Navigating the Uncharted Waters: Managing Concurrent Cytomegalovirus Myocarditis and Allograft Rejection in a Patient With Heart Transplantation

Abstract A 49–year–old female with hypertrophic cardiomyopathy underwent orthotopic heart transplantation. She was cytomegalovirus(CMV)–positive and received a heart from a CMV–negative donor, so prophylaptic therapy was not administered. Initial immunosuppression included cyclosporine and induction with Basiliximab in a steroid–free regimen. The first routine biopsy (EMB) showed mild focal cellular rejection (grade 1A) and C4d positivity with granular aspect. Mycophenolate mofetil (MMF) was added. The second EMB, 7 days later, showed mild diffuse cellular rejection (grade 1B) and diffuse C4d positivity. Anti–HLA donor–specific antibodies (DSA) had increased anti–B13 levels (MFI=21298) compared to pre–transplantation tests. Echocardiography showed a normal ejection fraction (LVEF) and mild concentric hypertrophy (LVH). Treatment included pulse methylprednisolone therapy (1 g/day for three days) followed by oral prednisone with a slow tapering regimen, and increased MMF. CMV count weekly monitored was negative. The next two EMBs performed one week apart from each other described a grade 1A mild focal pattern while the 5th EMB (1 month and 2 weeks post–transplant) showed a grade 1A rejection together with focal mild fibrosis and eosinophils, so we replaced cyclosporine with tacrolimus, increased MMF and prednisone. At this time, the patient had no overt clinical signs of CMV infection but a CMV–PCR of 100847 IU/mL so ganciclovir 5 mg/Kg bid was started and CMV–PCR decreased to 42308 IU/mL after 1 week. Subsequently, she developed sinus tachycardia, mildly reduced LVEF, moderate LVH and diastolic dysfunction. Troponin was elevated. A new EMB revealed interstitial edema, diffuse ischemic injury, and eosinophilic inclusions suggesting CMV myocarditis. Treatment involved down–titrating MMF and Prednisone, administering standard intravenous immunoglobulin (IVIG), and high–dose Ganciclovir (7.5 mg/Kg bid). Leukopenia subsequently led to Ganciclovir down–titration. In the next days, the patient improved, CMV cleared, and leukocyte count normalized. She was discharged on Tacrolimus, MMF, Prednisone and Valganciclovir. Subsequent tests showed no cellular or antibody–mediated rejection (AMR), no CMV inclusions, recovered cardiac function, and markedly reduced anti–B13 DSA (MFI 3000). This case raises some concerns: in this context, the use of IVIG in the treatment of CMV infection and AMR appears reasonable, in support of antiviral and immunosuppressive therapy.