ABSTRACT
BACKGROUND: Procalcitonin (PCT) has previously been proposed as useful marker to rule out bloodstream-infection (BSI). The objective of this study was to evaluate the sensitivity of different PCT cut-offs for prediction of BSI in patients with community (CA)- and hospital-acquired (HA)-BSI. METHODS: A total of 898 patients fulfilling systemic-inflammatory-response-syndrome (SIRS) criteria were enrolled in this prospective cohort study at the Medical University of Graz, Austria. Of those 666 patients had positive blood cultures (282 CA-BSI, 384 HA-BSI, enrolled between January 2011 and December 2012) and 232 negative blood cultures (enrolled between January 2011 and July 2011 at the emergency department). Blood samples for determination of laboratory infection markers (e.g. PCT) were collected simultaneously with blood cultures. RESULTS: Procalcitonin was significantly (p < 0.001) higher in SIRS patients with bacteremia/fungemia than in those without. Receiver operating characteristic curve analysis revealed an area under the curve (AUC) value of 0.675 for PCT (95% CI 0.636-0.714) for differentiating patients with BSI from those without. AUC for IL-6 was 0.558 (95% CI 0.515-0.600). However, even at the lowest cut-off evaluated (i.e. 0.1 ng/ml) PCT failed to predict BSI in 7% (n = 46) of patients. In the group of patients with SIRS and negative blood culture 79% (n = 185) had PCT levels > 0.1. CONCLUSION: Procalcitonin was significantly higher in patients with BSI than in those without and superior to IL-6 and CRP. The clinical importance of this is questionable, because a suitable PCT threshold for excluding BSI was not established. An approach where blood cultures are guided by PCT only can therefore not be recommended.
Subject(s)
Bacteremia/diagnosis , Calcitonin/blood , Protein Precursors/blood , Systemic Inflammatory Response Syndrome/diagnosis , Aged , Area Under Curve , Biomarkers/blood , Calcitonin Gene-Related Peptide , Cohort Studies , Female , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Systemic Inflammatory Response Syndrome/blood , Systemic Inflammatory Response Syndrome/complicationsABSTRACT
Galactomannan detection in bronchoalveolar lavage (BAL) fluid samples (GM test) is currently considered the gold standard test for diagnosing invasive pulmonary aspergillosis (IPA). The limitations, however, are the various turnaround times and availability of testing. We compared the performance of GM testing with that of conventional culture, an Aspergillus lateral-flow-device (LFD) test, a beta-d-glucan (BDG) test, and an Aspergillus PCR assay by using BAL fluid samples from immunocompromised patients. A total of 78 BAL fluid samples from 78 patients at risk for IPA (74 samples from Graz and 4 from Mannheim) collected between December 2012 and May 2013 at two university hospitals in Austria and Germany were included. Three patients had proven IPA, 14 probable IPA, and 17 possible IPA, and 44 patients had no IPA. The diagnostic accuracies of the different methods for probable/proven IPA were evaluated. The diagnostic odds ratios were the highest for the GM, PCR, and LFD tests. The sensitivities for the four methods (except culture) were between 70 and 88%. The combination of the GM (cutoff optical density index [ODI], >1.0) and LFD tests increased the sensitivity to 94%, while the combination of the GM test (>1.0) and PCR resulted in 100% sensitivity (specificity for probable/proven IPA, 95 to 98%). The performance of conventional culture was limited by low sensitivity, while that of the BDG test was limited by low specificity. We evaluated established and novel diagnostic methods for IPA and found that the Aspergillus PCR, LFD, and GM tests were the most useful methods for diagnosing the disease by using BAL fluid samples. In particular, the combination of the GM test and PCR or, if PCR is not available, the LFD test, allows for sensitive and specific diagnosis of IPA.
Subject(s)
Antigens, Fungal/analysis , Aspergillus/isolation & purification , Bronchoalveolar Lavage Fluid/microbiology , DNA, Fungal/analysis , Invasive Pulmonary Aspergillosis/diagnosis , Microbiological Techniques/methods , Adult , Aged , Aspergillus/chemistry , Aspergillus/growth & development , Austria , Bronchoalveolar Lavage Fluid/chemistry , Chromatography, Affinity/methods , Female , Galactose/analogs & derivatives , Germany , Glucans/analysis , Hospitals, University , Humans , Immunocompromised Host , Male , Mannans/analysis , Middle Aged , Polymerase Chain Reaction/methods , Prospective Studies , Retrospective Studies , Sensitivity and Specificity , Young AdultABSTRACT
BACKGROUND: Frequent blood donations may lead to a depletion of body iron stores resulting in manifest anemia. Reticulocyte hemoglobin content (CHr) - a marker for impaired hemoglobinisation (IH) caused by functional iron deficiency (FID) - was investigated regarding its value as a routine screening parameter in frequent whole blood donors. METHODS: In a prospective study, 917 frequent blood donors and 688 first time or reactivated donors were tested for iron status and red blood cell count, including CHr. The ferritin index as a marker to indicate absent iron stores (AIS) was calculated. RESULTS: Depending on the number of donations during the preceding 12 months, AIS were detected in up to 21.4% of male and 27.8% of female donors, respectively. IH was present in up to 6.4% male and 16.7% female donors with 2 and 4 preceding donations, respectively. The defined CHr cut-off value was 28.0 pg to detect IH in frequent whole blood donors with AIS, leading to a test specificity of 98.2% (positive predictive value, PPV: 57.7%) in male and of 97.8% (PPV: 82.9%) in female donors. CONCLUSION: Determination of CHr is feasible to detect FID resulting in IH in frequent blood donors. It may help to prevent the development of anemia in frequent blood donors and also can help to decide whether donor deferral or even iron substitution need to be recommended.
