Birgitta Versluijs

48 Results and predictors were used as independent variables. Univariate predictors of outcome with a P value <.10 were used for multivariate logistic regression analysis. Results are expressed as odds ratio (ORs) and corresponding 95% CIs. CIs not including 1 were con- sidered statistically significant. Probabilities of allo-LS andOSwere calculated using the Kaplan-Meier estimate; the 2-si- ded log-rank test was used for comparisons. All statistical analyses were performed using SPSS 15.1 (SPSS Inc, Chicago, IL). Results Patient characteristics A total of 110 patients were included in the study, 42 from January 2004 to August 2006 (before routine NPA testing), and 68 after from August 2006 to May 2008. Six patients who underwent transplantation during this period were excluded from the study be- cause they experienced autologous recovery (n = 2), early graft rejection (within 1 month after transplantation; n = 2), or early death (before engraftment; n = 2) and thus were considered not prone to alloreactive disease. The median age at transplantation was 5.0 years (range, 2 months to 21 years), and body weight ranged between 2 and 100 kg. Base- line characteristics of the RV-positive and RV-negative groups are shown in Table 1. No significant differences between the 2 groups were evident, although there were slightly more matched donor transplants in the RV-negative group and more CB donors in the RV-positive group. RV infections and presenting symptoms In this cohort of patients, 55 (50%) had an RV infection. The median day of onset was day 116 posttransplantatio (range, day 27 to day 1100). Symptoms were usually mild. The majority of patients with RV infection (n = 43) had URTI symptoms only. Eleven patients required extra oxygen, and 1 patient needed ventilator support (associated with a bacterial infection). Two patients, both with influenza A infection, were treated with a neuraminidase inhibitor; all other patients experienced spontaneous clinical recovery within 7-14 days. Although symptoms disappeared, virus was detected in NPAsamples for weeks to months afterward, with high viral loads (PCR Ct values of 17-24; see Patients and methods ). Thirty-eight patients had a single RV, and 14 patients had multiple viruses. In 3 patients, no RV was detected, but the clinical picture was typical for RV infection. These patients had mild respiratory symptoms (rhinorrhea) with no other cause, and all recovered spontaneously. The distribution of the various viruses is shown in Table 2. 3