Post-transplant renal failure

Background

Common complication of renal transplant
May be broadly classified as:
- Acute allograft dysfunction, with increase in serum creatinine, failure of creatinine to decrease after transplantation, or proteinuria within about 1 to 3 months
- Chronic allograft dysfunction, with slowly worsening renal function
- Delayed graft function, where dialysis is required within the first week of transplantation
May also be classified as:
- Immediate or hyperacute (<1 week post-transplant)
- Early (within 6 months post-transplant)
- Late (6 or more months post-transplant)

Hyperacute rejection, often diagnosed intraoperatively on reperfusion of transplant
Postischemic acute tubular necrosis causing delayed graft function
Volume depletion
Surgical complications:
- Vascular thrombosis (either transplant renal artery or vein)
  - RAT: painless anuria and AKI, high risk of graft loss
- Fluid collections (lymphocele, urinoma, perinephric hematoma)
- Multiple renal arteries
Atheroembolism
Calcium oxalate deposits

Acute rejection, usually within the first 12 months
- Either cellular (usually after the first week) or antibody-mediated
Calcineurin inhibitor nephrotoxicity, usually within the first three months
Fluid collections (usually early)
- Urinoma (within first few weeks)
- Lymphocele (usually 2 to 6 weeks, but can be up to one year)
Thrombotic microangiopathy
Recurrent primary disease
Transplant renal artery stenosis (usually late), caused by recurrent infections, rejection, or BK virus
Urinary obstruction, from bladder or ureteric obstruction, which can result from fluid collections, urolithiasis, bladder dysfunction (especially in diabetes), or benign prostatic hypertrophy
Viral infections, including BK virus and CMV, and, rarely, adenovirus
New glomerular disease
- Atypical HUS (>50%)
- Membranoproliferative GN, including type 1 (20-50%) and type 2 (>50%)
- Focal segmental glomerulosclerosis (20-40%)
- IgA nephropathy (10-25%)
- Membranous nephropathy (5-30%)
- ANCA-associated GN (15-20%)
- Lupus (5-30%)
- Anti-GBM disease (<5%)
Less commonly, retained ureteral stent and arteriovenous fistula after kidney allograft biopsy

Tacrolimus or cyclosporine levels
BK level
dd-cfDNA level
US with Dopplers of renal artery and vein, looking for collections, thombosis, and patency of ureter

For patients >1 week post transplantation
If fever, abdominal pain, or graft tenderness, assess for pyelonephritis
If hypovolemic, increase oral fluid and follow creatinine
If recent medication change, change it back and follow creatinine
If CNI is supratherapeutic, decrease it and follow creatinine and CNI levels
If above fails, check dd-cfDNA and BK viral load
- If viral load of 10,000 copies/mL or greater, decrease immunosuppression and trend every 2 to 4 weeks
If above fails, allograft biopsy is needed