immune deficiency

Question 1

How many URI, otitis media and gastroenteritis do children get per year

Answer 1

First 10 yrs - 6-8 URI / year. First 2-3 yrs - ≤ 6 episodes otitis media, 2 episodes gastroenteritis / year

Question 2

sources of immunodeficiency

Answer 2

1. malnutrition- PEM/ total calorie ( kwashiorkor/ marasmus), Vit A, iron, micronutrients. 2. HIV-1/ AIDS. 3. Age

Question 3

2. Name four components of immune function.

Answer 3

1) Anatomic (skin, mucosal barriers). 2) Phagocytes - neutrophils and macrophages. 3) Cellular immunity - CD4+ T cells, CD8+ T cells (CTL), Natural killer cells (NK). 4) Humoral immunity -Specific antibodies (B cells), Complement

Question 4

List primary and secondary immunodeficiencies related to Anatomic barriers and the pathogens involved

Answer 4

Primary: eczema, CF. Secondary: Burns, IV lines, post-viral (lungs), chemo (GI/oral)

Question 5

pathogens involved in Burns/ eczema

Answer 5

Staph aureus, Pseudomonas aeruginosa

Question 6

pathogens involved in IV lines

Answer 6

staph aureus

Question 7

Pathogens involved in CF or post viral infection of lungs

Answer 7

Pseudomonas aeruginosa, strep pneumoniae, staph aureus.

Question 8

Pathogens involved in chemo immunodeficiency

Answer 8

e. coli, candida (both GI/ oral)

Question 9

List the normal percentages of PMNs and monocytes

Answer 9

PMN: 60%. Monocytes: 10%

Question 10

List common infections associated with chemo- induced neutropenia- intestine, periodontal and skin

Answer 10

Intestine: GNR (e coli), candida, enterococcus. Transcytosis from epithelium or perirectal abscess. Periodontal: anaerobic abscess, oral streptococci. Skin/ catheters: MRSA, strep, GNR (pseudomonas aeruginosa)

Question 11

describe chronic granulomatous dz- cause, sx, diagnosis

Answer 11

Primary immunodeficiency. Sufficient phagocyte number but decreased function due to defect in NADPH oxidase. Recurrent skin abscesses, severe prolonged pneumonia, bone. Diagnose by NBT test of PMNs

Question 12

List bugs involved in chronic granulomatous dz

Answer 12

Risk for catalase positive organisms that destroy oxygen radicals: Staph. aureus, Serratia, Nocardia, Salmonella, Aspergillus*

Question 13

Causes of decreased cellular immunity

Answer 13

Malnutrition, oral steroids, immunotherapy, chemo, transplantation, HIV/ AIDS. All are secondary

Question 14

List common causes of pneumonia in elderly, young adult, AIDs, nosocomial, Asia/Africa

Answer 14

elderly: S. pneumoniae, H. influenzae, Influenza (winter). Young adult: M. pneumoniae, C. pneumoniae, S. pneumoniae. AIDS: strep pneumonia, P. jirovecii (PCP). Nosocomial: GNR, Staph aureus. Asia/Africa: TB

Question 15

List bacterial infections associated with impaired cellular immunity

Answer 15

Listeria* - Mycobacteria - Legionella - Nocardia* - Salmonella*

Question 16

List fungal infections associated with impaired cellular immunity

Answer 16

Cryptococcus - Aspergillus sp. - Candida (mucosal) - Pneumocystis* - Cocci. immitis -Histoplasma

Question 17

List viral infections associated with impaired cellular immunity

Answer 17

HSV, CMV, varicella

Question 18

List protozoan/helminth infections associated with impaired cellular immunity

Answer 18

toxoplasma, cryptosporidium, strongyloides

Question 19

Antibody structure

Answer 19

F(ab): binds to antibody. Fc: defines isotypes (IgA, IgG, etc) and binds phagocytes via Fc receptors

Question 20

List the infections associated with antibody deficiencies

Answer 20

Mostly respiratory infections, encapsulated bacteria (S. pneumoniae),some viruses (enteroviruses); Giardia lamblia

Question 21

IgG1 vs IgG2

Answer 21

IgG1: recognizes proteins. IgG2: recognizes polysaccharides

Question 22

Which bacteria have polysaccharide capsules

Answer 22

H flu type B, strep pneumoniae, N. meningitidis, Group B strep, Klebsiella, salmonella typhi

Question 23

IgM vs IgA

Answer 23

IgM is found in blood and mucosal. IgA is mucosal > blood

Question 24

List primary and secondary causes of humoral immunodeficiency

Answer 24

primary: IgA deficiency, CVID, IgG 2 subclass deficiency, Hyper IgE syndrome (Jobs syndrome). Secondary: CLL ( low Igs), Multiple myeloma (High monoclonal IgG, low IgM and IgA)

Question 25

selective IgA deficiency

Answer 25

Most common primary “immunodeficiency.” Increased autoimmune dis; + malignancy. Normally we produce more IgA than IgG and IgM.

Question 26

CVID- what is it, age of onset, Sx, risks

Answer 26

Common Variable Immunodeficiency - Decreased IgG, IgM, IgA, with nl number of B cells and normal T cells. Onset in teens or 20s. Sx: chronic diarrhea ( G. lamblia, C. jejuni) with GI lymphoid hyperplasia, increased risk of bacteremia, increased PCP, fungi, mycobacteria, recurrent HSV. Increased risk of autoimmune dz, gastric cancer and lymphoma

Question 27

function of complement

Answer 27

Classical pathway (Ig), lectin or alternative pathway activates C3 > activates C5-C9 > membrane attack complex lyses GNR. Also, C3 opsonizes bacteria and facilitates phagocytosis

Question 28

complement deficiency

Answer 28

C2 is most common. C1-2 (classical) is pyogenic. C5-9 (terminal) - Neisseria

Question 29

define CD4 T cell count in early, intermediate and advanced HIV/ AIDS

Answer 29

Early: >500cells/ul. Intermediate: 200-500 cells/ul. Advanced/ AIDs: < 200cells/ul

Question 30

Immunodeficiency in HIV

Answer 30

Low CD4+ T cells number, Decreased CD4+ T cell function, NK cell dysfunction, B cell dysfunction ( hypergammaglobulinemia, decreased memory B cells, decreased response to new antigens, high rates of autoimmunity), PMNs and macrophages are normal

Question 31

Which bacterial infection is common in HIV

Answer 31

cryptococcus- 30-70% mortality in 3 months. Median T cell cound is 19. cryptococcus has a large polysaccharide capsule (usually responded to by Ig2, complement and phagocytes)

Question 32

Labs to test for phagocytic immunodeficiency

Answer 32

CBC and diff. PMN <100-500. Decreased function seen with NBT test

Question 33

labs for cellular immunodeficiency

Answer 33

CBC and diff: lymphs < 500.

Question 34

Labs for humoral immunity

Answer 34

protein/ albumin: decreased globulin, anti-A/B (RBC) for function tests. SPEP: decreased gamma globulin. Quantitative Igs: decreased IgG, M, A. CH50 decreased

Question 35

describe NBT test

Answer 35

Nitroblue tetrazolium dye reduction; clear NBT reduced by H2O2->blue (CGD-not blue [chronic granulomatous disease])