Immunology Flashcards
What is part of adaptive versus innate immune system?
Innate: immediate rxn
- epithelial barrier
- Phagocyte
- Complement
- NK cells
Adaptive: day 1-7
- Humoral= B lymphocyte + Antibody
- Cell Mediated= T cells
Most common primary immunodeficiency?
IgA deficiency
List as many warning signs known for primary immunodeficiency:
min. 4 AOM in 1 yr
min. 2 sinus in 1 yr
min. 2 mon. of Abx
min. 2 pneumonia in 1yr
**FTT
recurrent deep abscess
persistent thrush
**Need IV Abx to clear bacterial infection
min. 2 invasive infection (including septicaemia)
**Fhx primary immune
**= most predictive
Delayed umbilical detachment, infections recur, leukocytosis. Dx?
Leukocyte adhesion defect
Atopic eczema. Bloody stool. Draining Ears. Dx?
Wiskott-Aldrich Syndrome
Recurrent staph abscess, staph pneumonia, dermatitis.
Hyper-IgE syndrome
Sinopulmonary infection + telangiectasia
Ataxia-telangiectasia
List two dx and type of bug=
- humoral
- cellular/combined
- complement
- phagocytic
Humoral= XLA, CIVD, Hyper IgM
= encapsulated (strep, h. influ)
= recurrent sinopulmonary
Cellular/Combined= SCID, DiGeorge, Hyper IgE
= virus (CMV, EBV), protozoa/fungal, mycobacteria, toxo
= candida
Complement= early or late defect
= Neisseria + encapsulated
= meningitis, septicemia
Phagocytic= CGD, LAD, Shwachman-Diamond, Congenital neutropenia
= Staph + gram (-) bugs
= abscess, cellulitis, osteo
Screening primary immunodeficiency BW?
CBC + diff
(low lymph= cell; low neut= phagocytic)
Humoral #= serum immunoglobulin \+/- IgG subclasses f'n= vaccine response
Cellular #= flow cytometry f'n= T cell proliferation study f'n= TST test, candida test, Mitogen Assay, Adenosine Deaminase
Phagocytic testing
= Neutrophil Oxidative Burst Index (NOBI) or Nitroblue tetrazolium Test (NBT)
Complement #= C3, C4 f'n= CH50, AH50
recurrent meningococcemia meningitis. Likely immunodeficiency?
C5 deficiency.
How can you tell C3 versus C5 deficiency?
C3/ C4/ C1= Auto-immune problems, sinopulmonary infections from encapsulated bacteria (send AH50)
C5-9= Meningococcal, invasive gonococcal (send CH50)
How do you screen for T cell defect.
#
- = CBC w/ diff (lymph)
- = Flow cytometry (CD…)
Function
*= T cell proliferation (response to mitogen)
*= Delayed hypersensitivity (need prior exposure; candida or TST)
= Adenosine Deaminase (ADA) or Purine Nucleoside Phosphorylase (PNP) level
= Thymic Bx
Deficiency in which can lead to anaphylaxis in pt with IVIG:
- IgA
- IgD
- IgG
- IgE
- IgM
IgA
Which dx is IgE NORMAL:
a. Wiskott aldrich
b. ITP
c. IgA def
d. KD
e. Ascariasis
ITP= Normal IgE
- High in Ascariasis, KD, Wiskott
- Can be low in IgA def
Eczema, low plt, recurrent pneumonia or AOM. Likely Dx.
Wiskott Aldrich
- X linked
“TIE”= thrombocytopenia + immunodef + eczema
“Wiskott Whiskey”= high EthAnol (IgE and IgA) makes mentation (IgM) go down.
3 y.o. w/ AOM or pharyngitis every 1-3 mo. Likely?
Multiple viral infections
List any traits you know of Familial Mediterranean Fever:
< 10 y.o.
1-3 d
every 1-2 mo.
trigger: exercise, stress, infection
Arab, Armenian, Turkish, Greek, Lebanese.
Fever
+ serositis (peritonitis, pleuritic, pericarditis)
+ pain (abdo, arthritis, chest)
Tx: Colchicine.
Complication: RF
15 y.o. M has 5 episodes of pneumonia. In different areas. Most helpful:
a. immunoglobulin w/ IgG subclasses
b. PFT
c. CT chest
d. TB skin test
e. sputum Cx
Immunoglobulin w/ IgG subclasses
Nelson: min. 2 resp bac/1 yr min. 1 invasive bac unusual site (brain, liver) unusual severity \+/- chronic oral candidiasis, FTT, infection after live vaccine etc.
What is true about chronic granulomatous disease:
- all F must be 45XO
- suppurative lymphadenopathy key feature
- low lymph in most
- low # of neut
- rarely < 5 y.o. ppt
Suppurative Lymphadenopathy KEY.
- X linked or AR
- most ppt as infant
- # of neut fine= function is issue (can’t kill so wall off = abscess)
- dx: flow cytometry to measure oxidant
- dx: nitroblue tetrazolium dye
- cure= transplant
In chronic granulomatous dx, all (+) BUT:
- male
- leukocytosis
- lymphadenopathy
- hepatomegaly
- hypogammaglobulinemia
Hypogammaglobulinemia
- 2/3 male
- yes lymph + big liver
- yes WBC up (neutrophils)
- Neutrophil Oxidative Burst Index (NOBI) or NitroBlue- Tetrazolium (NBT) test
What are the most common bugs for chronic granulomatous dx?
*S. aureus
*Serratia Marcescens.
*B cepacia
*Salmonella
Nocardia
Aspergilis
Candida
Which is true of Wiskott Aldrich?
- AR
- Poor response to protein antigen
- CA risk
- low IgE
- leukopenia
Cellular/Combined
Immunodeficiency + Thrombocytopenia + Eczema
X linked
Poor response to polysacc antigen
IG…..EthAnol high= Mentation Low.
Lymphopenia
Poor response to polysacc vaccine.
YES- EBV associated CA, leukaemia, lymphoma
T or F: you can get paralysis w/ administration of live polio vaccine in X linked agammaglobulinemia?
True.
*Avoid live vaccine in X-linked-agamma
No lymph
No B cell
= no antibody
Which lab abnormality is seen in Ataxia-Telangiectasia?
- low IgA
- low IgE
- IgG up
Low IgA
A for Ataxia.
PID: extensive mucutaneous candida..
T cell issue
SCID, Digeorge, WAS, hyperIgE
PID: meningitis, septicemia
Complement issue
Skin abscess, lymphadenitis, osteo. Which category of PID?
Phagocytic
CGD, LAD, Shwachman-Diamond
Recurrent Sinopulmonary only. Which category of PID?
Humoral
XLA, CVID, IgA deficiency
Post polio paralysis. Which PID?
XLA
Post bCG or varicella vaccine dissemination. Or hypo-Ca tetany infant. Which PID category?
Cellular/Combined
SCID, DiGeorge, WAS, hyper IgE
Which PID category is linked with lots of AI conditions?
Complement and Common Variable Immunodeficiency
18 mon. with arthritis, meningitidis, CSF meningitis. Which test?
#: C3, C4 Function: CH50, AH50
What are key Severe combined immunodeficiency (SCID) features?
Lack T + B + NK, No immunoglobulins
CC: recurrent diarrhea, FTT, AOM, sepsis
- Lack thymic tissue on XR (XLA only other one with no lymphoid tissue)
- Severe bacterial/ viral/ fungal/ opportunistic infections
- Live vaccine= ER
How is SCID tested for on the newborn screen?
No TREC (T-cell receptor excision circles)
TREC clip off to make T cell in thymus. If no T cell= No TREC.
Tx: transplant
4 mo. Eczema. Recurrent pneumonia. Absent Thymus on XR. Likely?
SCID
Thrombocytopenia. Normal Hgb. Bad eczema. Chronic fingernail Staph infection. What finding confirm dx?
- absent radi
- no LN/tonsil
- Draining ear
- hypoplastic patellae
Draining ear= recurrent AOM common in Wiskott-Aldrich Syn
Immune deficient
+ Low small Plt + Eczema
B/L no radii= TAR.
Recurrent severe staph abscess of skin + lungs. IgE++++
HyperIgE syndrome (Job Syndrome)
Other findings: coarse facial features, failure or delay of shedding of primary teeth, recurrent fractures, hyperextensible joints, and scoliosis
Pneumatocele= AD Dermatitis= AR form
What is the hallmark sign of familial Mediterranean fever?
Erysipelas-like erythema (esp over ankle)
1-3 d
Fever
serositis
arthritis or rash
What is the SLE mnemonic?
SOAP BRAIN MD
Serositis (pleurites, pericarditis)
Oral ulcers
Arthritis
Photosensitivity
Blood (all low) Renal (proteinuria) ANA Immunologic (dsDNA) Neuro (psych, sz)
Malar rash
Discoid Rash
List 4 investigations for W/U of pt with suspected immunodeficiency.
1.** CBC + Diff
(low lymph= cell mediated; low neut= phagocytic)
2. **serum immunoglobulin (humoral)
3. **vaccine titre (like tetanus, diphtheria; humoral f’n)
4. **flow cytometry (cellular function)
Other: - Cellular f'n= **Candida test, T cell proliferation test - Phagocytic testing = DHR or NBT - Complement #= C3, C4 f'n= **CH50, AH50
Name two organ systems + two organism typically affected by granulocyte defect:
- Skin + soft tissue (impetigo, deep abscess, lymphadenitis)
- Lungs (pneumonia)
- Bones (osteomyelitis)
Bugs:
- Staph aureus
- Serratia marcescens
- Klebsiella and other
List four findings that suggest immunodeficiency:
SPUR (Serious, Persistent, Unusual, Persistent)
1 systemic (sepsis, meningitis)
2 or more serious resp (pneumonia, cellulitis) within 1 yr
Unusual site w/ serious infection (liver, brain)
Unusual pathogen (pneumocystis jiroveci, aspergillus, serratia marcescent)
Usual childhood bug but very severe
Multiple AOM + pneumonia. IgG, IgM normal but IgA low. Warn child about?
Selective IgA Deficiency
Warn about possible anaphylaxis to blood products
Warn about association w/ spur like syndrome (that gluten free may or may not help w/)
T or F: IgA deficiency may remit after d/c phenytoin (dilantin).
True.
T or F: IgA may evolve into CVID?
True.
Tips for vaccine hesitate parents:
- Vaccine safety sys rigorous
- Vaccine recommendation based on dx epidemiology and evidence of vaccine safety
- Kids exposed to more antigen in daily routine activities compared to routine vac schedule.
3 indications for conjugated quadrivalent vaccine for meningococcus?
Medical RF:
- Asplenia or functional asplenia (i.e. sickle cell)
- Properdin, factor D or complement deficiency
- HIV
Exposure RF:
- Close contact to invasive meningococcal dx.
- Travellers to endemic area (sub-saharan africa, Hajj)
- Lab who work w/ meningococcus.
- Military personnel in close quarters.
Child with ataxia. Most appropriate screening test for immunodeficiency?
Alpha fetoprotein level.
= Ataxia-telangiectasia
- Mutation in DNA repair. Effects rapidly dividing cells
- Present in childhood w/ cerebellar ataxia, regression in motor milestones, followed by dev of telangiectasias (at 3-6yrs)
Recurrent sinopulmonary infections with encapsulated bacteria
Depressed IgA, high IgM, variably decreased IgG and T lymphocyte deficiency
Increased risk of malignancy
T or F: you should delay live vaccine until T cell competence established.
True.
What are the two primary immunodeficiencies that have absent lymphoid tissue (no tonsil, no lymph node)
XLA (X-linked Agammaglobulinemia) - small tonsils
SCID
Examples of humeral deficiencies.
Typical Onset
Typical Infections
IgA deficiency
X-Linked Agammaglobulinemia
Common Variable immune deficiency
Onset after 6 mos when maternal Abs gone
Recurrent sinusitis and pulmonary infections with encapsulated bacteria - strep. pneumonia, H. flu
Intact cellular immune system - able to fight viruses and fungi
Features of CVID
Common Variable Immune Deficiency
Hypogammaglobulinemia
May present in childhood, but often as adults
Most patients have B cells
Frequent GI symptoms - malabsorption, chronic diarrhea
Nodular lymphoid hyperplasia
Increase in autoimmunity - arthritis, autoimmune heme d/o
systemic granulomatous disease
Increase incidence of malignancy
Poor vaccine response due to decreased IgG antibody response (MMRV, tetanus, diptheria, pneumococcal).
Tx: IVIG to prevent recurrent pulmonary infections and decrease bronchiectasis
Features of IgA Deficiency
Most common immunodeficiency
Often asymptomatic
Sinusitis and Pulmonary infections as well as GI involvement
Normal immune response to vaccines
X-Linked Agammaglobulinemia
Arrest of B cells - severe IgA/IgG/IgM deficiency or total absence
Recurrent bacterial infections starting before 1 year, usually at 4-6 mos
Risk of enteroviral meningoencephalitis most commonly a/w echovirus
Arthritis - often due to infections with Ureaplasma or mycoplasma)
Don’t give live vaccines (risk of paralytic polio)
Examples of T cell or combined T/B cell Immunodeficiencies
SCID WAS Ataxia Telangiectasia Di-George X linked hyper IgM
Features of DiGeorge
22q11 Deletion
- abnormal migration of the third and fourth branchial pouches during embryogenesis, with hypoplasia or aplasia of the thymus and parathyroid glands.
- Cardiac malformations (e.g., truncus arteriosis, TOF) and dysmorphic facial features.
- Reduced CD3+ T-cell count and hypocalcemia
