Hypersensitivity and Asthma Flashcards
Type I
Immediate. Anaphylaxis, allergy and atopy
Type II
Antibody mediated. Complement and recruitment
Type III
Immune complexes - pathology determined by which tissues they are deposited in
Ab-Ag interaction but soluble complexes not cleared
Complement, neutrophils and macrophages
Type IV
Cell mediated (delayed response: 24-48 hours)
CD4 ->Th1, 2 and 17 activated -> cytokines
CD8 response
Which type of asthma responds well to ICS?
Allergic asthma
Which type of asthma is eosinophilic?
Allergic asthma
Which cells are contained in non-allergic asthma sputum?
Neutrophils/Eosinophils/neither
Does non-allergic asthma respond well to ICS?
Less so than allergic
Diagnosis of asthma:
Skin prick wheal > 3mm
IgE > 100 IU/ml
Tryptase levels (transient over 24-48 hours)
Radio-allergo sorbent test; BAT; MAT
Leukotrienes from which inflammatory cell cause vasodilation, bronchoconstriction and inflammation?
Basophil
Which interleukin causes eosinophil degranulation?
IL-5
Which interleukin causes mucus production?
IL-13
Degranulation of which inflammatory cell causes bronchoconstriction and inflammation?
Eosinophil
What are the airway symptoms of asthma?
Wheezing, SOB, rhinitis, sneezing, runny nose
What are the eye symptoms of asthma?
Conjunctivitis
What are the skin symptoms of asthma?
Atopic dermatitis
What are the gut symptoms of asthma?
Food allergy
Which type of asthma tends to present later and to which demographic?
Non-allergic, women
What are the symptoms of long-standing asthma?
Fixed airflow limitation and airway remodelling
What makes up inflammatory infiltrate?
Recruitment, Th2 cells, mast cells and eosinophils
Histology of asthma:
Leaky epithelium, reticular BM thickening, airway SM thickening, submucosal gland hypertrophy
Key features of asthma!
Irreversible airway narrowing, constant bronchoconstriction to random stimuli, mucosal inflammation and airway remodelling
Which type II hypersensitivity condition is characterised by Abs against the TSH receptor?
Grave’s disease
Which type II hypersensitivity condition is characterised by Abs against the Ach receptor?
Myasthenia gravis
Which type is late-onset asthma?
Type IV
Which type is early onset asthma?
Type I
What does reduction in FEV1 mean?
Lower volume of air can be expelled in the first second
If an asthma patient is using their accessory muscles what is their status?
Sever exacerbation
What is the immediate treatment for an acute asthma exacerbation?
SABA: 4-10 puffs pMDI + spacer (every 20 mins for an hour)
Prednisolone: 1 mg/kg adults; 1-2 mg/kg children
What are the target O2 sats for an acute asthma exacerbation?
90-95%
What is the urgent treatment for a severe acute asthma exacerbation? (6 drugs)
SABA (nebuliser) Ipratropium bromide O2 Systemic corticosteroid IV Magnesium High dose ICS
What are the features of a life-threatening asthma exacerbation?
Drowsy, confused or silent chest
Clinical features of a mild/moderate asthma exacerbation:
Raised RR
PR: 100-120 bpm
O2: 90-95%
PEF > 50% predicted/ best
Clinical features of a severe asthma exacerbation:
RR > 30
PR > 120 bpm
O2 < 90%
PEF lower than/equal to 50% predicted/best
Discharge from acute exacerbation criteria:
SABA not needed, PEF > 60-80% predicted/best, O2 > 94% on room air + resources at home
Stage 1 treatment =
SABA (< twice a month with no night waking/exacerbations)
Stage 2 treatment =
Low does ICS and SABA as needed
Stage 3 treatment =
Low dose ICS and LABA
Stage 4 treatment =
Medium-high ICS and LABA
Stage 5 treatment =
Refer for additional treatment of monoclonal Abs
Formaterol, salmeterol and volanterol are all examples of what?
LABA
SABA and LABAs are examples of?
Selective beta-2 adrenoreceptor agonists (bronchodilators)
Name short and long acting anticholinergic/muscarinic receptor antagonists: (also bronchodilators in addition to -BAs)
Ipratropium (short)
Tiotropium , umeclodinium (long)
What added effect does Tiotropium have over other bronchodilators?
Attenuates IL-13 induced goblet cell hyperplasia and reduces mucus secretion
What is the only licensed once daily inhaler drug combination?
Futicasone furoate and vilanterol
What do ICSs suppress?
Th2 ‘type 2’ airway inflammation and eosinophilia
Which ICS has a long action?
Futicasone Furoate (FF)
Which treatment is used for AERD asthma?
LTRA - Montelukast (once daily, oral)
What are the side effects of prednisolone?
Obesity, diabetes, cataracts, reflux, glaucoma, osteoporosis, skin disease, psychological conditions
Which monoclonal antibody drugs target IL-5?
Mepolizumab, Reslizumab and Benralizumab
Which monoclonal antibody drug targets IgE?
Omalizumab
What action to biologics against IgE and IL-5 share?
Stop the activation of eosinophils
What is the most common cause of exacerbations?
Can be normalised by omalizumab
Viral infection
Anti - IL-4R biologic?
Dupilumab (stops Th2 activation of B cells)
Anti - TSLP biologic?
Tezepelumab (reduces IL-13,5 release)
CRTH2 antagonist biologic?
Fevipiprant (reduces IL-13,5 release)
