immunology

Question 1

IgA deficiency

Answer 1

Second most common after CVID. Often asymptomatic. Increased allergy and eczema incidence, and celiac. Difficulty clearing rota. More sinopulmonary infections.
Icnreased risk of malignancy and autoimmune disease.

Question 2

IgG deficiency

Answer 2

Look for repeated organ specific infections, especially pyogenic lower resp and sinupulmonary infections from repeated, often encapsulated/polysaccharide bacteria. May present as “asthma”. Bronchiectasis. Otitis media. Sinopulmonary.

Question 3

X-linked Immunodeficiency With Hyper IgM

Answer 3

X Linked disease. Abnormal CD40. Can’t make IgA, IgE or igG, with consequent high levels of circulating IgM.
Chronic pneumonias (esp PCP but of all variations), lots of diarrhea (think cryptococcus). Failure to thrive.
Chronic or cyclic neutropenia. Sclerosing cholangitis. Autoimmune disease. Malignancy.

Question 4

Common Variable ImmunoDeficiency

Answer 4

CVID is the most common deficiency. Affects ability of B cell to mature to plasma cell. IgA, IgG and sometimes IgM is lower. Recurrent infections, unusual organisms like mycoplasma, PCP and giardia.
Granulomatous disease, lymphoid hyperplasia, autoimmune diseae and malignancy risk.

Question 5

X-linked agammaglobulinemia (Bruton’s)

Answer 5

X linked. BTK mutation (needed for B cell maturation-Pre-B cell). Unlike CVID, has no rate of autoimmune disease. Low or absent mature B cells. No IgG, IgA or IgE. Absent/reduced lymphoid tissue.
Lots of in ifections, including skin infections.
Post vaccine polio infection. Fungal and viral infections handled well except enteroviruses.

Question 6

Severe combined immunodeficiency

Answer 6

SCID is a life-threatening syndrome of recurrent infections, diarrhea, dermatitis, and failure to thrive. Untreated, usually dead by 2.
Pediatric emergency.
Usually lymphopenic (but may just be nonfunctional) and Ig’s of all types decreased.

Question 7

DiGeorge Syndrome is associated with what immune dysfunction?

Answer 7

T cell dysgenesis.

Question 8

Wiskot Aldrich Syndrome

Answer 8

eczema-thrombocytopenia-immunodeficiency syndrome. X linked. Has bloody diarrhea because of thrombocytopenia.

Question 9

Hyperimmunoglobulinemia E (Job) Syndrome

Answer 9

High IgE levels. Recurrent mucocutaneous candidiasis, lichenifications, eczema, wheeze. Abnormal facies.

Question 10

Most common food allergies

Answer 10

egg, milk, soy, tree nuts, peanuts, shellfish, fish.

Question 11

Prognosis of egg and milk allergies

Answer 11

85% outgrown by age 5.

Question 12

peanut, tree nuts, fish, and shellfish allergy natureal history

Answer 12

more persistent.

Question 13

Natureal history of non-IgE food “allergies”

Answer 13

The proctocolitis and enterocolitis resove usualyl in first year of life. Eosinophilic esophagitis is persistent.

Question 14

Causes of secondary immunodeficiency…

Answer 14

HIV, CMV, starvation, metabolic disease, steroids, radiation and nutrients like zinc, copper, iron, and selenium.

Question 15

B-lymphocyte defects

Answer 15

• X-linked agammaglobulinemia (Bruton’s)
• Common Variable Immunodeficiency (CVID)
• Selective Ig-A Deficiency
• Transient Hypogammaglobulinemia of Infancy
• Functional Hypogammaglobulinemia
• IgG Subclasses deficiency
• Hyper Ig-M Syndrome

Question 16

T cell Dysfunction : Clinical Characteristics - organisms

Answer 16

Infections with intracellular microorganisms

Viruses (HSV, VZ, CMV, EBV)

Protozoa (Cryptosporidium, toxoplasma)
Mycobacteria

Fungal (Candida, P. carinii )
Bacteria, gram negative enteric (T cell)

Bacteria, polysaccharide encapsulated
(B cell)

Question 17

T Cell Dysfunction: Clinical Characteristics

Answer 17

• Anergy to recall antigens
• Graft versus host disease
• Failure to thrive (especially with 
diarrhea)
• Increased B-cell malignancies
• Eosinophilia, thrombocytopenia
• Eczema, alopecia

Question 18

Classification of Food reactions

Answer 18

1) Autoimmune: ie celiac
2) Non-Immune: enzyme defects/deficiencies, drug reactions, food additive reactions, metabolic diseases (PKU, fructose intolerance, galactosemia… etc.)
3) Immune Mediated: IgE mediated (allergies), mixed IgE/non-IgE: eosinophilic esophagitis; non-IgE (enterocolitis, proctocolitis, chronic constipation).

Question 18

Red flags with fevers

Answer 18

Inconsolable, poor tone, altered LOC, not feeding, Anuria, lethargy, seizure

Question 19

Prematurity and infections

Answer 19

Increased risk

Question 20

Good antiobiotics for fever without a source in a baby

Answer 20

Amp and cefotaxime

Question 21

Vaccine schedule

Answer 21

Antibacterial for first 6 months: DTaP, menC, pneumo, HiB (IPV though).
Influenza at 6 months.
12mo: mmr, vsv,
Grade 5 hep b and hpv.

Question 22

People at greater risk of opv induced polio disease

Answer 22

B cell immunodefiencies.

Question 23

Red flags for vaccines

Answer 23

Previous anaphylactic reactions, recent steroids, recent blood transfusion products

Question 24

People that should really get vaccines

Answer 24

Splenectomy/hyposplenia, elderly, neonates, immunodeficiency, HIV, cops, heart failure,

Question 25

Types of vaccines

Answer 25

Live attenuated (mmr, vsv, oral typhoid, oral polio, yellow fever, bcg).

Whole inactivated (Salk)

Parts/protein +_ conjugate

Question 26

Parts of vaccines

Answer 26

Additives to enhance immunogenicity (aluminum salt)

Preservatives (thimerosal)

Support growth (egg, animal protein)

Question 27

Education points for vaccines

Answer 27

Very safe, even multiple early in childhood. Most even with active mild disease.

No link to autism.
No safety reason to avoid thimerosal
Benefits
Risks: common(pain, swelling, irritability, rash, fever); rare (fever, seizure, hypotonia, parotitis); life threat: GBS, allergic,

Question 28

Vaccine contraindications:

Answer 28

Anaphylactic rxns: prev vaccine, neomycin, streptomycin, egg, gelatin, bakers yeast.
Live vaccines in immunodeficiency or steroids.
Pregnancy, defer till post partum