Week 12: Organ Recipient Flashcards
Histocompatability
- The ability of the cells and tissues to live withut the interference from the immune system.
- Histocompatability complexes (MHC)
- Special molecules that allow the body to identify foreign bodies
- Human leukocytes antigens (HLA)- appears in pairs on cells and are genetically determined.
- Two groups of MHCs
- MHC I (Class I) Antigens: those that are found in the surface of potentially all nucleated cells
- MHC II (Class II ) Antigens: found on b-lymphocytes
donor recipient compatability testing
Tissue Typing: actual identification of the HLA antigens and looks at both the donor and recipient to see if there is a degree of compatability between those two
Crossmatching: looking for antidonor antibodies (had presensitization to antigens coming from recipient tissue).
A_BO Typing_: Identifies blood group of donor and recipient
technical post transplant complications
- Vascular Thrombosis: the actual tissue organ being grafted has clot formation within the vasculature itself (arteries).
- Bleeding: In liver transplant recipients, it’s often difficult to differentiate if bleeding is secondary to coagulopathy from liver or surgical problem. More difficult to manage. Allow bleeding to continue until coagulopathy has resolved and there is normal liver function. Treat symptoms but not try to correct was causes it. Coagulopathy will self correct.
- Anastomosis Leakage: At site where graft was placed. Occurs 1-3 weeks after.
*Have to do with the actual performing of the transplant
Graft Rejection
*activation of immune response against transplanted tissue. Triggers auto-immune response. Seen as a result of T and B lymphocyte activites. Rejection is based on time and speed
Hyperacute: type 3 hypersensitivity response occuring within minutes to hours.
Acute Rejection: Sudden onset within days or months, typically beginning as hypersensitivy response. HLA antigens are recognized as being foreign, triggering immune response
Chronic Rejections: Slow. Begins any time following transplant, up to years. Over time the organ becomes ischemic and dies
immunosuppressant-related problems
- Infection: Leading cause of death in post-transplant pts. Common sources include pneumonia, absecces, and point of access from a catheter or wound, CMV, CDiff, fungi
- Organ dysfunction:toxicity from medications
- Malignancy: At increased risk for this. Non-hodkins, lymphoma, caposes carcoma etc.
- Steroid-Induced Problems: Long term use results in hyperglycemia, weight gain, bone diseases, increased risk for infections
Cylosporine
- Concentration controlled drug: regular blood draws are obtained to evaluate serum levels
- CyA or CsA (abbreviations). Prevention of allograft rejections.
- Formulations
- Sandimmune
- Neoral
- Gengraf
- Targets helper T cells
- Hepatotoxicity, nephrotoxicity, neuronal toxicity, hyperglycemia, facial hair growth, hyperplasia of gingivae
Corticosteroids
- Have both anti-inflammatory and immunosuppressant qualities
- Interfere with the production and secretion of interleukin-2 (T lymphocyte)
- High doses impact immunoglobulin G (IgG) (B lymphocytes)
- Suppression of the macrophages
- Used as a rescue therapy for those experiencing rejection
Antimetabolites
Cytotoxic agents. Used in pts to target t and b cells
Azathioprine (AZA)
- Inhibits DNA and RNA synthesis
- Target T cells but has effect on B cells
- Imuran: significant effects on pts blood cell production (anemias and thrombocytopenias, leukopenia)
Mycophenolate Mofetil (MMF): Newer agent, less likely to cause anemias, thrombocytopenias, and leukopenias, LESS TOXIC
- Less toxic than AZA
- Produced from PCN mold
- Inhibits DNA and RNA synthesis
- Targets T and B cells
- Cellcept
Antibodies
Antilymphocyte antibodies
Two catagories:
- Monoclonal Antibodies (mAB): increase attack targeted to the lymphocytes to prevent immune rejection.
- Cytokine-release syndrome (CRS): reaction associated with initiation of this therapy. See it with very first dose. Severe flu-like symptoms.
- OKT3
- Polyclonal antibodies
Macrolide Antibotics
- Tacrolimus (Prograf): attacks helper T lymphocytes. Been associated with onset of DM. Reversible with cessation of Prograf.
- Sirolimus (Rapamune): Blocks both T and B cells (cytokine proliferation). Similar to Prograf, but has less toxicity.
Used to cause cellular death
Kidney transplantation preparation of recipient and post op
Preparation
- Prophylactic antibiotics
- Crossmatching
- Immunosuppressant tx
Post op
- IV fluids to keep UO greater than 100cc/hr
- Diuretic therapy
- Daily weights
- CVP and vital signs
- Prophylactic antibiotics
- Monitor: serum creatinine and electrolytes, H&H, glucose, BUN, ABG’s, WBCs
- Hourly I&O
*
heart, heart-lung, and lung transplant prep and post-op
Preparation for transplant
- Most require aggressive treatment to bridge to transplant
Post-operative management
- similar to that of any open heart surgery.
- However, increase risk of pulmonary dysfunction.
liver transplant
Preparation of the recipient
- similar to any other organ transplant
Post-operative management
- Monitor bile drainage
- PT/PTT
- ALT
- AST
- Bilirubin (total and direct)
- Ammonia levels
- Glucose
- Neuro status
*Rejection often is noted with increase in ALT/AST, Bilirubin, WBC, and s/s malaise, fever, confusion, hepatomegaly, and RUQ pain.
