AUTOIMMUNITY Flashcards
DAMAGE TO ORGANS OR
TISSUES RESULT FROM THE
PRESENCE OF THE
AUTOANTIBODY OR
AUTOREACTIVCE CELLS
AUTOIMMUNE DISEASE
SELF TOLERANCE
- Clonal deletion of relevant effector cells.
- Activation regulation of T cell
TOLERANCE MECHANISM
- Release of sequestered
antigens - Molecular mimicry
3.Polyclonal B cell activation
Antigen that are protected from
encountering the circulation are not
exposed to potentially reactive
lymphocyte
sequestered
antigen
EXAMPLE OF SEQUESTERED ANTIGEN
Myelin Basic proteins – sequestered by BBB
Sperm – Blood-testis barrie
Viral or bacterial agent contain antigens
that closely resemble self antigen.
Exposure can trigger antibody production
that in turn react with similar self-antige
MOLECULAR MIMICRY
MOLECULAR MIMICRY EXAMPLE
Poliovirus VP2 – acetylcholine receptors
Measles VP3 – Myelin Basic Protein (MBP)
Papilloma Virus E2 – insulin receptors
B CELL DEFECTS
B cell defects:
1. Abnormal expression or function of Regulatory signaling
molecules.
2. Dysregulation of cytokines
3. Changes in B cell development
the receptor for antibody that normally regulate
antibody production, may cause continual B cell stimulation.
Induce the proliferation of numerous clones of B cells
that express IgM in the absence of T helper cells. B cell can
be reactive to self antigen can be activated.
Defect: Fc receptor polymorphism
Other factors in autoimmunity
. Influence of hormones
2. Environmental condition
3. Defects in NK cells
4. Defects in the secretion of cytokines
5. Defects in apoptosis
6. Defects in complement componen
Systemic Lupus Erythematosus
(SLE)
Classic model of an autoimmune
disease
Systemic rheumatic disorder involving
multiple system
The immune response is directed
against the broad range of target
antigens
FORMS OF SLE
- Discoid (cutaneous)
Limited to the skin and is identified by biopsy of the rash that may
appear on the face, neck and scalp. - Systemic
More severe and can affect the skin, joints and almost all body system
“lupus” - Drug-induced
Antiarrhythmic – procainamide hydrochloride
Antihypertensive – Hydralazine hydrochloride
Anticonvulsants- phenytoin
Chlorpromazine, Isoniazid, Penicillin, sulfonamides - Neonatal
From passage of maternal autoantibodies, specifically anti-Ro/SS-A or
anti-La/ SS-B that can affect the skin , heart and blood of the fetus and
newborns
ETIOLOGY OF SLE
Idiopatic
1. Hormonal influences
Estrogen
Antiphospholipid syndrome – complication of surgery
2. Genetic predisposition
3. Environmental factor
UV lights may cause DNA to form thymine dimers that
can result to anti DNA
SIGNS AND SYMPTOMS OF SLE
Signs and Symptoms
Achy joints (arthralgia)
Frequent fevers >37C
Arthritis (swollen joints)
Prolonged extreme fatigue
Skin rashes
Anemia
Kidney involvement
Pain in the chest on deep breathing (pleurisy)
Butterfly-shaped rash across the cheek and nose
Photosensitivity
Hair loss
Abnormal clotting problems
Raynaud’s phenomenon
Seizure
Mouth and nose ulcers
DIAGNOSIS OF SLE
Diagnosis:
1. Malar rash
2. Discoid rash
3. Photosensitivity
4. Oral ulcers
5. Arthritis
6. Serositis
7. Renal disorders
8. Neurologic disorders
9. Hematologic disorders
10. Immunologic disorders
Ab to dsDNA, SM Ag, phospholipids
11. Presence of ANA
Neutrophil that has engulfed the antibody-coated
nucleus of another neutrophi
LE cells
Anti ds-DNA
Most specific for SLE (diagnostic)
1. Indirect Immunofluorescence (IIF)
Crithidia luciliae
2. Immunodiffusion
3. Radioimmunoassay (RIA)
4. Enzyme immunoassay (EIA) – sensitive
-most widely used
Anti-histone antibody
Histone is a nucleoprotein that is a major
constituent of chromatin
Drug induce Lupus- w/ ss-DNA
Also found in RA and biliary cirrhosis
Immunofluorescence assay
Immunoblotting
EIA
IIF- homogenous
DNA complexed to histone
Deoxynucleoprotein (DNP)
Anti- Sm (Smith)
Specific for lupus, It cannot be found in
other autoimmune
Extractable nuclear antigens represent a
family of small nuclear proteins that are
associated with uridine rich RNA
Measured by immunodiffusion,
immunoblotting, immunoprecipitation and
EIA
Anti SS-A/Ro and SS-B/Ro
Often found in cutaneous manifestations of
SLE, especially photosensitivity and
dermatitis.
Highly prevalent in scleroderma and
Sjogrens syndrome
Detected by immunoprecipitation ,
immunoblotting and EIA.
Anti- nRNP antibody
Coarsely speckled IIF pattern.
Immunoblotting, immunoprecipitation , EIA
and IIF
Produces prolonged activated partial
thromboplastic time (aPT) and prothrombin time
(PTT)
Antiphospholipid antibodies
Heterogenous group of antibodies that bind to
phospholipid alone or are complexed with protein.
Associated with deep-vein and arterial thrombosis
and with morbidity and pregnanc
Antiphospholipid antibodies
TREATMENT FOR SLE
Fever and arthritis- aspirin , antiinflammatory drug
Skin manifestation – hydroxychloroquine or
chloroquine, topical steroids
Acute fulminant lupus, lupus nephritis ,CNS
complications- systemic corticosteroids
Rheumatoid Arthritis
Strikes between 35 and 50
Characterized as chronic, symmetric and erosive
arthritis of the peripheral joints that can also affect
multiple organism such as the heart and lungs.
Can affect organs such as heart and lungs.
Associated with MHC class II which codes for beta chaiN