Flashcards in UWorld_Immunology Deck (11)
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1
Characteristics of IgA deficiency
- due to failure of B cells to switch from IgM to IgA production
- recurrent sinus & GI infections
- ==> reaction to blood products due to presence of anti-IgA IgG in patient serum
2
Characteristics of NK cells
- no CD3/4/8 on surface ==> express CD16 or CD56
- do not require thymus; present in athymic patients
- contain porphyrins & granzymes ==> apoptosis
- activated by INF-gamma & IL-12
- kill cells with decreased or absent MHC I on surface
- e.g. tumor cells
- no antigen-recognition/memory
- e.g. tumor cells
3
Characteristics of Wiskott-Aldrich syndrome
- X-linked
- combined B & T cell disorder
- immunodeficiency
- eczema
- thrombocytopenia
4
Characteristics of MHC Class I moleculues
- gene loci: HLA-A/B/C
- binds to: TCR & CD8 receptors
- expressed on all nucleated cells (except RBCs)
- Fxn
- present endogenously synthesized antigens (e.g. viral)
- CD 8+ cytotoxic T cells
- antigen loading
- antigen loading onto MHC I in RER after delivery via TAP peptide trasnporter
- mode of transport to cell surface
- B2 microglubulin
- present endogenously synthesized antigens (e.g. viral)
- CD 8+ cytotoxic T cells
- antigen loading onto MHC I in RER after delivery via TAP peptide trasnporter
- B2 microglubulin
5
Microscopic steps of inflammation
- margination
- rolling
- activation
- tight adhesion and crawling
- transmigration
6
Key molecular components of rolling
- loose binding via sialyated carbohydrate groups
- @ PMNs = L-selection
- @ endothelial cells = E-selectin/P-selectin
7
Key molecular components of tight adhesion and crawling
- CD18 beta 2 integrins (Mac-1 and LFA-1) bind to ICAMs on endothelial cells
8
Key molecular components of transmigration
- PMNs squeeze between cells and out of vasculature
- migrate via integrin attachments and adherence to platelet endothelial cell adhesion molecule 1 (PECAM-1)
9
Recurrent false positive RPR w/negative T. palludum immunoassay ==> dx?
- anti-phospholipid ab in lupus
- prolonged PTT no corrected by mixing
- parodoxical b/c clotting risk = increased
- parodoxical b/c clotting risk = increased
10
Causes of hyper-IgM
- absence of CD40 on T-lymphs or deficiency of enzyems that modify DNA in isotype switching
11
Characteristics of polymyositis
