Pathology Flashcards
Pathergy Test-Disease, positive test?
Behcets Disease
within few days of pricking the skin with a sterile hypodermic needle–Papule/pustule/ulceration
no size requirements
Type of HS reaction in Myasthenia/Graves?
Type V (subtype of Type II)
Longest serum half life of which Ig?
GAMDE
IgG-21-23 days
IgA-6 days
IgM-5 days
IgD-3 days
IgE-2 days
Which Ig readily crosses human placenta
IgG (actively and passively), small amounts of IgA (passively)
Gene defect in Retinoblastoma
Rb gene on long arm of chromosome 13
Pentameric Ig?
IgM
Which Ig not detected in tear samples?
IgD
Primarily IgA found in tears
Oldest Ig phylogenetically?
IgM
First antibody produced against a newly encountered antigen ?
IgM
IgM peaks earlier and disappears earlier than IgG during the primary immune response.
Most common oncogene in human tumours?
ras oncogene
Mediators derived from plasma (and not cells)?
Complement,clotting factors,fibrinogen,kinin
Which Ig may exist in polymeric form?
IgA-dimeric,IgM-pentameric
IL 2 is produced by which cells?
Mainly by CD 4+ T cells
Which Igs are important in responses to previously encountered antigens?
IgG,IgE
Which immunoglobulin classes is/are important in antigen reception at the surface of lymphocytes in primary immune responses?
IgM,IgG,IgD can be demonstrated on the surface of virgin B-lymphocytes and are involved with initial binding of antigen in the primary response, leading to the activation of the cells.
First cell that an antigen typically contacts in the cascade of immune response is?
Macrophage phagocytoses the antigen and presents it to T cells (APC)
Most abundant Ig in serum?
IgG
(G>A>M>D>E)
Which complement component is present in the highest serum concentrations?
C3
SJS-type of HS reaction?
Type IV HS reaction, subtype C
Wesley rings-type of HS reaction?
Type III
Wesley ring aka immune infiltrate occurs due to encounter of Stromal antigen with antibody from peripheral blood vessels.Contains complement factors and PMNs.
Role of integrins?
Heterodimeric transmembrane protein- attaches cells to the extracellular matrix and to ligands on other cells
Has alpha and beta subunits
Requires Ca and Mg to function
Most common site for ocular metastases?
Choroid
MC primaries- breast, prostate, lung, colon
Mutations in receptors for TGF b leads to ?
Hereditary hemorrhagic telangiectasia
