Quantification Of Neutrophil Extracellular Traps Research Articles

Association of neutrophil extracellular traps with endometriosis-related chronic inflammation

ObjectiveTo study if neutrophil extracellular traps (NETs) are present in the peritoneal fluid of endometriosis patients. NETs play a crucial role in fighting against microorganisms. However, exaggerated NET production may lead to tissue damage in their vicinity in pathological conditions. Our study evaluates the presence of NETs in endometriosis peritoneal fluid. Study designPeritoneal fluid (PF) was collected in a case-control study from 52 women, who underwent either diagnostic or operative laparoscopy. The control group consisted of 17 women with infertility, chronic pelvic pain, simple or functional cysts or irregular bleeding. The endometriosis group, altogether 35 patients, comprised 19 patients with stage I and II and 16 patients with stage III and IV endometriosis. First we tested whether the PF is able to stimulate NET production. Neutrophils from healthy volunteers were treated with the PF of endometriosis patients and controls and NETs were detected with Sytox orange extracellular DNA dye and immunofluorescence microscopy. Then we evaluated if NETs were already present in the collected PF using the specific myeloperoxidase (MPO)-DNA capture ELISA method, based on the MPO associated with the NET scaffold. ResultsThe PF of endometriosis patients did not stimulate NET release from healthy granulocytes. However, pre-existent NETs could be detected in 17 endometriosis patients out of 35 (49%). In contrary, in the control group NETs were present in only 3 patients out of 17 (18%), (p=0.03, OR: 4.4). Moreover, the quantification of NETs showed a significantly higher amount of NETs in endometriosis compared to the controls (0.097 vs. 0.02, p=0.04). ConclusionThis is the first study, which evaluated and described the presence of NETs in the PF of endometriosis patients. Our study shows, that NETs may be involved in the complex pathophysiology of endometriosis.

Neutrophil extracellular traps in bronchial aspirates: a quantitative analysis

Neutrophil extracellular traps (NETs) are structures composed of DNA and granular proteins, which rapidly trap and kill pathogens. The formation of NETs has been detected during infection in animal experiments, but their role in humans is unclear. The purposes of this study were to quantitatively evaluate the production of NETs during acute respiratory infection and to study the relationship between the NET length and various inflammatory mediators. We examined bronchial aspirates collected from nine intubated patients in an intensive care unit. Samples were collected at the onset of acute respiratory infection (day 0) and on days 1, 3-5, and 6-8. The NET length was visualised by immunohistochemistry and quantified using computer tracing software. The NET length was measured and compared at each time point. The length differed significantly between time points (p<0.001). NETs were significantly longer on day 1 than on day 0 (p<0.001). Neutrophils released NETs abundantly in response to respiratory infection and regression analysis showed that NET length correlated with six clinical parameters (white blood cells, platelets, lactate, CXC ligand-2, interleukin-8, and procalcitonin) as the explanatory variables. NETs in bronchial aspirates may reflect disease progression of respiratory infections. Quantification of NETs in bronchial aspirates may provide a new indicator of inflammation.

Characterization of neutrophil extracellular traps in cats naturally infected with feline leukemia virus

Feline leukemia virus (FeLV), a common, naturally occurring gammaretrovirus in domestic cats, is associated with degenerative diseases of the haematopoietic system, immunodeficiency and neoplasia. FeLV infection causes an important suppression of neutrophil function, leading to opportunistic infections. Recently, a new microbicidal mechanism named NETosis was described in human, bovine and fish neutrophils, as well as in chicken heterophils. The purpose of the present study was to characterize NETosis in feline neutrophils, as well as to evaluate neutrophil function in FeLV naturally infected symptomatic and asymptomatic cats through the phagocytosis process, release of neutrophil extracellular traps (NETs) and myeloperoxidase (MPO) activity. The results showed that feline neutrophils stimulated with protozoa parasites released structures comprising DNA and histones, which were characterized as NETs by immunofluorescence. Quantification of NETs after neutrophil stimulation showed a significant increase in NET release by neutrophils from FeLV(-) and FeLV(+) asymptomatic cats compared with FeLV(+) symptomatic cats. Moreover, the number of released NETs and MPO activity in unstimulated neutrophils of FeLV(+) symptomatic cats were higher than those in unstimulated neutrophils from FeLV(-) and FeLV(+) asymptomatic cats. This study reports, for the first time, NET release by feline neutrophils, along with the fact that NET induction may be modulated by a viral infection. The results indicate that the NET mechanism appears to be overactivated in FeLV(+) cats and that this feature could be considered a marker of disease progression in FeLV infection.

Comparison of orocaecal transit times assessed by the lactulose/breath hydrogen and the sulphasalazine/sulphapyridine methods.

The lactulose/breath hydrogen and the sulphasalazine/sulphapyridine methods of assessing orocaecal transit time have been compared. In a two part crossover study in healthy normal subjects the median orocaecal transit time by the SLZ/SP method was 4.84 hours but only 2.92 hours by the lactulose/breath hydrogen method. Coadministration of lactulose and sulphazalazine to nine subjects with assessment of orocaecal transit time by hydrogen breath determination and plasma sulphapyridine assay gave orocaecal transit times of 2.33 and 2.25 hours respectively suggesting that the lactulose reduces transit time and that the lactulose/breath hydrogen method, which is so convenient to use, gives artificially low transit times. A third experiment was undertaken to compare the orocaecal transit times after 1.5 and 3.0 g sulphazalazine. The orocaecal transit times after the two doses were not statistically different.