Autoimmunity Flashcards Preview

Immunuology > Autoimmunity > Flashcards

Flashcards in Autoimmunity Deck (31)
Loading flashcards...

when does autoimmunity occur?

when the immune systems self-tolerant mechanisms breakdown


what develops in autoimmunity?

autoreactive antibodies and autoreactive T cells develop


what do autoreactive antibodies and autoreactive T cells recognise?

self antigens i.e normal components of the body


Describe the spectrum of autoimmunity.

Can be organ-specific or involve many organs


what causes enlarged thyroid in Hashimotos thyroiditis (organ specific)?

antibodies are directed against thyroglobulin


Describe the changes in Hashimoto's thyroiditis.

-Normal thyroid gland- Acinar epithelial cells (aec)
secrete thyroglobulin into
colloid spaces (cs)
-Hasimotos thyroid gland-Normal architecture virtually
destroyed, replaced by invading cells (ic) - lymphocytes, macrophages
& plasma cells


what do autoantibodies bind to in autoimmunity?

self antigens


what does antibodies in serum of hashimotos disease patient bind to?

thyroglobulin in colloid
and acinar epithelial cells


what does antibodies in serum of SLE patient bind to?

nuclei (N) of acinar epithelial cells


Name organ-specific autoimmune disease.

-Thyroid i.e hashimotos, thyroiditis
-Stomach-pernicious anaemia
- Adrenal- Addison's disease
-Pancreas-insulin dependent diabetes mellitus


Name non organ-specific disease.

-Joints-rheumatoid arthritis


What are important facts of autoimmune diseases?

1. An individual may have more than one autoimmune disease e.g. Rheumatoid Arthritis often associated with SLE
2.Autoimmune diseases can occur in families, Certain HLA haplotypes predispose to autoimmunity


how prevalent is autoimmune disease?

3.5% population have autoimmune disease


what gender is more likely to develop autoimmune disease?

Overall, women are 2.7x more likely than men to develop autoimmune disease
-Female:male ratio can be even higher eg 10:1 in SLE


What can human autoantibodies be directly?

pathogenic i.e graves disease


Describe the cause of graves disease.

-AutoAb produced to receptor for Thyroid Stimulating Hormone (TSH)
-Act on receptor
-stimulate thyroid cell
-overproduction of thyroid hormones


what causes pernicious anaemia?

AutoAb directed against Intrinsic Factor


Describe the cause of pernicious anaemia.

Normally dietary vitamin B12 is absorbed as a complex with intrinsic factor (IF)
In pernicious anaemia autoantibodies directed against IF are produced
Binding of autoantibody to IF prevents interaction with Vit B12
As a result, Vit B12 is not absorbed


Describe immunopathological damage (specific organ).

-When autoAg is localised to a particular organ
-type II hypersensitivity and cell-mediated reactions
-damage due to complement activation and phagocyte degranulation


Describe immunopathological damage (non specific organ).

-immune complexes appear to be pathogenic in systemic autoimmunity e.g. in SLE deposits of IC in the kidney
-type III hypersensitivity reactions
-acute tissues damage


Describe the pathology of rheumatoid arthritis.

-Inflammatory infiltrate found in synovial membrane
-Erosion of synovial cartilage and bone
-IC and neutrophils present in joint space
-IC can arise through self association of rheumatoid
factors = IgG molecules with unusual oligosaccharides


Name 3 examples of autoimmune diseases affecting head and neck (affect thyroid).

-Hashimotos thyroiditis
-autoimune colloid goiter
-graves disease


Describe the spectrum of autoimmune thyroid disease.

-thryoid destruction
-cell division :stimulation or inhibition
-thyroid hormone synthesis :stimulation or inhibition


What is sjogren syndrome?

Chronic inflammatory autoimmune disorder


how can sjogren syndrome occur?

Can occur in isolation or with SLE, RA or other rheumatic autoimmune disorders


what are the majority of patients with sjogren syndrome?

-Majority of patients are women :
-symptoms develop in 4th-5th decade
-actual onset probably in 1st-2nd decade


How much of the population does sjogren syndrome affect?

1-2% of population


how issjogren syndrome characterised?

-Characterised by a lymphocytic infiltrate in
salivary and lacrimal glands :slow destruction and replacement of glandular tissue with fibrotic tissue

-Lack of salvia and tear secretion : dental caries, oral candida

-condiiton confirmed (60% of patients) by presence in serum of autoantibodies


What are side effects of sjogrens syndrome ?

-dry lips
-dry and lobulated tongue


Describe some ways treatments of autoimmune disorders.

1. In some organ-specific diseases, metabolic control is
sufficient e.g. anti-thyroid drugs in Graves’ disease

2. Anti-inflammatory drugs - e.g. corticosteriods or non-steroidal anti-inflammatory drugs (NSAIDs)

3. Immunosuppressive drugs - e.g. cyclosporin

4.Monoclonal antibodies to blockade certain cytokines or their receptors
e.g. Infliximab blocks action of Tumour Necrosis Factor (TNF) which Inhibits immune response and alleviates symptoms