Immunodeficiency management Flashcards
What is the role of the immune system?
Protect from infection
What 3 conditions can present when the immune system goes wrong?
Immunodeficiency
Allergy
Autoimmunity
What 2 functions of the immune system should always stay balanced?
The ability to protect from infection - recognise and eliminate pathogens, destroy infected cells
AND
The ability to tolerate self-antigens - tolerate commensal organisms and tolerate healthy self-antigens
If an individual has immunodeficiency, in what way are the functions of the immune system not balanced?
Less able to recognise and eliminate pathogens and destroy infected cells
If an individual has allergy/autoimmunity, in heat way are the function of the immune systems not balanced?
Less able to tolerate commensal and self-antigens
What type of immune system is constant, the 1st level of defence and does not change in individuals?
Innate immune system
What are the first physical barriers to infection? What type of immune system is this a part of?
Skin, endothelium
Innate
Name some chemical barriers to infection?
What type of immune system is this a part of?
Enzymes (lysozyme), low pH in stomach, complement
Innate
What cells are involved in the innate immune system?
Phagocytes - link with adaptive immune system by activating lymphocytes
Name the 3 pathways that activate complement?
Classical, lectin, alternate
What are the 3 functions of complement?
Opsonisation, activation of inflammatory cells, lysis
What organ are involved in the adaptive immune system?
Lymphoid organs
How are lymphoid organs classified and what are the functions of each?
Primary lymphoid organs - where lymphocytes are produced (bone marrow, thymus)
secondary lymphoid organs - where adaptive responses start (apendoids, tonsils, lymph nodes, spleen, Peters patch)
What is the main function of the adaptive immune system?
Formation of specific antibodies
What is the first type of immunoglobulins produced?
IgM not very specific
What cells produce antibodies?
B cells
How are B cells activated?
TFH cells (T follicular helper cells)
What is the function fo CD4+ T helper cells?
Help other cells by producing activating cytokines to help recognise antigen presented by DCs
What is the function of CD8+ cytotoxic T cells?
Recognise and kill infected cells
What is immunodeficiency?
When one or more components fo the immune system is defective
How can immunodeficiency be classified?
Primary (inherited) and secondary (acquired)
Consequences of immunodeficiency?
Infection, increased autoimmune disease, malignancy
What are the symptoms of immunodeficiency? (SPUR)
Serious infection
Persistence of infections
Unusual sites or organisms
Recurrent infections
Signs of immunodeficiency?
Acute infection Chronic infection Damage from infections (bronchiectasis) Autoimmune features (endocrine disease) Specific findings e.g. eczema, thrombocytopenia
Warning signs of immunodeficiency?
8 or more new ear infections in 1 yea
2 or more serious sinus infections in 1 year
2 or more pneumonias in 1 year
Recurrent, deep, skin or organ abscesses
2 or more deep-seated infection such as osteomyelitis, cellulitis
Antibiotics for 2 months without effect
Persistent thrush in mouth or else where after age 1 year
Family history
How can primary immuodeficienies be classified?
By the type of cell it effects e.g. Antibodies (B cells) T cells Neutrophils Complement Innate
How will an immunodeficiency caused by a B cell defect present?
Increased bacterial infections especially capsulated bacteria e.g. streptococci, staphylococci
How will an immunodeficiency caused by a T cell defect present?
Increased fungal and viral infections
e.g. candida, herpes etc
What kind of immunodeficiency is likely to get abscesses forming?
a) B cell defect
b) T cell defect
B cell defect
How will an immunodeficiency caused by a phagocytic defect present?
Abscesses
Bacterial infection
Fungal infection
Viral infections uncommon
How will an immunodeficiency caused by a complement defect present?
This depends on the pathway
Defect in classical pathway will cause recurrent bacterial infections (meningitis)
Viral and fungal infections are rare
If the alternate or lectin pathway are defected it will present as meningitis but due to neisserial infection
What is SCID?
Severe combined immunodeficiency
What is the cause of SCID?
Multiple genes effected causing absence of T cells and B cells
How will patient with SCID present?
Lots of recurrent infections of viral, fungal and bacterial origin
At what age will SCID usually present?
From birth
What does X-linked agammaglobulinaemia result in? (cause)
Lack of B cells and reduced immunoglobulins due to mutation in a gene that makes tyrosine kinase which is involved in B cell maturation
How will patients with X-linked agammaglobulinaemia present?
Recurrent bacterial infections, absent tonsils
What are the causes and effects of common variable immunodeficiency?
Multiple gene defects causing ow but not absent antibodies
How does a patient with common variable immunodeficiency present?
Recurrent bacterial infections in sinus, lungs, ears and eyes
high risk of lymphoma
What is the cause of chronic granulomatous disease?
Genetic defects causing neutrophils that do not produce oxidative bursts, so they cannot kill invading organisms
How does a patient with chronic granulomatous disease present?
Recurrent abscesses
- deep-seated
- in the liver, soft tissues
- fungal origin
- high risk of gingivitis
What are the causes and effects of chronic mucocutaneous candidiasis?
Cytokine abnormalities causing failure to clear candida
What cell is reduced in DiGeorge syndrome?
Thymus doesn’t develop so no/reduced T cells
How does DIGeorge syndrome present?
Viral, fungal and bacterial infections, learning difficulties
What causes causes secondary immunodeficiency?
Malnutrition Medication Infection Radiotherpay Splenectomy
How can drugs cause immunodeficiency?
Cytotoxins can reduce T and B cells and neutrophils
Immunosuppressive drugs
How can immunodeficiency affect a dental history taking?
Look for recurrent infections, family history, drugs they are taking
What oral manifestations are common in immunodeficney patients?
Candidaisis, oral hairy leukoplakia, severe gingivitis, ulceration
What can cause oral candida?
Antibiotic therapy, dentures, steroid inhalers, secondary immunodeficiency, primary immunodeficiencies
