Citations

AbstractEosinophil degranulation is thought to play a pivotal role in the pathogenesis of allergic disorders. Although mouse models of allergic disorders have been used extensively to identify the contribution of eosinophils to disease, ultrastructural evidence of active granule disassembly has not been reported. In this investigation, we characterized the degree of eosinophil activation in the bone marrow, blood, lung tissue, and airways lumen [bronchoalveolar lavage fluid (BALF)] of ovalbumin-sensitized and aero-challenged wild-type and interleukin-5 transgenic mice. Degranulation was most prominent in and primarily compartmentalized to the airways lumen. Eosinophils released granule proteins by the process of piecemeal degranulation (PMD). Accordingly, recruitment and activation of eosinophils in the lung correlated with the detection of cell-free eosinophil peroxidase in BALF and with the induction of airways hyper-reactivity. As in previous studies with human eosinophils, degranulation of isolated mouse cells did not occur until after adherence to extracellular matrix. However, higher concentrations of exogenous stimuli appear to be required to trigger adherence and degranulation (piecemeal) of mouse eosinophils when compared with values reported for studies of human eosinophils. Thus, mouse eosinophils undergo PMD during allergic inflammation, and in turn, this process may contribute to pathogenesis. However, the degranulation process in the allergic lung of mice is primarily compartmentalized to the airway lumen. Understanding the mechanism of eosinophil degranulation in the airway lumen may provide important insights into how this process occurs in human respiratory diseases.

OBJECTIVE: To report a case of vancomycin-induced anaphylaxis (or anaphylactoid reaction) in a patient with a fever of unrecognized noninfectious origin. CASE SUMMARY: An 83-year-old white man, who was a patient of the Veterans Affairs Medical Center, developed a serious anaphylactic (or anaphylactoid) reaction while receiving intravenous vancomycin as empiric therapy for a nosocomial fever of unknown origin. The fever was subsequently proved to have been due to acute polyarticular gout rather than an infection. DISCUSSION: This patient developed respiratory distress and an increased serum troponin concentration, suggestive of a myocardial enzymatic leak as a result of vancomycin therapy. Vancomycin was given before the noninfectious cause of his fever was recognized. CONCLUSIONS: Even with cautious slow infusion, intravenous vancomycin can precipitate life-threatening infusion-related reactions in some patients. Because of this, and to reduce selective pressure for vancomycin resistance, sources of fever that do not require treatment with vancomycin should be diligently investigated prior to the institution of empiric vancomycin therapy in febrile patients, particularly when the past medical history is suggestive of an alternative diagnosis.

Abstract Background: Newborn screening for congenital adrenal hyperplasia (CAH) involves measurement of 17α-hydroxyprogesterone (17-OHP), usually by immunoassay. Because this testing has been characterized by high false-positive rates, we developed a steroid profiling method that uses liquid chromatography–tandem mass spectrometry (LC-MS/MS) to measure 17-OHP, androstenedione, and cortisol simultaneously in blood spots. Methods: Whole blood was eluted from a 4.8-mm (3/16-inch) dried-blood spot by an aqueous solution containing the deuterium-labeled internal standard d8-17-OHP. 17-OHP, androstenedione, and cortisol were extracted into diethyl ether, which was subsequently evaporated and the residue dissolved in LC mobile phase. This extract was injected into a LC-MS/MS equipped with pneumatically assisted electrospray. The steroids were quantified in the selected-reaction monitoring mode by use of peak areas in reference to the stable-isotope-labeled internal standard. We analyzed 857 newborn blood spots, including 14 blood spots of confirmed CAH cases and 101 of false-positive cases by conventional screening. Results: Intra- and interassay CVs for 17-OHP were 7.2–20% and 3.9–18%, respectively, at concentrations of 2, 30, and 50 μg/L. At a cutoff for 17-OHP of 12.5 μg/L and a cutoff of 3.75 for the sum of peak areas for 17-OHP and androstenedione divided by the peak area for cortisol, 86 of the 101 false-positive samples were within reference values by LC-MS/MS, whereas the 742 normal and 14 true-positive results obtained by conventional screening were correctly classified. Conclusion: Steroid profiling in blood spots can identify false-positive results obtained by conventional newborn screening for CAH.

ABSTRACT The VERSANT hepatitis B virus (HBV) 3.0 Assay (branched DNA [bDNA]) (referred to herein as VERSANT 3.0) was evaluated at four external sites for analytical sensitivity, specificity, reproducibility, linearity of quantification, and limits of detection. In addition, each of the test evaluation sites provided HBV DNA-positive clinical samples that were previously analyzed by one of three commercially available HBV DNA quantitative tests: Digene Hybrid Capture II HBV DNA Test (Digene); VERSANT HBV DNA 1.0 Assay (bDNA) (VERSANT 1.0); and COBAS AMPLICOR HBV Monitor Test (COBAS AMPLICOR). These samples were reexamined using VERSANT 3.0. The results from these studies showed that VERSANT 3.0 has high specificity (99.3%), excellent reproducibility (between-run coefficient of variation [CV] = 1.6 to 9.4%; within-run CV = 6.5 to 20.7%), and a broad linear range of quantification (2.0 × 10 3 to 1.0 × 10 8 HBV DNA copies/ml) that facilitate the monitoring of HBV DNA levels at diagnosis and throughout the course of treatment. In general, correlation was very good between results obtained from clinical samples analyzed by VERSANT 3.0 and the comparative HBV DNA quantitative assays (VERSANT 1.0, R 2 = 0.900; Digene, R 2 = 0.985; COBAS AMPLICOR, R 2 = 0.771). The greatest differences in comparative quantitation occurred at HBV DNA levels approaching the limits of the dynamic ranges for the comparative assays. The performance characteristics of the new VERSANT 3.0 assay demonstrated that it provides a reliable and robust method for routinely monitoring serum HBV DNA levels in assessing disease activity and determining response to antiviral treatment.

ABSTRACTMice immunized with irradiatedOnchocerca volvulusthird-stage larvae developed protective immunity. Eosinophil levels were elevated in the parasite microenvironment at the time of larval killing, and measurements of total serum antibody levels revealed an increase in the immunoglobulin E (IgE) level in immunized mice. The goal of the present study was to identify the role of granulocytes and antibodies in the protective immune response to the larval stages ofO. volvulusin mice immunized with irradiated larvae. Immunity did not develop in mice if granulocytes, including both neutrophils and eosinophils, were eliminated, nor did it develop if only eosinophils were eliminated. Moreover, larvae were killed in naïve interleukin-5 transgenic mice, and the killing coincided with an increase in the number of eosinophils and the eosinophil peroxidase (EPO) level in the animals. To determine if EPO was required for protective immunity, mice that were genetically deficient in EPO were immunized, and there were no differences in the rates of parasite recovery in EPO-deficient mice and wild-type mice. Two mouse strains were used to study B-cell function; μMT mice lacked all mature B cells, and Xid mice had deficiencies in the B-1 cell population. Immunity did not develop in the μMT mice but did develop in the Xid mice. Finally, protective immunity was abolished in mice treated to eliminate IgE from the blood. We therefore concluded that IgE and eosinophils are required for adaptive protective immunity to larvalO. volvulusin mice.