Immunology Flashcards
SLE
systematic lupus erythematosus, chronic autoimmune disease resulting in inflammation and tissue damage
Signs and symptoms of Lupus
painful or swollen joints and muscle pain, unexplained fever, rashes, chest pain when deep breathing, hair loss, Raynaud’s, sun sensitivity, edema, mouth ulcers, swollen glands, extreme fatigue
Malar rash
erythema, spares the nasolabial folds, photosensitive, can be transient
Discoid lupus
Can be part of SLE or by itself, 10% will develop SLE, coin-shaped scaly plaques, expand to form lesions with depressed central scarring, increase skin pigment around edge, anywhere on body
Cardiac manifestations of SLE
pericarditis, myocarditis, congestive heart failure, hypertension, coronary vasculitis, Libman-Sacks endocarditis, valvular insufficiency
First line of defense is
Skin
Cilia
sweep mucus into the throat for coughing or swallowing
Acid
swallowed bacteria are broken down by acids in stomach
Second line of defense is
WBCs
Third line of defense is
antibodies
Passive immunity
immunity from an external source, like antibodies through placenta
Active immunity
you produce the antibodies, exposed to antigen and fought off
FAB
fragment, antigen binding
Fc
fragment, crystalline
Monomer
Y-shaped molecule with 4 protein chains, 2 identical light chains and 2 identical heavy chains
Variable regions
2 sections at the end of Y’s arms, contain FAB, identical on same antibody, but vary from one antibody to another
Constant regions
stem of monomer and lower parts of Y arms
Fc region
stem of monomer only, can bind to complement or cells
IgM
produced as 1st response, levels remain high transiently
IgG
produced after IgM, higher levels in small amounts throughout life, produced in large amounts during secondary phase
IgA
neutralizes microbes and toxins
IgE
anaphylaxis, immunity to helminthic parasites
B cells are stimulated by
CD40, which is expressed on T cells
Plasma cells
mature B cells, produce high affinity antibodies against original antigen
T cells receptors
recognize pieces of antigen, antigenic peptides are presented to TCRs by antigen presenting cells like Macrophages or dendrocytes
What are the co-receptors for the TCR?
CD4 and CD8
Activated T cells increase expression of
CD25
CD8+ T cells
generated in the Thymus and express the TCR, express CD8, recognize peptides presented by MHC Class 1 molecules
What happens when a CD8+ T cell recognizes an antigen and is activated?
Cytokines TNF-alpha and IFN-y are secreted, cytotoxic granules are released, Fas/FasL destroy infected cells
Types of memory T cells
Central memory T cells and Effector Memory T cells
Central Memory T Cells
circulate through secondary lymphoid tissues, slower but more robust response
Effector Memory T Cells
in non-lymphoid tissues, respond immediately
Regulatory T cells
CD4+ and CD25+, produce IL-10, TGF-beta, and IL-35, must recognize same MHC peptide as the effector T cell
Cytokines
TGF-beta1 and IL-10
TLRs
pattern recognition receptors that initiate innate immune response by detecting possible antigens
What TLR recognize bacterial lipids?
TLR 1, 2, 4 and 6
What TLR recognize viral RNA?
TLR 3, 7, and 8
What TLR recognize bacterial RNA?
TLR 9
What TLR recognize bacterial or parasite proteins?
TLR 5 and 10
TLR adaptors
TLR signaling initiates with the recruitment of adaptors proteins to their tail, MYD88 and TRIF
What 3 pathways are activated by TLRs?
MAP kinase pathway, NFkB pathway, and IRF pathway
Innate immunity
protection by skin and mucous membranes, phagocytic cells, NK cells, complement system
Natural immunity
Lymphocytes, macrophages, Mast cells, and dendritic cells
Steps of phagocytosis
- physical contact between the white cell and the foreign particle
- formation of a phagosome
- fusion with cytoplasmic granules to form a phagolysosome
- digestion and release of debris to the outside
4 complement functions
lysis, opsonization, activation of inflammatory response, and clearance of immune complexes
Cell lysis
lyse bacteria, parasites, viruses, erythrocytes, and nucleated cells (tumor cells)
Inflammatory response
C3a, C4a, and C5a bind to complement receptors on mast cells and basophils and induce degranulation with release of histamine and other mediators
Anaphylatoxins
induce smooth-muscle contraction increase vascular permeability, extravasation and chemoattraction, induce by C5a, C3a, and C5b67
Opsonization
C3b is the major opsonin of the complement system
Viral neutralization
deposits of antibody and complement on viral particles neutralize viral infectivity by blocking viral attachment to susceptible host cells and facilitates binding of viral particle to FcR or CR1
Risks of Asplenia
Fulminant sepsis
What does ToRCHeS stand for?
Toxoplasma gondii, RSV, CMV, HSV, and Syphilis
Complement fixation?
classical technique for detection and identification of the presence of Ag-Ab complexes
Positive complement fixation test
Antibody in sample + antigen + complement -> Ag-Ab complex fixed with complement
Complement fixed Ag-Ab + indicator system -> no change
Negative complement fixation test
Sample with no antibody + antigen + complement -> free complement
antigen + antibody in indicator system -> Ag-Ab complex
Ag-Ab complex + complement -> fixed complement system -> hemolysis
Meconium
Meconium in the amniotic fluid because the baby does not poop, Causes infants death.
Necrotizing enterocolitis (NEC) is
a serious gastrointestinal problem that mostly affects premature babies.
Galactosemia
a rare, hereditary disorder of carbohydrate metabolism that affects the body’s ability to convert galactose to glucose.
PJP infection has what CD4 count?
200, treated with TMP/SMX
Toxo and Crypto have what CD4 count?
100, treated with TMP/SMX
CMV and MAC have what CD4 count?
50, treated with Z-pak
Toxoplasma gondii
no vaccine, seen commonly in cats
Vertical transmission
If it is tested on the torch panel it can be transferred using vertical transmission
Disgnosing syphilis not in newborns
RPR/VDRL, MHA-To/FTA-ABS
RPR
non-treponemal, agglutination assay
Low avidity
If it is tested on the torch panel it can be transferred using vertical transmission
The strength with which a multivalent antibody binds to a multivalent antigen is termed ______?
Avidity
Syphilis culture
T. pallidum cannot be grown in culture, Warthin Starry stain used
IgG in infants
can last up to 6 months
Secondary and tertiary syphilis
RPR positive
If a person has HBeAg
super infectious and easily spreads virus