Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrine > Immunology of Endocrine Disorders > Flashcards

Immunology of Endocrine Disorders Flashcards

1
Q

Immunologic tolerance

A

unresponsiveness to an antigen that is induced by
previous exposure to that antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When lymphocytes encounter antigens what might happen?

A

they may be activated, leading to
immune responses, or inactivated or eliminated, leading to tolerance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what might an antigen producing an immune response or tolerance depend on?

A

depending on the conditions of exposure and the presence or absence of other stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are antigens that induce tolerance called?

A

tolerogens or tolerogenic antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is tolerance to self antigens?

A

self-tolerance, is a fundamental property of the normal immune system, and failure of self-tolerance results in immune
reactions against self (autologous) antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are reactions against self (autologous) antigens?

A

autoimmunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the diseases reactions against self (autologous) antigens cause called?

A

autoimmune diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the immune system capable of generating?

A

a diversity of T-cell antigen receptors and immunoglobulin molecules by differential genetic recombination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does the immune system generate?

A

produces many antigen-specific receptors capable of binding to selfmolecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does the immune system avoid autoimmune disease?

A

the T and B cells bearing these self-reactive molecules must be either eliminated or downregulated so that the immune system is made specifically tolerant to self-antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what mechanisms are involved in avoiding autoimmune disease?

A

Several mechanisms are involved (central and peripheral tolerance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does a breakdown of any immunological tolerarance mechanism result in?

A

A break down of any of the immunological tolerance mechanisms results in
autoimmune responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is central tolerance?

A

Self-tolerance may be induced in immature self-reactive lymphocytes in the generative lymphoid organs

The thymus plays an important role in eliminating T cells with high affinity to self-antigens

Bone marrow is important in B cell tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is peripheral tolerance?

A

Mature lymphocytes that recognize self antigens in peripheral tissues become incapable of activation by re-exposure to that antigen or die by apoptosis

An important mechanism for the induction of peripheral tolerance is antigen recognition without co-stimulation or “second signals.”

Peripheral tolerance is also maintained by regulatory T cells (Tregs) that actively suppress the activation of lymphocytes specific for self and other antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is an important mechanism for the induction of peripheral tolerance?

A

An important mechanism for the induction of peripheral tolerance is antigen
recognition without co-stimulation or “second signals.”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is peripheral tolerance also maintained by?

A

regulatory T cells (Tregs) that
actively suppress the activation of lymphocytes specific for self and other antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens to some self antigens?

A

Some self antigens are sequestered from the immune system (immune privileged sites), and other antigens are ignored.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how might antigens be sequestered from the immune system?

A

Antigens may be sequestered from the immune system by anatomic
barriers, such as in the CNS, testes and eyes, and thus cannot engage
antigen receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the three mechanisms of peripheral tolerance?

A

Anergy (functional unresponsiveness)

Treg Suppression

Deletion (cell death)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how can peripheral tolerance be overcome?

A
  • Inappropriate access of self-antigens
  • Inappropriate or increased local expression of co-stimulatory molecules
  • Alterations in the ways in which self-molecules are presented to the
    immune system.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

when is peripheral tolerance more likely to be overcome?

A

More likely to happen when inflammation or tissue damage is present due to
the increased activity of proteolytic enzymes which can cause intra- and extracellular proteins to be broken down, leading to high concentrations of
peptides (cryptic epitopes) being presented to responsive T cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what might the structures of self peptides be altered by?

A

The structures of self-peptides may be altered by viruses, free radicals or ionising radiation, thus bypassing previously established tolerance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when does autoimmunity happen?

A

when normal tolerance breaks down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

describe the epidemiology of autoimmune disease?

A

It is estimated that 3% of the population have some sort of autoimmune
disease.

  • Autoimmune diseases show clustering within families.
  • Peak years of onset 15-65 years (exception; Type 1 Diabetes mellitus)
  • Almost all types of autoimmune diseases are more common in women
    (Exception, ankylosing spondylitis).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what are non organ specific autoimmune diseases?

A

They affect multiple organs

  • Associated with autoimmune responses against self-molecules which are
    widely distributed throughout the body
  • Intracellular molecules involved in transcription and translation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are organ specific autoimmune diseases?

A

Restricted to one organ

Endocrine glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

describe effect of autoimmune disease targetting the TSH receptor?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

describe effect of autoimmune disease targetting the insulin receptor?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

describe effect of autoimmune disease targetting the acetylcholine receptor?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

describe effect of autoimmune disease on other self antigens?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what genetic factors are responsible for the aetiology of autoimmune disease?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

describe the environmental factors that may be resposible for autoimmune disease?

A

Infections
* Molecular mimicry
* Upregulation of co-stimulation
* Antigen breakdown and presentation changes

  • Drugs
  • Molecular mimicry
  • Genetic variation in drug metabolism
  • UV radiation
  • Trigger for skin inflammation
  • Modification of self-antigen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is molecular mimicary?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how is autoimmune disease treated?

A

Suppression of the damaging immune
response
* Before irreversible tissue damage
* Early detection is a challenge
* Problem with specificity of
treatments and toxicity

Replacement of the function of the
damaged organ
* Hypothyroidism
* Insulin dependent diabetes
mellitus

35
Q

describe your knowledge of diabetes mellitus?

A
36
Q

what makes up the endocrine pancreas?

A

Islets of Langerhans

  • About a million islets scattered within the exocrine tissue of the pancreas
  • 1% of the total pancreas mass
  • Clusters of compact cells
  • Four different types according to hormone content
37
Q

what four different types of islets of langerhans cellls are there?

A
38
Q

what are the characteristics of type 1 diabetes?

A

Ketoacidosis

Inadequate insulin secretion

Lymphocytic infiltration of the islets of Langerhans with specific
destruction of beta cells

Aetiology: autoimmune destruction, genetic factors, viral infections

39
Q

what is the aetiology of type one diabetes?

A

autoimmune destruction, genetic factors, viral infections

40
Q

what are the characteristic features of type 2 diabetes?

A
  • More common
  • Middle age
  • Non-ketoic coma (occasional)
  • Normal or increased insulin secretion
  • Reduction of cell surface receptors to insulin
  • Genetic factors
  • Evidence against autoimmunity
41
Q

describe autoimmune destruction in type one diabetes?

A

Circulatory antibodies to islet cells

Patients prone to develop other organ specific autoimmune diseases

42
Q

describe genetic factors in type 1 diabetes?

A
  • Association with certain HLA types
  • Environmental factors play a role too (40% concordance in twins in
    comparison to 100% in Type 2)
43
Q

describe viral infection in type 1 diabetes?

A
  • Antibodies to certain viruses are high in patients.
  • Viruses may act as triggers for autoimmune destruction
  • Coxsackie B
  • Mumps
44
Q

what are complications of type 1 diabetes?

A
45
Q

describe the thyroid gland

A
  • Follicles lines by cuboidal cells
  • Proteinaceous stores secretions
  • Synthesis of T3 and T4 under negative feedback by TSH (anterior pituitary)
  • C-cells scattered throughout the gland that secrete calcitonin
46
Q

what does secretory dysfunction of the thyroid result in?

A

Hyperthyroidism

Hypothyroidism

47
Q

what does swelling of the entire thyroid gland result in?

A

goitre

48
Q

what are examples of solitary masses of the thyroid?

A
  • Nodular goitre
  • Adenoma
  • Carcinoma
49
Q

what is the cause of hyperthyroidism?

A
  • Excess T3 and T4
  • Very rarely due to excess TSH
50
Q

what conditions may hyoerthyroidism result from?

A
  • Graves thyroiditis
  • Functioning adenoma
  • Toxic nodular goitre
  • Exogenous thyroid hormone (rare)
  • Ectopic secretion by ectopic
    thyroid tissue or tumours
51
Q

what is graves thyroidititis the most common cause of?

A

thyrotoxicosis

52
Q

what is graves thyroiditis usually associated with?

A

diffuse goitre

53
Q

what is shown histologically in graves thyroiditis?

A

Increased vascularity.

  • Histologically:
  • hyperplasia of the acinar epithelium
  • reduction of stored colloid
  • local accumulations of lymphocytes with lymphoid follicle formation
54
Q

what is graves thyroiditis?

A
  • Graves thyroiditis is an ‘organ-specific’ autoimmune diseases.\
  • Autoantibody (IgG), long-acting thyroid stimulator (LATS) which binds to
    the thyroid epithelial cells and mimics the action of TSH.
  • LATS stimulates the function and growth of thyroid follicular epithelium.
  • Exophthalmos, pretibial myxoedema (accumulation of mucopolysaccharides in
    the deep dermis of the skin) and finger clubbing.
55
Q

what is exopthalmos?

A

common and results from infiltration of the orbital tissues by
fat, mucopolysaccharides and lymphocytes, and may be due to an additional
autoantibody reacting with these tissues.

56
Q

what is the cause of hypothyroidism?

A
  • Insufficient circulating T3 and T4
  • When congenital, causes
    cretinism
  • Most common cause is
    Hashimoto thyroiditis, an
    autoimmune disorder
  • The metabolic rate is lowered
57
Q

what is cretinism?

A
  • If hypothyroidism is present in the new-born, physical growth and
    mental development are impaired, sometimes irreversibly (cretinism).
  • Cretinism may be endemic in geographical areas where the diet
    contains insufficient iodine for thyroid hormone synthesis.
58
Q

when might there be sporadic cases of cretinism?

A
  • Sporadic cases are usually due to a congenital absence of thyroid
    tissue, or to enzyme defects blocking hormone synthesis
59
Q

what is hashimoto thyroiditis the most common cause of?

A

The most common cause of acquired hypothyroidism in adults is Hashimoto thyroiditis.

60
Q

what are the effects of hashimoto thyroiditis?

A
  • Hashimoto thyroiditis may initially cause thyroid enlargement, but later there may be
    atrophy and fibrosis.
  • In the early stages of Hashimoto thyroiditis, the damage to the thyroid follicles may
    lead to release of thyroglobulin causing a transient phase of thyrotoxicosis.
61
Q

what is shown histologically in hashimoto thyroiditis?

A
  • Densely infiltration by lymphocytes and plasma cells, with lymphoid follicle
    formation.
  • Colloid content is reduced
  • Thyroid epithelial cells show a characteristic change in which they enlarge and
    develop eosinophilic granular cytoplasm due to proliferation of mitochondria;
    they are then termed Askanazy cells, Hürthle cells or oncocytes.

In advanced cases, there may be fibrosis.

62
Q

what is hashimoto thyroiditis?

A
  • Hashimoto thyroiditis is an ‘organ-specific’ autoimmune diseases.
  • Two autoantibodies can be detected in the serum of most patients:
  • one reacting with thyroid peroxidase
  • the other reacting with thyroglobulin.
  • These autoantibodies are probably formed locally by the plasma cells infiltrating the
    thyroid, and are possibly the result of a loss of specific suppressor T lymphocytes.
  • Female preponderance
  • Certain HLAs are commonly found in affected individuals
63
Q

what are polyendocrine syndromes?

A
  • A diverse group of clinical conditions
    characterized by functional
    impairment of multiple endocrine
    glands due to loss of immune
    tolerance.
64
Q

what do autoimmune polyendocrine frequenly include conditions wise

A
  • Frequently include conditions such as
    alopecia, vitiligo, celiac disease, and
    autoimmune gastritis with vitamin B12 deficiency that affect
    nonendocrine organs.
65
Q

what are autoimmune polyendocrine syndromes?

A
  • Circulating autoantibodies and lymphocytic infiltration of the
    affected tissues or organs
  • Eventually leading to organ failure.
66
Q

when can autoimmune polyendocrine syndromes affect a patient?

A
  • The syndromes can occur in patients from early infancy to old age,
    and new components of a given syndrome can appear throughout
    life.
  • Variation in the frequencies and patterns of autoimmunity in
    affected patients and their families.
  • Combination of genetic susceptibility and environmental factors.
67
Q

what is autoimmune polyendocrine syndrome type 1?

A
  • APS-1, also named autoimmune
    polyendocrinopathy–
    candidiasis–ectodermal
    dystrophy is a rare autosomal
    recessive disease caused by
    mutations in the autoimmune
    regulator gene (AIRE).
68
Q

what is the prevalence of autoimmune polyendocrine syndrome?

A
  • The estimated prevalence is
    roughly 1:100,000 in most
    countries, with a higher
    prevalence in some countries
69
Q

what are clinical features of APS-1 during childhood?

A
  • At least two of three cardinal components during childhood:
  • Chronic mucocutaneous candidiasis
  • Hypoparathyroidism
  • Primary adrenal insufficiency (Addison’s
    disease)
70
Q

what are other typical clinical componenets of APS-1?

A
  • Enamel hypoplasia * Enteropathy with chronic diarrhoea or
    constipation.
  • Primary ovarian insufficiency
    (approximately 60% of women with APS - 1 before they reach 30 years of age).
71
Q

what are less frequent clinical components of APS-1?

A
  • Bilateral keratitis (accompanied by severe photophobia)
  • Periodic fever with rash
  • Autoimmunity-induced hepatitis,
    pneumonitis, nephritis, exocrine
    pancreatitis, and functional asplenia
72
Q

what are rare findings of clinical features of APS-1?

A
  • Retinitis
  • Metaphyseal dysplasia
  • Pure red-cell aplasia
  • Polyarthritis
73
Q

what is the prevalance of autoimmune polyendocrine syndrome type 2?

A
  • APS-2 is more common than APS-1 (estimated prevalence 1:1000).
  • Women predominate among patients with APS-2
74
Q

what do patients with APS-2 have?

A

Patients with APS-2 have at least two of the following three endocrinopathies:

  • Type 1 diabetes
  • Autoimmune thyroid disease
  • Addison’s disease
75
Q

what other autoimmune conditions often develop in affected patients?

A
  • Celiac disease
  • Alopecia, vitiligo
  • Primary ovarian insufficiency
  • Pernicious anaemia
76
Q

when is the typical onset of APS-2 in patients?

A
  • The onset of APS-2 typically occurs in young adulthood, later than the onset of APS-1
77
Q

what is X-Linked Immunodysregulation, Polyendocrinopathy, and Enteropathy (IPEX), and what is it characterised by?

A

An extremely rare inherited syndrome (1:1000000) characterized by:

  • Early-onset type 1 diabetes
  • Autoimmune enteropathy with intractable diarrheal and malabsorption.
  • Dermatitis that may be eczematiform, ichthyosiform, or psoriasiform.
78
Q

what levels are elevated in X-Linked Immunodysregulation, Polyendocrinopathy, and Enteropathy (IPEX)?

A

Eosinophilia and elevated IgE levels are frequently present

79
Q

what disease develops in some patients with X-Linked Immunodysregulation, Polyendocrinopathy, and Enteropathy (IPEX)?

A

Kidney disease, most often membranous glomerulonephritis or interstitial nephritis, develops
in some patients

80
Q

what are later manifestations of X-Linked Immunodysregulation, Polyendocrinopathy, and Enteropathy (IPEX)?

A
  • Autoimmune thyroid disease
  • Alopecia
  • Various autoimmune cytopenias
  • Hepatitis
  • Exocrine pancreatitis.
81
Q

when is IPEX frequently fatal?

A

in the first few years of life unless patients are promptly treated with
immunosuppressive agents or, if possible, with allogeneic bone marrow transplantation,
which can cure the disease.

82
Q

when does IPEX usually develop?

A
  • Many features overlap with APS-1, but they usually develop much earlier in life than in APS-1.
83
Q

summarise the classification and characteristics of autoimmune polyendocrine syndromes?

A

Endocrine (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions