococcal M protein & Heart muscles,Nephritogenic strains of Streptococci Ags & Renalglomeruli shares similar epiotes.5. Loss of Immunoregulation Loss of Self tolerance - caused by over activity orlowered activity of T and B- cellsCauses of autoimmunediseases..
  8. 8. Broadly classified into 3 groups 1. Haemolytic autoimmune diseases 2. Localised autoimmune diseases 3. Systemic autoimmune diseasesClassification ofautoimmune disorders
  9. 9.  Clinical disorder due to destructions of bloodcomponents. Auto Ab are formed against one’sown RBCs, Platelets or Leucocytes. E.g. Haemolytic anaemia Thrombocytopenia Leucopenia1. Haemolytic autoimmunediseases
  10. 10.  A particular organ is affected due to auto Abs.For example: Thyroiditis Multiple sclerosis Myasthenia gravis Type I Diabetes Mellitus Graves’ Disease2. Localised autoimmune diseases orOrgan specific autoimmune diseases
  11. 11.  Immune complexes accumulate in many tissues andcause inflammation and damage Affects many organs or the whole body E.g. Systemic lupus erythematosus Rheumatoid arthritis Rheumatic fever3. Systemic autoimmune disease ornon-specific autoimmune disease
  13. 13.  Graves disease is an autoimmune disease where thethyroid is overactive, producing an excessiveamount of thyroid hormones (a serious metabolicimbalance known as hyperthyroidism andthyrotoxicosis). This is caused by thyroid autoantibodies thatactivate the TSH-receptor, thereby stimulatingthyroid hormone synthesis and secretion, andthyroid growth (causing a diffusely enlarged goiter).Graves’ Disease
  14. 14.  The body produces antibodies to the TSH-Rs(Thyroid Stimulating Hormone Receptors).*(Antibodies to thyroglobulin and to the thyroidhormones T3 and T4 may also be produced.) These antibodies (TSHR-Ab) bind to the TSH-Rs,which are located on the cells that produce thyroidhormone in the thyroid gland (follicular cells), andchronically stimulate them, resulting in anabnormally high production of T3 and T4.Graves’ Disease…
  15. 15.  This causes thestimulation of Thyroidgland to secrete moreTH (Hyperthyroidism)resulting inExophthalmus , bulgingeyes & Goitre.Graves’ Disease…Davidson’s book
  17. 17.  Hashimotos thyroiditis is a condition caused byinflammation of the thyroid gland. It is the most common thyroid disease in the U.S. Is characterized by the destruction of thyroid cells byvarious cell- and antibody-mediated immuneprocesses. Caused by auto Ab of IgG & IgM type against theconstituents of thyroid glandHashimoto’s thyroiditis
  18. 18. Abs are specifically formed for thyroid perioxidase &thyroglobulin.Abs interact with the enzymeDevelopment of inflammation in the thyroid glandThyroid gland is destroyedPatient ultimately rendered hypothyroid (too little thyroidhormone)Hashimoto’s thyroiditis pathogenesis
  19. 19. Comparison of Hashimoto’sthyroiditis & Graves DiseaseNature Reviews Immunology 2
  20. 20.  Characterised byGoitre, enlargedthyroid gland,deficiency of TH(Thyroxin)’s thryoiditis
  22. 22.  Addisons disease, or primary adrenocorticalinsufficiency, is an autoimmune diseasecharacterized by the presence of autoantibodiesdirected predominantly against 21-hydroxylase, akey regulator of mineralocorticoid andglucocorticoid synthesis.Addison’s Disease
  23. 23.  The myriad clinical manifestations of Addisonsdisease, including muscle weakness andfatigue, hypotension and hyponatremia, and loss ofaxillary and pubic hair in women, are the result ofcortisol, aldosterone and sex hormonedeficiencies, respectively.Addison’s Disease
  25. 25.  MG is a chronic autoimmune neuromuscular diseasethat affects the myoneural junction that ischaracterized by varying degrees of weakness of theskeletal (voluntary) muscles of the body. Classified as a “B cell” Disease Autoantibodies against nicotinic acetylcholinereceptorsMyasthenia Gravis
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  27. 27.  Myasthenia gravis is caused by a defect in thetransmission of nerve impulses to muscles. It occurs when normal communication between thenerve and muscle is interrupted at theneuromuscular junction - the place where nerve cellsconnect with the muscles they control. Normally when impulses travel down the nerve, thenerve endings release a neurotransmitter substance,acetylcholine.Myasthenia Gravis
  28. 28.  Acetylcholine travels through the neuromuscularjunction and binds to acetylcholine receptors whichare activated and generate a muscle contraction. In myasthenia gravis, auto Abs block, alter, ordestroy the receptors for acetylcholine at theneuromuscular junction which prevents the musclecontraction from occurring.Myasthenia Gravis
  29. 29. Diplopia (double vision)Ptosis (drooping of eyelids)Current Mdeical Diagnosis & Treatment 2007, 46th Ed.
  31. 31.  Insulin dependent diabetes mellitus (type 1) is an inflammatoryautoimmune disease of the pancreas, resulting in a lack ofinsulin. Insulin is produced in the pancreas by beta cells of the islets ofLangerhans. Insulin is necessary for glucose to get into cells andbe used for energy production. After eating, the glucose level inblood rises, which leads to insulin being released from thepancreas. In a person with type 1 diabetes mellitus, the beta cells ofLangerhans are damaged by autoimmuneinflammation, leading to an insufficiency of insulin. Theglucose level in blood rises and cells do not have enoughenergy for metabolism.Diabete Mellitus Type 1
  32. 32.  Type 2 diabetes (non-insulin-dependent diabetesmellitus) Insulin concentrations are mostly increasedbut peripheral tissues are resistant to insulin (insulinresistance). Beta cells are not able increase secretionof insulin to overcome this resistance. Type 2diabetes usually develops after 40 years of age inoverweight people, lately in obese adolescents.Type 2 Diabetes Mellitus
  33. 33. Immunobiology 6th Ed.
  34. 34.  Nature Reviews Immunology 2, p.195-204 (March2002) Dr.T.V.Rao’s lecture note on Autoimmunity Robbins Basic Pathology, 8th Edition’s disease gravis Burmester GR, Pezzuto A. Colour Atlas ofImmunology . 2003. www.diseases_john_hopkins_medical_institute/type1_diabetes_mellitus
  35. 35. THE END..