LAUSR

Critical Care Medicine • Volume 46 • Number 1 (Supplement) www.ccmjournal.org Learning Objectives: Cytomegalovirus (CMV) reactivation in sepsis may indicate acquired immunosuppression and is associated with higher morbidity and mortality in adults. Data on CMV reactivation in pediatric sepsis is lacking. We tested the incidence and significance of CMV reactivation as well as lymphopenia, a more common marker of immunosuppression, in pediatric sepsis. We hypothesized that CMV reactivation occurs in 30% of pediatric sepsis, similar to adults, and both CMV reactivation and lymphopenia are associated with complicated course, defined as ≥2 organ dysfunctions by day 7 or death by day 28. Methods: We performed a prospective observational study of patients aged 2–17 years treated for sepsis with ≥1 organ dysfunction in a large academic PICU. Blood was collected at enrollment for CMV serology and quantitative viremia, with subsequent CMV measurements on days 2, 6, 10, and 22. Lymphopenia, defined as absolute lymphocyte count < 1,000/μL, was determined from clinical tests. Data are reported as medians (interquartile range) or proportions. We used multivariable logistic regression to test association of CMV reactivation and lymphopenia with complicated course. Results: Of 37 patients enrolled, 33 were evaluable. Median age was 11 (6–13) years, 3 patients (9%) were undergoing chemotherapy. Median PRISM III score was 10 (6–15) and 18 (55%) patients had > 3 comorbidities. Twelve (36%) patients were CMV seropositive; 1 patient developed CMV viremia on day 6. However, 21 (64%) patients had lymphopenia, suggesting acquired immunosuppression was common despite low CMV reactivation. The patient with CMV reactivation did not have a complicated course, but this outcome trended higher in those with lymphopenia compared to those without lymphopenia (24% vs 17%; p = 0.23). After controlling for age, PRISM III, and presence of > 3 comorbidities, lymphopenia was not associated with complicated course (aOR 1.78, 95% CI 0.24, 13.1; p = 0.57). Conclusions: Although common in adult sepsis, CMV reactivation was rare in pediatric sepsis. Given high rate of lymphopenia, low CMV reactivation may be due to low prior exposure rather than lack of acquired immunosuppression. CMV reactivation could not be tested for association with complicated course, and lymphopenia was not associated with complicated course in this small study.