Uworld 2017

Question 1

Disseminated mycobacterial disease in infancy and early childhood

Answer 1

Defect involving IFN-gamma signaling pathway

IL-12 receptor deficiency

Question 2

Anaphylaxis treatment

Answer 2

IM epinephrine
Airway management and volume resuscitation
Adjunctive therapy (glucocorticoids, antihistamines)

Question 3

Impairment of complement-mediated cell lysis by…

Answer 3

Staphylococcal protein A

Question 4

Promotion of intracellular survival by…

Answer 4

Inhibition of phagosome-lysosome fusion or resistance to lysosomal enzymes.

Question 5

Responsible for the apoptosis of cells with decreased or absent MHC class I proteins (virus-infected or tumor cells)

Answer 5

Natural Killer cells

Question 6

Which IL is responsible for B-cell growth, isotype switching, secretion of IgE, predisposition to HS type I, and differentiation into Th2 helper?

Answer 6

IL-4

Question 7

The first IL produced by T-cells after contact with Ag

Answer 7

IL-2

Question 8

5 manifastations of Ataxia-Telangiectasia

Answer 8

Cerebellar ataxia (atrophy)
Oculocutaneous telangiectasia
Severe immunodeficiency (IgA, IgE, IgG def)
Repeated sino-pulmonary infections
Increased risk of cancer (hemato)

Question 9

5 inherited disorders caused by deficient DNA-repair enzymes

Answer 9

Ataxia-Telangiectasia
Xeroderma pigmentosum
Fanconi anemia
Bloom syndrome
HNPCC

Question 10

Infection following live vaccine

Answer 10

Deficiency of T-cell mediated immunity

Question 11

Recurrent infections by Neisseria

Answer 11

Deficiency of C5b-C9

Question 12

Triad of Wiskott-Aldrich syndrome

Answer 12

Eczema
Thrombocytopenia
Immunodefficiency (recurrent inf)

Question 13

3 manifestations of Leukocyte Adhesion Deficiency (absence of CD18)

Answer 13

Recurrent skin and mucosal infections without purulence
Delayed seperation of umbilical cord
Persistent leukocytosis

Question 14

5 mechanisms that trigger apoptosis

Answer 14

Deprevation of growth factors
DNA damage
Intracellular accumulation of misfolded proteins
Mediation by cytotoxic T lymphocytes
Activation of receptors in the TNF receptor family (Fas)

Question 15

2 lab findings and the only treatment for Severe Combined ImmunoDeficiency

Answer 15

Lymphopenia
Hypogammaglobulinemia

Stem cell transplant

Question 16

Triad of Hemolytic Uremic Syndrome

Answer 16

Microangiopathic hemolytic anemia
Thrombocytopenia
Acute renal failure

Question 17

2 diseases caused by blood type O mother and blood type A or B fetus

Answer 17

Erythroblastosis fetalis

Hemolytic disease of the newborn

Question 18

4 seronegative spondylarthropathies (absence of serum rheumatoid factor) + higher incidence of HLA-B27

Answer 18

Ankylosing spondylitis
Reactive arthritis
Arthritis associated with IBD
Psoriatic arthritis

Question 19

2 most important opsonins and 2 others

Answer 19

IgG
C3b

Mannose-binding lectin
CRP

Question 20

Classic triad of reactive arthritis

Answer 20

Nongonococcal urethritis
Conjunctivitis
Arthritis

Question 21

2 causes of Angioedema

Answer 21

Mast cell activation (ass w/ pruritus and urticaria)
Excess bradykinin (No pruritus, No urticaria)

Question 22

Pneumococcal vaccines

Answer 22

Conjugate: strongly immunogenic in infancy: B + T cells recruitment; Higher, longer-lasting Ab

Polysaccharide: poorly immunogenic in infancy (immature humoral response)

Question 23

Ataxia telangiectasia

Answer 23

Triad: Cerebellar ataxia, Telangiectasias, Increased risk of sinopulmonary infections
ATM gene: role in DNA break repair
IgA deficiency (sinopulm inf)

Question 24

Disseminated mycobacterial ds in infancy/early childhood

Answer 24

Inherited defect of IFNg signaling

Lifelong ttt w/ antimycobacterial agents

Question 25

3 findings in Selective IgA deficiency

Answer 25

Recurrent sinopulmonary + GI infections Autoimmune disease Severe: anaphylaxis during transfusion of blood products w/ IgA

Question 26

3 findings in Rheumatoid arthritis

Answer 26

AutoAb against autoAg in joints Infiltrating CD4+ cells secrete cytokines + stimulate B cells B cells produce RF (IgM against Fc of IgG) + anti-citrullinated protein Ab (chronic infl)

Question 27

IFNa + IFNb

Answer 27

In response to viral infections | Help suppress viral replication: halt protein synthesis + promote apoptosis of inf cells

Question 28

Expression of MHC II

Answer 28

Foreign Ag taken into APC by phagocytosis or endocytosis Loaded onto MHC II within acidified endosomes Ag-MHC II expressed on cell surface Failure to acidify lysosomes: deficient expression of Ag-MHC II + of interaction btw APC-Tcell

Question 29

High-affinity IgE receptor (FcERI)

Answer 29

On surface of mast cells + basophils Binds Fc of IgE (HS I) Aggregation of FcERI receptors when cross-linking of multiple bound IgE by multivalent Ag then degranulation + allergic reaction

Question 30

4 findings in Chronic renal allograft rejection

Answer 30

Months to years Worsening HTN, slowly progressive rise in creatinine Chronic, indirect immune response against donor alloAg Obliterative intimal thickening, tubular atrophy, interstitial fibrosis

Question 31

4 characteristics of Kartagener sd

Answer 31

Form of primary ciliary dyskinesia Impaired structure/function of cilia (dynein arms) Triad: situs inversus, chronic sinusitis, bronchiectasis Infertility (sperm flagella, fallopian tube cilia)

Question 32

Giant cells in Mycobacterium tuberculosis inf

Answer 32

Langhans giant cells formed by macrophages | These macroph activated by CD4+ Th1 lymphocytes

Question 33

Fas receptor role in apoptosis

Answer 33

Initiate extrinsic pathway of apoptosis | Mutations in Fas recept or Fas ligand: prevent apop of autoreactive lymphocytes, high risk of autoimmune ds (SLE)

Question 34

Calcineurin

Answer 34

Activation of IL2 which promotes growth+differentiation of T cells Cyclosporine + tacrolimus inhibit calcineurin activation

Question 35

Acute hemolytic transfusion reaction

Answer 35

Ab-mediated HS (type II) by pre-existing anti-ABO Ab Against donor RBCs Complement activation: RBCs lysis, vasodilation, fever, hypotension, chest/back pain, hemoglobinuria

Question 36

Pancytopenia + nephritis in SLE

Answer 36

Pancytopenia: autoAb against blood cells (HS type II) Nephritis: immune complex deposition in glomerulus (HS type III)

Question 37

Cells + cytokines

Answer 37

Sensitized TH2: IL4, IL13 together promote B-cell switching for IgE synthesis. IL5 activ eosino + IgA synthesis Excess of TH2 products: extrinsic allergic asthma Macrophages: IL1 stimulates Th cells Th cells: IL3 recruits BM stem cells + IFNg activates macrophages TGFb for tissue regen + repair

Question 38

Chemotactic agents

Answer 38

Leukotriene B4: neutro migration to sites of infl 5-HETE C5a IL8