Evaluation of CMV-specific cellular immune response by EliSPOT assay in kidney transplant patients

Immunological monitoring for CMV can be useful in transplant patients; however, few centers perform it on a routine basis.

In this study, CMV-specific cellular response was evaluated in a population of kidney transplant recipients and related to viral infection/reactivation and other demographic and clinical features.

Three hundred and twenty-eight patients were studied by EliSPOT assay: 201 prospectively monitored in the first year posttransplantation, 127 with a single determination at >1 year. Clinical features, including occurrence of CMV-DNAemia, CMV serostatus, anti-viral strategies and immunosuppressive protocols, were evaluated.

Overall, 66.5% of patients were CMV-responders at EliSPOT assay. No episode of infection occurred at follow-up (mean 24.5 months) in 73.4% responders versus 55.5% non-responders (p<0.005); CMV-free period was significantly longer in responders (p<0.001). Although no significant difference of peak viral load was found, prevalence of CMV-DNAemia values >10(5)copies/mL was significantly higher in non-responders versus responders (8.2% and 2.3%, p<0.05). Non-responder status was significantly associated to CMV-seronegativity (p<0.0001), anti-viral prophylaxis use (p<0.0001), and immunosuppression induction with basiliximab (p<0.005). No significant association was found for other clinical features and immunosuppressive protocols.

Immunological data for CMV could be used in the clinical evaluation and decision-making process, in combination with virological monitoring, in kidney transplant recipients.