Renal transplantation

Renal transplanatation

-best chance of long term survival

Contraindication

Absolute

1.       Active malignancy (translant only if >2years complete remission)

2.       Active vasculitis or anti GBM (>1 year on remission)

3.       Severe IHD

4.       Severe occlusive aorto-iliac vascular disease

Relative

1.       Age - <1yo or >75yo

2.       ↑risk of disease recurrent in transplant kidney

3.       Disease of lower urinary tract e.g. impaired bladder function àileal conduit may be considered

4.       Significant co morbid

Type of grafts

1.       Cadaveric donor – w supported circulation and ventilation

2.       Non-heart beating donor – no active circulation

3.       Living related donor

4.       Live unrelated donor

Pre-op

Anti-interleukin 2 receptor antibodies e.g. basiliximab

-↓rate of early rejection

Macthing

1.       ABO compatibility

2.       Major histocompatibility (MHC) antigen

-cytotoxici Ab vs. HLA antigen

-T- & B-cell cross match

Post-op management

Immunosuppresants - Triple therapy

   1)ciclosporin  or tacrolimus

   2)azathioprine or mycophenolate

± 3)prenisolone

Complications post-op

Early

1.       Bleed

2.       Thrombosis

3.       Infection

4.       Urinary leak

5.       Oliguria

Long term

1.       ↑ incidence of infection – dt ↓ T cell immunity

-skin infection e.g. fungi, warts, HSV, VZV

-oppurtunistic org e.g. CMV, P.jirovecii

2.       ↑risk of malignancy

-skin (basal & squamous) ca

-lymphoma (EBV related)

-anogenital ca

3.       Atheromatous vascular disease

4.       HTN

5.       Graft rejection

Acute Rejection (<6m)

-characterized by rising serum creatinine, fever, graft pain

-Biopsy – immune cell infiltrate, tubular damage

Rx

– high-dose IV methylprednisolone

-if resistant à anti-thymocyte globulin (ATG)

Chronic Rejection (>6m)

-gradual rise in serum creatinine and proteinuria

-biopsy – vscular change, fibrosis, tubular atrophy

-not responsive to ↑ immunosuppresion

Prognosis

1 yr graft survival

        I.            HLA identical 95%

      II.            1 mismatch 90-95%

    III.            Complete mismatch 75-80%

Average half life of cadaveric graft ~ 10years

HLA identical living related donor   ~ 20 years

Discussions

Creatinine

-breakdown product of creatine phosphate in muscle

-produced at fairly constant rate depending on muscle mass

-rises on hyperbolic curve as renal function decline

Reciprocal creatinine plot

- Straight line, parallel to fall in GFR

-F(x) = used to  monitor renal function &  predict need for dialysis

Creatinine clearance formulae, Cockcroft-Gault

GFR = (140-age) * (Wt in kg) * constant

72 * SCr (µmol/L)

Constant M=1.23. F=1.03

GFR = (140-age) * (Wt in kg) * (0.85 if female)

72 * SCr (mg/dL

Reason for rapid decline greater than expected

         i.            Infection

       ii.            Dehydration

      iii.            ↑BP

     iv.            metabolic disturbance

       v.            obstruction

     vi.            nephrotoxin drugs

Why creatinine not a good marker for CKD?

Initially, small change in creatinine might be responsible for significant change for GFR

Significant change of creatinine only appear when GFR is very low.