Week 3/4 - F - Primary Immunodeficiency disorders - IgA deficinecy, Transient of newborn, C.V.I.D, Bruton's x-linked, S.C.I.D

Question 1

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Answer 1

Bacteria - Antibody and B lymphocytes, Phagocytes, (complement) Viruses - T-lymphocytes (antibody and B lymphcoytes) Fungi - Phagocytes, T lymphocytes (eosinophils) Protozoa - T lymphocytes (eosinophils) Worms - Eosiniophils (mast cells)

Question 2

Immunodeficiency disorders can be inherited, acquired through infection, or produced unintentionally by drugs such as those used to treat people with cancer or those who have received transplants. What are the major hallmarks of immune deficiencies? (SPUR)

Answer 2

* Serious infections - unresponsive to oral antibiotics * Persistent infections - early structural damage or chronic infections * Unusual infections - unusual organisms or sites * Recurrent infection - two major or one major and recurrent minor infections in one year

Question 3

Are primary or secondary immunodeficiency disorders more common? What is the difference between the two?

Answer 3

Secondary immunodeficiencies are far more common In contrast, primary immunodeficiency diseases (PIDD) are a group of disorders caused by inherited or genetic defects in the cells and tissues of the immune system. A secondary immune deficiency disease occurs when the immune system is compromised due to an environmental factor. Examples of these outside forces include HIV, chemotherapy, severe burns or malnutrition.

Question 4

What is the main and initial manifestation of primary immunodeficiency disorders? It is also the most common manifestation?

Answer 4

Respiratory diseases are the main and initial manifestation in most cases and the most common complication

Question 5

Which of the primary immunodeficiency disorders are most frequently associated with sinusitis and otitis media?

Answer 5

Primary antibody deficiencies are the most frequent PID associated with sinusitis and otitis media

Question 6

The main types of primary antibody deficiencies are as follows : * Ig A deficiency * Transient hypogammaglobulinaemia of infancy * Common variable immunodeficiency (CVID) * Agamma * Bruton’s X-linked agammaglobulinaemia * IgG subclass deficinecy * Severe combined immunodeficiency Which of the above is the most common?

Answer 6

IgA deficinecy is the most common primary antibody deficiency

Question 7

What shape is IgA and where is it found?

Answer 7

IgA is dimeric and is the main antibody in body secretions such as saliva and tears as well as lining the resp and gastrointestinal tract It is the immunoglobulin found in breast milk

Question 8

How does selective IgA deficiency usually present and at what age? What is selective IgA deficiencies defined as?

Answer 8

In 2/3rds of people this deficiency is asymptomatic with 1/3rd presenting with upper respiratory tract infections People with this deficiency lack immunoglobulin A (IgA), a type of antibody that protects against infections of the mucous membranes lining the mouth, airways, and digestive tract.It is defined as an undetectable serum IgA level with a normal IgM and IgG level in patients over 4 years old.

Question 9

What may happen to patients with undiagnosed selective IgA deficiency upon transfusion of blood?

Answer 9

There may be an anaphylactic reaction to the blood due to the presence of IgA immunoglobulins in the blood that the body has not seen before

Question 10

What is transient hypogammaglobulinaemia of infancy?

Answer 10

Transient hypogammaglobulinemia of infancy is a form of hypogammaglobulinemia appearing after birth, leading to a reduction in the level of IgG, and also sometimes IgA and IgM.

Question 11

When is usual onset of transient hypogammaglobulinaemia of infancy and when do levels become normal?

Answer 11

It usually occurs around 3-6 months and is due to a temporary delay in antibody production but immunoglobulin levels usually become normal around 2-4 years of age

Question 12

What is common variable immunodeficiency? How does it tend to present?

Answer 12

Common variable immunodeficiency is an immune disorder characterised by reccurent infections due to low levels of antibodies - either IgA, IgM or IgG There is usually recurrent infections - usually affecting respiratory tract and the ears - the disease usually presents around 10-30 years of age

Question 13

What causes CVID disease? What other diseases is it associated with?

Answer 13

Thought to be due to a defect in B cell maturation pathway CVID - also associated with autoimmune conditions and cancers

Question 14

What is the treatment of common variable immunodeficiency?

Answer 14

Treatment consists of immunoglobulin replacement therapy, which replenishes Ig subtypes that the person lack. This treatment is given at frequent intervals for life, and is thought to help reduce bacterial infections and boost immune function

Question 15

What is x-linked agammaglobulinaemia caused by? WHat is it also known as?

Answer 15

It is caused by a gene mutation in the Bruton’s tyrosine kinase gene (Btk gene) that leads to a severe impairment in the B cell development causing reduced immunoglobulin production (absent Ig) Also known as Bruton’s agammaglobulinaemia

Question 16

What infections are people susceptible to in Bruton’s x-linked agammaglobulinaemia?

Answer 16

People are susecptible to bacterial but not viral infections with this disease (absent B cells)

Question 17

X-linked agammaglobulinaemia usually presents at 3months-3years of ages What is the mode of inheritance? What is the treatment?

Answer 17

The disorder is inherited in an X-linked recessive fashion as the gene linked to it is on the X chromosome) and is almost entirely limited to the sons of asymptomatic female carriers The treatment is IV IG treatment for life Having a marrow transplant followed usually cures the disease

Question 18

What happens to the secondary lymphoid organs in x-linked agammaglobulinaemia?

Answer 18

There is usually lymphoid hypoplasia - tonsils and adenoids with no splenomegaly and lymphadenopathy

Question 19

What is severe combined immunodeficiency also known as?

Answer 19

SCID - bubble baby syndrome

Question 20

What happens in SCID? What infections are patients suceptible to?

Answer 20

There is Tcell dysfunction usually causing combined immunodeficiency as T cells are necessry for B cell differentiation - patients therefore become combined to bacterial, viral, fungal and protozal infections The result is a near complete failure of the immune system to develop and function, with low or absent T cells and NK cells and non-functional B cells.

Recurrent infections, failure to thrive, diarrhoea, dermatitis

Question 21

What is the prophylactic treatment for SCID and what is the definitive treatment?

Answer 21

Prophylactic treatment Avoid infections Prophylactic antibiotics Prophylactic antifungals No live attenuated vaccines Intravenous immunuglobulin Definitive treatment * Bone marrow transplant

Question 22

CASE 1 A 15y/o pupil presents with the third episode of fever, producive cough and fatigues in tow years. In addition, he’d had one episode otitis media the previous year. Inn each case, a course of antibiotics and some rest had solved the problem. Otherwise the youngster is fine. The history makes you wonder about immunodeficiency. Which of the following is most likely underlying primary immunodeficiency. A - Severe combined immunodeficieny B - common variable immunodeficiency C - selective IgA defiency D -AIDS E -Leukaemia

Answer 22

B -Common variable immunodeficiency Recurrent Sinusitis and otitis media makes you think primary antibody deficiency Patient presented in second to third decade of life

Question 23

Which of the follwoing aspects of history are essential to explore either primary or secondary immunodeficiency: 1. Detailed account of diet 2. Smoking status 3. Social status in school 4. Family history for diabetes and for infectionss 5. Anxiety states and sleep patterns A -1,2,4 B - 2,3,5 C - 1,2,3 D 1,2,5 E all of the above

Answer 23

E - all of the above Important to explore causes and how it is affecting their living

Question 24

Which of the following elements of physical examination, and investigations would NOT be helpful/important? A - FBC B - Plasma viscosity C - ANA levels D - HIV test E - Immunoglobulin levels

Answer 24

C - ANA levels Plasma viscosity - could show hyperviscous syndromes