IMMUNOLOGY/ALLERGOLOGY

Question 1

The _____ region comprises several genes implicated in allergic disease pathogenesis

Answer 1

5q23-35

Question 2

ALLERGIC RHINITIS CLASSIFICATION

Answer 2

Question 3

drug of choice for allergic rhinitis

Answer 3

Intranasal steroids

Question 4

A 3 year-old male patient comes to the clinic for right ear pain without discharge and fever that started 1 day ago which prompted consult. Patient had cough and colds 3 days ago. The mother says that the patient has been having repeated ear infections and colds since infancy. He was also hospitalized twice for pneumonia at ages 9 months and 18 months with concomitant urinary tract infection. He is also known to have allergies to certain milk products. Further work up revealed IgA <10mg/dL, IgG, IgM and IgE within normal limits, what is the most likely condition?

Answer 4

Selective IgA Deficiency

* cluster of repeated symptoms involving the respiratory and urinary tract systems with a less than normal IgA level. This deficiency has characteristically recurrent R-U-G infections!!! (respiratory – urogenital – gastrointestinal)

Question 5

10 Warning signs of Primary Immunodeficiency

Answer 5

Question 6

A 1 year-old male patient comes to the clinic due to cough, fast breathing, and fever. It started 1 day ago which prompted consult. Patient had cough and colds 3 days ago. There was history of repeated ear infections at 8 months and 11 months. He was also admitted for pneumonia at 8 months of age. At present, HR 120, RR 55, T 38.5°C, (+) crackles bilateral lung fields with decreased breath sounds over the right lung, (-) cervical lymphadenopathies, (-) tonsillar tissue. After antibiotic treatment, further workup was done which revealed depressed levels of IgG, IgA, IgM, and IgE below that of appropriately aged matched controls. What is the most likely diagnosis in this case?

Answer 6

Bruton Agammaglobulinemia (B-CELL IMMUNODEFICIENCY DISORDER: X-LINKED AGAMMAGLOBULINEMIA)

Question 7

• A block in the development of pre-B cell to B-cell due to a defect in heavy chain gene rearrangement
• Healthy infants until 6 months old → recurrent ear infections, bronchitis or pneumococcal pneumonia, and/or dermatitis
• Low or absent Igs; few or absent B-cells
• Total Ig < 250 mg/dL
• Gamma globulin IM once a month at interval of 2-3 weeks
• Maintenance of trough level > 400 mg/dL

Answer 7

B-CELL IMMUNODEFICIENCY DISORDER: X-LINKED AGAMMAGLOBULINEMIA (BRUTON)

Question 8

A 6 month-old male infant was seen for persistent diarrhea for the past 2 weeks. The patient has visible wasting, underweight, and appears weak and irritable. The mother said that the patient has been having repeated bouts of diarrhea since 4 months of age. He also was admitted for pneumonia at 3 months of age. The infant on examination has oral thrush, no visible tonsillar tissue, no palpable lymphadenopathies. Previous X ray at 3 months of age show no thymic shadow. Further workup was done which revealed depressed levels of IgG, IgA, IgM and IgE below that of appropriately aged matched controls. What is the most likely diagnosis?

Answer 8

Severe Combined Immunodeficiency

Question 9

• Selective defect in cell-mediated immunity with susceptibility to chronic candida infection of the skin and & mucous membranes w/ or w/o endocrinopathy
• 50% are due to deficiency of adenosine deaminase due to deletion or mutation of the encoding gene → deoxyadenosine & deoxy-ATP accumulate inside lymphocytes → cell death
• Infants usually succumb within the first 2 years of life

Answer 9

Severe Combined Immunodeficiency

Question 10

• Increased susceptibility to viral, fungal & protozoal infections

• Aberrant thymus or its absence occurs in the 12 th week of gestation
• Symptoms at birth: abnormal facies, hypothyroidism, congenital heart disease
• Low lymphocyte count
• Fetal thymus transplant as early as possible results in reconstitution of T-cell immunity

Answer 10

DiGeorge syndrome

Question 11

DiGeorge syndrome

Answer 11

Question 12

A 10 month-old male patient is brought to the clinic by his mother because of a rash on his face. This started 1 week ago and he was seen by his mother to be scratching or touching the facial area. She also noticed rashes in the area over the upper extremities. There was no use of new soaps/shampoos, no substance was applied to the skin; mother is a known asthmatic. On close examination, there is an eczematous rash over the face particularly the cheeks and the extensor surfaces of the upper extremities. What is the most likely diagnosis?

Answer 12

Atopic Dermatitis

Question 13

• X-linked recessive syndrome
• With normal appearing megakaryocytes but small defective platelets
• Often have prolonged bleeding from the circumcision site or bloody diarrhea during infancy
• Treatment: nutrition, routine IVIG, use of killed vaccines, platelet transfusion, splenectomy
• Treatment of choice: bone marrow or cord blood transplantation

Answer 13

WISKOTT-ALDRICH SYNDROME

Question 14

WISKOTT-ALDRICH SYNDROME

Answer 14

Question 15

gold standard in the diagnosis of food allergy

Answer 15

Double Blind Placebo Controlled Food Challenge

Question 16

TREATMENT OF B CELL DEFECTS

Answer 16

• Stem cell transplant recommended for XLP and Hyper IgM type 3
• Judicious use of antibiotics for infections and regular IVIG (or subcutaneous IG) are the only effective treatment for primary B cell defects
• Dose of 400 mg/kg per month

Question 17

• No antibody production (total Ig <100 mg/dL)
• lack of B cells
• Bacterial infections (resp. tract) and esp. enteroviruses;
• small to absent tonsils;
• no palpable lymph nodes

Answer 17

XLA or Bruton agammaglobulinemia

Question 18

• Low IgG with normal B cells
• Later age of onset of infections;
• echovirus meningitis is rare;
• normal nodes & tonsils; cancer;
• ↑ risk of granuloma

Answer 18

Common variable immunodeficiency (CVID)

Question 19

• Low or absent IgA (<10 mg/dL)
• resp., GI (giardiasis),
• urogenital tract infections

Answer 19

Selective IgA deficiency

Question 20

• Failure to produce IgG, IgA, IgE antibodies with normal or inc IgM
• Become symptomatic during the 1 st or 2nd year of life with recurrent pyogenic infections;
• profoundly neutropenic;
• P. jiroveci pneumonia

Answer 20

Hyper IgM syndrome

Question 21

• low Ig;
• lack of anti-EBNA and long-lived T cell immunity
• Inadequate immune response to EBV;
• affected males are usually healthy until they acquire EBV infection;
• fatal infectious mononucleosis, lymphomas, acquired hypogammaglobulinemia

Answer 21

X-linked lympho-proliferative disease or Duncan disease

Question 22

• Low number of T cells and impaired T cell function
• Partial or complete
• CATCH 22 syndrome
• susceptible to fungi, viruses, and P. jiroveci

Answer 22

Thymic hypoplasia or DiGeorge syndrome – hypoplastic or aplastic thymus and parathyroid

Question 23

• poor response to Candida antigen;
• autoimmune responses
• chronic and severe Candida skin & mucous membrane infections in the 1st mo or until 2 nd decade of life;
• APECED

Answer 23

Chronic mucocutaneous candidiasis

Question 24

TREATMENT OF T CELL IMMUNODEFICIENCY

Answer 24

• Thymic tissue transplant
• Some have been given nonirradiated unfractionated BM or peripheral blood transplant from HLA-identical sibling
• Treatment of choice for fatal combined T- and B-cell defects:

transplantation of MHC-compatible sibling or T-cell depleted parental hematopoietic stem cells

Question 25

most severe immunodeficiency

Answer 25

SCID

Question 26

• Absence of T- and B-cell functions
• present w/in the 1st few months of life with recurrent or persistent diarrhea, pneumonia, OM, sepsis, skin infections;
• persistent infections with opportunistic agents;
• unable to reject foreign tissue

Answer 26

SCID

Question 27

• T cell deficiency;
• poor Ab production to polysaccharides
• Immunodeficiency with thrombo-cytopenia and eczema;
• prolonged bleeding from circumcision site or bloody diarrhea during infancy;
• survival beyond the teens is rare

Answer 27

Wiskott-Aldrich syndrome

Question 28

• Coarse facies, coronary artery aneurysm, mortality in adulthood;
• pathologic fractures
• Recurrent bacterial infections (S. aureus, pneumococcus, H. influenzae),
• Aspergillus, mucocutaneous candidiasis

Answer 28

Hyper IgE syndrome (AD or sporadic or Job syndrome)

Question 29

• Higher incidence of lymphomas;
• skin cancer;
• mortality in childhood
• Abscesses, HPV, HSV, VZV, MCV, mucocutaneous candidiasis; asthma, allergies / anaphylaxis

Answer 29

Hyper IgE syndrome (AR)

Question 30

Degranulation abnormality

Answer 30

Chediak-Higashi syndrome

Question 31

• AR;
• disordered coalescence of lysosomal granules

• Decreased chemotaxis, degranulation and bactericidal activity;

• impaired NK function
• Recurrent pyogenic infections;
• neutropenia;
• hepatosplenomegaly;
• mild bleeding diathesis;
• partial oculo-cutaneous albinism
• progressive peripheral neuropathy;
• light skin and silvery hair;
• photophobia;
• rotary nystagmus;
• Gram +, Gram -, fungi;
• prolonged BT with normal platelet

Answer 31

Chediak-Higashi syndrome

Question 32

Adhesion abnormality

Answer 32

Leukocyte adhesion deficiency (1-3)

Question 33

• AR
• Impaired neutrophil adhesion and platelet activation;
• decreased binding of C3bi to neutrophils
• Neutrophilia;
• recurrent bacterial infection associated with a lack of pus formation;
• bleeding tendency; delayed umbilical cord separation with significant omphalitis;
• slow healing ulcers;
• S. aureus, E. coli, Candida, Aspergillus

Answer 33

Leukocyte adhesion deficiency (1-3)

Question 34

(+) in Microbicidal activity

Answer 34

Chronic granulomatous disease

Question 35

• X-linked and AR;
• due to a defect in the generation of microbicidal oxygen metabolites

• Failure to activate neutrophil respiratory burst leading to failure to kill catalase-positive microbes

• Recurrent pyogenic infections with catalase-positive microorganisms;
• onset in early infancy;
• S. aureus, Serratia, B. cepacia, Candida; pneumonia,
• osteomyelitis,
• skin infections,
• lymphadenitis;
• hallmark is granuloma formation and inflammatory process

Answer 35

Chronic granulomatous disease