Pancreatic allograft exocrine urinary tract diversion. Pathophysiology

Area of Science:

• Transplantation immunology
• Gastroenterology
• Nephrology

Background:

• Pancreas allografts are sometimes drained into the urinary tract.
• This can lead to complications such as chronic metabolic acidosis.

Purpose of the Study:

• To investigate the complications of urinary drainage of pancreas allografts.
• To identify the cause of metabolic acidosis in these patients.
• To evaluate treatment strategies and the effect of drainage conversion.

Main Methods:

• Retrospective analysis of 16 pancreas allograft recipients with urinary drainage.
• Clinical data collection including metabolic parameters, renal function, and graft outcomes.
• Biochemical assays of urine and serum bicarbonate, and urinary enzyme activity.

Main Results:

• Seven of 16 allografts functioned, with six experiencing chronic metabolic acidosis due to bicarbonate wasting.
• Metabolic acidosis correlated inversely with urine bicarbonate and directly with serum creatinine.
• One patient developed severe balanitis/urethritis from activated pancreatic enzymes; conversion to enteric drainage resolved symptoms.

Conclusions:

• Urinary drainage of pancreas allografts can cause significant bicarbonate wasting and metabolic acidosis.
• Conversion to enteric drainage can effectively resolve these complications.
• Urinary amylase is not a reliable indicator of graft rejection or function.