Diagnostic potential of circulating cell-free DNA in patients needing mechanical ventilation: promises and challenges

Prognostic utility of circulating nucleic acids in acute brain injuries

INTRODUCTION

Acute brain injuries represent major causes of morbidity and mortality worldwide. Nevertheless, therapeutic options are centered mainly on supportive care, and accurate prognosis prediction following traumatic brain injury (TBI) or stroke remains a challenge in clinical settings. Areas covered: Circulating DNA and RNA have shown potential as predictive molecules in acute brain injuries. In particular, plasma cell-free DNA (cfDNA) levels have been correlated to severity, mortality, and outcome after TBI and stroke. The real-time quantitative polymerase chain reaction (qPCR) is the most widely used technique for determination of cfDNA in brain injuries; however, to consider the use of cfDNA in emergency settings, a quicker and easier methodology for detection should be established. A recent study proposed detection of cfDNA applying a rapid fluorescent test that showed compatible results with qPCR. Expert commentary: As a promising perspective, detection of cfDNA levels using simple, rapid, and cheap methodology has potential to translate to clinic as a point-of-care marker, supporting the clinical decision-making in emergency care settings. Conversely, miRNA profiles may be used as signatures to determine the type and severity of injuries. Additionally, in the future, some miRNAs may constitute innovative neurorestorative therapies without the common hurdles associated with cell therapy.

Cell-free DNA: the role in pathophysiology and as a biomarker in kidney diseases

Cell-free DNA (cfDNA) is present in various body fluids and originates mostly from blood cells. In specific conditions, circulating cfDNA might be derived from tumours, donor organs after transplantation or from the foetus during pregnancy. The analysis of cfDNA is mainly used for genetic analyses of the source tissue -tumour, foetus or for the early detection of graft rejection. It might serve also as a nonspecific biomarker of tissue damage in critical care medicine. In kidney diseases, cfDNA increases during haemodialysis and indicates cell damage. In patients with renal cell carcinoma, cfDNA in plasma and its integrity is studied for monitoring of tumour growth, the effects of chemotherapy and for prognosis. Urinary cfDNA is highly fragmented, but the technical hurdles can now be overcome and urinary cfDNA is being evaluated as a potential biomarker of renal injury and urinary tract tumours. Beyond its diagnostic application, cfDNA might also be involved in the pathogenesis of diseases affecting the kidneys as shown for systemic lupus, sepsis and some pregnancy-related pathologies. Recent data suggest that increased cfDNA is associated with acute kidney injury. In this review, we discuss the biological characteristics, sources of cfDNA, its potential use as a biomarker as well as its role in the pathogenesis of renal and urinary diseases.

Year in review 2011: Critical Care--Cardiology

We review key research papers in cardiology and intensive care published during 2011 in Critical Care and quote related studies published in other journals whenever appropriate. Papers are grouped into the following categories: cardiovascular therapies, mechanical therapies, biomarkers, prognostic markers, hemodynamic monitoring, cardiovascular diseases, microcirculation, hypertension in critically ill patients, and miscellaneous.

Year in review 2011: Critical Care - respirology

Management of acute respiratory failure is an important component of intensive care. In this review, we analyze 21 original research articles published last year in Critical Care in the field of respiratory and critical care medicine. The articles are summarized according to the following topic categories: acute respiratory distress syndrome, mechanical ventilation, adjunctive therapies, and pneumonia.