Clinical impact of HSV-1 detection in the lower respiratory tract from hospitalized adult patients.

The occurrence and clinical impact of herpes simplex virus (HSV) were evaluated in 342 bronchoalveolar lavage specimens from 237 patients. HSV-1 and HSV-2 were detected in 32.1% and <1% of patients, respectively. A significant difference of HSV-1 prevalence and load was found in relation to admission to intensive care unit, mechanical ventilation and mortality within 28 days; in particular, a viral load ≥10(5) copies/mL bronchoalveolar lavage fluid was significantly associated with critical features. No association was found with immune status or other characteristics. Nine of 21 (42.9%) cases of ventilator-associated pneumonia were positive for HSV-1, with poor outcome in six.

The lack of cytomegalovirus-specific cellular immune response may contribute to the onset of organ infection and disease in lung transplant recipients.

Cellular immune response has been demonstrated to play a role in the control of human cytomegalovirus (HCMV) replication in organ transplant recipients. Herein, HCMV-specific T-cell response and association to the onset of organ infection/disease were prospectively evaluated by EliSPOT assay in a population of 46 lung transplant (LT) recipients at 1, 3, 6, 9 and 12 months post-transplantation. According to our centre?s practice, a combined prolonged antiviral prophylaxis (HCMV-IG for 12 months and ganciclovir or valganciclovir for 3 weeks from postoperative day 21) was given to all LT recipients. HCMV-DNA was concomitantly detected on bronchoalveolar lavage (BAL) and whole blood by real-time PCR. Approximately one third of patients resulted HCMV persistently non-responder; the rate of HCMV infection, as evaluated by HCMV-DNA positivity, tended to be higher in non-responders. Mean viral load on BAL was significantly higher in non-responders vs other patients (p < 0.001). Temporal profile of infections appeared related to the HCMV responder status with a shorter time to onset of infection post-transplantation and a longer duration in non-responders. The occurrence of organ disease (i.e. pneumonia) tended to be higher in non-responders, with poor prognosis, as death occurred in one of three non-responder patients that developed HCMV pneumonia. The lack of HCMV-specific cellular response can contribute to the onset of organ infection and disease also in patients in which antiviral prophylaxis was adopted; this could be due to the potential occurrence of incomplete control of replication in lungs or a delayed priming of T-cell reconstitution.