Immunodeficiencies

Question 1

B cell Deficiency

Answer 1

recurrent sinopulmonary infections
chronic GI infections
esp. encapsulated organisms
S. pneumo, Hib, S. aureus (b/c no IgM, IgG)
Enterovirus (b/c no IgA)
Protozoa like Giardia (b/c no IgA, IgE)

Question 2

T cell Deficiency

Answer 2

intracellular organisms and opportunistic infections
bacteria: salmonella, syphilis
mycobacteria
viruses (CMV, HSV, VZV, EBV)
Fungi (crypto, aspergillus, cocci, candida, histo)
Protozoa (PJP, toxo)
think HIV/AIDS pts

Question 3

Phagocytic Disorder

Answer 3

skin and organ abscesses
bacteria: esp staph aureus
Catalase + organisms: s aureus, serratia, aspergillus, chromobacterium, burkholderia, nocardia

Question 4

Complement Deficiency

Answer 4

overwhelming sepsis
early complement: pyogenic infxn
late complement: neisseria mening.

screen with CH50

Question 5

What are the B cell immunodeficiencies

Answer 5

X-linked agammmaglobulinemia
CVID
specific antibody deficiency
Hyper-IgM deficiency
X-linked lymphoproliferative syndrome
Transient hypogammaglob of infancy

Question 6

X-linked Agammaglobulinemia

Answer 6

B cell deficiency
aka Bruton’s
No mature B cells - no antibodies

Encapsulated organisms, sinopulm infxn, enterovirus, giardia

Dx: flow-cytometry shows no mature B cells (CD19+)
no abs, no ab fxn

Question 7

Common variable immunodeficiency

Answer 7

B cell deficiency
aka CVID
age 5-10 onset
mature B cells can’t differentiate into plasma cells

Encapsulated organisms, sinopulm infxn, enterovirus, giardia
sacroid likd dz with noncaseating granulomas; sprue-like illness

Dx: Flow cytometry shows present B cells (CD19+) but LOW antibody levels, poor ab fxn

*higher risk for autoimmune disease and lymphomas

Question 8

Specific Antibody Deficiency

Answer 8

B cell deficiency
Normal mature B cells, normal antibody levels, POOR antibody response

Encapsulated organisms, sinopulm infxn, enterovirus, giardia

Dx: flow cytometry shows B cells present, nml ab levels, but poor ab function (no response to vaccines)

Question 9

X-linked Hyper-IgM Syndrome

Answer 9

B cell deficiency
Inability for B cells to class-switch from IgM to other classes; T cells cannot interact with macrophages
Defect in CD40L

normal/high levels of IgM; low levels IgG and IgA

Encapsulated organisms, sinopulm infxn, enterovirus, giardia; also PJP PNA because T cells cant interact

Dx: Flow cytometry lacks CD40L

Question 10

X-linked Lymphoproliferative Syndrome

Answer 10

B cell deficiency
AKA Duncan syndrome

overwhelming, near-fatal infections with EBV
fulminant hepatitis
bone marrow failure

progression to lymphoma

Question 11

Transient Hypogammaglobulinemia of Infancy

Answer 11

dx of exclusion

abnormal prolongation of physiologic hypogammaglobulinemia

infants have delayed production of IgG

Low IgG levels but normally functioning

Question 12

What are the combined B and T cell deficiencies?

Answer 12

Severe combined immunodeficiency
Wiskott-Aldrich syndrome
Ataxia - Telangiectasia 
Bloom syndrome
Nijmegen breakage syndrome

Question 13

SCID

Answer 13

combo deficiency

eczematous-like skin lesions
chronic lung infections
chronic diarrhea
FTT
absent thymus shadow
lymphopenia
sepsis

two main types: X-linked SCID and adenosine deaminase deficiency

Question 14

X-linked SCID

Answer 14

type of SCID
IL-2R gammaa defect
most common form (50%)
T-/B+/NK-

Question 15

Adenosine deaminase deficiency

Answer 15

type of SCID
T-/B-/NK-: toxic metabolites kill off all cells
autosomal recessive
dx: low ADA in RBCs

Question 16

Wiskott-Aldrich Syndrome

Answer 16

Combo deficiency
EXIT
Eczema
X-linked
Immunodeficiency
Thrombocytopenia

*small platelets on peripheral smear

Question 17

Ataxia Telangiectasia

Answer 17

Combo deficiency
Ataxia
Telangiectasia
Immunodeficiency

autosomal recessive

higher risk of cancer

*high alpha-fetoprotein

Question 18

what are the phagocyte disorders

Answer 18

Neutropenia syndromes: Kostmann syndrome, severe chronic neutropenia, cyclic neutropenia
Chemotaxis defects: LAD
Killing defects: Job syndrome (hyper IgE), Chediak Higashi, Chronic granulomatous disease

Question 19

Leukocyte adhesion defect type 1

Answer 19

Phagocyte deficiency

defect in CD18
severe leukocytosis
delayed umbilical cord separation
sterile abscesses

Question 20

Leukocyte adhesion defect type 2

Answer 20

Phagocyte deficiency

defect in Sialyl Lewis X moiety

ID
poor growth and abnormal facies
sterile abscesses
Bombay blood type

Question 21

Job syndrome

Answer 21

Phagocyte deficiency

STAT 3 mutation

IgE usually elevated but not necessarily

recurrent abscesses, eczema, scoliosis, hyperextensible, delayed eruption of primary teeth, pneumatoceles
coarse facies
osteopenia/osteoporosis resulting in pathological fractures

Question 22

Chediak Higashi syndrome

Answer 22

phagocyte deficiency

impaired lysosomal degranulation

recurrent cutaneous and sinopulm infections

partial oculocutaneous albinism
ID progressive peripheral neuropathy

*periph smear shows giant granules

Question 23

Chronic granulomatous disease

Answer 23

phagocyte deficiency

Inability to generate respiratory burst

recurrent organ and skin abscesses

catalase + organisms
walled off granulomas form

Dx: DHR ( hihydrorhodamine oxidation test)