A Primed Neutrophil Subset Predicts the Risk of Bloodstream Infections in Allogeneic Hematopoietic Stem-Cell Transplant Patients: A Prospective Study.

BACKGROUND: Bloodstream infections (BSIs) are the most common infectious complication in patients who receive allogeneic hematopoietic stem-cell transplants (allo-HSCTs). Polymorphonuclear neutrophils (PMNs) are quantified to monitor the susceptibility to BSIs; however, their degree of activation is not. We previously identified a population of primed PMNs (pPMNs) with distinct markers of activation representing approximately 10% of PMNs in circulation. In this study, we investigate whether susceptibility to BSIs is related to the proportion of pPMNs rather than strictly PMN counts. METHODS: In this prospective observational study, we used flow cytometry to assess pPMNs in blood and oral rinse samples collected from patients receiving an allo-HSCT over the course of their treatment. We used the proportion of pPMNs in the blood on day 5 post-transplant to categorize patients into a high- or a low-pPMN group (>10% or <10% pPMNs). These groups were then used as a predictor of BSIs. RESULTS: A total of 76 patients were enrolled in the study with 36 in the high-pPMN group and 40 in the low-pPMN group. Patients in the low-pPMN group had lower expression of PMN activation and recruitment markers and displayed a delay in PMN repopulation of the oral cavity after the transplant. These patients were more susceptible to BSIs compared with patients in the high-pPMN group with an odds ratio of 6.5 (95% confidence interval, 2.110-25.07; P = .002). CONCLUSIONS: In patients who receive an allo-HSCT, having <10% pPMNs early in the post-transplant phase can be an independent predictor of BSI in allo-HSCT patients.

Preemployment screening for tuberculosis in a large health care setting: comparison of the tuberculin skin test and a whole-blood interferon-γ release assay.

OBJECTIVE: Determine the performance of an interferon-γ release assay in a health care occupational surveillance program. METHODS: From January 11, 2005, through January 31, 2006, all new employees (n = 652) undergoing standard, preemployment evaluation at Mayo Clinic, Rochester, Minnesota were evaluated for tuberculosis using a standard process of symptom screening combined with tuberculin skin test (TST) and QuantiFERON-TB Gold test (QFT-G). RESULTS: Comparing the results of QFT-G directly to TST, QFT-G showed an overall agreement of 92.5%. CONCLUSIONS: False-positive TST were the most significant issue affecting agreement, and in a low-tuberculosis prevalence population, the need for an effective strategy offering low false-positive results may be best met by combining the TST with QFT-G.