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Immunology 9: Immunodeficiency

Terms in this set (93)

What is meant by immunodeficiency?
Absence or failure of the normal function of the immune system, resulting in increased susceptibility to infection
What is the overall result of immunodeficiency?
Increased susceptibility to infection
What type of immunodeficiency involves abnormalities of B or T cells?
Specific Immunodeficiency
What type of immunodeficiency involves abnormalities in complement or phagocytes?
Non-specific Immunodeficiency
What is the cause of Primary Immunodeficiency?
Intrinsic defects, often congenital/genetic
What may be the cause of Secondary Immunodeficiency?
- Age related decline
- Drug therapies for cancer or autoimmune disease
- Irradiation (e.g. cancer treatment)
- Organ or bone marrow transplantation
- Malnutrition, alcoholism
What is the main feature of SPECIFIC immunodeficiency?
Involves abnormalities of B or T cells
What is the main feature of NON-SPECIFIC immunodeficiency?
Involves abnormalities in complement or phagocytes
Type of immunodeficiency due to intrinsic defects, often genetic in origin
Primary immunodeficiency
Type of immunodeficiency due to several factors, such as age, drug therapies and organ transplantation
Secondary immunodeficiency
What is the main feature of B cell immunodeficiencies?
Low levels of Immunoglobulins in serum - hypogammagobulinaemia
Name a presentation/symptom of B cell immunodeficiency
Recurrent pyogenic infections, such as pneumonia, sinusitis and otis media (infection or inflammation of middle ear)
What is the treatment for B cell immunodeficiencies?
Intravenous replacement therapy with Immunoglobulins
For immune system defects involving No Production of Immunoglobulins, name an example of the disease, two examples of susceptibility and example oral manifestations
No Immunoglobulin production

- X-linked agammaglobulinaemia
- 1. Respiratory infections with extracellular bacteria 2. Enterovirus infections
- Possible sepsis from abscessed teeth
For immune system defects involving Severely decreased or no Immunoglobulin G Production, name an example of the disease, an example of susceptibility and example oral manifestations
1. Common Variable Immunodeficiency (CVID)
2. Respiratory infections with extracellular bacteria
3. Possible sepsis from abscessed teeth (although some patients may be asymptomatic)
For immune system defects involving Severely decreased or no Immunoglobulin A Production, name an example of the disease, an example of susceptibility and example oral manifestations
1. Selective IgA deficiency
2. Respiratory and GI tract infections (though some patients may be asymptomatic)
3. Candidiasis, Oral Ulcerations
X-linked agammaglobulinaemia is an immune system defect caused by the absence of Immunoglobulin production. Name an oral manifestation of this disease
Possible sepsis from abscessed teeth
Common Variable Immunodeficiency is an immune system defect caused by severely decreased or no Immunoglobulin production. Name an oral manifestation of this disease
Possible sepsis from abscessed teeth, but some patient may be asymptomatic
Selective IgA deficiency is an immune defect caused by severely decreased or no IgA production. Name an oral manifestation of this disease
Possible sepsis from abscessed teeth, but patient may be asymptomatic
What is T cell immunodeficiencies?
T cell deficiency is a deficiency of T cells, either caused by lymphocytopenia of T cells, or decreased function of individual T cells
Name TWO causes of T cell deficiency
1. Lymphocytopenia of T cells
2. Decreased function of individual T cells
What is meant by Lymphocytopenia?
Condition presenting with abnormally low levels of lymphocytes in the blood
Patients with no T cells or pr T cell function (T cell immunodeficiency) are susceptible to what type of infections? ams two examples
Opportunistic infections, such as:

1. Candida
2. Herpes
T cell immunodeficiencies are characterised by no T cells or poor T cell function. Name FOUR possible causes of T cell immunodeficiency
1. Major Histocompatability Complex (MHC) defects
2. CD40 ligand deficiency
3. CD3 mutations
4. Decreased T cell number e.g. due to abnormally developed thymus, as in DiGeorge syndrome
What is CD40 and what is it's function?
Molecule found on activated T cells, necessary for Antigen resenting Cell and T cell interactions
Disease with abnormally developed thymus, which may lead to decreased numbers in T cells and T cell immunodeficiency
DiGeorge syndrome
What is meant by SCID?
Severe Combined Immunodeficiency (SCID)
What is meant by CVID?
Common Variable Immunodeficiency (CVID)
Name THREE features of SCID seen in patients
1. Failure to thrive
2. Repeated infections such as Candida, Varicella, Herpes simplex, Cytomegalovirus
3. Antibodies acquired from mother offer some protection during first 6-9 months, thereafter bacterial infections are common
Name FOUR oral manifestations seen in SCID
Severe Combined Immunodeficiency:

1. Candidiasis
2. Herpes infection
3. Recurrent ulcerations of tongue and buccal mucosa
4. Severe necrotising gingivostomatitis
What does AIDS stand for?
Acquired Immunodeficiency Syndrome
What is the cause of AIDS?
AIDS is caused by infection with HIV (Human Immunodeficiency Virus)
What type or classification of immunodeficiency is AIDS?
AIDS is a secondary T cell immunodeficiency
Give FIVE examples of how AIDS can be transmitted
1. Sexual contact
2. Transfer via placenta or milk from mother to infant
3. Blood transfusion
4. Needle sharing - intravenous drug use
5. Needle stick injuries
Symptoms associated with HIV infection
1. Transient fever
2. Swollen lymph nodes
3. Sore throat
4. Rash

Although many individuals are asymptomatic
How much time does it tae for Antibodies to develop against HIV proteins?
2-6 weeks
What happens after the primary infection with HIV?
Period of latency, with few or no symptoms
How long does it take for HIV infection to progress to AIDS?
2-15 years
When is a disease classified as AIDS/how is AIDS classified?
When CD4+ T cells are <200 cells per mL (micolitre)
What is Thrombocytopenia?
Low platelet count/deficiency of platelets in the blood.

- causes bleeding into the tissues, bruising, and slow blood clotting after injury
What is meant by Hypogammaglobulinaemia?
Abnormally low levels of immunoglobulins in the blood
Hypogammaglobulinaemia is characteristic of what disease?
Common Variable Immunodeficiency
What is meant by Agammaglobulinaemia?
Absence of immunoglobulins in the blood
Treatment of HIV infection - how can HIV infections be controlled?
With HAART - Highly Active Antiretroviral Therapy
When is HAART recommended for treatment of HIV infection? Give THREE examples
1. When CD4+ T cell count is below 350 cells per mL (micro litre)
2. In all patients with AIDS defining illness
3. When serum HIV RNA is >50,000-100,00 copies/ml
Due to a weakened immune system, oral problems are common. Name SIX examples of oral problems associated with HIV/AIDS
1. Herpes (fever blisters)
2. Hairy leukoplakia
3. Oral candidiasis
4. Aphthous ulcers
5. Oral warts
6. Dry mouth (from medication)
Complement deficiencies often present as?
Recurrent infections or Immune Complex disease
Name a type of Human Complement Deficiency disease
HAE - Hereditary Angioedema
Hereditary Angioedema is a deficiency disease. What type of deficiency causes this disease?
Deficiency (absence or dysfunction) in the main inhibitor of the Classical Pathway, C1 inhibitor
What disease is due to deficiency (absence or dysfunction) in the main inhibitor of the classical pathway, C1 inhibitor?
HAE - Hereditary Angioedema
HAE is the inherited form of C1 inhibitor deficiency. C1 inhibitor deficiency may also arise later in life due to?
1. Autoantibodies
2. Certain B cell leukaemia's
What is the main symptom of HAE?
HAE - Hereditary Angioedema

- recurrent episodes of angioedema (rapid swelling of tissues such as dermis, submucosa etc.)
Where may these symptoms of HAE occur? Name THREE examples
1. Intestines
2. Periphery
3. Upper airways
What symptoms may a patient with HAE of the intestine present with? Name THREE
1. Severe/excruciating pain
2. Cramps
3. Vomiting
What symptom may a patient with HAE of the periphery present with?
Unslightly swelling
What symptom may a patient with HAE of the upper airways present with?
Respiratory obstruction which can be fatal
What is the treatment recommended for HAE?
Long term treatments of HAE include:

- Danazol (attenuated androgen)
- Antifibrinolytic agents
- C1 Inhibitor (C1 INH)
A patient experiences a spontaneous case of oedema following a tooth extraction, which also provokes oedema of the upper airways. Which disease is the patient likely to suffer from?
Hereditary Angioedema (HAE)
A patient experiences a spontaneous case of oedema following a tooth extraction, which also provokes oedema of the upper airways. How should this disease be treated?
HAE swelling treatment:

- With C1 inhibitor (C1 INH) concentrate, which should resolve oedema in 30 minutes to 2 hours
A patient experiences a spontaneous case of oedema following a tooth extraction, which also provokes oedema of the upper airways. How can this be prevented?
Prevention of HAE swelling/oedema:

- Daily Danazol 100-600mgs, for 5 days before dental treatment and 2 days after dental treatment

or

- C1 INH (C1 inhibitor) concentrate of 500-1500 units up to 24 hrs before dental appointment
What is meant by Neutropenia?
General deficiency in neutrophils
What term is used to describe immunodeficiencies associated with abnormally low levels of immunoglobulins in the blood?
Hypogammaglobulinaemia
What term is used to describe immunodeficiencies associated with the absence of immunoglobulin in the blood?
Agammaglobulinaemia
Defects in which components of the immune system result in "Specific" immunodeficiency?
B cells and T cells
Defects in which components of the immune system results in "Non-specific" immunodeficiency?
Complement or Phagocytes, such as Neutrophils
Name the general causes of "secondary" immunodeficiencies?
1. Age
2. Drug therapies for cancer or autoimmune disease
3. Irradiation (e.g. cancer treatment)
4. Organ or bone marrow transplantation protocols
5. Malnutrition, alcoholism
Which symptoms are patents with B cell immunodeficiencies likely to present with?
Recurrent pyogenic infections, such as pneumonia, sinusitis and otis media (infection or inflammation of middle ear)

- due to low Ig levels in serum
What is the most usual treatment for a primary B cell immunodeficiency?
Intravenous Replacement Therapy with Immunoglobulin
Give the FULL name of the causative agent of AIDS
Human Immunodeficiency Virus (HIV)
What are the different ways in which the agents causing AIDS may be transmitted from an infected individual to another?
1. Sexual contact
2. Transfer via placenta or milk from mother to infant
3. Blood transfusion
4. Needle sharing (intravenous drug use)
5. Needlestick injuries
The causative agent of ADS binds specifically and directly to one type of immune cell via a particular cell surface molecule or maker. Which are the cells targeted in this way, and what is the marker?
1. T cells
2. CD4+ markers
What treatment may be used to control HIV infections, and what does this treatment consists of?
HAART - Highly Active Antiretroviral Therapy

- combination of nucleoside analog reserve transcription inhibitors and non-nucleoside RT inhibitor or protease inhibitor
What is HAART, and when is it recommended?
Highly Active Antiretroviral Therapy for control of HIV infections

HAART recommended:

- when CD4+ T cell count is below 350 cells/micro litre
- in all patients with AIDS defining illness
- when serum HIV RNA is >50,000-100,000 copies/ml
What term is used to describe the general deficiency in neutrophils?
Neutropenia
Define Neutropenia
The presence of abnormally few neutrophils in the blood, leading to increased susceptibility to infection (particularly bacterial)
Name THREE important genetic defects in phagocytes
1. Chronic Granulomatous Disease (CGD)
2. Leucocyte Adhesion Deficiency
3. Chediak-Higashi syndrome
What is meant by the term Leukopenia?
Deficit in the number of white blood cells
A patient presents with an overwhelming bacterial infection, and has been told that due to a deficiency, this may lead to the susceptibility to severe infections which can be fatal. What deficiency does he suffer from, and what is the term used for this deficiency?
Neutrophil deficiency/abnormally low levels of neutrophils

- Neutropenia
Granuloma/granulomata
Collection of immune cells (histiocytes) which is formed when the immune system tries to wall of substances perceived as foreign, but is unable to eliminate; e.g. bacteria or fungi

e.g. in Tuberculosis
A boy presents with recurring eczema and pneumonia, and with dental disease and several gum abscesses. What disease might be the cause?
Chronic Granulomatous Disease
What is CGD and what is the cause of this disease?
Chronic Granulomatous Disease

- due to defective NADPH oxidase, the enzyme responsible for generation of superoxide anions
Chronic Granulomatous Disease is due to a defective enzyme (NADPH oxidase) which is responsible for the generation of superoxide anions. What is the role of these superoxide anions?
These superoxide anions normally help phagocytes kill ingested bacteria (.e.g Staph. aureus) and fungi (Candida albicans)
What is the treatment used for CGD
Prophylactic daily antibiotics and IFN
THREE defects associated with phagocytosis
1. Chronic Granulomatous Disease
2. Leukocyte Adhesion Deficiency
3. Chediak-Higashi syndrom
Complications of CGD
Granuloma formation associated with Chronic Granulomatous Disease can obstruct GI and urogenital systems

- intraoral granulomas can also form, but rare
Treatment for CGD
Prophylactic daily antibiotics and IFN
Cause of Leukocyte Adhesion Deficiency
Lack of integrin subunit which is important in adhesion and homing of leukocytes
LAD and its effect on the body
Leukocyte Adhesion Deficiency

- phagocytic cells are unable to bind properly to endothelial cells and emigrate through vessel walls to infected tissue, resulting in repeated pyogenic infections
Pyogenic infection
Infection characterized by severe local inflammation, usually with pus formation, generally caused by one of the pyogenic bacteria (e.g. Staphylococcus spp., Streptococcus spp.)
Oral Manifestations of LAD
1. Early childhood periodontitis
2. Oral ulcerations
3. Delayed wound healing
Cause of Chédiak-Higashi syndrome
Arises through rare autosomal recessive disorder due to mutation in gene that regulates lysosome trafficking
Result of Chédiak-Higashi syndrome
Giant lysosomal granules in neutrophils, monocytes and lymphocytes, rendering them defective in chemotaxis, phagocytosis and bactericidal acidity
Oral manifestations of Chédiak-Higashi syndrome
1. Early childhood periodontitis
2. Possibly increased bleeding
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