Diseases

Question 1

Congenital asplenia

Answer 1

No defense against blood-borne pathogens

Howell-Joly bodies indicate lack of function

Question 2

C5-C9 or properdin deficiency

Answer 2

Associated with increased susceptibility to infections by neisseria
(Doesn’t totally knock out complement function)

Question 3

Immune complex disease

Answer 3

Deficiencies in C1, C2, C4

Aggregation and precipitation of immune complexes at basement membrane

Question 4

Systemic lupus erythematous

Answer 4

Deposition of IgG autoantibodies against DNA

Characteristic butterfly rash

Question 5

Mixed essential cryoglobulinemia

Answer 5

Common in patients with chronic hep C infections

Question 6

Hereditary angioedema

Answer 6

Result of a C1INH deficiency

Chronic activation of complement leads to production of C2 kinin, causing extensive swelling

Question 7

Factor I deficiency

Answer 7

Uncontrolled convertase activity results in C3 depletion–>reduced complement fixation–>reduced bacterial clearance–>patients more susceptible to encapsulated bacterial infections

Question 8

Paroxysmal nocturnal hemoglobinuria

Answer 8

CD59 deficiency–>constant MAC pore formation
Sunlight triggers RBC hemolysis
Severe hemolytic anemia

Question 9

TLR3/TRIF deficiency

Answer 9

Causes recurrent herpes simplex virus encephalitis

Question 10

MyD88 deficiency

Answer 10

Lack of inflammatory cytokine production
Patients develop severe infections by pyogenic bacteria
Cannot develop fever

Question 11

NEMO deficiency

Answer 11

Hypohidrotic ectodermal dysplasia
Susceptible to pyogenic bacteria
Characteristic abnormalities of ectoderm-derived tissues
Conical-shaped teeth

Question 12

Septic shock

Answer 12

Systemic bacterial infection induces macrophages to release TNF-a, leading to massive leakage of fluid into body tissues

Question 13

Disseminated intravascular coagulation

Answer 13

TNF-a causes increased blood flow, vascular permeability, and endothelial adhesiveness of WBCs and platelets leading to blood clots in venules

Question 14

Severe congenital neutropenia

Answer 14

Deficiency of neutrophils at birth or soon after

Life-threatening pyogenic infections, acute gingivostomatitis, chronic periodontal disease

Question 15

Leukocyte adhesion deficiency

Answer 15

Problem in recruiting neutrophils
Mutations of integrin beta chain
Recurrent skin infections, periodontal disease, delayed wound healing, candidiasis
Leukocytosis–increased WBC count

Question 16

Chronic granulomatous disease

Answer 16

Caused by mutations in NADPH oxidase enzyme complex
Heightened susceptibility to infections by intracellular bacteria
Form granulomas due to inability to kill phagocytosed bacteria
No respiratory burst after phagocytosis

Question 17

XLA

X-linked agammaglobulinemia

Answer 17

Lack of functional Bruton’s tyrosine kinase

No circulating B cells and no antibodies

Question 18

DiGeorge Syndrome

Answer 18

Microdeletion in chromosome 22q11.2
CATCH-22
Cardiac abnormality
Abnormal facies
Thymic aplasia
Cleft palate
Hypocalcemia/hypoparathyroidism

Question 19

Autoimmune lymphoproliferative syndrome (ALPS)

Answer 19

Mutation in Fas gene leading to uncontrolled lymphocyte proliferation in the absence of infection or malignancy
Splenomegaly and lymphadenopathy; later autoimmunity and lymphoma

Question 20

IPEX

Answer 20

Absence of T-reg cells

Immune dysregulation, polyendocrinopathy, enteropathy X-linked disease

Question 21

Agammaglobulinemia

Answer 21

total lack of B cells

Question 22

Hyper IgM syndrome

Answer 22

defect in AID gene

susceptible to pyogenic infections

Question 23

Severe combined immunodeficiency disease

Answer 23

total lack of T cells

B cells can’t function without T cells, so loss of both humoral and cell-mediated immunity

Question 24

Omenn syndrome

Answer 24

type of SCID

Mutations in RAG gene lead to decreased enzyme activity

Question 25

X-linked Hyper IgM Syndrome

Answer 25

CD40L deficiency
Cell-mediated and humoral defects
No class-switching