686. Elevations in TNFα and IL-18 are Associated with Increased Risk of Probable Cytomegalovirus Tissue Invasive Disease in Solid Organ Transplant Recipients

Abstract

BackgroundHuman cytomegalovirus (CMV) continues to cause significant morbidity and mortality in solid organ transplant (SOT) recipients despite prophylaxis. Tissue invasive CMV disease (TI-CMV) can lead to end-organ damage and graft loss. Diagnosing TI-CMV can be challenging as CMV viral load in the blood does not always correlate with episodes of TI-CMV and therefore definitive diagnosis often requires an invasive procedure such as bronchoscopy or colonoscopy. The purpose of this study was to determine if proinflammatory cytokines, including IL-18, are elevated in SOT recipients with probably TI-CMV as a way to identify patients at risk for this severe form of CMV disease.MethodsThe electronic medical record was searched for adult SOT recipients who were tested for CMV via blood qPCR during an 11-month period.Twenty-nine SOT recipients were identified that had episodes of CMV DNAemia without other concomitant infections during this time period. Patients were divided into those that had probable TI-CMV and those with CMV DNAemia alone, by chart review. Inflammatory cytokines (IFNγ, TNFα, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-18, and IL-1RA) were measured in residual plasma from these patients using a commercially available multiplex assay for at least two time points during the study period. Wilcoxon-Rank-Sum, logistic regression, and principal component analysis was performed comparing patients with and without probable TI-CMV.ResultsPatients with probable TI-CMV had significantly higher IL-18, TNFα, and IL-1β than patients with CMV DNAemia alone (p < 0.001, < 0.001, and < 0.05 respectively). When adjusting for transplant type and CMV recipient serostatus, elevations in TNFα (OR 1.43, 95% CI 1.07-1.92) and IL-18 (OR 2.00, 95% CI 1.06-3.75) were associated with increased odds of having probable TI-CMV. In principal component analysis the combination of CMV viral load, IL-18, TNFa, and IL-1β accounted for 80% of the variance in the data.ConclusionTNFα and IL-18 in combination with CMV viral load may be useful in predicting likelihood of TI-CMV. This is important in situations where tissue biopsies are not feasible, and adds to our diagnostic capability for TI-CMV in SOT recipients.Disclosures Stuart C. Ray, MD, miDiagnostics, Inc. (Board Member, Research Grant or Support) Robin K. Avery, MD, Aicuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)Chimerix (Scientific Research Study Investigator)Merck (Grant/Research Support, Scientific Research Study Investigator)Oxford Immunotec (Scientific Research Study Investigator)Qiagen (Scientific Research Study Investigator)Takeda/Shire (Scientific Research Study Investigator)