Table 2.
Characteristics of HHV-6 detection
| Summary | Pre-LTV N=376 |
Post-LTV N=362 |
|---|---|---|
| Patients with at least one HHV-6 test | 63/376 (16.8) | 46/362 (12.7) |
| Patients with at least one HHV-6 test in blood | 51/376 (13.6) | 40/362 (11.1) |
| Patients with at least one HHV-6 test in CSF | 24/376 (6.4) | 15/362 (4.1) |
| Number of tests per patient, median (range) | 1 (1, 9) | 1 (1, 16) |
| Days to first test (blood and/or CSF), median (IQR)a | 38 (18, 58) | 26 (13, 42) |
| Patients with at least one positive HHV-6 test among tested a | 10/63 (15.9) | 10/46 (21.7) |
| Patients with at least one positive HHV-6 test in blooda | 8/51 (15.7) | 10/40 (25) |
| Patients with at least one positive HHV-6 test in CSFa | 2/24 (8.3) | 2/15 (13.3) |
| Days to first positive HHV-6 test (any site), median (IQR)b | 37 (18, 58) | 26.5 (25, 34) |
| Number of positive HHV-6 tests in blood, median (IQR)c | 1 (1,1) | 2 (1,4) |
| HHV-6 viral load; log10 copies/mL, median (IQR) | ||
| Viral load in blood at first positiveb | 3.00 (2.40, 4.10) | 2.70 (2.40, 5.00) |
| Peak viral load in bloodb | 3.17 (2.51, 4.14) | 4.03 (2.89, 5.00) |
| Peak viral load in CSFd | 2.62 (2.40, 2.84) | 3.39 (3.18, 3.61) |
| Patients treated for HHV-6 e, f | 6/376 (1.6) | 4/362 (1.1) |
Results are reported as number with percentage in parenthesis unless specified otherwise.
CSF: cerebrospinal fluid, HHV-6: human herpesvirus-6, IQR: interquartile range, LTV: letermovir
Among tested patients
Among patients with a positive test (any site)
Among patients with a positive test in blood
Among patients with a positive test in CSF
Indications for treatment: in the pre-LTV cohort: neurological symptoms (n=5) (proven HHV-6 encephalitis (n=2), possible HHV-6 encephalitis (n=3)), rash (n=1); in the post-LTV cohort: altered mental status (n=3) (proven HHV-6 encephalitis (n=2), possible HHV-6 encephalitis (n=1)), delayed engraftment (n=1).
Antiviral therapy: ganciclovir in 5 patients in the pre-LTV cohort and 2 in the post-LTV cohort; foscarnet in 1 patient in the pre-LTV cohort and 2 in the post-LTV cohort.