Allergy/Immunology Flashcards
(26 cards)
Immune markers for
1. B cells
2. T cells
3. NK cells
4. Complement
- CD19/20
- CD3 (and 4, 8)
- CD 16, CD56
- CDH 50
Immunodeficiency in ataxia telangiectasia
T cell number and function are low
Absent IgA is common
Often low or normal IgG, may have elevated IgM
Can have poor antibody response to some vaccines
Results in recurrent sinopulmonary infections, bronchiectasis, and poor mucociliary clearance
X-linked agammaglobulinemia
Defect in B cell development
Low IGAMS, absent circulating B cells
Small to absent tonsils, no palpable lymph nodes
Present after 6-9 months (mat IgG gone)
Sinopulmonary, meningoencephalitis
Manage with IVIG or SQIG
No live vaccines
Infectious organisms with XLA (4)
Strep pneumo
H flu
Mycoplasma
Enterovirus
5 immunodeficiencies where live vaccines are NOT contraindicated
Selective IgA deficiency
IgG deficiency
Complement deficiency
Phagocytic disorders
Anatomic/functional asplenia
Cyclic neutropenia
Neutropenia ever 21 +/- 3 days
Lasts for 3-10 days then resolves
AD disorder
Can get fever, malaise, mouth sores
Treat with G-CSF
FMF attacks
Fever 1-3 days
Serositis (peritonitis, pleuritis, pericarditis, synovitis)
Erysipelas like rash
Hereditary angioedema
Pathophys, presentation, course, diagnosis, treatment
AD defect in C1 inhibitor enzyme
Leads to decreased C4, bradkykinin is a key mediator
Recurrent episodes of localized angioedema, not urticaria, not itchy
Can get erythema marginatum on trunk/limbs
Screen with low C4, diagnose with decreased C1-INH level and function
Treat by replacing C1-INH, FFP if not available
What is allergen immunotherapy good for
Stinging insects
Allergic rhinitis
Organisms with Complement deficiency
Neisseria meningitidis is classic
Strep pneumo
Clues to complement deficiency
Most are autosomal recessive, can be X linked
Similar to B cell deficiencies (sepsis, meningitis, pneumonia)
Neisseria is big clue
Early (C1-4) = rheumatic, SLE
Late (C5-9) = meningitis
C3/4 levels are usually normal
Diagnose with specific complement testing
Need abx prophylaxis and immunizations
SCID
Profound defect of B and T cell function
Presents between 2-6 months
Opportunistic infections, sinopulmonary, fungal, chronic diarrhea, FTT, eczema
Absent lymph nodes, tonsils, thymus
NBS for TRECs
Absent abs to vacines
No BF if mom is CMV+
Avoid live vaccines
HSCT
DiGeorge immunodeficiency
T cell immunodeficiency because of thymic hypoplasia or absence
More severe T cell function = more severe B cell function
HSCT does not work (need thymus for T cells)
RAST test
Radioallergosorbent test
Immunoassay for IgE specific to an allergen of interest
Not great
Pros: No risk of allergic reaction, not affected by meds, not impacted by skin disease
Cons: expensive, false positives in high IgE, not great sensitivity or specificity
Negative test with strong history does NOT rule out allergy
Chronic granulomatous disease
Disorder of neutrophils (can ingest, but cannot kill so makes granulomas)
Skin infections, oral ulcers, pneumonia, enteritis and diarrhea, abscesses, obstructions
Dx: oxidative burst, NBT test
Tx: HSCT curative
Organisms in chronic granulomatous disease
Catalase positive
S aureus
Nocardia
Bukholderia
Salmonella
Candida
Aspergillus
Leukocyte adhesion deficiency
Neutrophils unable to adhere to infected cells or mobilize to site of infection
Delayed cord separation, omphalitis, gingivitis, necrotizing infections, perirectal abscesses
No pus forms at site of infections
Impaired wound healing
Dx: No CD18
Tx: abx, HSCT
Common variable immunodeficiency
B cells are unable to class switch
Sinopulmonary infections, Giardia, granulomas
Autoimmunity!
Poor vaccine responses
Low Ab levels but some B cells are present
IVIG/SQIG
CVID vs XLA
Similar types of infections
Both have hypogammaglobulinemia
Equal sex distribution in CVID
CVID does not typically get enterovirus meningoencephalitis
CVID later age of onset, less severe
Wiskott-Aldrich syndrome
X-linked recessive
T cell dysfunction (leads to B cell dysfunction)
EXIT: eczema, Xlinked R, immunodeficency, thrombocytopenia
Increased risk of autoimmunity and malignancy
Elevated IgA and IgE, low IgM, normal/low IgG
Low T cell numbers and function
Avoid live vaccines
HSCT
Encapsulated bacteria
“Yes Some Killer Bacteria Have Pretty Nice Capsules”
* Yersinia
* Salmonella, Strep pneumo
* Klebsiella
* Bacillus
* H. flu
* Pseudomonas
* Neisseria
* Cryptococcus, Capnocytophaga
Selective IgA deficiency
Unmeasurable IgA, but rest are normal
Increased risk of anaphylactic transfusion reactions
May progress to CVID
2/3 asymptomatic
1/3 have recurrent sinopulmonary, giardia, autoimmune
Dx after 4 years with low IgA
Should not get IVIG or SQIG!!!
Contraindications for live attenuated influenza vaccine
< 2 years
Severe asthma (current high dose ICS or systemic steroids)
Wheeze in past 7 days
Immunodeficiency
Pregnancy
ASA treatment
Oral allergy syndrome
Localized form of IgE mediated food allergy
Caused by cross reactivity between fruit/veggies and pollen (usually tree)
Confirm pollen sensitization with skin prick testing
Avoid eating foods raw
