Primary Immunodeficiency Flashcards
(46 cards)
What are the 2 types of immune system
Innate
Adaptive
What does the immune system start, describe the process
- Danger signals (PAMPs and DAMPs) in the tissue are recognised by antigen presenting cells
- Antigen presenting cells present the antigen to CDT tell cells
- CD4 cells give instructions to b cells
- B cells produce antibodies which act as opsonins and activate complement
What is the role of b cells
Produc antibodies
What are the the types of t cells and what are the functions
Cd4 t cells: produce cytokines to support b cells
Cd8 t cells: cytotoxic cells that destroy virally affected cells and tumour cells
T reg cells: help suppress auto reactive t cells
What is the role of phagocytes
Engulf and destory extracellular pathogens and present antigens
What is the role of complement
Opsonination (c3b)
Immune complex clearance (c1q)
Membrane attack complex
What is the role of nk cells
Destroy virally infected cells and tumour cells
When should we consider immunodeficiency
When we see recurrent infections
Where could the defect be in immunodeficiency
Non immune defect e.g non Anatomical structure problem T cell defect B cell defect Combined defect of t and b cells Innate defect (neutrophils and complement problems) Global defect (signalling molecular and cytokines)
What are the 4rs in the immune response
- Problem in the recognition of pathogen
- Probelm in the response to pathogen
- Problem in the regulation of immune response
- Problem in generation resolution and memory
What makes you think of immunodeficiency
Severe Recurrent invasive infection
Unusual organism or site of infection
Severe recurrent or disproportionate inflammation
Unexplained lymphoproliferation
If a baby has lymphocytes count less than 1 what does this suggest if unless proven otherwise
Severe combined immunodeficiency
Where do normal lymphocytes come from
- Common lymphoid precursor differentiate into b cell, t cell and nk cell precursors
- B cell precursor turn into naive b cells
- T cell precursor turn into t naive cell
- Nk cell precursor turn into nk cells
What can stop this differentiation of lymphocytes from occuring
Genetic disease
What is ADA SCID
Leads to build up toxic metabolite in the common lymphoid precursor that causes it to die. You therefore get negative t, negativ b and negative nk cell SCID.
What does genetic disease that causes tcr rearrangement failure in t cell and b cell precursor lead to
B negative, t negative and nk cell positive SCID
What does t cell lineage specifc loss of survival signals lead to
T cell negative, b cell positive and nk cell positive SCID
Wgat does cell sruvival signal failure in t cell precursor and nk cell lead to
T cell negative, nk cell negative and b cell positive SCID
What is the presentation of SCID
Early onsent of infection that fail to clear
Child fails to thrive
Erythrodemic rash- caused by mothers lymphocytes attacking the baby
Eosiniophillia
Lymphopenia
What is the management of SCID
Initiate prophylactic antifungal, antibiotics, antiviral and IVIG
Strict infection control
No live vaccine or breast feeding
CMV negative and irradiarted blood production to prevent engrafment of lymphocytes
What is the aim of the management of SCID
To get child into a position for bone marrow transplant
What are the function of antibodies
Opsonistation
Antibody dependent cytoxicityt with NK cells
Phagocytosis
Neutralise
Agglutinate pathogen to make them easier to phagocytosis
If there is antibody deficiency what are the types of infections you can get
Pneumonia
Bronchiectesis
Conjunctivitis
Otitis media
What is the characteristic pattern of pathogen that you can get in antibody deficiency
Streptococcal infection
Haemophillus infection
Staphyloccocal infection
Giardiasis, campylobacter, salmonella
