Successful treatment with foscarnet for ganciclovir-resistant cytomegalovirus infection in a kidney transplant recipient: A case report.

Cytomegalovirus (CMV) infection is the most common infectious complication following solid organ transplantation. Ganciclovir (GCV)-resistant CMV infection may be fatal, and is difficult to treat while avoiding allograft rejection. A 31-year-old woman received a second ABO-incompatible kidney transplant, from her father. Induction therapy consisted of basiliximab and rituximab followed by maintenance immunosuppression with tacrolimus, mycophenolate mofetil, and methylprednisolone. Her CMV serostatus was D(+) /R(-) at second transplant and she received prophylactic low-dose valganciclovir (VGCV). BK polyoma virus nephropathy (BKVN) developed 7 months after transplant concurrent with CMV hepatitis and retinitis. VGCV was increased to a therapeutic dose combined with reduced immunosuppression with minimal methylprednisolone (2 mg/day) and everolimus (0.5 mg/day). However, pp65 antigenaemia continued to increase for 6 weeks. Her CMV was defined as ganciclovir (GCV)-resistant. Foscarnet was therefore administered and her CMV disease resolved within 2 weeks. Kidney allograft dysfunction developed 9 months after transplant, and graft biopsy showed tubulointerstitial injury with crystal deposition suggesting foscarnet nephrotoxicity, with no findings of BKVN or rejection. Kidney function recovered after cessation of foscarnet and the patient had good graft function 18 months after transplant. This case demonstrates the successful use of foscarnet to treat GCV-resistant CMV infection after ABO-incompatible kidney transplant complicated with BKVN, without acute allograft rejection. This case further highlights the need to establish appropriate management for CMV D(+) /R(-) patients to avoid the acquisition of GCV-resistant gene mutations.