Cardiac Transplant #2 Flashcards

0
Q

What are the contra-indications for cardiac transplantation

A

Age (some say > 65 years)
Active infection
Diabetes with end-organ damage
Signficant symptomatic carotid peripheral vascular disease
Active or recent malgnancy. Ideally, patient should have a 5 year disease-free interval
Excessive obessity (BMI
Chronic renal failure
Hepatic impairment with bilirubin leve of > 25 mmol or ALT/AST ratio > 2, not due to congestion
significant chronic lung disease
Irreversible pulmonary hypertenions
PVR > 5 woods units
Transpulmonary gradient < 18mmHg
Systolic pulmonary hypertension > 60 mmHg.
Evidence of drug abust 6 months
Recent peptic ulcer disease
Poor social supports and history of poor medical compliance

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1
Q

What are indications for cardiac transplantations

A

International society of heart and lung transplantation (ISHLT)
Definite indications
a. HIgh-risk heart failure survival score
b. peak myocardial oxygen consumption < 10 ml/kg/min
c. NHYA class IV heart failure, refractory to maximal medical treatment
d. recurrent hospitalisation for heart failure
e. refractory ischemia, a left ventricular ejection fraction of < 20% and coronary artery disease
f. recurrent symptomatic verntricular arrhythmias refractory to medical treatment, implantable cardio-defrillator
Probable indications
a. medium-risk heart failure, refractory to medical treatment
b. NHYA class III heart failure
c. recent hospitalisations for heart failure
d. Peak myocardial oxygen consumptions < 14ml/Kg/min

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2
Q

Describe the criteria used for matching donor to recipient in cardiac transplantation

A

Limit the organ ischemia (< 6 hours)
ABO blood group compatibility
Human leucocyte antigen (HLA) compatibilty
Matching patiet’s size
CMV positive donors given to CMV positive reipients

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3
Q

What are the complications of cardiac transplantation and immunosuppression

A
Early graft failure
Rejection
Infection
Allograft vasculopathy (50% at 5 years) 
Malignancy--especially lympohmas and malignant tumors of the skin
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4
Q

What is the classification of organ rejection

A

Hyperacute rejection–complement-mediate response by pre-existing anti-bodies that are circulating in the recipient. They bind to donor ABO blood group antigens

Acute rejection–T lymphocytes respond to differences between the human leucocyte antigens (HLA) of the donor and recipient

Chronic rejection–manifests its as allograft vasculopathy with diffuse intimal hyperplasi in the coronary arteries of a transplanted heart.

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5
Q

WHat are the agents used for immunosuppression following cardiac transplantation

A

Corticosteriods
Anti-thymocyte globulin (ATG)
azathioprine

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6
Q

What drugs are used for permanent maintenance phase

A

CyclosporineA or tracrolimus, which are calcineurin inhibitors that inhibit the transcription of interleukin-2 (IL-2) and T- lymphocyte signal transduction

Azathioprine or mycophenolate mofetil (MMF) which are purine synthesis inhibitors

Corticosteriords, which inhibit the production of cytokines (such as IL-1, TNF-alpha and interferons)

OKT3 which is monoclonal antibody that binds to the CD3 receptor on T-lymphocytes

Daclizumab and basiliximab, which are monoclonal antibodies that bund to the IL-2 receptors of T-lymphocytes

Sirolimus (rapamycin), which stops IL-2-induced activation of T-lymphocytes.

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7
Q

List the major side effect of each of the following immunosuppressive drugs

Tacrolimus (FK 506)

OKT3

Mycophenolate mofeti (CellCept)

Prednisone (Cortiocosteroids)

A

Tacrolimus = Nephrotxicity

OKT3 = Allergic reaction or increased rate of infection

MMF= Pancytopenia or anemia

Predinsone0- = hypertension/diabetes

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8
Q

List 5 absolute medical contra-indications for donation of a heart for transplantation

A

Severe structural/valvular heart disease
Severe coronary artery disease
prior myocardial infarction
active malignancy (excluding primary brain or skin cancer)
HIV positive
Death from carbon monoxide poisoning with a carboxy-hemoglobin level > 20%
Prolonged cardiac arrest

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9
Q

List in any order the three most common causes of death following cardiac transplantation

A

Infection

Rejection

Accelerated Coronary disease

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10
Q

45 year old post transplantation with first ednomyocardial biopsy performed at 8 days and showed Grade 1 A rejection. What are the hallmarks of grade 1, and what is treatment.

Grade 3b and what is treatment

A

Grade 1 is mild rejection with focal infiltrates of lymphocytes with myocyte damage

No treatment is required.

Grade 3 is diffiuse mononuclear cellular infiltrate with myocyte damage

Treatment is pulse intravenous steriords usually for 3 days

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11
Q
Describe the mechanism of action of the following
Cyclosporine
Azathioprine
Steroids
Thymocyte Globulin
Monoclonal Antibody
A

Cyclosporine: prevents the development of T-cells by the inhibition of IL-2. It effects gene activation necessary of IL-2 production by inhibiting the function of calcium calcineurin phosphatase which is essential for IL-2 Gene actiatoin.

Azathioprine (Imuran) is an anti-metaolite that effects both DNA and RNA synthesis and therefore reduces or prevents rapid cells devision thus bluting the ability of the host to generate cytotoxic T- Cells.

Steroids: inhibit a variety of intracellular enzymes that depress DNA, RNA, and protein synthesis there, by depressing cell-mediated immunity.

Immunoglobin ATG) Polyclonal antibody that decreases that level of circulating T-cells by attaching to ciculating lymphyocytes and promoting cytolysis

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12
Q

Define the following

Autograft

Allograft

Heteorgraft

Xenograft

A

Autograft: organ or tissue from same individual is re-implanted

allograft: organ or tissue from another non identical individual of same species is transplanted
heterograft: organ or tissue from another non identical individual of same species is transplanted
xenograft: organ or tissue from individual of another species is transplanted

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13
Q

List 5 histological changes currently used to grade the severity of cardiac rejection as per ISHLT

A
Lymphocyte infiltration 
Necrosis
Myocyte damage
Inflammatory infiltration 
Polymorphous infiltration 
Edema
Hemorrhage
Vasculitis
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14
Q

On which cells are Class I antigens (HLA-A, B, C)

A

All cells of an organism

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15
Q

On which cells are Class II antigens (DP, DQ, DR) expressed

A
On Antigen presenting cells such as 
	B lymphocytes
	Activated T Lymphocytes
	Marcophages
	Dendtritic cells
	Endothelial cells
16
Q

Describe the prognostic vale of peak oxygen consumption (Vo2) during exercise as criterior for the evaluation of a potential candidate for heart transplantation

A

Measurement of peak oxygen consumption during exercise provides an index of overall cardiovascular reserve that is useful both to quantitate functional limitation and to estimate limitation.

Value of 10 to 14 ml/KG/min or lower indicates a very poor prognosis and is generally the cufoff for transplantation.

Patients with peak 16 to 18 ml/kg/min have survival rates similar to that of of a transplantation.

17
Q

59 year old males with low Po2 (50mmHg) . CXR—abnormal, PEEP lowered it?

What is diagnosis? Describe physiology? Why does PEEP make it worse? How would you manage it?

A

The patient has an ASD or PFO

Post transplant the right ventricle becomes stif and dysfunction. This increases afterload on the right side. Can develop a right to left shunt.

PEEP increases right ventricular afterload and will increase the right to left shunting

Treatment includes decreasing right ventricular afterload with meds such as milrinone. Nitric oxide may be uses. Can consider closing surgically.

18
Q

What is the most common organ infected at 3 weeks post Cardiac transplant?

What is most common organism.

A

lung

CMV

19
Q

Describe PRA test and its importance in the pre operative assessment of potential heart transplant recipients

A

Prior to transplantation the serum of a potential recipient is expose to panels of cells that express most HLA types.

This makes it possible to determine if a potential recipient has pre formed antiobodies to common HLA antigens. If a candidate is known to react to more that 10% of the panel specific pre-transplant crossmatching between the the donor and the recipient is required.

20
Q

CMV remains the most important infection affecting heart transplant recipients and may have both direct and indirect effects on the recipient

List 4 direct manifestations of CMV on heart transplant pts

A
Fever
Mononucleosis  (leukopenia and thrombocytopenia)
Hepatitis 
GI ulceration 
Mycocarditis
Pneumonia
21
Q

What type of virus is CMV

A

Herpes virus

Direct effects: asympotmatic viral shedding, flu-like illness, pneumonititis, encephalitis, infection of retina,GI tract, pancrease

Indirect effects: allograft rejection, bacterial superinfection, immunosupprresion, chronic graft rejection (Accelerated coronary artery disease)

22
Q

What features of Donor-recipient matching

A

Size: the donor great than 80% of recipient body weight
Blood type: identical or compatible
HLA-typig: generally not done

23
Q

What happens with a cross-match

A

Crossmatch tests recipient sera for anti-HAL antibodies against range of donor lymphocytes
A positive crossmatch = lymphocyte lysis
The probability of hyperacute rejection is high if the crossmatch is positive

24
Q

What is treatment of a high PRA levels

A
IVIG
Plasmapheresis
Cyclophosphamide
Total bone marrow irradiation 
Rituximab-specific CD20 receptors
25
Q

What are features of Class II human leukocyte antigents (HLA)

A

DP, DQ, DR
Helper T cells express CD4
HLA-A, HLA-B and HLA-DR are used for typing
2 possible alleles for each
0-6 antigen mismatch
Registries show reduction in risk with any degree of matching
HLA matching unlikely to influence chronic graft rejection

26
Q

What is Chronic Allograft vasculopathy

A
Leading cause of death > 1 year after transplantation 
Equivalent to 
	chronic rejection in renal 
	vanishing bile ducts in hepatic 
	bronchiolitis obliterans
27
Q

What is pathogenesis of cardiac allograft vasculopathy

A

concentric intimal thickening and plaques
may be related to endothelial injury at procurement
CMV infection
Donor age
HLA-mismatch, at DR Locus (?)

28
Q

What is prevalence of angiographically detecable cardiac allograft vasculopathy

A

1 year 10-20%

5 years 30-50%

29
Q

What are features of malignancy after transplantation

A

Incidence if 2-4% of patients per year
Excessive immunosuppression is a risk factor
Most common are cutaneous: squamous and basal cell carcinoma
Lymphmas are of B cell origian and are related to Epstein-Barr virus
Seronegative recipient with EBV seropositive organ is at 50% risk for developing lymphoproliferative disease

30
Q

What is rate of Osteoporosis

A
10% incidence of transplant recipients
Rapid during first 6 months after transplant
Treatment
	Calcium 
	Vitamin D
	Alendronate