Preemptive therapy for systemic and pulmonary human cytomegalovirus infection in lung transplant recipients.

The incidence and treatment of both systemic and pulmonary
human cytomegalovirus (HCMV) infection as
well as HCMV-specific T-cell immune responses were
investigated in 57 consecutive lung transplant recipients
(LTR) by using as cutoffs for preemptive therapy:
300 000 DNA copies/mL whole blood for systemic infections
and 100 000 DNA copies/mL bronchoalveolar
lavage fluid for lung infections. Results showed that
out of 29/57 LTR (50.9%) needing preemptive antiviral
therapy, 15 (51.7%) reached the blood cutoff, 8 (27.6%)
the pulmonary cutoff and 6 (20.7%) both the blood
and the lung cutoff (3 simultaneously and 3 subsequently).
Recovery of HCMV-specific T-cell immune responseswas
achievedmuch earlier for CD8+ than CD4+
T cells. However, protection from HCMV reactivation
was conferred by the presence of both arms of the Tcell
response. In two LTR reaching the pulmonary cutoff
and not preemptively treated, a full HCMV-specific
CD4+ and CD8+ T-cell response was associated with
resolution of lung infection. Antirejection steroid therapy
suppressed T-cell immune responses, thus facilitating
HCMV reactivation. In conclusion, in LTR, monitoring
HCMV infection in both blood and lungs, may
improve preemptive therapy efficacy. In addition, monitoring
the HCMV-specific T-cell immune response appears
useful for predicting control of HCMV infection
in the posttransplant period.