Immune Deficiencies Flashcards
Infections in Pure B cell deficiency
antibody is not made
chronic bacterial infections (pneumonia and diarrhea)
from “high grade”, extracellular, bacterial pathogens- Staph aureus, Haemophilus influenza and Strep pneumonia.
Susceptible to enteroviruses (polio) entering mucous membranes because no IgA
Infections in Pure T cell deficiency
severe intracellular infections of viruses, certain bacteria and yeasts and fungi.
Common infections are Candida albicans and Pneumoncystis carinii.
DiGeorge Syndrome
Deletion of Chromosome 22–> 3rd and 4th pharyngeal pouches (arches) to develop abnormally
Symptoms of Digeorge
immune deficiency from abnormal or absent stromic cells in the Thymus
no parathyroid glands –> hypocalcemia
large blood vessels malformed
abnormal facies (low ears, fish mouth, cleft palate)
incidence of selective IgA deficiency
Most common immune disease
1/400-500
Selective IgA Deficiency syndromes
mostly asymptomatic because IgM takes over IgA
if IgM insufficient
1) severe allergies
2) infection of mucosa (diarrhea, sinopulmonary infection)
Immunological problem of Nude mouse
Fail to make thymic stroma
name the human immunodeficiency condition nude mice resembles
no T cells
DiGeorge Syndrome
Name the enzyme which is absent in some cases of SCID
autosomal recessive cases of SCID –> absent functioning of the enzyme adenosine deaminase (ADA).
Adenosine accumulates in all cells
Toxic to lymphoid cells so can’t develop
Absence of lymphoid derived cells.
mutation to the Rag V(D)J recombination machinery
inability to arrange the heavy and light chains of B cells and the alpha and beta chains of T cells
Treatments for SCID
Purified ADA
Bone marrow transplantation has about a 50% success rate, but graft vs host disease is an ongoing problem
purified stem cells
gene replacement therapy but can cause leukemia
transplantation therapy in immunodeficiency diseases
Thymic transplantation for DiGeorge patients by harvesting fetal thymus or culture thymic stromal cells
Minimize graft vs host with cultured thymic stromal cells
Bone marrow transplantation for SCID (50% success)
Minimize graft vs host with purified stem cell
Test for B cell deficiency
quantitating antibody levels (IgG, IgA and IgM)
(measuring “titers” or levels of a specific antibody to prior immunizations )
testing ABO isohemagglutinins
Test for T cell deficiency
total lymphocyte count
skin tests with antigen panels
Complement tests
the CH50 test which tests the integrity of the entire classical pathway
assay for C1 inhibitor
Phagocyte tests
WBC count with differential
peripheral smear morphology
NBT test to test for functional oxidative bursts
T and B cell areas in lymph node
Outer Cortex made of Follicles = B cells
Germinal Center = Dividing B cells
Medulla = B cells
Paracortex = T cells
Describe the contents and routes of administration of commercial gamma globulin
Human gammaglobulin given monthly via IV,
New subq infusion at home
Immunoglobulin is clean (few broken molecules) and composed almost entirely of IgG with a little IgA
Conditions to use IVIG
Any immune deficiency where there is deficient B cell function (SCID, Brutons, CVID
Problem with IVIG
contain small amounts of IgA
bad for selective IgA deficiency because IgA can be recognized as foreign –> immune reaction
two viruses which are immunosuppressive in humans
measles, Mononucleosis and CMV
In mono, herpes viruses (such as EBV) infect B cells, causing T cells to destroy the infected B cells
HIV destroys helper T cells by forming syncytia.
Patients can’t fight off intracellular viruses, bacteria and fungi
