Immunodeficiency Flashcards
1
Q
Children have recurrent infections
A
- toddlers have ~6 respiratory per year
- daycare attendees average 9
- children exposed to second hand smoke average 12
- symptoms from a common cold last for 4-12 days (mean 6.8 days)
2
Q
When should an immune evaluation be considered
A
- two or more invasive bacterial infections is unusual
- persistent or recurrent sinopulmonary infections warrant further evaluation
- unusual etiologic agents or unsual severity of an otherwise common infection may be a red flag
3
Q
Evaluation for immunodeficiency
A
- history
- physical exam
- Labs
4
Q
History of children with immunodeficiency
A
- growth and development
- types and sites of infections
- severity of infections, complications
- specific organisms
- HIV risk factors
- diarrhea, malabsorption
- autoimmune or allergic phenomenon
- family history- any unexplained earl infant deaths
5
Q
Physical Exam with immunodeficiency
A
- physical and anatomic barriers
- growth and development
- tonsils, nodes, liver and spleen
- thrush
- rash: eczyma, seborrhea, petechiae, others
6
Q
Nonimmunologic lines of defense
A
- skin and mucous membranes- eczyma, burns, open fractures, sinus tracts
- adequate drainage of body fluids- eustation tube dysfunction, ciliary immotility, cystic fibrosis, ureteral reflux
- foreign bodies- medical, accidental
7
Q
Four limbs of the immune system
A
- Cellular immunity- T-cells, NK-cells, cytokines-7%
- Humoral immunity- B- cells, immunologlobulins-46%
- complement-2%
- phagocytes-20%
- Combined- 25%
8
Q
Severe Combined Immunodeficiency: SCID
A
- 6 week old, failure to thrive, oral thrush, skin rash, diarrhea
- 75% patients are male
- X linked and autosomal recessive
- early death without bone marrow transplant
- IL-2 gamma chain defect
- Adenosine deaminase (ADA) deficency)
- Purine nucleotide phosphorylase deficiency
- T Cell signal transduction defects
9
Q
Beta chain
A
- this is often the defect with SCIDS
- problems with IL-21 (B cell maturation_
- Il-15- NK cell development
- IL-9- hematopoiesis
- IL-7- T cell development
- IL-4- class switch recombination
- IL-2 peripheral T cell homeostasis
10
Q
SCIDs Labs
A
-lymphopenia
-enumeration of specific lymphocytes subsets assists in diagnosis
-analysis of lymphocyte proliferation in response to
1- Mitogens (PHA, concanavalin A, pokeweed)
2- Non-self HLA antigens in a mixed lymphocyte culture
3- Specific antigens
11
Q
Treatment for SCIDs
A
- immediate bone marrow transplant
- risks include invasive, life threatening viral, fingal, and bacterial infections
- thrush is commno
- aggressive treatment with antibiotics, replacement immunoglobulin, and often antivirals and antifungals while awaiting transplant
12
Q
Humoral Immunodeficiency
A
- present with pneumonia, bronchiectasis (thickening and scarring), chronic problems with sinusitis
- have to rule out cystic fibrosis, immotile cilia syndrome and HIV
- B cell enumeration (C19 and/or CD20)
- Quantitative immunoglobins- IgG, A and M, consider IgG subclasses, pre and post vaccine titers, isohemmagglutins
13
Q
Types of Humoral Immunodeficiency
A
- X-linked Agammaglobulinemia- absence of B cells due to mutation in Bruton’s tyrosine kinase (BTK)
- CD40 ligand deficiency- hypogammaglobulinema with hyper-IgM
- common variable immunodefiency
- selective defect in anti-polysaccharide antibody production
- TH1 cell -> opportunistic infections because macrophages aren’t properly being active
- infectious risk include encapsulated bacterial pathogens, especially Strep pneumoniae
- unique susceptibility to chronic enterovirus meningoencephalitis
- autoimmune disease common
- lifelong risk of lymphoma
14
Q
Medical Management of Humoral Immunodeficiency
A
- immunoglobulin replacement, usually monthly
- early identification and treatment of infections,including enteroviral disease
- aggressive pulmonary follow-up
15
Q
Selective IgA deficiency
A
- incidence 1:600
- 2/3 are asymptomatic
- can be associated with IgG subclass 2 deficiency
- recurrent sinopulmonary infections
- defect in producing antibodies to polysaccharide antigens
