Transplantation: Immunology Flashcards
What is HLA matching has the greatest influence on short term and long-term graft survival?
Short-term: B and DR
Long-term: A
What does a high PRA level mean?
Corresponds with an elevated anti-HLA Ab load
When is the highest risk of CMV infection?
3-6 months after transplant, without prophylaxis. In those who have received prophylaxis, the risk is highest in the 3-6 months after prophylaxis has been discontinued.
Which patient is at the highest risk for CMV viraemia?
D+ / R- (40-58% incidence)
What is the typical schedule for screening with BKV?
- monthly in the first 6 months
- every 3 months until the 2nd post transplant year
What are the most common fungal infections among transplant recipients?
- candida (49%), yeast
- Cryptococcus (15%), yeast
- Aspergillus (14%), mold
- Endemic mycoses (10%), yeast or cold
What is an important cause of fungal infection in Arizona?
- Coccidodomycosis
- Incidence 3.8-6.9%
Do the mTORi have any effect on CMV?
- Both sirolimus and everolimus have anti-CMV activity
What are the direct and indirect effects of CMV infection?
Direct effects:
- CMV syndrome
- GI disease
- Pneumonitis (rare)
- Retinitis (very rare)
Indirect effects:
- Increase susceptibility to other infections
- Possible increased risk for rejection
- Increased risk of death and cardiovascular mortality longterm.
When do cryptococcus infections tend to occur after transplant?
- late
- 83-85 months
What is the spectrum of disease with cryptococcus?
- Fungaemia
- Meningitis
- Pulmonary infection
- Soft tissue or bone infection (rare)
What agents are used to treat cryptococcosis?
- Amphotericin
- Fluconazole
- 5-flucytosine in CNS disease
What is the likelihood of 2, 1, and no haplotype match among siblings?
- 2 haplotype match 25%
- 1 haplotype match 50%
- 0 haplotype match 25%
What cell type express HLA class I?
- all nucleated cells
- present peptides (smaller proteins)
What cell type express HLA class II?
- professional antigen presenting cells
- B-cells
- macrophages
- dendritic cells
Why do HLA identical siblings still require some immunosuppression after transplant?
- Minor histocompatibility antigens; these are small endogenous peptides that occupy the antigen-binding site of the donor MHC molecules.
What allorecognition pathways have been implicated in chronic ABMR?
- Indirect pathway
- Semi-indirect pathway
What is the basic procedure in CDC crossmatch?
- Recipient’s serum is added to potential donor lymphocytes
- Complement is added
- If recipient anti-donor antibodies are present, the added complement will result in cell lysis
- Cells that are treated in this way are then examined using a fluorescent dye, which by colimetry tells if cells have lysed or not.
- Semiquantitative
What is the anti globulin-enhanced CDC crossmatch?
- The procedure is identical to the standard CDC crossmatch
- EXCEPT Anti-human Ig potentiating reagent is added before complement
- Can detect antibodies that are present in small amounts or non-complement binding antibodies.
What is the benefit of flow crossmatch over the standard procedure?
- It is more sensitive
What is the PRA, in basic terms?
- The percentage of potential donors cells that were ‘killed’ by the patients serum
- The higher the PRA, the more likely that the crossmatch will be positive, I.e. 80% PRA means 20% chance of negative CM
What are the most common causes of death in transplant recipients?
- Cardiovascular disease
- Infection
- Malignancy
How many weeks should be allowed elapse between the administration of a live vaccine and kidney transplantation?
- 4-6 weeks
Live vaccines are contraindicated in transplant recipients. True/False
True
Examples include:
- MMR
- Varicella live
- Nasal influenza
- Zoster-live (Zosta-vax)
