Cytomegalovirus and Epstein-Barr Virus DNA Kinetics in Whole Blood and Plasma of Allogeneic Hematopoietic Stem Cell Transplantation Recipients.

Currently, no consensus has been reached on the optimal blood compartment to be used for surveillance of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNAemia. Although several comparative studies have been performed correlating CMV and EBV DNA loads in whole blood (WB) versus plasma, to our knowledge, no studies to date have analyzed the kinetics of both viruses in the 2 blood compartments. In this retrospective noninterventional multicenter cohort study, the kinetics of CMV and EBV DNA in 121 hematopoietic stem cell transplantation (HSCT) recipients were investigated by analyzing in parallel 569 and 351 paired samples from 80 and 58 sequential episodes of CMV and EBV DNAemia, respectively. Unlike previous studies, this study used a single automated molecular method that was CE-marked and Food and Drug Administration-approved for use in quantifying CMV and EBV DNA in both plasma and WB. Furthermore, the complete viral replication kinetics of all episodes (including both the ascending and the descending phases of the active infection) was examined in each patient. The previously observed overall correlation between CMV DNA levels in WB and plasma was confirmed (Spearman's ρ = .85; P < .001). However, although WB and plasma CMV DNAemia reached peak levels simultaneously, in the ascending phase, the median CMV DNA levels in plasma were approximately 1 log10 lower than WB. Furthermore, in patients who received preemptive therapy, CMV DNA showed a delayed decrease in plasma compared with WB. A lower correlation between EBV DNA levels in plasma versus WB was found (Spearman's ρ = .61; P < .001). EBV DNA kinetics was not consistent in the 2 blood compartments, mostly due to the lower positivity in plasma. Indeed, in 19% of episodes, EBV DNA was negative at the time of the EBV DNA peak in WB. Our results suggest a preferential use of WB for surveillance of CMV and EBV infection in HSCT recipients.

Persistent rhinovirus infection in pediatric hematopoietic stem cell transplant recipients with impaired cellular immunity.

BACKGROUND: HRV infections are generally self-limiting in healthy subjects, whereas in immunocompromised hosts HRV infections can lead to severe complications and persistent infections. The persistence of HRV shedding could be due to the inefficient immunological control of a single infectious episode. OBJECTIVES: To investigate the clinical, virologic and immunologic characteristics of pediatric HSCT recipients with HRV-PI infection. STUDY DESIGN: During the period 2006-2012, eight hematopoietic stem cell transplant (HSCT) recipients presented with persistent rhinovirus infection (HRV-PI, ≥30 days). Viral load and T-CD4(+), T-CD8(+), B and NK lymphocyte counts at the onset of infection were compared with those of fourteen HSCT recipients with acute HRV infection (HRV-AI, ≤15 days). RESULTS: The median duration of HRV positivity in patients with HRV-PI was 61 days (range 30-174 days) and phylogenetic analysis showed the persistence of a single HRV type in all patients (100%). In HSCT recipients with HRV-PI, T-CD4(+), T-CD8(+) and NK cell counts at the onset of infection were significantly lower than those observed in recipients with HRV-AI (p<0.01), while B cell counts were similar in the two groups (p= 0.25). A decrease in HRV load was associated with a significant increase in T-CD4(+), T-CD8(+)and NK lymphocyte counts in HRV-PI patients (p<0.01). CONCLUSIONS: This study suggests a role for cellular immunity in HRV clearance and highlights the importance of its recovery for the control of HRV infection in HSCT recipients.