Clinical Case Scenanio

Jonathan Hayes, a 50-year-old kidney transplant recipient, presented with a gradual decline in graft function one-year post-transplant. His creatinine had risen from 1.72 mg/dL to 3.75 mg/dl with proteinuria, with a urea level of 90 mg/dL, despite unremarkable renal ultrasound findings. He remained on tacrolimus and mycophenolate mofetil, with a tacrolimus trough level of 6.4 ng/mL. Laboratory tests showed an elevated C-Reactive Protein of 28.7 mg/dL, but no obvious source of infection was identified on imaging or urinalysis, and CMV-PCR was negative. The abdominal CT-angiogram showed the following:

Wrong Answer: A. Renal artery thromboembolismA. Renal artery thromboembolism

Wrong Answer: B. Renal vein thrombosis

Wrong Answer: C. Tacrolimus toxicity

Right Answer: D. Renal vein stenosis

Explaination:
In assessing declining renal function after renal transplant, factors to consider include renal vein stenosis, ureteral obstruction, transplant artery stenosis, acute rejection, and BK virus nephropathy. In this case, there was no evidence of rejection, infection, or external compression, and USG showed no abnormalities. The gradual decline in renal function suggested a possible acquired renal vein stenosis as shown in CT-Angiogram, likely due to chronic external pressure from the crossing iliac artery, leading to fibrosis and vessel narrowing The evaluation of these complications necessitates a comprehensive approach that includes imaging studies such as Doppler ultrasound and MR or CT angiography to identify vascular obstructions.

Renal vein stenosis is best treated with percutaneous stent angioplasty.
Renal artery thromboembolism and renal vein thrombosis (RVT) in a transplanted kidney, both are serious complications, characterised by sudden onset of flank pain, oliguria and sudden decline in renal functions. However, RVT may uniquely present with hematuria (blood in the urine) and swelling of the transplanted kidney.
Nephrotoxic tacrolimus doses cause gradual graft dysfunction, often accompanied by hypertension, hyperkalemia, and neurological symptoms like tremors, headaches, or seizures. Levels exceeding 15 ng/mL are considered toxic and necessitate dose adjustment.

Complications post renal transplantation