ABSTRACT
Infective endocarditis (IE) can cause multiorgan dysfunction and chronic kidney disease, in addition to cardiac sequelae. The presentation may be vague and can manifest as acute glomerulonephritis. While the most common pathogens of infective endocarditis are Staphylococcus and Streptococcus species, we report a rare pathogen Bordetella holmesii causing infective endocarditis associated glomerulonephritis. A 20-year-old male patient with tetralogy of Fallot with pulmonary atresia and aortopulmonary collaterals underwent several cardiac surgeries including prosthetic pulmonary valve replacement in the past. He was admitted for 3 days at an outside hospital for fever, cough, and hemoptysis, and diagnosed with streptococcal pharyngitis, for which he received antibiotics. Five weeks later, he presented to our institution with lower extremity edema and gross hematuria. On examination, he was afebrile, normotensive, had a 7-kg weight gain with anasarca, and a systolic murmur, without rash. Investigations revealed elevated serum creatinine, nephrotic range proteinuria, hematuria, and hypocomplementemia, consistent with acute glomerulonephritis. Given his cardiac history, blood cultures were collected from three sites. Broad-spectrum antibiotics were initiated when he subsequently developed fever. Renal pathology on biopsy showed diffuse proliferative immune complex-mediated glomerulonephritis. Transesophageal echocardiogram visualized a vegetation on the pulmonary valve. Bordetella holmesii was ultimately cultured from the prior and current hospitalization. A serum sample detecting microbial cell-free DNA sequencing confirmed Bordetella holmesii at very high levels. After completing 6 weeks of intravenous antibiotics with concurrent angiotensin receptor blockade, his kidney function recovered with improvement in hypocomplementemia and proteinuria. This case report highlights the early recognition and comprehensive evaluation of a rare organism causing IE-associated GN, which allowed for renal recovery and preserved cardiac function.
ABSTRACT
Introduction: The diagnosis of a post-surgical uroenteric fistula can be challenging and may be delayed for months after symptoms begin. A normal anion gap metabolic acidosis has been reported in up to 100% of patients after ureterosigmoidostomy, and bladder substitution using small bowel and/or colonic segments. Here, we describe a rare case of a pediatric patient who developed a uroenteric fistula from the transplant ureters into the small bowel, after an en-bloc kidney transplantation resulting in profound acidosis and deceptive watery diarrhea. Case Presentation: The patient is an 8-year-old girl with end stage kidney disease (ESKD) secondary to focal segmental glomerulosclerosis. Through a right retroperitoneal approach, she underwent a right native nephrectomy and a pediatric deceased donor en-bloc kidney transplant including two separate ureters. One month later, she had a renal allograft biopsy for suspected rejection. During the week after the biopsy, she experienced abdominal pain followed by watery diarrhea and metabolic acidosis requiring continuous bicarbonate/acetate infusions. An extensive gastro-intestinal evaluation for the cause of the diarrhea including endoscopy was inconclusive. The urine output decreased to <500 ml daily; although, the kidney function remained normal. After 2 weeks of unexplained watery diarrhea a magnetic resonance urogram with contrast was performed which demonstrated extravasation of urine from both ureters with fistulization into the small bowel. She underwent corrective surgery which identified the fistulous tract, which was resected and both ureters were re-implanted. The diarrhea and acidosis resolved, and she has maintained normal renal allograft function for over 1 year. Conclusion: An important aspect in the early diagnosis of a uroenteric fistula is the sudden onset of severe hyperchloremic metabolic acidosis that results when urine is diverted into the intestinal tract. The mechanism is similar to that described in cases of urinary diversions and/or bladder augmentation using the intestine. Important diagnostic tools are the measurements of solute excretion and pH in the urine as compared to the "watery diarrhea" or bowel output. Summary: We describe a case of a uroenteric fistula in a pediatric-en-bloc kidney transplant patient that went undiagnosed for almost 3 weeks due to the deceptive nature of the watery diarrhea which was actually urine. A uroenteric fistula should be considered in the differential diagnosis of diarrhea and hyperchloremic metabolic acidosis as a complication of kidney transplant. The simultaneous comparison of stool and urine pH and solute excretions may lead to the diagnosis, appropriate imaging and surgical intervention.