Diagnosis and treatment of human adenovirus infection following allogeneic stem cell transplantation

Background Human adenovirus (HAdV) infections are increasingly recognized as a frequent cause of potentially fatal infections in paediatric allogeneic stem cell transplantation (SCT) recipients. Aim To analyse data in the field of diagnosis and treatment of human adenovirus infection following allogeneic haematopoietic stem cell transplantation. Materials/Methods A review of PubMed references based on evidence-based recommendations and own experience. Results Incidence of HAdV infections is higher in paediatric than in adult SCT recipients, which might be related to the high exposure to HAdV at young age, while HAdV-specific immunity has still to be mounted, especially in children receiving a T-cell depleted graft and/or a graft of another than an HLA-genotypically identical related donor. In subsequent retrospective and prospective studies evidence has been provided that monitoring of serum/plasma by RQ-PCR is a sensitive tool for the recognition of patients at risk of potentially fatal infection, and that quantification of HAdV DNA is instrumental to make decisions on clinical intervention, and to accurately monitor the response to antiviral therapy. Several antiviral drugs (ribavirin and cidofovir) are being used to treat HAdV infections and variable efficacy has been reported. Reports on possible clinical efficacy of drugs are often biased, because of the heterogeneity of patients and lack of information about the level of simultaneous immune reconstitution. Data from several retrospective and prospective studies have demonstrated that lymphocyte recovery is essential for the elimination of HAdV infection. Conclusions Based on current knowledge, boosting of immunity by tapering of immunosuppression or infusion of lymphocytes from the donor seems to be an essential element in treatment of patients at risk of HAdV viraemia. Simultaneous analysis of lymphocyte reconstitution will further improve the identification of individuals that will require and benefit most from the immunotherapeutic interventions.