(033) Clinical Significance of Varicella Titers in the Post Cellular Therapy Setting

Poster Abstract:

Background/Purpose:
Cellular therapy (CT), including chimeric antigen receptor T-cell infusions and stem cell transplantation are associated with a variety of infectious complications increasing morbidity and mortality. The majority of varicella zoster virus (VZV) reactivations present as a localized or disseminated infection, occurring within 3-12 months post CT. VZV reactivation most commonly manifests as a dermatomal infection and less commonly as a neurological or visceral infection. Vaccination, in addition to standard antiviral prophylaxis, is required for all individuals undergoing cellular therapy, to suppress reactivation and enhance cell-mediated immunity against VZV. Titer collection to evaluate immunity is generally not recommended and its utility remains controversial. The goal of this study is to evaluate the clinical significance of varicella titers in the post CT setting to determine possible correlation to the rate of VZV reactivation.

Methods:
This study is a single center, retrospective, chart review including adults 18 years of age and older who underwent CT within the Memorial Healthcare System (MHS) from Sept 1, 2017 to Sept 30, 2023. Data will be collected by reviewing the patient's electronic medical record. Data collection will consist of age, legal sex, race, hematological malignancy, vaccination received, preliminary serology status, conditioning regimen, donor stem cell source, type of cellular therapy, post vaccination markers, presence of acute and chronic graft-versus-host-disease (GVHD), treatment agents administered for acute and chronic GVHD, time from vaccine to titer collection, rate of VZV reactivation, treatment for reactivation, and presence of other viral infections. The primary outcome is to determine the rate of VZV reactivations in the post CT setting, based on clinical findings. VZV infection will be defined by the appearance of cutaneous vesicular lesions or the detection of the VZV antigen. Localized zoster will be defined as the presence of vesicular lesions in a dermatomal distribution. Disseminated zoster will be defined as a generalized vesicular eruption of varicella. Visceral dissemination will be defined as clinical evidence of internal organ involvement in the absence of other identified pathogens precipitating the clinical syndrome. VZV reactivation will be confirmed by detection of VZV DNA collected from these vesicular lesions by either culture or polymerase chain reaction. The secondary outcome is the correlation of varicella titer values with actual viral reactivation. Data will be analyzed using descriptive statistics.

Results: Results pending

Conclusions/

Discussion: Conclusions/discussion pending

References (must also be included in final poster): 1. Haynes, Andrew S., et al. “An Immune Recovery-Based Revaccination Protocol for Pediatric Hematopoietic Stem Cell Transplant Recipients: Revaccination Outcomes Following Pediatric HSCT.” Transplantation and Cellular Therapy, vol. 27, no. 4, Apr. 2021, pp. 317–26. DOI.org (Crossref), https://doi.org/10.1016/j.jtct.2021.01.017
2. Barrett AJ, et al. The Coming of Age of Adoptive T-cell Therapy for Viral Infection After Stem Cell Transplantation. Ann Transl Med. 2015 Apr;3(5):62. doi: 10.3978/j.issn.2305-5839.2015.01.18
3. Aoki, Takatoshi, et al. “Safety and Seropositivity after Live Attenuated Vaccine in Adult Patients Receiving Hematopoietic Stem Cell Transplantation.” Biology of Blood and Marrow Transplantation: Journal of the American Society for Blood and Marrow Transplantation, vol. 25, no. 8, Aug. 2019, pp. 1576–85. PubMed, https://doi.org/10.1016/j.bbmt.2019.04.006
4. Lee CJ et al. Varicella Zoster Virus Reactivation in Adult Survivors of Hematopoietic Cell Transplantation: How do we Best Protect our Patients? Biol Blood Marrow Transplant. 2018;24(9):1783-1787. doi:10.1016/j.bbmt.2018.04.003