Prolyl endopeptidase activity in bronchoalveolar lavage fluid: a novel diagnostic biomarker in a guinea pig model of invasive pulmonary aspergillosis

Recent Advances and Novel Approaches in Laboratory-Based Diagnostic Mycology

What was once just culture and microscopy the field of diagnostic mycology has significantly advanced in recent years and continues to incorporate novel assays and strategies to meet the changes in clinical demand. The emergence of widespread resistance to antifungal therapy has led to the development of a range of molecular tests that target mutations associated with phenotypic resistance, to complement classical susceptibility testing and initial applications of next-generation sequencing are being described. Lateral flow assays provide rapid results, with simplicity allowing the test to be performed outside specialist centres, potentially as point-of-care tests. Mycology has responded positively to an ever-diversifying patient population by rapidly identifying risk and developing diagnostic strategies to improve patient management. Nowadays, the diagnostic repertoire of the mycology laboratory employs classical, molecular and serological tests and should be keen to embrace diagnostic advancements that can improve diagnosis in this notoriously difficult field.

Rodent Models of Invasive Aspergillosis due to Aspergillus fumigatus: Still a Long Path toward Standardization

Invasive aspergillosis has been studied in laboratory by the means of plethora of distinct animal models. They were developed to address pathophysiology, therapy, diagnosis, or miscellaneous other concerns associated. However, there are great discrepancies regarding all the experimental variables of animal models, and a thorough focus on them is needed. This systematic review completed a comprehensive bibliographic analysis specifically-based on the technical features of rodent models infected with Aspergillus fumigatus. Out the 800 articles reviewed, it was shown that mice remained the preferred model (85.8% of the referenced reports), above rats (10.8%), and guinea pigs (3.8%). Three quarters of the models involved immunocompromised status, mainly by steroids (44.4%) and/or alkylating drugs (42.9%), but only 27.7% were reported to receive antibiotic prophylaxis to prevent from bacterial infection. Injection of spores (30.0%) and inhalation/deposition into respiratory airways (66.9%) were the most used routes for experimental inoculation. Overall, more than 230 distinct A. fumigatus strains were used in models. Of all the published studies, 18.4% did not mention usage of any diagnostic tool, like histopathology or mycological culture, to control correct implementation of the disease and to measure outcome. In light of these findings, a consensus discussion should be engaged to establish a minimum standardization, although this may not be consistently suitable for addressing all the specific aspects of invasive aspergillosis.

Sample collection in clinical proteomics--proteolytic activity profile of serum and plasma

PURPOSE

Proteolytic enzymes are promising diagnostic targets since they play key roles in diverse physiological processes and have been implicated in numerous human diseases. Human blood is a relatively noninvasive source for disease-specific protease biomarker detection and subsequent translation into diagnostic tests. However, the choice of serum or plasma, and more specifically, which anticoagulant to choose in plasma preparation, is important to address in the sample preparation phase of biomarker discovery.

EXPERIMENTAL DESIGN

We have previously utilized a combinatorial library of internally quenched fluorogenic probes to successfully map the global proteolytic profiles of various biological fluids. In this study, we utilized the platform to ascertain the impact of three commonly used anticoagulants (EDTA, heparin, and citrate) on the proteolytic activity profile of plasma and serum collected from a healthy Caucasian male.

RESULTS

Serum and plasma citrate were observed to be most proteolytically active, followed by plasma heparin and then plasma EDTA. Detailed analysis of the amino acid distribution of motifs cleaved and not cleaved by the samples offered significant insights in to active proteolytic components within them.

CONCLUSION AND CLINICAL RELEVANCE

Broad quantitative comparison of proteolytic profiles of these samples revealed several novel insights related to the differential substrate recognition of proteases present in these biological fluids.