Lymphocyte subset counts as diagnostic and prognostic markers for carbapenem-resistant Enterobacteriaceae (CRE) infection in critically ill patients

This study investigated the use of lymphocyte subset counts as diagnostic and prognostic markers for carbapenem-resistant Enterobacteriaceae (CRE) infection.We assessed the lymphocyte subset populations and other clinical parameters of septic patients upon intensive care unit (ICU) admission, and evaluated their potential impact on CRE infection diagnosis and outcome.Among 373 septic patients, 51 were diagnosed with CRE infection. The 28-day mortality was significantly higher in CRE than non-CRE patients (35.3% vs 14.9%). The T lymphocyte count and CD4+CD28+ T cell count were both independent risk factors for CRE infection, with the latter had the best diagnostic ability (AUC: 0.908; p < 0.0001). Lower CD4+CD28+ T cell counts were associated with higher likelihoods of CRE infection. The CRE incidence and 28-day mortality of CRE-infected patients could be predicted using cutoff values of 242 (sensitivity: 83.9%; specificity: 87.5%) and 58.5 (sensitivity: 100%; specificity: 61.1%) CD4+CD28+ T cells/μl at ICU admission, respectively.Septic patients with CRE infection had higher 28-day mortality. Given that the CD4+CD28+ T cell count was significantly lower in CRE than non-CRE septic patients and a lower cell count was significantly associated with higher 28-day mortality, CD4+CD28+ T cell counts may be useful markers for early diagnosis of CRE infection and outcome prediction.