Human Renal transplantation

Dr. Edmond Wong

EAU 2010

History

• Carrel established the modern method of vascular suturing at the turn of the 20th century,

• Nobel Prize in 1912 for his work on organ grafting

• 1933 : first human renal allograft by Voronoy in the Ukraine

• Boston in 1954 :kidney from one twin was transplanted into the other

History • 1958 :first histocompatibility antigen described • 1959 : Radiation for immunosuppression• 1961: azathioprine became available • 1962 : corticosteroids became part of a standard immun

osuppression regimen • 1966: direct crossmatch between donor lymphocytes an

d recipient serum • 1960s : human renal preservation over 24 hours with pul

satile machine perfusion or cold storage after flushing with an ice-cold intracellular electrolyte solution

• Pretransplantation transfusion protocols are no longer routinely prescribed because donor-specific sensitization and the transmission of viral illnesses

History

• 1978 :first clinical trials of cyclosporine were reported by Calne

• 1984, Congress passed the National Transplant Act • late 1980s :The University of Wisconsin (UW) solution • 1989 :Recombinant erythropoietin reduce risk of the d

evelopment of anti-human leukocyte antigen (HLA) antibodies

• 1990 : Joseph E. Murray received the Nobel Prize in Medicine

• 1995: Laparoscopic donor nephrectomy was introduced• Current development: novel immunosuppressive agents

and approaches to graft tolerance

Ethical issue in transplantation

Ethical issue in transplantation

Supply and use of decease donor

• Gap btw supply and demand of kidneys tended to stabilized in countries with a donation rate >40 kidneys per million population (PMP)

• It is difficult to recommend specific , donor-promoting activities for countries and organization

Ways to promote deceased donor

• Donor cards: opt in • Computerized donor register: reduce refusal by

family• Maintain adequate ICU bed & educational

program for ICU physicians• Opt out (presume consent) legislation• Non-heart beating donor (NHBD)

– With continuous perfusion machine for IA cold perfusion until family arrived

• Elderly donors (>60): better 6m survival then pt without transplant

How to enhance donation?

Enhanced living donation

Why living donor is suitable

• Living donor graft has better graft and patient survival than deceased donors

• Kidney transplant results have improved thus more patient with ESRD opt for transplant rather than dialysis

• Lap donor nephrectomy is safe and successful

1. Accepting graft with anatomical anomalies

• Anatomical anomalies: renal cyst, PUJO, renal stone> 1cm, Duplex ureteral system , multiple arteries & veins

• Graft with multiple a&v do not carry increase risk of complication in experience center

2. ABO-incompatible donors

• Once a contraindication for renal transplantation• New techniques: antibody adsorption columns & new im

munosuppressive tools (anti-CD20 monoclonal antibody , rituximab)

• Adv: immediate availability of living donor• Initial result show similar outcome, but lack long term dat

a• Require more intense and most costly immunosuppressi

ve therapy• Remains EXPERIMENTAL• Other chose: cross-over transplantation

3. Cross-match-positive living-donor kidney transplant

• Once consider contraindication• Plasmapheresis : extensive antibody elimination strategi

es• IVIG• Intense immunosuppresion with antibody induction & use

of B-cell depleting agents(anti-CD20 AB rituximab)• No long term result• Remain EXPERIMENTAL

4. Living unrelated kidney donation

• Altruistic non-consanguineous kidney donation is allowed legally

• Provided checks are made for altruistic motivation & financial gain excluded

• Result comparable to related living donation

5. non-direct living-donor transplantation

• Between an altruistic donor and a recipient unknown to the donor

• There are ethicial and legal concerns

• NOT recommended

6. Payment to living donor from central organization

• Payment of living donors to donate organs is ethically unjustifiable

• All organ donors should have adequate lifelong access to medical care for prevention of renal failure and side effect of organ donation

Ethical ways to show appreciation for organ donation

• Donor “medal of honour”

• Cross-over transplantation or paired organ exchange

• Medical leave for organ donation

• National insurance plan that provide life and disability insurance for all living donors

Kidney donor selection

Why is kidney transplant good?

• Prolongs life

• Reduce morbidity

• Improves quality of life

• Enable social and medical rehabilitation

• Reduce cost associated with medical care

Definition

• Isograft: – A graft of tissue that is obtained from a donor genetic

ally identical to the recipient

• Xenograft: – A type of tissue graft in which the donor and recipient

rare of different species

• Allograft: – A graft of tissue obtained from a donor of same speci

es as , but with different genetic make up (e.g transplatn btw two human being)

Basic immunology

• T cell : – Detect processed Ag via T-cell receptor– Produced cytokines– Kills infected cells via interactions with cell surface mo

lecules• B cell:

– Detect tertiary structures of antigens– IgD & IgM antibodies act as receptors– Need cytokine signals from T cell for activation– Produce antibodies when activated– Mediated complement fixation– Responsible for Humoral immunity

MHC class

• MHC: – Combination of various HLA haptotype create genetic variability– Improve chance of population survival against few pathogens

• MHC Class I: – HLA A, B, C– Expressed by most nucleated cells– Binds to CD8 on T lymphocytes

• MHC Class II: – HLA DR, DP, DQ– Expressed by specialized antigen-presenting cells (APCs): dend

ritic cells, macrophages & endothelial cells

Kidney donor selection

• Diagnosis of brain death in deceased donor (refer to HAHO 2007)

1. Any transmissible disease?2. Any malignancy 3. Quality of organs for transplantation ?

• Vascular condition• Renal function

4. Age?– > 65 donor, similar short-term result but lower long term graft

survival– But more on physical condition of donor rather than age– Thus no absolute age limits to donation– Living donor: 55 yr

Cadaver Donor

1. Normal renal function

2. HTN

3. Diabetes mellitus

4. No malignancy

5. No generalized viral or bacterial infection

6. Age 6-45

7. Negative serologies(syphilis, HIV, hepatitis, T-lymphoprolif

erative virus)

• Resuscitation– 90 mm Hg, UO 0.5

ml/kg/hr

Donor selection : Infection

• History of drug abuse?• Serological test must be repeat, because

– Incubation period : HIV (2m), Hepatitis (6m)– Fluid resuscitation with dilution effects

Donor selection: Malignancy

• Absolute contraindication as a donor: 1. Active cancer2. Hx of metastatic cancer (except testicular c

a)3. Cancer with high recurrence rate (breast , m

elanoma, leukaemia, lymphoma)4. Brain hemorrhage of unknown etiology (mus

t exclude metastasis)

• Acceptable if 5yr absence of recurrence after cure

Donor selection: vascular condition and renal function

• Factors for excluding potential donors: 1. Previous MI2. CABG or angina3. Severe systemic vascular disease4. Prolong hx of DM 5. Serious HT6. Events of long-lasting hypotension7. Oliguria8. Long-lasting ICU stay

• Donor renal fxn : CrCl (Gockcroft-Gault formula): not suitable if CrCl <50ml/min

• 24-hr Proteinuria• USG kidney• ARF is not itself a contraindication

Marginal donors

• Age: – >70 yo without other risk factors– 60-70: hx of DM , HT, proteinuria 1g/24h, or retinal va

scular changes• Renal function:

– CrCl 50ml/min: still valuable for single graft– CrCl <50ml/min: used as a dual graft or discarded if hi

stologically abnormal– ~5-20% glomerulosclerosis at bx with >25 glomeruli ta

ken from both kidney: organs still valuable for a single of double graft

– > 20% glomerulosclerosis : individual decision base on renal function

One graft or two graft per patient?

• Two conflicting concepts: – Single marginal kidney has reduced renal mass , whic

h are further reduced by cold ischemic time, transplant trauma and nephrotoxicity of immunosuppressive therapy. Thus both kidney to same recipient may increase nephron mass and prevent kidney damage

– Marginal kidney have functional reserve which will increase post-transplant. Dual transplantation is redundant

• Double –kidney transplants: safe, well tolerated and no more surgical complication than single-graft operation

Explantation surgery

Explantation

• Deceased donor organ recovery: – Each organ should be procured as quickly as

possible to minimise ischemic injury– Heart, lungs, liver and pancrease, before kidn

ey retrieval– Continuous machine perfusion reduces injurie

s and improve post-op graft outcome

Living donor

Living donor

• Must not be coerced and paid for their donation• Should be considered a gift of extraordinary

value

Living Related Renal Transplant

1. Improved graft survival

2. Less recipient morbidity

3. Limits time on dialysis

4. Partially alleviates supply problem of cadaver kidneys

5. Timing of transplantation

Living donor assessment

• Complete history and PE• Routine laboratory testing• Serological evaluation:

– EBV, Herpes, CMV– HIV– Hep B& C

• Urinalysis and C/ST• 24-h urine collection: CrCL , Protein• Blood pressure measure: 3-10 x• Imaging:

– CT scan with 3D reconstruction– MRI angiography– Renal angiography indicated if CT & MRI not available

Living Donor Selection

• Contraindications– Mental disease– Renal disease– Morbidity, Mortality Ris

k– ABO incompatibility– Crossmatch +– Transmissible disease

• Evaluation– Serology– Three-dimensional

CT

Consent

• Mortality: 0.03%

• Major morbidity: 0.2%

• Minor morbidity: 8%

• Not associated with increase risk of renal failure or HT

• Associated with asymptomatic proteinuria

• < 1% later regretted the donation

Choice of kidney

• Left kidney is preferred because of longer length of the left renal vein

• Donor should always be left with the better kidney

• Donor diuresis increase with mannitol : 0.5g/kg (usually 25g)

• Arterial spasm prevented by externally applied papaverine

Choice of kidney: Number of RA

• CTA: provide both renal anatomy and vascular road-map for the surgeon

• Right kidney selected if multiple left renal artery and single Right renal artery

• Right kidney donor: 30%

• Question: in multiple left RA , is lap Rt donor nephrectomy just as safe?

Problems of Right LLDN

• Technically much more challenging:• Need retraction of the liver• short right renal vein (RRV)• further shortening of RRV after a stapled transect

ion• presence of friable venous branches draining int

o the IVC in proximity to the RRV

• Initial experience show almost 40% of graft loss [Mandai 2001]

Modification of Rt LLDN

• Relocation of ports: • make GIA stapler transects the RRV in a

plane parallel with the inferior venna cava (IVC)

• more of the RRV length can be preserved

• Relocate the incision for kidney extraction

• Use of panel graft to lengthen the RRV with great saphenous vein

How about using the left kidney with vascular reconstruction?

•Close to each other:

•1. Conjoined anastomosis:

•2. End-to-side anastomosis:

•Far away:

•1. autogenous graft reconstruction– Epigastric or hypogastric graft

•2. pseudo-Carrel patch technique – segment of great saphenous vein

Results of vascular reconstruction

• Many studies showed:• 1-year graft survival rates: 91–98%

• Kuo PC et al. Am J Surg 1998;176: 559–63• Hsu TH et al. Urology 2003;61:323–7

• no difference for single renal artery VS MRAs

• However: more renal arteries are associated with more ureteral complications in the recipient

Left single artery

Left LDN

Left multiple arteries

Left LDN + reconstruction

& Or

Right single artery

Right LDN

Both multiple arteries

Chose another recipient

Left kidney better

Right LDN

Recommendation for choice of allograft

Lap living-donor nephrectomy (LLDN)

• Good evidence base for LLDN• Compare to OLDN: similar rate of

– graft fxn– rejection rate, – urological complication – patient and graft survival

• Advantage: analgesic requirement, pain , hospital stay , time to return to work , cosmesis

• NO effect long term risk of ESRD• Mortality rate: 0.03% (same as OLDN)

Organ preservation

• Euro-Collins is no longer recommended• Celsior-solution• UW solution (University of Wisconsin) • HTK (histidine-tryptophane –ketoglutarate)

Methods of kidney preservation

2 motheds

• Initial flushing with cold preservation solution followed by ice storage

• Continuous pulsatile hypothermic machine-perfusion (relevance for non heart-beating donors and marginal donors)

Duration of organ preservation

• As short as possible

• Marginal and elderly (>55) donors are more sensitive to ischemia

• Relies on hypothermia: 1. Lower metabolic rate

2. Conserves ATP

3. Prevents formation of oxygen-free radicals during reperfusion phase

Kidney recipients

Cause of ESRF

• DM: 40%• GN: 20%

– IgA nephropathy:60%– Focal glomerulosclerosis : 10%

• Out of the total number of patients on renal replacement therapy– 50% on Peritoneal Dialysis– 10% on Haemodialysis– 40% have had renal transplantation

• Among the patients on dialysis treatment, 81.6% were on PD.

ERRF: definition

ESRF (NKF-K/DOQI)

Am J Kidney Dis 2002 39 (Suppl 1: S1-S266)

RRT

• Dialysis– Hemodialysis

• SCUF / CVVH / CVVHD / CVVHDF / SLEDD

– Peritoneal dialysis• CAPD / CCPD / NPD / TPD

• Renal transplantation

Kidney recipient

• Careful pre-op workup of all transplant candidates is mandatory to improve organ and patient survival in the post-transplant period

• The workup should be repeated regularly

Selection and preparation of recipients

• Purpose: to diagnose the primary renal disease and its risk of recurrence in the kidney graft and to rule out active invasive infection, a high probability of operative mortality, noncompliance, active malignancy, and unsuitable conditions for technical success ( Barry, 2001 ; Kasiske et al, 2001 ).

Pre-transplant therapy

• Abnormal urogenital tract

• Urinary diversion

• Pre-transplant nephrectomy

1. Abnormal urinary tract

• Urinary tract abnormali should be correct before transplantation

• Congenital: PUV, Spina bifida, prune belly syndrome, VUR, bladder extrophy , VATER syndrome

• Acquire: Shrunken or neurogenic bladder• Low-compliance bladder: CISC or bladder augm

entation or SP diversion• Anatomical or functional disorder seems not to c

hange outcome of renal transplantation

2. Urinary diversion

• Sphincter insufficiency or absent bladder: conduits or continent catheterisable pouches or artificial sphincters

• Low-compliance bladder with intact sphincter: bladder augmentation + continent pouches

• Urinary diversion at least 10-12 weeks before transplantation

• Bladder augmentation after transplantation

3. Pre-transplant nephrectomy

Indication for pre-transplant nephrectomy:

1. Suspicious of malignancy

2. Large size (ADPKD)

3. Grade 4-5 VUR

4. Massive proteinuria

5. Intractable HT

6. Recurrent stones or UTI

Contraindication of transplant recipient

• Malignancy: immunosuppresant may aggravate underlying malignancy

• Infection– Active infection: jeopardize immediate post-transplant outcome– Chronic infection:

• Does not cause immediate post-op risk• Repeat serology for CMV, HBV, HCV & HIV even if previous –ve ser

ology• May have implications for allocation of organs• Consult ENT, dentist, dermatologist, gynaecologist to firmly rule out

infection

• Short life expectancy• Severe psychiatric disease

Infection screening

• HBV, HCV: – hepatitis is the major cause of liver disease post renal transplant – Liver bx to assess disease status– Antiviral therapy before transplantation

• HIV: CI to transplant • CMV: immunosuppressant asso with life-threatening CM

V disease, need prophylaxis• EBV :

– in children and young adults– Risk of EBV-related lymphoproliferative disease

• TB: need isoniazid prophylaxis • Syphilis : TPHA-test (Treponema haemaglutination)

Other pre-transplant workup

• Cardiovascular workup– Pt with cardiac disease have higher peri-op risk– Indicated in: hx of CVD, PVD, stroke, CVA, long hx of

renal failure /dialysis, elderly or DM – Investigation:

• ECHO : valvular disease, systolic / diastolic LV dysfxn• Exercise ECHO/ thallium scan in pt with low exercise capacit

y• Coronary angiography

– Revascularisation should be performed in every suitable transplant candidate before transplantation

Other pre-transplant workup

• Peripheral artery disease, CVA: – Common in ureamic patients– Significant cause of graft failure– Pelvic radiography should routinely be done– Duplex USG incase of vascular calcification– Angiography and arterial repair as indicated– Avoid contrast enhanced MRI with risk of nep

hrogenic systemic fibrosis

Other pre-transplant workup• DM

– Increase mortality and reduce long-term graft outcome– Combine kidney –pancreas transplant in Type I DM improve glucose control a

nd slow progression of CVD– Watch out for CVD & bladder neuropathy

• Obesity: – Higher surgical and non-surgical complication– No recommend exclusion based on BMI

• Coagulopathies: – Early graft thrombosis or post-transplant thrombotic complication– Esp in pt with recurrent shunt thrombosis – ATIII, protein C, activated protein C resistance (Factor V Leiden) , protein S, Anti-

phospholipid antibodies• Other disease aggravated by immunosuppressant:

– Diverticulosis– Cholecystolithiasis– Hyperparathyrodism

Other consideration

• Age: – Itself not a CI to transplantation– Transplant reduced mortality in pt over 65 co

mpare to pt on waiting list– Attention for co-morbidities (esp cancer /deme

ntia)– High fatality rate in the 1st year

• Recurrence risk (original renal disease) – < 10% graft loss due to recurrent disease after 10 yr– Disease with high recurrence rate + immediate graft

loss1. Light-chain deposit disease (LCDD): not recommended2. Primary oxalosis : combined liver-kidney transplant3. Anti-glomerular basement (anti-GBM) antibodies: can be

given after disappearance of anti-GBM Ab4. Systemic disease (lupus, vasculitis, haemolytic uraemi

c syndrome)5. Focal and segmental glomerulosclerosis (FSGS) : txn wit

h plasmapheresis +/- rituximab6. Renal amyloidosis / cystinosis / Fabry’s disease

Pt with previous transplant

• Look specially for malignancy , CVD & development of antibodies against 1st graft

• Gradual tail down immunosuppressant after graft failure , as continue therapy increase risk of RRT

• Graft nephrectomy or embolisation if symptomatic

• Prophylatic transplantectomy not beneficial• Avoid repeat alloantigen mismatches

Transplantation in pregnancy

• Planning pregnancy– Sex life and fertility improved after kidney transplantati

on– Pregnancy should be at a time of good general and gr

aft health : 1-2yr after transplant– Similar outcome if stable graft fxn & immunosuppressi

ve therapy , no sign of rejection , HT, proteinuria, hydronephrosis or chronic infection

– Hydronephrosis increase risk of infection & stone– Early adjustment of immunosuppresant

• Graft survival: – Pregnancy rate increase to 5%

Care during pregnancy

• Control of proteinuria• HT (pre-eclampsia)• RFT• Rejection• Infection:

– Monthly MSU– Treat bacteriuria always– Antibiotics: penicillin & cephalosporine – Antibiotic prophylaxis in all uro procedure– Amniotic culture to screen for fetal infection

Immunosuppressive txn

• Cyclosporine , with or without azathioprine and prednisone

• Pass placental barrier but not teratogenic• Cyclosporine level decrease due to increase vol

ume distribution , thus should augment dosage• Tacrolimus may be safe• MMF & sirolimus is CI : teratogenic

FU• No increase rate of spontaneous (14%) or thera

peutic (20%) abortions• Higher rate or pre-term and Caesarean section d

ue to high incidence of prematurity• 20% babies are low birth rate• No higher congenital abnormalities• Breastfeeding is not recommended• Weekly fetal RFT for 3 months• Delay vaccination until infant is 6m old

Transplant technique

Transplantation Techniques

Renal vasculature

• Preserve lower pole artery to supply the ureter if possible

• Use Carrel patch

• Small lower pole vessels may anastomose end-to-ed to Inf epigastric artery

Lower urinary tract

• Extravesical ureteroneocystostomy is normally performed

Complications

Early

1. Wound infection and abscesses (5%)

2. Hemorrhage

3. Hematuria

4. Incisional hernia (5%)

5. Urinary fistulae (5%)

6. Arterial thrombosis (0.5%)

7. Venous thrombosis (0.5% adult , 2.5% paed)

Complications

Late

1. Ureteral stenosis (5%)

2. Reflux (30-80%) and acute pyelonephritis (10%)

3. Kidney stones (1%)

4. Renal artery stenosis (10%)

5. AVF & pseudo-aneurysm after renal biopsy (10%)

6. Lymphocele (1-20%)

1. Wound infection

• Risk factors: – Obese, old, DM , hematoma, rejection or over-immun

osuppression

• Prevention: – Minimise electro-coagulation– SC aspiration drain

• Txn: – Opening of wound– Surgical drainage for deep abscess– Rule out urinary fistulae

2. Hemorrhage

• Risk factors: – Acetylsalicylic acid (aspirin)– Poorly prepared transplant hilus– Multiple renal artery– Renal biopsies– Hyper-acute rejection (HAR)

• Treatment: surgical exploration & drainage• Check uretero-vesical anastomosis & inser

t double-J stent

3. Hematuria

• After renal biopsy: look for AVF

• Txn: selective percutaneous embolisation

4. Incisional hernia

• Risk factors: – Obesity , DM , hematoma, rejection– m-TOR inhibitor

• Treatment: – Surgical with or without synthetic mesh

5. Urinary fistula

• 3-5% without double J stent use• Cause: ischaemic necrosis of the ureter• Occur on the ureter, bladder or parenchyma• Mx:

– Diversion: PCN, double-J, foley– Reimplantation if distal necrosis and long ureter– Uretero-ureteral anastomosis with native ureter– Vesical fistula: SP or transurethral catheter– Calyceal fistula: JJ stent + foley or polar nephrectomy & omental

plasty

6. Arterial thrombosis• 0.5% in 1st week post-op• Risk factor:

– Atherosclerosis – Unidentified intimal rupture– Poor suture technique– Kinking of artery longer than vein– Incorrect sited anastomosis– Multiple arteries– Paediatric transplant

• Presentation: primary non-fxn or sudden anuria• Investigation: Doppler USG or technetium scan, CT • Txn:

– Surgical exploration always necessary– Radiological thrombectomy if within 1st 12 hours– Graft nephrectomy

7. Venous thrombosis

• Presentation: primary non-fxn , hematuria or anuria

• Dx: Doppler USG or DTPA scan• Treatment:

– Salvage thrombectomy very poor success rate– Graft nephrectomy

Late : 1. Ureteral stenosis• 5% of transplant• Dx: USG show hydronephrosis & derange RFT• Most occur in 1st yr, increase to 9% in 10yr• Cause or hydronephrosis

1. High vesical pressure + ROU: bladder drainage2. VUR: not obstruction3. VU stenosis due to scar formation or poor surgical technique(80%)

• Risk factors: multiple A, age, delay graft fxn, CMV infection • Treatment:

• PCN + monitor RFT• AP to determine level of stenosis, degree & length • Endoscopic or percutaneous treatment• Outcome: better if early , distal & short• Open surgery: uretero-ureteral ana or vesicopyelostomy

2. Reflux & pyelonephritis

• Reflux is common– Laedbetter (30%)– Lich-Gregoire (80% short tunnel, 10% long tunnel)

• Acute pyelonephritis: 80% with reflux, 10% without reflux

• Treatment: – Endoscopic injection of deflux (40% success)– Uretero-ureteral anas if native ureter not refluxive– Ureterovesical re-implantation with long tunnel

3. kidney stones

• Transplant with kidney or acquired• Presentation: hematuria, infection or obstruction• Dx: NCCT• Treatment:

– Double J or PCN– ESWL for calyceal or small renal stone– PCNL or open nephrolithotomy for larger stone– Ureteric stone: ESWL or URSL

4. Renal artery stenosis• Presentation:

– HT refractory to medical txn– Deranges RFT without hydronephrosis

• Investigation: Doppler USG >2m/s• Treatment:

– Medication with HT FU– Intervention when stenosis > 70%– Transluminal dilatation +/- stenting (70% success) – Open surgery : resection with direction reimplantation with highe

r success rate– Repair with saphenous vein MUST be avoided

5. AVF & pseudo aneurysm

• Presentation: repeated hematuria• Investigation: Doppler USG /MRI / angiography• Treatment:

– Regress spontaneously– Indicated if persistent hematuria or diameter > 15mm– Selective embolisation– Pseudo aneurysm due to mycotic infection and can b

e fetal

6. Lymphocele• Cause: insufficient lymphostasis of the iliac vess

els and/or of the transplant kidney• Risk factor: obesity , m-TOR inhibitor• Presentation: asymptomatic, pain cause by urete

r compression or infection• Treatment:

– Mild with no compression on ureter or vessel: observe– Laparoscopic marsupialisation– Open surgery

Donor and recipient matching

Donor & Recipients matching

1. ABO compatible

2. HLA-A, B & DR phenotype

3. Lymphocyte cross-match test (avoid hyper-acute rejection)

ABO compatibility

• Blood gp antigens can behave as strong transplant antigens (i.e expression on renal vascular endothelium)

• Incompatibility may cause early HAR

• Gp O donor theoretically can be transplant to A, B or AB recipients

• Ways for ABO incompatible transplant: – Antibody elimination: anti-B agents

Histocompatibility (HLA)matching

• Transplant outcome correlated with number of HLA mismatch

• Remarkable polymorphism: must determine HLA-A, HLA-B & HLA-DR phenotypes

• Less important in living- than decease donor• HLA incompatibility:

– Proliferation & activation of recipients CD4+ & CD8+ T-cell

– Activation of B-cell allo-antibody– Lead to cellular & humoral graft rejection

HLA testing

• HLA-testing and cross-matching must follow the standard of e.g European Federation of Immunogenetics

Cross matching

• Pt at risk: have HLA-specific allo-Ab or allo-immunising events – Pregnancy– Blood transfusion– Previous transplantation

• Cross match: detect preformed allo-antibodies in recipient’s serum directed against lymphocytes of the potential donor

• Complement-dependent lymphocytotoxicity (CDC) assay is used

• Donor: obtain unseparated lymphocytes or T-enriched lymphocytes

• T-lymphocytes: express only HLA class I Ag• B- lymphocytes: express HLA class I & II Ag (from splee

n) • Spleen have more B-lymphocyte than peripheral blood • Thus, unseperately lymphocytes from spleen is more se

nsitive than from peripheral blood• +ve T-cell cross match: contraindication for transplantati

on• +ve B-cell cross match: may be due to

– Anti-HLA class I/II antibodies or allo-Ab– Immune complexes– Therapy with anti-B cell Ag (rituximab, alemtuzumab)– Non-HLA allo-antibodies– Thus decision depends on recipient’s antibody status & immunol

ogical hx

• False +ve cross match result– Autoimmune disease (IgM auto-Ab)– IgM-anti-HLA allo-antibodies

• Ways to decrease false +ve:– Txn with dithiothreitol (DTT) – Flow cytometry cross-match– Enzyme-linked immunosorbent assay (ELISA)

cross-match test: use solid-phase technology to detect donor-specific anti-HLA antibodies

HLA-antibodies testing

• Potential recipients should be screened for HLA-specific antibodies every 3 months or

• 2 & 4 weeks after every immunising event (blood transfusion, transplantation , pregnancy and graft explantation)

• Panel of lymphocytes use cover most of the common HLA-alleles in the donor population, and at least >50 different HLA-type cells

• Result is expressed as the percentage of panel reactive antibodies (% PRA) and as the HLA specificity against which these antibodies react

Immunosuppresion

Immunosuppression

• A balance of survival• Dosage of drug high enough to suppress rejection withou

t endangering the recipient’s health• Sensitized lymphocyte activity against a transplant• Most important in initial post-transplant period to prevent

rejection• Later stage: graft adaptation occurs, very low rejection ra

tes in maintenance patient• Reduced over time by steroid tapering & gradual lowerin

g of calcineurin inhibitor (CNI)• Common side effect: malignancy , opportunistic infection• Synergistic regimen: dose reduction reduce side-effect w

hile maintaining efficacy

Standard initial immunosuppression

1. CNI (cyclosporine or tacrolimus)

2. Mycophenolate (MMF or enteric-coated mycophenolate sodium, EC-MPS)

3. Steroids (prednisolone or methylprednisolone)

4. With or without induction therapy

Calcineurin inhibitors (CNIs)

• Cyclosporin & tacrolimus• Improve kidney survival• Cornerstone of immunosuppresion• Both are nephrotoxic• Long term use is major cause of chronic allograft

dysfunction• Both drug Similar outcome: overall patient & graf

t survival (LE: 1a)• Tacrolimus may provide better rejection prophyla

xis with better graft survival

Cyclosporine A

• Cyclosporine A micro-emulsion(CsA-ME; Neoral) • Use associated with reduced rejection rate 1 yr po

st transplant (LE: 1b)• “Critical-dose” drug: deviation from exposure lead

to severe toxicity or failure of efficacy• Need close surveillance & drug level monitoring• Drug level 2 hour after intake (C2 level)• Major side effect: hypercholesterolaemic, HT, Gu

m hypertrophy, constipation , hirsuitsm & acne (LE : 1a)

Tacrolimus

• More powerful than cyclosporine• More potent prophylaxis for transplant rejection• Overall similar outcome vs cyclosporine (LE: 1a)• Advagraf : allow once daily dose but need higher

dosage • Monitor using trough level • SE: DM, termor , headache, hair loss, GI , hypo

Mg• Over-immunosuppression with MMF: polyoma n

ephritis (LE: 1b)

• Complete CNI withdrawal in first 3 yr asso with increase rejection risk & worse outcome

• However, CNI withdrawal under MPA & steroid is safe after 5 yr and resulted in improved RFT

Mycophenolates

• MMF and EC-MPS• Both base on Mycophenalic acid (MPA) inhibits inosin

e monophosphate dehydrogenase (IMPDH)• Decrease synthesis of guanosine monophosphate in puri

ne pathway• Lymphocyte proliferation is more dependent on purine n

ucleotide synthesis compare to other cell types• Provide more specific lymphocyte-targeted immunosuppr

ession• Not Nephrotoxic• Main side effect: inhibits bone marrow fxn & GI (diarrhoe

a)• Both drug equally effective & identical safety profile

Effect

• MMF + prednisolone + CNI profound reduction of bx proven rejection (LE: 1b)

• MMF reduce chronic allograft rejection by 27% vs azathioprine

• MPA dose reduction are associated with inferior outcome

• Regular monitoring for polyoma is recommend when given with tacrolimus

Dosage

• With cyclosporine: MMF 1g BD or EC-MPS 720mg BD • Not approved usage with tacrolimus but is use widely wo

rldwide• Same initial dosage as with cyclosporine• But dose reduction are frequent due to GI side effect • After 6-12 months:

– MMF: 1000-1500mg QD– EC-MPS: 720-1080 mg QD

• In maintenance: potency of MPA can be used for steroid withdrawal (LE: 1a) or dose reduction of CNIs (better RFT)

• MPA drug monitoring is not recommended

Side effect

• Bone marrow suppression• GI toxicity : diarrhoea • Over-immunosuppression: CMV infection

– Screening for CMV viraemia (LE: 1a)– CMV prophylaxis : valganciclovir use in all CMV +ve recipient or

CMV +ve organ (proven to reduce CMV asso motality + long-term graft survival )

• Polyoma virus nephropathy: esp when combine with tacrolimus (LE: 1b)

• Progressive multifocal leukoencephalopathy is a progressive and ultimately fatal white-matter disease of the brain that is associated with polyomavirus infection

Azathioprine

• Replaced by MMF in most place• Inferior to MPA in reduction of rejection rate• Usually reserved for low-risk pt or who cannot tol

erate MPA• No additional advantage in additional to cyclosp

orine and steriod (LE : 1a)

Steroid

• Most still consider steroid as fundamental adj to primary immunosuppression

• Many successful steroid withdrawal (LE: 1a)• Potential benefit of steroid less prominent after p

rolong treatment

m-TOR inhibitor

• Sirolimus and everolimus• MOA: Suppress lymphocyte proliferation and differentiati

on• Inhibit both Ca-dependent & Ca-independent pathway, bl

ock cytokine signals for T-cell proliferation• Also affect B-cell, endothelial cell, fibroblasts and tumor

cells• As effective as MPA when combine with CNIs in preventi

ng rejection (LE: 1b)• Require monitoring of trough level due to narrow therape

utic window & risk of drug-to-drug interaction

m-TOR inhibitor

• Side effects: – Dose dependent bone marrow toxicity– Hyperlipidemia– Oedma– Lymphoceles– Wound healing problem– Penumonitis (PCP): need septrin prophylaxis– Proteinuria– Impair fertility– Aggravate nephrotoxicity with combine with CNIs (but itself not n

ephrotoxic)

• CNI dosage should be reduce in combination therapy with m-TORi

m-TORi

Sirolimus: • ½ life: 60hr• Once a day dose• Kidney recipients only• Should be given 4hr a

fter cyclosporine• Use with steroid for cy

closporine withdrawal

Everolimus: • ½ life: 24hr• BD dose• Kidney & heart transpl

ant• Use with cyclosporine

simultaneously

Can m-TORi replace CNIs?

• NOT at initial phase: lower efficacy & problem with wound healing & lymphocele (LE: 1a)

• NOT if proteinuria > 800mg/day / GFR <30ml/min• YES at later stage (3m): improvement in RFT (LE: 1a)• YES who are at risk of or develop malignancy after trans

plantation• Sirolimus +steroid vs Cyclosporine + steroid + sirolimus:

better long term survival, RFT & fewer malignancy (LE: 1b)

• Only few data on long term FU of m-TORi

T-cell depleting induction therapy

• “Induction” treatment with biological T-cell depleting agents: – Anti-thymocyte globulin (ATG)– OKT3– Anti-CD52 antibody (Campath1-H)

• Effective rejection prophylaxis while starting CNIs after recovery of graft from ischemic injury (LE: 1b)

• Initial lower graft rejection rate, but no evidence of better long-term graft outcome

• Side effect: increase risk of opportunistic infection & cancer, post-transplant lymphoproliferative disease

Interleukin-2 receptor antibodies• Daclizumab & basiliximab• For rejection prophylaxis• Given as short course post-transplant reduce acute cellular reject

ion by 40% (LE: 1a)• No comparative study for both drug but appear similar efficacious• No effect on patient or graft survival (LE: 1a)• Study support quadruple therapy with these agents• Allow early steroid withdrawal but with higher rejection rate• Allow reduction of CNIs, with excellent renal fxn

Immunological complication

• Immunological rejection is a common cause of early and late transplant dysfunction

Diagnosis• Gold standard: transplant biopsy• Banff criteria• Class 1 is a "normal biopsy." • Class 2 is "antibody-mediated changes."  Ideally, both positive C4d staining and cir

culating donor-specific antibodies are present in the setting of a rising creatinine to make this diagnosis. Acute & chronic

• Class 3 refers to "Borderline Changes" which is essentially a mild form of T-cell-mediated rejection..

• Class 4 is a more full-blown form of T-cell mediated rejection.  As with humoral rejection, there are both acute & chronic forms:

• The acute form of T-cell mediated rejection is furthermore subclassified – Class IA: there is at least 25% of parenchymal showing interestitial infiltration and foci of mo

derate tubulitis (defined as a certain number of immune cells present in tubular cross-sections).  

– Class IB:  just like Class IA except there is more severe tubulitis.– Class IIA:  there is mild-to-moderate intimal arteritis.– Class IIB:  there is severe intimal arteritis comprising at least 25% of the lumenal area.– Class III:  there is transmural (e.g. the full vessel wall thickness) arteritis.

• Class 5 refers to interstitial fibrosis and tubular atrophy (IFTA), which is the new preferred term for "chronic allograft nephropathy."  Grade I refers to <25%>50% of cortical area involved.

• Class 6 is a catch-all term describing changes not considered to be due to rejection--for example, recurrent FSGS or CNI toxicity.  

Hyper-acute rejection (HAR)• MOA:

– Result of circulating , complement-fixing IgG Ab against incompatible donor antigens

– Engage & destroy vascular endothelium– ABO-incompatible grafts: pre-existing IgM iso-Ab against blood gp antig

ents– ABO compatible grafts: anti-donor HLA IgG antibodies

• Incidence: RARE• Presentation:

– Seen at time of surgery– Kidney becomes mottled , dark & flabby minutes of hours of vascularisat

ion– Within 7 days: acute anuria , swollen graft

• Renal biopsy: generalized infarction of graft• Treatment: Graft nephrectomy• Prevention:

– Ensure ABO compatible– CDC cross-match– Screening for anti-HLA antibodies (pregnancy, previous transplant , bloo

d transfusion)

Acute allograft rejection

• Classification (Banff criteria) – T-cell mediated (acute cellular rejection ACR) – Antibody mediated (acute humoral rejection A

HR)

• Acute cellular rejection– Histo: tubulo-interstitial infiltrate of T-cell, macr

ophages & neutrophils

• Diagnosis: renal biopsy or serum antibody• Prognosis is poor with ACR + AHR

Txn of ACR

• IV methylprednisolone 500mg -1g QD for 3 day• If anuria or raised Cr another 3-day course• Cyclosporine A level to ensure adequate exposu

re• Change CycA to Tacrolimus• ALG or OKT-3 in severe steroid-refractory cases

Txn of AHR

• Similar to ACR• Pulse steroid (500mg/day) x 3 days• Conversion to tacrolimus with trough level > 10ng/ml• Use of anti-CD20 Ab , rituximab (LE:1b)• Remove antibodies with phasmapheresis or immunoads

oprtion columns• IVIG: 0.2-2.0g/kg (experimental)

Chronic allograft dysfunction /

Interstitial fibrosis and tublar atrophy (IF/TA)

• Take months to years to develop• Presentation: Proteinuria, HT, rise Cr over

months• Ddx: Chronic nephrotoxicity (CNIs) or chro

nic kidney damage from marginal donor kidney

• Histology: fibrosis, cortical atrophy, intimal fibroplasia or larger artery , thickened base membrane

• Diagnosis: Renal biopsy• Treatment:

– Conversion to CNI-free regimen: m-TORi or MPA

– To m-TORi if proteinuria < 800mg/day– To MPA if beyond 3 years– To azathioprine: need close monitoring– ACE-I slow down renal decompensation– Re-transplant or dialysis

Post-Transplant infection• HSV:

– Acyclovir 400mg PO 5x/day for 5-10 days or– Valacyclovir 1g PO TDS for 5-10 days

• CMV: – Fever, pneumonia, GI ulcer, diarrhoea, retinitis– Dx: shell viral culture, pp65 Antigenemia assay , PCR. RNA-DNA hydridi

zation assay– Txn: Ganciclovir 5mg/kg IV Q12H x 2/52, then 1g TDS to complete 6 we

eks• EBV:

– Post-transplant lymphoproliferative disease• Polyomavirus:

– BK virus, JC virus, SV40– Asso with use of tacrolimus, MMF & sirolimus– Polyomavirus nephropathy (PVAN)– Dx: urine cytology– Txn: reduction of immunosuppresion

Malignancy

Three cause of malignancy in recipients:

1. Transmitted malignancy from donor

2. Known or latent prior malignancy in the recipients

3. “De-novo” malignancies in recipient after transplantation

1.Trasmitted malignancy from donor

• Risk: 0.2% (increase in margin or elderly)• Donor with pre-operative dx of cancer: (4.4%) sh

ould not be donor if – Active cancer – History of metastatic cancer– Cancer with high risk of recurrence (medulloblastoma

or glioblastoma multiform)– Brain tumor of any grade with VP shunt

• Watch out for IC hemarrohage due to tumor• Most common transmitted malignancy: melanom

a & choriocarcinoma

Tumor not CI to donation

• Basal cell carcinoma• Non-metastatic spinocellular carcinoma of the sk

in• Cervical CIS• Vocal cord CIS• Low grade (1-2) brain tumor

• TaG1 TCC? Controversial• Transplant of kidney with small RCC post PN? C

an be done with inform consent

What if donor was dx to have cancer post-transplant?

• Graft nephrectomy or suspension of immunosuppression are not always necessary

• Discuss risk and benefit with patient

2. Prior malignancy in the recipient• Active tumor in recipient is absolute CI for kidney transpl

antation• But prior malignancy is not • But WHO? When?• Base on Cincinnati registry

– Consider type of tumor (TNM)– Delay btw treatment and kidney transplantation– Risk of recurrence

• 2 yr waiting period eliminate risk of recurrence in : CRS (13%) , breast (19%) , Prostate (40%)

• 5 yr will eliminate most recurrence but not practical for elderly pt

• No evidence of support fixed waiting time period before transplantation

• Note: use of m-TORi associated with reduced incidence of malignancy

3. De-novo tumor in recipient

• Risk of malignancy after transplantation is several times higher

• Most common: Skin (40%) or lymphatic system (11%)

1. Skin Cancer & Kaposi’s sarcoma

Skin cancer: • Risk factor

– Age (>50)– Sun & UV exposure – HLA-B27 antigne exposure– Cyclosporine, duration of immunosuppression (5% at

5yr)• Incidence: 40% of post-transplant tumor• 50% SCC, Male to female: 5 : 2• Prevention: annual derma examination + sun blo

ck

Kaposi’s sarcoma

• Incidence: 4%

• Risk factor: HHV8 +ve serology, CNIs

• Prevention: use m-TORi

2. Post-transplantation lymphoproliferative disease (PTLD)

• Extra-nodal dissemination & poor outcome• Incidence: 1-5%• Risk factor: cyclosporine, induction regimen (ALG, OKT3

& SIR)• Presentation:

– Within 1st year– non-Hodgkin’s lymphoma– EBV-iinfected B-lymphocytes

• Treatment: remission 60%– Immunosuppressive therapy reduction or suspension– Anti-CD20 Ab +/- chemotherapy + antiviral drug (acyclovir, ganci

clovir)

3. Gyn cancer

• Cerival Ca : 3x higher• CIS in 70%• Risk: HPV infection , re-activation of latent

HPV• Young recipients may benefit from HPV im

munization• FU:

– annual cloposcopy + cytology– USG + mammogram

4. Ca prostate

• 1% of transplant population

• FU: annual PSA + DRE in Pt >50

• Most CaP are clinically localised disease

5. Urothelial Ca

• 3x higher risk

• Patho: TCC, adeno , nephrogenic adenoma

• FU: urine cytology, hematuria workup

6. RCC

• In native or graft kidney

• Prevalence: 2% (100x higher)

• Risk factor:– ACKD (main)– Previous RCC– VHL

• Patho: RCC & tubulopapillary ca

• FU: annual USG

Annual screening

• Renal fxn & SE of immunosuppressant• Derma examination , tumor screening

– Nodal exam– FOB– CXR– Gyn & Uro exam

• Investigation: Abd USG (graft+ native kidney)• Detect cardiac risk• Monitor BP, glucose , lipid profile

Graft & patient survival

Factors to consider

• Graft survival: – Living-donor kidney better than deceased donor (bett

er selection ,shorter cold ischemic time)– HLA-matched better than non-matched– Number of mismatch– Recipient’s age – Time on dialysis– Donor age: younger the better– Cold ischemic time: marginal influence up to 24 hr– Preservation soln: UW solution better– Use of cyclosporine-A– Number of previous transplantation