T-Lymphocyte Subtyping: A Potential Diagnostic and Prognostic Indicator of Cytomegalovirus Infection in Sepsis Patients

Background: This study aimed to investigate the use of T-lymphocyte subtyping as a diagnostic and prognostic marker for cytomegalovirus (CMV) infection in sepsis patients.Methods: We assessed T-lymphocyte subtyping and other commonly used clinical parameters in sepsis patients upon admission to the intensive care unit (ICU), and evaluated their potential impact on diagnosis and outcomes of CMV infection.Results: Among 599 sepsis patients, 82 were diagnosed with CMV infection. The 28-day mortality was significantly higher in CMV-infected than non-CMV-infected patients (20.7% vs. 9.9%). Both CD28+CD8+ and CD8+ T-cell counts could be combined with natural killer cell count, Acute Physiology and Chronic Health Evaluation II score, and immunoglobulin G as independent risk factors for CMV infection. Among 82 CMV-infected sepsis patients, 51 were assessed to have CMV-DNA negative conversion, while the other 31 were persistently positive for CMV DNA. The CD8+ and CD28+CD8+ T-cell counts were both independent risk factors for CMV-DNA negative conversion, with the latter having the better predictive ability. Lower CD28+CD8+ T-cell count was associated with higher 28-day mortality in CMV-infected sepsis patients. The CMV-DNA negative conversion and 28-day mortality of CMV-infected sepsis patients could be predicted using cutoff values of 151 (74.5% sensitivity and 87.1% specificity) and 64.5 (52.9% sensitivity and 92.3% specificity) CD28+CD8+ T cells/ml at ICU admission, respectively. Conclusions: Sepsis patients with CMV infection had higher 28-day mortality than those without CMV infection. CD28+CD8+ T-cell count was significantly higher in patients with CMV-DNA negative conversion than in those with persistently positive CMV DNA, and lower cell count was significantly associated with higher 28-day mortality. Therefore, CD28+CD8+ T-cell count may be a potential marker for early diagnosis of CMV infection and outcome prediction.Trial registration: Peking Union Medical College Hospital, registered at chictr.org.cn (identifier ChiCTR-ROC-17010750)