Investigation of the genomic representation of plasma DNA in pregnant women by comparative genomic hybridization analysis: a feasibility study

Neutrophil extracellular traps: a walk on the wild side of exercise immunology

Intense exercise evokes a rapid and transient increase in circulating cell-free DNA (cf-DNA), a phenomenon that is commonly observed in a variety of acute and chronic inflammatory conditions. While the potential value of cf-DNA for the prediction of disease outcome and therapeutic response is well documented, the release mechanisms and biological relevance of cf-DNA have long remained enigmatic. The discovery of neutrophil extracellular traps (NETs) provided a novel mechanistic explanation for increased cf-DNA levels. Now there is increasing evidence that NETs may contribute to cf-DNA in diverse infectious, non-infectious and autoinflammatory conditions, as well as in response to acute exercise. NETs have now been firmly established as a fundamental immune mechanism used by neutrophils to respond to infection and tissue injury. On the other side, aberrant formation of NETs appears to be a driving force in the pathogenesis of autoimmunity and cardiovascular disease. Thus, the emergence of NETs in the 'exercising vasculature' raises important questions considering beneficial effects, as well as occasional adverse effects, of exercise on immune homeostasis. This review gives an overview of the current state of research into the mechanisms of how NETs are released, contribute to host defence and participate in inflammatory disorders. We discuss the impact of exercise-induced NETs, considering a potentially beneficial role in the prevention of lifestyle-related diseases, as well as putative detrimental effects that may arise in elite sports. Finally, we propose that exercise-induced cf-DNA responses could be exploited for diagnostic/prognostic purposes to identify individuals who are at increased risk of cardiovascular events or autoimmunity.

Plasma-based detection of clonality in lymphoid malignancies

OBJECTIVES

Plasma has been found to be enriched with tumor-specific DNA, RNA, and protein in patients with hematologic disease. We assessed the utility of plasma as a DNA source for detection of genetic abnormalities in patients with suspected B- or T-cell lymphoproliferative disorders.

METHODS

DNA was extracted from paired peripheral blood (PB) cells and plasma for polymerase chain reaction (PCR)-based detection of immunoglobulin heavy chain (IgH) and T-cell receptor gamma chain (TCR-gamma) rearrangements, and B-cell leukemia/lymphoma (BCL)-1/IgH and BCL-2/IgH translocations.

RESULTS

Concordance between plasma and PB cell analysis was 100% for IgH (n = 57), TCR-gamma (n = 57), and BCL-1/IgH (n = 37) rearrangements, and 94% (60/64) for BCL-2/IgH; four of 11 plasma samples positive for BCL-2/IgH tested negative in paired cells. No plasma or PB cell samples from 195 healthy donors showed genetic abnormalities.

CONCLUSIONS

These findings indicate that plasma is a reliable sample type for detection of abnormalities associated with B- and T-cell lymphoproliferative disorders, providing sensitivity equal to or greater than that of PB cells.