Immunology Flashcards
ANAPHYLAXIS
i) what type of hypersensitivity reaction is it? what type of Ig is involved? which cells are involved? what is the key defining feature?
ii) name three ways it may present? name three other symptoms? what can be measured to confirm it?
iii) what approach should be taken in management? which three medications are given to treat it?
iv) why should all children have a period of observation/assessment afterwards?
i) severe type I hypersens reaction that involved IgE and degranulation of mast cells
defined by airway, breathing and or circulation compromise
ii) px with urticaria, itching, angioedema (swell around eyes or lips), abdo pain
also with SOB, wheeze, laryngeal swelling > stridor, tachycardia, light headed
measure serum mast cell tryptase to confirm within 6 hours of the event
iii) A-E approach
IM adrenaline (repeat after 5 mins if required), antihistamines (oral chlorphenamine or cetirizine), steroids (IV hydrocrotisone)
iv) biphasic reactions can occur - second anaphylactic reaction after the first
ALLERGIC RHINITIS
i) what type of hypersens reaction is it? what causes the allergic reaction?
ii) name three ways it may present? what is it associated with in the history? how is a diagnosis usually made?
iii) which type of test may be useful? name four triggers
iv) what conservative mx can be done? what medication can be given prior to exposure to allergen to reduce symptoms?
v) which two things can be given in a nasal spray? what should not be done when administering the nasal spray
i) IgE mediated type 1 hypersensitivity reaction caused by environmental allergens
ii) can px with runny, blocked, itchy nose, sneezing, itchy or swollen eyes
associated with FH of atopy
dx usually made on history
iii) may do skin prick test - especially good for pollen, animals and house dust mite allergy
triggers - tree pollen/grass, house dust mites, pets, mould
iv) avoid the trigger
oral anti histamines can be given - non sedating (cetirizine, loratidine, fexofenadine) or sedating (chlorphenamine, promethazine)
v) nasal corticosteroid spray eg fluticasonem mometasone to supress local allergic symptoms
nasal antihistamines
dont sniff at the same time as spraying as sends it to the back of the throat
COWS MILK PROTEIN ALLERGY
i) who does it usually affect? what is it a reaction to? how quickly will IgE mediated happen? how quick will non IgE mediated happen?
ii) who is it more common in? (2) what age does it usually present before? name three GI symptoms?
iii) name three allergic symptoms that may be seen? what occurs rarely?
iv) how is a diagnosis made? what can be used to support it? what advice should be given to breastfeeding mothers?
v) what are hydrolysed formulas? what can be done every 6 months with the child? by what age will they probably outgrow it?
i) affects infants and children under 3 years
reaction to protein in cows milk
IgE mediated - rapid reaction within 2 hours of ingestion
non IgE - slower and occurs over several days
ii) more common in formula fed babies and those with FH of atopic conditions
usually presents before 1 year of age - bloating, wind, abdo pain, diarrhoea, vomiting
iii) allergic - urticarial rash, angioedema, cough, wheeze, sneeze, watery eyes
rarely anaphylaxis can occur
iv) dx with full hx and exam and do skin prick testing to support
breastfeeding - mum to avoid dairy
v) hydrolysed formula - contain cows milk but proteins have been broken down to they dont trigger immune response
may also need elemental formulas made of basic AAs
most children outgrow by age 3
every 6 months move up the milk ladder, gradually/slowly introduce small amounts more milk until they can have a normal milk containing diet
COWS MILK PROTEIN ALLERGY
i) who does it usually affect? what is it a reaction to? how quickly will IgE mediated happen? how quick will non IgE mediated happen?
ii) who is it more common in? (2) what age does it usually present before? name three GI symptoms?
iii) name three allergic symptoms that may be seen? what occurs rarely?
iv) how is a diagnosis made? what can be used to support it? what advice should be given to breastfeeding mothers?
v) what are hydrolysed formulas? what can be done every 6 months with the child? by what age will they probably outgrow it?
i) affects infants and children under 3 years
reaction to protein in cows milk
IgE mediated - rapid reaction within 2 hours of ingestion
non IgE - slower and occurs over several days
ii) more common in formula fed babies and those with FH of atopic conditions
usually presents before 1 year of age - bloating, wind, abdo pain, diarrhoea, vomiting
iii) allergic - urticarial rash, angioedema, cough, wheeze, sneeze, watery eyes
rarely anaphylaxis can occur
iv) dx with full hx and exam and do skin prick testing to support
breastfeeding - mum to avoid dairy
v) hydrolysed formula - contain cows milk but proteins have been broken down to they dont trigger immune response
may also need elemental formulas made of basic AAs
most children outgrow by age 3
every 6 months move up the milk ladder, gradually/slowly introduce small amounts more milk until they can have a normal milk containing diet
SCID
i) what is it the result of? when does it present?
ii) name four presenting features? how may they appear after vaccinations?
iii) what are more than 50% cases caused by? what is the inheritance pattern? name another mutation that can cause it
iv) what is omenn syndrome? name three classic features
v) what can be given to treat it? where must the patint be kept?
i) absent or dysfunctioning T and B cells
presents in first few months of life
ii) persistent severe diarrhoea, failure to thrive, opportunistic infections eg severe chickenpox, pneumocystis jiroveci pneumonia, CMV
iii) mutation in common gamma chain on X chromo that codes for IL receptor on T and B cells
X linked recessive inheritance
also caused by jac3 gene mutation
iv) omenn syndrome - mutation in RAG1 or RAG2 > auto recessive
abnormally func T cells that attack tissues in neonate > red, scaly, dry rash, alopecia, diarrhoea, fail to thrive, lymphadenopathy, hepatosplenomegaly
v) mx with tx underlying infection, Ig therapy and keep patient in a sterile environment
B CELL AND IG DISORDERS
i) what is selective IgA deficiency? name three places IgA is found? what does it protect against? how to paatients with SIGA defic present? what type of infections may they have?
ii) screening for what condition may pick up selective IgA defic? why?
iii) which cells is there a mutation in in common variable chain immunodeficiency? which Igs are defic? (2) which Ig is present in normal amounts? what type of infections does the person get?
iv) why are vaccinations not useful for patients with CVI? name two conditions they are more prone to? how is it managed?
v) what is X linked agammaglobulinaemia? which Igs are affected? what is the inheritance?
i) most common Ig deficiency - low levels of IgA, normal IgG and IgM
IgA is gound in secretions of mucus membranes eg saliva, resp tract, GI, tears, sweat and protects from opportunistic infections in the mucus membranes
Ig is mild and most patients never present
may get recurrent mucus membrne infections eg LRTI nd auto immune conditions
ii) screening for coeliac may pick it up as you test for IgAa levels of anti TTG and EMA
iii) common variable immdefic is caused by mutation in genes coding for components of B cells
defic of IgG and IgA but not of IgM
recureent respiraatory tract infections and chronic lung disease over time
iv) cant develop immunity to vaccinations
prone to RA and cancer such as NHL
manage with regular Ig infusion and treating. infections as they occur
v) X linked reccessive conditions > abnormal B cell development and defic in all Igs
T CELL DISORDERS
i) which chromosome is affected in di george? which embryological structures are affected? (2) why may patients not make functional T cells?
ii) features of di george CATCH 22 mnemnonic
iii) what is PNP deficiency? what levels of T cells, B cells and Ig are seen?
iv) what chromosome is affected in ataxia telengiectasia? what levels of T cells and Ig are seen? which organ may there be failure in
i) 22q11.2 deletion > microdeletion of chr 22 leading to a developmental defect of the third pharyngeal pouch and third branchial cleft
underdeveloped thymus gland > cant make functional T cells
ii) congenital heart disease, abnormal facies (charac facial appear), thymus incomplete dev, cleft palate, hypoPTH > hypocalcaemia, 22 chromo defect
iii) PNP defic is auto recessive > cant break down purines
get low T cells, normal B cells and Ig
iv) chromosome 11 > low T cells and Ig
liver fail
COMPLEMENT DISORDERS
i) what do deficiencies in complement proteins result in? what other type of disorders are complenet deficiency assoc with? what is the most common complement defic?
ii) vaccination against what is important for those with complement defic? name three
iii) how does hereditary angiodema present? what is there a deficinecy in? what complement protein levels will be low?
iv) which pathway of complement system is affected in MBL deficiency? is this common or rare?
i) defic result in vulnerability to certain infective organisms and recurrent infections of resp tract, ears and throat
also assoc with immune complex disorders eg SLE > build up of immune complexes in tissues and chronic inflammation
most common is C2 deficiency
ii) vacc against encapsulated organisms is important eg haemoph influenza B, strep pneumonia, neisseria meningitidis
iii) px with inermittent angioedema in response to minor triggers
defic in C1 esterase inhibitor (usually inhib bradykinin)
levels of C4 will be low - use this to test
iv) MBL defic > inhibition of alternative pathway > doesnt cause major immunodefic and is relatively common
