Vanishing Kidney Allograft

Introduction: Emphysematous pyelonephritis is a severe infection of the kidney characterized by necrosis and gas accumulation in kidney parenchyma, adjacent tissues and urinary collecting system. We present a case of severe emphysematous pyelonephritis with a very rapid evolution to complete destruction and a sonographically vanishing kidney allograft. Case Description: 60-year-old female with a history of end stage renal disease from diabetic nephropathy received a deceased donor kidney transplant. Her immediate post operative course was complicated by early ureteral stricture and revision of ureteral anastomosis resulting in good allograft function with average creatinine of 2-2.5mg/dl on quadruple immunosuppression. She had two admissions for uncontrolled hyperglycemia and Escherichia coli (E. coli) urinary tract infection (UTI) at 3 months and Klebsiella UTI at 5 months post-transplant. At month 8, she presented with sepsis secondary to E. Coli UTI with bacteremia, diabetic ketoacidosis, and AKI requiring dialysis initiation. CT of the abdomen and pelvis at admission had normal findings of transplanted kidney. Ultrasound on day 3, performed due to worsening clinical condition and graft function was reported as no visible kidney allograft. Repeat CT showed complete liquefaction of her transplant kidney replaced by pockets of air and abscess formation. She underwent transplant nephrectomy following unsuccessful abscess drainage. Surgical cultures were positive for E. Coli and Vancomycin resistant enterococcus faecium. Eventually, targeted antibiotic therapy resulted in complete resolution of her infection. Discussion: Vanishing kidney is an advanced presentation of emphysematous pyelonephritis where a kidney previously visible sonographically disappears as layers of encasing gas pockets block penetration of ultrasonographic waves. While uncommon, it is a life-threatening disease with major risk factors including poorly controlled diabetes, immunosuppression, and urinary obstruction. E. Coli is the causative pathogen in 70% of cases. Emphysematous pyelonephritis frequently requires nephrectomy. High index of suspicion upon non visualization of kidney allograft on ultrasound warrants immediate confirmation with CT imaging, as early diagnosis and timely intervention are essential in this life-threatening condition.