CASE STUDY: AN APPROACH TO TREATING A DIFFICULT RESISTANT CYTOMEGALOVIRUS INFECTION POST KIDNEY TRANSPLANT
Dr Neesan David1, Dr Stephen May1
1Tamworth Rural Referral Hospital, Tamworth, Australia
Background: Resistant cytomegalovirus (CMV) disease occurs in 1-2% of kidney transplant recipients and is associated with allograft loss and mortality. Treatment uses specific anti-viral therapies; however, these are nephrotoxic and/or prohibitively expensive. Post-transplantation immunosuppression regimes utilising mammalian target of rapamycin (mTOR) inhibitors show successful prophylaxis against CMV.
Case report: A 59-year-old gentleman with resistant CMV disease presented with severe colitis eleven months post living kidney transplant (HLA 5/6 mismatch, CMV D+/R-) for IgA nephropathy. His background includes idiopathic cirrhosis and large fibre neuropathy on monthly intravenous immunoglobulin (IVIG). He had acute cellular rejection three months post-transplant treated with pulse methylprednisolone. On diagnosis, his eGFR was 40ml/min/1.73m2, he remained on prophylactic valganciclovir 450mg daily, had a coincidental cutaneous fungal infection with Alternaria, and six months of persistent covid-19 positivity. His immunosuppression regime was prednisone 10mg daily, tacrolimus target 8-10ng/mL and mycophenolate mofetil 500mg twice-daily. Following four weeks of ganciclovir without improvement, resistant CMV disease with UL97 H520Q gene mutation was identified. He continued receiving IVIG which has evidence as adjunctive therapy. He transitioned to a two-month course of mirabavir, costing $80,000, with resolution of fevers and suppression of viral replication. One week following commencement of post-treatment surveillance, CMV replication was evident at CMV-DNA 6.82×101 IU/ml. Mycophenolate was stopped and he commenced everolimus 0.25mg twice-daily and uptitrated. CMV titres rose for the subsequent two weeks before reducing and became undetectable after four weeks. He has continued everolimus 1mg twice-daily for over two months without recurrence of CMV replication.
Conclusion: This case highlights the potential therapeutic option of the mTOR inhibitor everolimus in the treatment of resistant CMV disease and reviewing dose and duration of valganciclovir prophylaxis.