Excellent Diagnostic Characteristics for Ultrafast Gene Profiling of DEFA1-IL1B-LTF in Detection of Prosthetic Joint Infections
JOURNAL OF CLINICAL MICROBIOLOGY
Authors: Fillerova, Regina; Gallo, Jiri; Radvansky, Martin; Kraiczova, Veronika; Kudelka, Milos; Kriegova, Eva
Abstract
The timely and exact diagnosis of prosthetic joint infection (PJI) is crucial for surgical decision-making. Intraoperatively, delivery of the result within an hour is required. Alpha-defensin lateral immunoassay of joint fluid (JF) is precise for the intraoperative exclusion of PJI; however, for patients with a limited amount of JF and/or in cases where the JF is bloody, this test is unhelpful. Important information is hidden in periprosthetic tissues that may much better reflect the current status of implant pathology. We therefore investigated the utility of the gene expression patterns of 12 candidate genes (TLR1, -2, -4, -6, and 10, DEFA1, LTF, IL1B, BPI, CRP, IFNG, and DEFB4A) previously associated with infection for detection of PJI in periprosthetic tissues of patients with total joint arthroplasty (TJA) (n = 76) reoperated for PJI (n = 38) or aseptic failure (n = 38), using the ultrafast quantitative reverse transcription-PCR (RT-PCR) Xxpress system (BJS Biotechnologies Ltd.). Advanced data-mining algorithms were applied for data analysis. For PJI, we detected elevated mRNA expression levels of DEFA1 (P < 0.0001), IL1B (P < 0.0001), LTF (P < 0.0001), TLR1 (P = 0.02), and BPI (P = 0.01) in comparison to those in tissues from aseptic cases. A feature selection algorithm revealed that the DEFA1-IL1B-LTF pattern was the most appropriate for detection/exclusion of PJI, achieving 94.5% sensitivity and 95.7% specificity, with likelihood ratios (LRs) for positive and negative results of 16.3 and 0.06, respectively. Taken together, the results show that DEFA1-IL1B-LTF gene expression detection by use of ultrafast qRT-PCR linked to an electronic calculator allows detection of patients with a high probability of PJI within 45 min after sampling. Further testing on a larger cohort of patients is needed.
Alpha defensins 1, 2, and 3 - Potential roles in dyslipidemia and vascular dysfunction in humans
ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY
Authors: Lopez-Bermejo, Abel; Chico-Julia, Berta; Castro, Antoni; Recasens, Monica; Esteve, Eduardo; Biarnes, Josefina; Casamitjana, Roser; Ricart, Wifredo; Fernandez-Real, Jose-Manuel
Abstract
Objectives - alpha-Defensins are natural antibiotics made by neutrophils that have been reported to modulate cholesterol metabolism and vascular function; however, their role in vivo remains largely unknown. We hypothesized that alpha-defensins 1 to 3 (DEFA1-3) are associated with serum lipids and vascular reactivity in humans. Methods and Results - One hundred thirteen apparently-healthy White men, participants in a prospective study of cardiovascular risk factors, were assessed for a lipid profile, insulin sensitivity (SI, frequently-sampled intravenous glucose tolerance test), and non-stressed circulating DEFA1-3 (ELISA). In a subset of 52 subjects, vascular reactivity (high-resolution ultrasound of the brachial artery) was also assessed. Subjects in the highest quartile for plasma DEFA1-3 were found to be leaner and more insulin sensitive, and to have significantly reduced total and LDL-cholesterol, compared with subjects in the lowest quartile for circulating DEFA1-3 (P < 0.0001 to P < 0.002 for linear trend ANOVA). The associations with serum lipids persisted after adjustment for age, body mass index, insulin sensitivity, and smoking (which was associated with reduced plasma DEFA1-3 concentrations). Finally, endothelium-independent vasodilation increased with increasing circulating DEFA1-3 (P < 0.003) and this association was not explained by age, body mass index, serum cholesterol, insulin sensitivity, or smoking. Conclusions - Circulating DEFA1-3 are associated with serum cholesterol and vascular reactivity in humans. alpha-Defensins may have clinical implications in patients with either hypercholesterolemia or vascular dysfunction.