Tacrolimus-Induced Gallstone Formation in the Early Post-renal Transplant Period: A Case Report.

Gallstone disease (GSD) is a known but relatively underrecognized complication in renal transplant (RT) recipients, particularly in those receiving cyclosporine. However, there is scarce data on the association between tacrolimus use and cholelithiasis. We present the case of a 33-year-old female with end-stage renal disease who underwent an ABO-compatible RT and was initiated on a standard triple immunosuppressive regimen consisting of tacrolimus (3.5 mg/day), mycophenolate mofetil (1.5 g/day), and prednisolone (20 mg/day). Six weeks post-transplant, she developed acute abdominal pain, nausea, and right upper quadrant tenderness with a positive Murphy's sign. Abdominal ultrasonography revealed multiple gallstones, the largest measuring 8 mm. She was managed conservatively and notably lacked traditional risk factors for gallstone formation. Pre-transplant imaging had not revealed any biliary abnormalities. Tacrolimus as a cause of GSD remains underreported. This report highlights the need for increased clinical awareness and further research to understand its potential role in post-transplant biliary complications.