High Incidence of Early Human Herpesvirus-6 Infection in Children Undergoing Haploidentical Manipulated Stem Cell Transplantation for Hematologic Malignancies.
Biol Blood Marrow Transplant
; 24(12): 2549-2557, 2018 12.
Article
em En
| MEDLINE
| ID: mdl-30067953
ABSTRACT
Human herpesvirus-6 (HHV-6) infection is increasingly recognized among allogeneic hematopoietic stem cell transplantation (HSCT) recipients, with 30% at risk of reactivation in the haploidentical setting. It has been associated with encephalitis, acute graft-versus-host disease, and graft failure. Here we report 2 cohorts of pediatric haploidentical manipulated HSCT in which, despite many differences, HHV-6 reactivation and disease occurred with very high incidence compared with data reported in the literature and represented the main early post-transplant infectious complication compared with other viral, bacterial, or fungal infections. The 2 cohorts were recruited at the pediatric transplant centers of Perugia (nâ¯=â¯13), Barcelona (nâ¯=â¯10), and Madrid (nâ¯=â¯15). All patients received myeloablative conditioning regimens and 2 different types of ex vivo graft manipulation CD34+ selection and regulatory T cell/conventional T cell infusion in 13 patients and CD45RA T cell depletion in 25 patients. Antiviral prophylaxis was acyclovir in 33 and foscarnet in 5 patients. HHV-6 DNAemia was checked by quantitative or qualitative PCR. In vitro experiments demonstrated that donor CD4+ T cells are the reservoir of HHV-6 and suggested a role of the graft composition in both transplant settings (rich in CD4+ T cells) in the high rate of HHV-6 infections. All patients presented very early HHV-6 DNAemia after transplantation, and although viremic, 9 patients (24%) developed symptomatic limbic encephalitis. All patients responded to antiviral treatment, and none died of infection, although 2 experienced long-term neurologic sequelae (22%). Moreover, 6 patients presented organ involvement in absence of other causes 1 hepatitis, 1 pneumonia, 2 gastroenteritis, and 2 multiorgan involvement(1 encephalitis, pneumonia, and gastritis; 1 pneumonia and enteritis). Incidences of other viral, bacterial, and fungal diseases were lower in both cohorts. In vitro, HHV-6 was found to infect only CD4+ fraction of the graft. Co-culturing CD4+ T cells with CD56+ natural killer (NK) cells eliminated the virus, demonstrating the main role of NK cells in the antiviral immune response. All 38 pediatric patients undergoing these manipulated haploidentical HSCTs showed HHV-6 reactivation, and 14 of 38 developed HHV-6 disease with similar features in terms of timing, morbidity, response to treatment, and outcome. The graft composition in both transplant platforms, rich in CD4+ T cells and poor in NK cells, seems to play a key role. HHV-6 DNAemia surveillance was useful to diagnose and treat preemptively HHV-6 infection.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Herpesvirus Humano 6
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Transplante de Células-Tronco Hematopoéticas
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Neoplasias Hematológicas
Tipo de estudo:
Incidence_studies
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Prognostic_studies
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Qualitative_research
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Male
Idioma:
En
Revista:
Biol Blood Marrow Transplant
Assunto da revista:
HEMATOLOGIA
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TRANSPLANTE
Ano de publicação:
2018
Tipo de documento:
Article