A Rare Case of Disseminated Cytomegalovirus Infection in a Late Transplant Recipient Using Belatacept

Introduction: Cytomegalovirus (CMV) is the most frequent infection post-kidney transplant, usually within 6 months. Belatacept, a CD28-blocking agent, preserves graft function with less toxicity than calcineurin inhibitors. We report a rare case of late disseminated CMV disease in a Belatacept-treated transplant recipient. Case Description: A 63-year-old female kidney transplant recipient (17 years ago for polycystic kidney disease) was admitted for recurrent graft pyelonephritis. She presented with asthenia, weight loss, abdominal pain, and decreased visual acuity in the left eye. PRA was 0%. She received Basiliximab as induction immunosuppressive and maintenance with Belatacept, mycophenolate mofetil and prednisone. Pre-transplant CMV IgG was positive, IgM negative. Baseline GFR was 94.31 mL/min, without AKI. Abdominal CT showed bladder thickening and hyperenhancement. Meropenem was initiated per urine culture with partial relief, prompting cystoscopy. Two hyperemic, elevated lesions were noted and biopsied. Light microscopy showed erosive cystitis (Fig 1) and immunohistochemistry was positive for CMV staining (Fig 2). Ophthalmological examination was performed (Fig 3) with anterior chamber paracentesis confirming CMV by qualitative PCR. Serum quantitative PCR showed a 65.366 UI/ml (4.82 Log) viral load. Full dose Valganciclovir was started. After 3 weeks, viral load dropped to 3,390 UI/mL. Although there were no cytopenias, rejection history or change in standard immunosuppression preceding hospitalization, the patient had high CMV viremia, fatigue, >2-fold ALT/AST elevation (ALT 124 U/L; AST 92 U/L), and biopsy-proven CMV cystitis and retinitis - fulfilling criteria for invasive CMV disease. Discussion: CMV infection is a common and serious complication in organ transplant recipients. Screening is usually limited to the first year post-transplant. This case highlights a severe late-onset CMV infection during a period of low incidence and clinical suspicion.