Late cytomegalovirus disease after hematopoietic cell transplantation: significance of novel transplantation techniques.

Preemptive therapy (PET) and letermovir prophylaxis are effective in preventing cytomegalovirus (CMV) disease within the first 100 days after allogeneic hematopoietic cell transplantation (HCT) but are associated with late-onset CMV disease. We retrospectively examined the clinical manifestations, risk factors, prevention algorithm, and outcome of late CMV disease in CMV seropositive day 100 survivors transplanted between 2001-2017 (PET cohort) and 2018-2021 (letermovir cohort). There were 203 episodes of late CMV disease among 2469 day 100 survivors, and the estimated cumulative incidence of first late CMV disease was 7.2% (95% confidence interval [CI], 6.2-8.3) with no difference between the PET (7.4%; 95% CI, 6.4-8.6) and the letermovir group (5.4%; 95% CI, 3.2-8.3). Thirty-seven patients (1.5%) had a second episode of CMV disease. In multivariable Cox regression models, posttransplant cyclophosphamide was associated with an increased risk of gastrointestinal CMV disease. CMV viremia or disease detected before day 100, corticosteroid treatment after day 100 at dose ≥1 mg/kg, acute and chronic graft-versus-host disease, lymphopenia, HLA-mismatched related donor status, were also associated with late CMV disease. HLA-mismatched donor status and late use of corticosteroids (≥1 mg/kg) were risk factors for late CMV disease recurrence. Late CMV disease occurred most frequently in a setting of prolonged low-level untreated viremia and was independently associated with death by 2 years after HCT. In summary, late CMV disease continues to occur in the present era. Improved prevention strategies for late CMV disease are needed.