Utility of C-Reactive Protein and Procalcitonin for Detecting Bloodstream Infection in Patients with HIV/AIDS

Human immunodeficiency virus (HIV) infected persons, are at high risk for developing a bloodstream infection. In order to evaluate the usefulness of C-reactive protein (CRP) and procalcitonin (PTC) in the detection of bloodstream infection in HIV, a case-control study was conducted from February to December 2012. PCT and CPR levels were measured in 2 groups. PCT concentrations were measured by the VIDAS®?Brahms PCT assay, and CRP concentrations were determined by CRP latex. Values were calculated for both biomarkers and discriminative ability of PCT and CRP was analyzed using ROC curves. There were no significant differences between the study group and the control groups with respect to CRP levels. However, they were much higher PCT levels in patients with bacteremia. PCT showed greater discriminating ability compared to CRP, and proved to be a valuable tool for the detection of systemic bacterial infections in HIV infected patients.

Interferon-Gamma Release Assay is Not Appropriate for the Diagnosis of Active Tuberculosis in High-Burden Tuberculosis Settings： A Retrospective Multicenter Investigation

Background：Interferon-gamma release assay （IGRA） has been used in latent tuberculosis （TB） infection and TB diagnosis,but the results from different high TB-endemic countries are different.The aim of this study was to investigate the value of IGRA in the diagnosis of active pulmonary TB （PTB） in China.Methods：We conducted a large-scale retrospective multicenter investigation to further evaluate the role of IGRA in the diagnosis of active PTB in high TB-epidemic populations and the factors affecting the performance of the assay.All patients who underwent valid T-SPOT.TB assays from December 2012 to November 2015 in six large-scale specialized TB hospitals in China and met the study criteria were retrospectively evaluated.Patients were divided into three groups：Group 1,sputum culture-positive PTB patients,confirmed by positive Mycobacterium tuberculosis sputum culture;Group 2,sputum culture-negative PTB patients;and Group 3,non-TB respiratory diseases.The medical records of all patients were collected.Chi-square tests and Fisher＇s exact test were used to compare categorical data.Multivariable logistic analyses were performed to evaluate the relationship between the results of T-SPOT in TB patients and other factors.Results：A total of 3082 patients for whom complete information was available were included in the investigation,including 905 sputum culture-positive PTB cases,914 sputum cultmre-negative PTB cases,and 1263 non-TB respiratory disease cases.The positive rate of T-SPOT.TB was 93.3% in the culture-positive PTB group and 86.1% in the culture-negative PTB group.In the non-PTB group,the positive rate of T-SPOT.TB was 43.6%.The positive rate of T-SPOT.TB in the culture-positive PTB group was significantly higher than that in the culture-negative PTB group （x2 =25.118,P 〈 0.01）,which in turn was significantly higher than that in the non-TB group （x2 =566.l 16,P 〈 0.01）.The overall results were as follows：sensitivity,89.7%;specificity,56.37%;positive predictive value,74.75%;negative predictive value,79.11%;and accuracy,76.02%.Conclusions：High false-positive rates of T-SPOT.TB assays in the non-TB group limit the usefulness as a single test to diagnose active TB in China.We highly recommend that IGRAs not be used for the diagnosis of active TB in high-burden TB settings.