Publication
Human Cytomegalovirus-Specific T-Cell Immune Reconstitution in Preemptively Treated Heart Transplant Recipients Identifies Subjects at Critical Risk for Infection
Publisher:
American Society for Microbiology
Date:
06-2012
DOI:
10.1128/JCM.06406-11
Abstract: Human cytomegalovirus (CMV) infection represents a major threat for heart transplant recipients (HTXs). CMV-specific T cells effectively control virus infection, and thus, assessment of antiviral immune recovery may have clinical utility in identifying HTXs at risk of infection. In this study, 10 CMV-seropositive (R + ) pretransplant patients and 48 preemptively treated R + HTXs were examined before and after 100 days posttransplant. Preemptive treatment is supposed to favor the immune recovery. CMV DNAemia and gamma interferon enzyme-linked immunosorbent spot (ELISPOT) assay were employed to assess the viremia and immune reconstitution. HTXs could be categorized into three groups characterized by high ( ), medium (50 to 100), and low ( ) spot levels. Early-identified high responders efficiently controlled the infection and also maintained high immunity levels after 100 days after transplant. No episodes of grade ≥2R rejection occurred in the high responders. Midresponders were identified as a group with heterogeneous trends of immune reconstitution. Low responders were 41% and 21% of HTXs before and after 100 days posttransplant, respectively. Low responders were associated with a higher incidence of infection. The effect of viremia on immune recovery was investigated: a statistically significant inverse correlation between magnitude of viremia and immune recovery emerged in particular, each 10-fold increase in viremia ( log 10 DNAemia/ml) was associated with a 36% decrease of the ELISPOT assay spot levels. All episodes of high viremia ( log 10 DNAemia/ml) occurred from 1 to 60 days after transplant. Thus, the concomitant evaluation of viremia and CMV immune reconstitution has clinical utility in identifying HTXs at risk of infection and may represent a helpful guide in making therapeutic choices.