Vaccination post-allogeneic hematopoietic stem cell transplantation: what is feasible?

International audienceINTRODUCTION: Allogeneic hematopoietic stem cell transplantation (HSCT) is a major curative treatment option for malignant and non-malignant hematological diseases, but is associated with an increased risk for infections, of which some are preventable by vaccination. Vaccination guidelines recommend repeated doses of most inactivated vaccines to achieve long-lasting immune responses. However, the efficacy of immunization is often hampered by graft-versus-host disease or severe opportunistic infections. Areas covered: This review summarizes the vaccine recommendations for adult allogeneic HSCT recipients and discusses the challenges and future directions regarding vaccine immunization in these patients. Expert commentary: Vaccination is a well-tolerated therapeutic intervention to prevent infections after allogeneic HSCT. Allogeneic HSCT recipients could benefit from experience regarding vaccine efficacy capitalized through specific data registries. An individualized immunization approach, modulating inception and intensity of vaccination schedule according to transplant characteristics, transplant-related complications and immune recovery status, might help to improve vaccine efficacy in this specific population. Identification of surrogate markers of the immune status and of vaccine efficacy, beyond antibody testing, as well as development of new vaccines are exciting fields of future research

Torque Teno Virus Viral Load as a Marker of Immune Function in Allogeneic Haematopoietic Stem Cell Transplantation Recipients

Torque teno virus (TTV) has been proposed as a surrogate biomarker of T-cell function in allogeneic–haematopoietic–stem-cell transplantation (allo-HSCT). Conflicting data exists regarding the value of TTV to assess the degree of immunosuppression. The aim of the present study was to investigate the correlation between TTV viral load and immune function. Using samples from a prospective cohort composed of healthy-volunteers (HV) and allo-HSCT recipients at 6 months post-transplantation, we assessed the correlation between TTV viraemia and immune cell counts or T-cell proliferation capacity post-phytohaemagglutinin stimulation. TTV viraemia was detected in 68% of HV (n = 80) and 100% of allo-HSCT recipients (n = 41; p < 0.001); it was significantly higher in allo-HSCT recipients (3.9 vs. 2.1 Log copies/mL, p < 0.001). There was no correlation between T-cell function and CD3+T-cell count (rho: 0.002) suggesting that T-cell count can normalise without full functional recovery. Furthermore, no significant correlation was observed between TTV viraemia and absolute total/subset lymphocyte counts (rho: <0.13). The highest correlation was observed between TTV viral load and T-cell proliferation capacity (rho: −0.39). We therefore report an inverse correlation between T-cell function and TTV viraemia that is independent of T-cell count. Monitoring of TTV viraemia could be a fast suitable option to objectively assess the competence of immune function in at-risk populations

Combined medico-surgical strategy for invasive sino-orbito-cerebral breakthrough fungal infection with Hormographiella aspergillata in an acute leukaemia patient

International audienceHormographiella aspergillata is a rare causative agent of invasive filamentous breakthrough infection, mostly arising after echinocandin exposure. We report a neutropenic patient who developed a severe sino-orbito-cerebral H. aspergillata infection while receiving empirical caspofungin, successfully controlled by an aggressive strategy associating surgical debridement and combined high-dose regimen of antifungal drugs