Miscellaneous - Uworld etc. Flashcards
What is X-linked (Bruton) agammaglobulinemia?
- Defect in B cell maturation
- Results in absent mature B cells and severely low immunoglobulin levels
- T cell numbers and function remain intact
- Primary lymphoid follicles and germinal centres do not form within lymph nodes
What cells secrete hepcidin?
Hepatic parenchymal cells
What are AIP attacks primarily due to?
Accumulation of Aminolevulinate (ALA) and porphorobilinogen (PBG)
- Trigger usually induces ALA synthase -> increase in ALA and PBG
What are AIP attacks treated with?
ALA synthase inhibitors (less build up of ALA and PBG)
- Glucose
- Hemin
What is cold-agglutinin disease due to?
- Cross-reactive IgM
- Type of autoimmune hemolytic anemia
How does G6PD deficiency result in hemolysis?
- NADPH + H+ isnt produced from NADP+
- Glutationine is not reduced -> remains oxidised which causes oxidative stress in the RBC
What is replaced and where in sickle cell?
- Valine replaces glutamic acid at position 6 on the hemoglobin beta-globin chain
- Chromosome 11
Tumour lysis syndrome has what electrolytes increased/decreased?
- Hyperphosphatemia
- Hypocalcemia
- Hyperkalemia
- Hyperuricemia
What is Uric acid converted into by urate oxidase?
Allantoin (secreted in urine)
What drug causes Uric acid to be converted to Allantoin?
Rasburicase
- Induces Urate oxidase
- Used in tumour lysis syndrome to prevent build up of uric acid
What are the layers of the secondary follicle from inside to out?
- Germinal centre
- Mantle
- Margin
Name the layers of the lymph node from inside to out?
- Cortex (contains follicles)
- Paracortex
- Medulla
- Medullary sinus
What cells are produced by what areas of the lymph node?
- Cortex (in follicles) - B cells
- Paracortex - T cells
- Medulla - Plasma cells
- Medullary sinus - Macrophages
Where are B-lymphocytes produced in the spleen?
Peripheral areas of the white pulp
Where are T-lymphocytes produced in the spleen?
Peri-arteriolar lymphatic sheath (PALS)
G6PD affects what pathway?
The pentose phosphate pathway
How do carcinomas and sarcomas differ in the way they spread?
- Carcinomas = lymph
- Sarcomas = blood (metastasise to lungs, liver)
What do secondary (mature) lymphoid follicles contain that primary do not?
Germinal centres
What cells produce EPO?
Peritubular fibroblast cells in the renal cortex
What are the symptoms associated with PNH?
- Hemolytic anemia
- Hypercoagulability
- Pancytopenia
What gene is defective in PNH?
PIGA
What protein is defective in PNH? (what dos PIGA code for)
Also what is its function?
Glycosylphosphatidylinositol (GPI) anchor
- Glycolipid necessary for the attachement of several cell-surface proteins, including CD55 and CD59
- Help inactivate complement and prevent the membrane attack complex from forming on normal cells
What does JAK2 do?
Induces the transcription of proteins that inhibit erythrocyte precursor apoptosis and promote survival
- Also activates signals that increase differentiation of erythrocyte precursors into mature erythrocytes
- Together increases the production of erythrocytes and improve RBC counts
Hypocalcemia and peripheral neuromuscular excitability after blood transfusion is due to what?
Citrate anticoagulants in high-volume blood transfusion can chelate plasma calcium, leading to hypocalcemia - causing peripheral neuromuscular excitability
- Can be seen in rapid transfusion and transfusion in patients w. hepatic insufficiency
