Stage of Life and Infectious Disease Flashcards
Where do hematopoietic stem cells go?
begin in yolk sac
go to fetal liver
end up in the bone marrow
both fetal liver & bone marrow send Pre-T cells to the thymus
What happens to hematopoiesis as you age?
it remains, but decreases
What’s the deal with the infant immune system?
functions, but selectively deficient
When can baby get infections from their mom?
sometimes during fetal development (prenatal, antepartum) during labor & going thru birth canal (perinatal or intrapartum) after birth (postpartum)
What are TORCH infections?
Toxoplasmosis,Other (syphilis, varicella zoster, parvovirus)Rubella,Cytomegalovirus andHerpes simplex
especially when these infections happen in the 1st trimester can get birth defects, miscarriage, preterm labor
Other important infections?
Streptococcus agalactiae, Escherichia coli, sexually transmitted diseases like Herpesvirus, Chlamydia, and Neisseria
An infant is born with low birth weight, microcephaly, seizures, petechial rash and moderate hepato-splenomegaly (with jaundice). The mother remembers having a “mononucleosis-like illness” during pregnancy but did not consult her medical provider. A diagnosis of ?
CMV
The infant will most likely have hearing loss, visual impairment, or diminished mental and motor capabilities.
What is considered pre-term labor? What is a major contributing factor?
What are the most common organisms that cause intrauterine infections?
Ureaplasma Urealyticum Mycoplasma Hominis Gardnerella vaginalis (BV) Trichomonas Neisseria Chlamydia
What are the most common organisms that cause intrauterine infections?
Ureaplasma Urealyticum Mycoplasma Hominis Gardnerella vaginalis (BV) Trichomonas Neisseria Chlamydia **can cause still birth **devastating potentially b/c kiddo doesn't have an immune system
Which antibodies cross the placenta?
IgG (via Fc receptor)
NOT IgM, IgE, IgA
@22 wks gestation-end of term
T/FAt birth, full-term human babies have plasma IgG levels comparable to mom in amount and antigen specificities
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When does IgM antibody production begin? IgG? When do babies have low IgG levels?
IgM sorta started by the time kid is born
IgG begins at 6 mo
IgG has half life of 2-3 wks, low levels around 4-5 mo
When is a baby more susceptible to infections?
3 mo–>1 year (mom’s immunity is waning & baby is still trying to produce)
What’s the deal with baby IgA?
IgA doesn’t cross the placenta
baby doesn’t make in big amounts until 6 mo
found in mom’s milk, esp colostrum
will protect kid against gut-localized pathogens
A neonate is delivered 3 weeks prematurely. Because she was uninsured, the mother did not receive adequate prenatal care; however, she reported no illness during pregnancy. The infant has no signs of illness at birth; however, develops meningitis soon afterward. A gram-positive, b-hemolytic, CAMP test positive coccus was isolated from the vagina of the mother as well as from the cerebral spinal fluid of the neonate. This organism would have been screened for during pregnancy had she received prenatal care.
What does she have?
Group B Strep (strep agalactiae)
most common cause of meningitis & sepsis in neonates
routine screening during pregnancy
What is the one exception to the rule of not vaccinating babies before 6 mo?
Hep B vaccine, 1/3 after birth. Only makes small response, though.
Which antigens do adult B cells v. infant B cells respond to?
B Cells from adults respond well to thymus-independent antigens like bacterial capsular polysaccharides
B cells from infants respond poorly or not at all; but they do respond to thymus-dependent protein antigens
Why are some vaccines conjugated with polysaccharide?
Conjugation of polysaccharide to an immunogenic protein allows B cells to receive help from helper T cells through linked-recognition
T/F Due to immunosenescence, elderly have worse response to vaccines.
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Describe the 2 lines of hematopoiesis.
Myeloid: erythrocytes, platelets, basophils, eosinophils, neutrophils, monocytes, macrophages, mast cells, or dendritic cells
Lymphocytic: B lymphocytes, T lymphocytes, and natural killer (NK) cells
Which hematopoietic lineage is more affected by aging?
lymphoid line is more affected
many fewer B cells & T cells
