PRACTICE Immunodeficiency Flashcards
A 6-year-old girl has pain and swelling of the right thigh for the past week. On physical examination there is swelling with erythema involving a 7 cm x 9 cm area of her lateral upper thigh with oozing of clear fluid from a central area with a break in the skin. Laboratory studies show her WBC count is 113,420/microliter with differential count of 90 segs, 7 bands, and 3 lymphs. Which of the following genetic abnormalities is she most likely to have?
a. Abnormal phagocyte oxidase enzyme
b. ADA deficiency
c. defective neutrophil lysosomal function
d. faulty beta chain of B2 integrin
c. mutant Btk
D.
Leukocyte adhesion deficiency type I is due to faulty integrins that interfere with leukocyte binding. There is a high WBC count but no exudate at the site of in
A 21-year-old man has a history of skin rashes and glomerolonephritis which have been recurrent for the past 15 years. On physical examination he has a erythematous malar rash. A skin biopsy is performed and on microscopic examination shows immune complex deposition at the dermal-epidermal junction. His WBC count is 7910/microliter. His total serum globulin is 2.6 g/dL. Which of the following is the most likely diagnosis?
a. chronic granulomatous disease
b. complement c2 deficiency
c. hyper IgM
d. IgG deletion
e. selective IgA deficiency
B.
Complement C2 deficiency results in a disease resembling systemic lupus erythematosus.
A 44-year-old man receives a blood transfusion during an orthopedic procedure for a fracture right femur. Within 30 minutes, the anesthesiologist notes a marked drop in his blood pressure. Which of the following laboratory test findings is most likely to have predicted this event?
a. c1 inhibitor deficiency
b. decreased CD4+
c. IgA deficiency
d. hypergammaglobulinemia
e. neutrophilia
C.
pt with selective IgA deficiency, and they have circulating IgA antibodies which can cause a transfusion reaction when blood products with serum containing IgA are transfused into them
cannot administer IVIG due to production of Anti IgA antibodies
A clinical study is conducted with subjects who are infected with HIV. These subjects are observed to be asymptomatic for years following initial infection. Within 10 years following infection, 90% of the subjects begin to develop opportunistic infections. Cells in the peripheral blood of these subjects are enumerated. Which of the following cells has most likely decreased with the onset of opportunistic infections in these subjects?
a. B cells
b. CD4 cells
c. CD8 cells
d. macrophages
e. neutrophils
f. NK cells
B.
CD4 cells proliferate at a high rate. Opportunistic infections are more likely to occur in patients with Tcell deficiency because they lead to activiation of many other cells like B cells and Macrophages.
Like Dr. Shnyra said T cell mediated immunity has alot of players, take one out and it has a large effect
During infancy, a baby boy has had multiple infections, spending most of his life in the hospital. He has had multiple bouts of pneumonia with Pneumocystis carinii (jirovecii), Pseudomonas aeruginosa, adenovirus, cytomegalovirus, and Staphylococcus aureus. He has had otitis media with Hemophilus influenzae and Streptococcus pneumoniae. Giardiasis and candidiasis have been documented causing diarrhea and diaper rash. Laboratory studies shown that his total serum globulin is 0.6 gldL. His WBC count is 3780/microliter with differential count 87 segs, 4 bands, 4 monos, 3 lymphs, and 2 eosinophils. Which of the following is the most likely underlying genetic defect that led to his findings?
a. abnormal common y chain of cytokine receptor
b. deletion of 22q11
c. mutant B cell tyrosine kinase
d. failure to express functional CD40L
e. deficient expression of B2 integrins
A
BOTH both cellular and humoral immune deficiencies and a history of severe infections. Half of cases result from an X-linked mutation in the IL2RG gene encoding for the common gamma chain of interleukin-2, which forms a receptor for many cytokines needed for T cell development. Normal or increased numbers of B lymphoyctes may be present.
A 10-year-old child has had numerous gastrointestinal, respiratory, and skin infections with bacterial organisms for the past 8 years. The organisms recovered from microbiologic cultures are observed to have capsules containing abundant polysaccharide antigen. The child has not been bothered with significant fungal, viral, or parasitic infections. Which of the following prior events in this child’s life is most likely to explain this phenomenon?
a. bone marrow transplant failure of thymus b. development c.HIV infection d.poor nutrition
E
B-2 marginal cells reside in the spleen, in T independent pathway they recognize polysaccharide ags
An 8-year-old girl is suffering from hyper-IgM syndrome due to a mutation in AID (autsomal recessive). In contrast to male patients with X-linked hyper-IgM syndrome, this girl is expected to have which of the following?
a. normal immunoglobulin responses to viral vaccines.
b. normal numbers of IgA+ plasma cells in mucosal-associated lymphoid tissue
c. normal T cell proliferative responses to mitogens.
d. normal DTH responses to commonly encountered fungal antigens such as Candida.
D.
d. Both types of hyper-IgM syndrome would have abnormally low or absent immunoglobulin responses to vaccines (IgG) and abnormally low or absent IgA plasma cells. Both would have normal T-cell proliferative responses to mitogens. This female patient would have normal DTH reactions because DTH is a response that does not involve B cells where her defect lies. Boys with X-linked hyper-IgM syndrome, however, would have absent or low DTH responses because, like immunoglobulin class switching, the response depends on CD40L–CD40 interactions and CD40L is absent. In the case of DTH, the interaction is between the T cell and macrophages.
A 2-year-old boy suffering from repeated painful bouts of inflammation of
mucosal surfaces, especially affecting the lips, is brought to the pediatrician’s
office. The mother remembers similar symptoms in previous generations of
her family and fears a heritable tendency toward food allergy. What laboratory
finding would best support the physician’s suspicion
a. depressed C3
b. depressed C4
c. Depressed C5
d. depressed C1
e. elevated C1, C2, C4
B.
A 28-year-old man was brought into court for nonpayment of child support. A
20-year-old woman insists that he is the father of her child. The court suggests
before hearing the paternity case that various genetic tests be performed on the
man, woman, and child. One of the sets of tests was for genetic immunoglobulin identification. Which immunoglobulin marker would be useful in this case?
a. allotype
b. idiotype
c. IgA2
d. IgM
e. isotype
A.
expression of allotype is genetictically inherited
