Herpesvirus Viremia and Engraftment Status of Umbilical Cord Blood in Children Undergoing Allogeneic Hematopoietic Stem Cell Transplant
Notice bibliographique
Résumé
Abstract Abstract 3021 Umbilical Cord Blood (UCB) is frequently used as a source of stem cells for children undergoing allogeneic hematopoietic stem cell transplant (HSCT) for both benign and malignant disorders. Despite algorithms using both nucleated cell numbers and HLA typing, the rate of engraftment failure remains higher than rates observed using other stem cell products. We conducted a retrospective review of our centre's experience with HSCT with UCB to evaluate the impact of herpesvirus viremia on the rate of engraftment. Children who underwent allogeneic HSCT with UCB between 06/2005 and 05/2010 inclusive were identified from the program database. Engraftment was defined as the first day of three consecutive absolute neutrophil counts of > 0.5 × 10[exp 9]/L within 42 days of UCB infusion and evidence of donor DNA on chimerism testing. Blood samples were sent for qualitative herpesvirus polymerase chain reaction (PCR) weekly (HHV-6, HHV-7, EBV, CMV, HSV or VZV). If either CMV or EBV results were positive, a quantitative assay was performed as well. Viremia was considered to have occurred if the qualitative assay became positive. Anti-viral therapy was initiated for measurable amounts of either CMV or EBV DNA or selectively for HHV-6 DNA. Eighty-one HSCT utilizing UCB were performed during this period. One child was unevaluable (NRM at day +15) so the analysis was performed using the remaining 80 patients. Thirty HSCT (37.5%) were performed for non-malignant indications and 50 (62.5%) for malignant disorders. Ninety per cent were performed using unrelated UCB; 27 were 6/6 HLA matched UCB, 42 were 5/6 HLA matches and 11 were 4/6 matches. Four children were recovering counts at day +42 but had not reached the threshold neutrophil value. They were considered as delayed engraftment rather than engraftment failure. Eleven (14%) failed to engraft. Forty-two (52.5%) of the transplants were complicated by the detection of 1 or more herpesviruses (24 for only 1 virus, 15 for 2 viruses and 3 for 3 viruses). None of gender, ABO matching, recipient CMV pre-HSCT serostatus, disease category, use of ATG or TBI in the conditioning regimen, use of methotrexate as GVHD prophylaxis or positivity for any single herpesvirus was associated with engraftment failure. Numbers of viable nucleated cells and CD34+ cells were not different between those that engrafted and those that failed to engraft. Transplants complicated by viremia of more than 1 herpesvirus had a significantly poorer engraftment rate than others (0.667 vs 0.933, P=0.007); more specifically viremia due to CMV and any other herpesvirus was associated with a worse engraftment rate than others (0.643 vs 0.921, P=0.006) (table). Notably viremia due to HHV-6 and others or EBV and others were not related to engraftment failure.PCR resultEngraftedFailed to engraftNo CMV516CMV positive185CMV alone90CMV plus: HHV-632 HHV-721 EBV22 HHV-6 & HHV-710 HHV-6 & EBV10 Conclusion: A significantly poorer engraftment rate in children undergoing HSCT using UCB was seen in those with CMV viremia in the presence of another herpesvirus. Further research is needed to define cause and effect and the therapeutic strategies to prevent it. Disclosures: No relevant conflicts of interest to declare.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,004 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,002 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».