Concentrations Of Alpha-defensins Research Articles

Human Neutrophil Alpha-Defensins Promote NETosis and Liver Injury in Alcohol-Related Liver Cirrhosis: Potential Therapeutic Agents.

Background: Neutrophils are thought to play a pivotal role in the pathogenesis of many inflammatory diseases, such as hepatitis, liver cirrhosis, etc. Activated human neutrophils release human neutrophil peptides (HNP1-3) or alpha-defensins that are antimicrobial peptides in azurophil granules. Furthermore, HNP1-3 build a scaffold of neutrophil extracellular traps (NETs) and promote the process of programmed cell death called NETosis. Our study aimed to investigate the role of alpha-defensins in the pathogenesis of alcohol-related liver cirrhosis (ALC). Methods: The concentrations of alpha-defensins in the plasma of 62 patients with ALC and 24 healthy subjects were measured by ELISA. The patients with ALC were prospectively recruited based on the severity of liver dysfunction according to the Child-Pugh and Model of End-Stage Liver Disease-Natrium (MELD-Na) scores, modified Maddrey's Discriminant Function (mDF), and the presence of ALC complications. Results: The concentrations of alpha-defensins in plasma were significantly higher in the ALC patients than in the controls. The plasma levels of HNP1-3 correlated with the MELD and mDF scores. ALC subgroups with MELD > 20 and mDF > 32 displayed significantly higher HNP1-3 concentrations. The plasma levels of HNP1-3 revealed a good predictive AUC for hepatic encephalopathy and ascites development (0.81 and 0.74, respectively) and for patient survival (0.87) in those over 40 years of age. Conclusion: These findings suggest that alpha-defensins play an important role in the assessment of ALC.

Does the Alpha-defensin Immunoassay or the Lateral Flow Test Have Better Diagnostic Value for Periprosthetic Joint Infection? A Meta-analysis.

BackgroundMeasuring alpha-defensin concentrations in synovial fluid may help to diagnose periprosthetic joint infection (PJI). There are two commercially available methods for measuring alpha-defensin in synovial fluid: the enzyme-linked immunosorbent assay-based Synovasure® alpha-defensin immunoassay, which gives a numeric readout within 24 hours, and the Synovasure lateral flow test, which gives a binary readout within 20 minutes. There is no compilation of the existing literature to support the use of one of these two tests over the other.Questions/purposesDoes the immunoassay or the lateral flow test have better diagnostic value (sensitivity and specificity) in diagnosing PJI?MethodsWe followed PRISMA guidelines and identified all studies on alpha-defensin concentration in synovial fluid as a PJI diagnostic marker, indexed to April 14, 2017, in PubMed, JSTOR, Google Scholar, and OVID databases. The search retrieved 1578 records. All prospective and retrospective studies on alpha-defensin as a PJI marker (PJI classified according to the criteria of the Musculoskeletal Infection Society) after THA or TKA were included in the analysis. All studies used only one of the two commercially available test methods, but none of them was comparative. After excluding studies with overlapping patient populations, four studies investigating the alpha-defensin immunoassay and three investigating the lateral flow test remained. Alpha-defensin immunoassay studies included 482 joints and lateral flow test studies included 119. The quality of the trials was assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The heterogeneity among studies was evaluated by the I2 index, indicating that the heterogeneity of the included studies was low. Pooled sensitivity, specificity, positive and negative likelihood ratios, and receiver operating curves were calculated for each method and compared with each other.ResultsThe alpha-defensin immunoassay had superior overall diagnostic value compared with the lateral flow test (area under the curve, 0.98 versus 0.75) with higher sensitivity (96% [90%-98%] versus 71% [55%-83%], p < 0.001), but no difference in specificity with the numbers available (96% [93%-97%] versus 90% [81%-95%], p = 0.060).ConclusionsMeasurement of alpha-defensin in synovial fluid is a valuable complement to existing diagnostic criteria, and the immunoassay test detects PJI more accurately than the lateral flow test. The lateral flow test has lower sensitivity, making it difficult to rule out infection, but its relatively high specificity combined with the advantage of a quick response time can make it useful to rule in infection perioperatively.Level of EvidenceLevel III, diagnostic study.

The Effects of a Botanical Blend on Post-Exercise Mucosal Antimicrobial Proteins

Exercise is a stressor that is known to in some cases suppress antimicrobial protein levels, particularly secretory immunoglobulin type A (IgA). Athletes in the midst of in-season training often demonstrate declining levels of sIgA as well as increased risk for ailments such as upper respiratory tract infections. Therefore, it is important to investigate natural supplements that may enhance post exercise mucosal immune function. Twenty healthy collegeaged males volunteered to participate in the present single blind, repeated measures study. Three treatments were administered (botanical spray, botanical drops, placebo) at the onset of 30 Min of 80% VO2 max cycle ergometer exercise. Secretory IgA and Human Alpha Defensin were quantified in saliva samples 30 Min and 90 Min post exercise. Analysis via repeated measures Anova revealed a significant treatment effect at 30 min (p=0.030) with post hoc testing revealing a difference between the botanical spray and placebo (p=0.027), but by 90 Min there was no differences by treatment (p=0.758). There was no difference by treatment observed at either 30 or 90 Min for human alpha defensin concentrations. Based upon these preliminary data, it appears that a single dose of the tested botanical blend delivered via mouth spray can increase sIgA, one of the primary anti-microbial proteins in the oral cavity, for a short time post exercise.

Alpha-Defensin Overexpression in Patients with Bell's Palsy and Ramsay Hunt Syndrome

To investigate the biological factors related to the onset of Bell's palsy, we sought to identify differentially expressed genes in peripheral blood mononuclear cells (PBMCs) and plasma of patients with Bell's palsy and Ramsay Hunt syndrome (RHS). We carried out DNA microarray analyses using PBMCs taken from patients with Bell's palsy at their initial visit and 2 to 4 weeks later. To validate these analyses, we measured the relative messenger RNA levels of alpha-defensin in paired PBMCs by reverse transcription-polymerase chain reaction. The plasma concentrations of alpha-defensin in patients and healthy volunteers were quantified by enzyme-linked immunosorbent assay. The DNA microarray analysis identified alpha-defensin as a candidate gene related to the onset of Bell's palsy. Reverse transcription-polymerase chain reaction analysis showed that the relative alpha-defensin messenger RNA levels in PBMCs from the later visit were increased at least twofold in 9 of 13 patients (69%) with Bell's palsy and in 4 of 6 patients (67%) with RHS. The plasma alpha-defensin concentrations in the patients with RHS were significantly higher than those in healthy volunteers (p = 0.0013) and in the patients with Bell's palsy (p = 0.0306). Elevations of plasma alpha-defensin were observed in 5 of the 9 patients with Bell's palsy who demonstrated alpha-defensin overexpression in PBMCs. alpha-Defensin may be one of the biological factors related to the onset of Bell's palsy and RHS.

Helicobacter pylori induces the release of α-defensin by human granulocytes

Little information is available on the potential role of alpha-defensins derived from neutrophils during H. pylori infection, or the effect of H. pylori on the alpha-defensin release. The effects of H. pylori on human granulocytes were investigated in vitro by flow cytometry and ELISA. Additionally we sought to identify by immunohistochemistry the alpha-defensins within the gastric mucosa of patients infected with H. pylori. The intracellular expression of alpha-defensin in human granulocytes and in mononuclear cells was determined by flow cytometry. Induction of alpha-defensin release from granulocytes, mononuclear cells, or from whole blood cultures by H. pylori was detected by measuring the HNP1-3 (alpha-defensin) concentrations in the supernatants by ELISA. Immunohistochemistry was used to identify HNP1-3 in infiltrating neutrophils in the gastric mucosa of eight patients. A considerable intracellular alpha-defensin staining was observed in granulocytes. Stimulation of granulocytes with H. pylori resulted in a decrease in intracellular staining which was due to the extracellular release of alpha-defensin. In whole blood cultures H. pylori infection resulted in significantly high alpha-defensin concentrations (131623 +/- 13986 pg/ml), which were mainly due to the activity of the granulocytes with only a minor amount furnished by the mononuclear cells. In H. pylori-infected mucosa, infiltrating neutrophils showed intense immunostaining with anti-HNP1-3. The intensity of alpha-defensin staining varied parallel with the density of H. pylori in the biopsy samples. H. pylori induce alpha-defensin release from granulocytes which may well be important in local host response to H. pylori infection in gastroduodenal diseases.

Plasma levels of α‐defensins 1–3 are an indicator of neutrophil activation in pregnant and post‐partum women

In severe preeclampsia and septic shock, excessively activated neutrophils are thought to injure tissue irreversibly. On the other hand, mild neutrophil activation is known to occur during normal pregnancy. The objective of this study was to determine whether elevated plasma levels of alpha-defensins 1-3 could be used as an indicator of neutrophil activation in pregnant and post-partum women. Defensin concentrations in 21 non-pregnant women and men, 184 normal pregnant women, and 55 post-partum women were quantified using an enzyme-linked immunosorbent assay (ELISA). The expression of the surface markers, CD11b and Toll-like receptor-4 (TLR-4), on the neutrophils were analyzed by flow cytometry in a cohort of subjects different from that used for the analysis of alpha-defensin levels. The concentrations of alpha-defensins were significantly higher in women that were in labor than in any of the other subjects. These levels diminished after delivery, but remained significantly elevated at one month post-partum. The expression of both CD11b and TLR-4 was significantly higher in women in labor compared to non-pregnant donors (controls). CD11b expression remained high on the third post-partum day, while TLR-4 expression fell to non-pregnant levels. Our results suggest that there is a positive association between defensin levels and neutrophil activation in pregnant and post-partum women.

Elevated concentrations of alpha-defensins in gastric juice of patients with Helicobacter pylori infection.

Defensins (alpha- and beta-defensins) are endogenous antimicrobial peptides. Little is known about alpha-defensins during Helicobacter pylori infection. The concentrations of human neutrophil peptides (HNP-1, -2, and -3), the major components of neutrophils-derived alpha-defensins, were measured by radioimmunoassay (RIA) in plasma and gastric juice of 61 H. pylori-infected and 33 uninfected subjects, and before and after anti-H. pylori treatment in 12 patients with H. pylori-associated gastritis. Interleukin (IL)-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay. Histological grades of gastritis and neutrophil counts (/mm(2)) infiltrating in the gastric mucosa were determined using two biopsy specimens taken from the antrum and corpus. Immunohistochemistry and reverse-phase high performance liquid chromatography (RP-HPLC) were used to identify HNPs 1-3. HNP 1-3 concentrations in gastric juice were significantly higher in H. pylori-positive than in H. pylori-negative patients and significantly decreased after cure. HNP 1-3 concentrations in gastric juice correlated with IL-8 levels and neutrophil densities in the gastric mucosa and were associated with histological degree of gastritis, especially the grades of activity. Intense immunoreactivity for anti-HNPs 1-3 antiserum was noted in infiltrating neutrophils in H. pylori-infected mucosa. In RP-HPLC analysis, all of the HNP 1-3 molecules were identified as their mature forms. Plasma HNP 1-3 concentrations were similar in H. pylori-infected and non-infected groups and showed no correlations with other parameters. We demonstrated significantly elevated levels of HNPs 1-3 in gastric juice during H. pylori infection. The elevation of HNPs is presumably secondary to H.pylori-associated gastric inflammation involving neutrophil infiltration.

Human α-Defensins HNPs-1, -2, and -3 in Renal Cell Carcinoma: Influences on Tumor Cell Proliferation

The alpha-defensins human neutrophil peptides (HNPs)-1, -2, and -3 have been described as cytotoxic peptides with restricted expression in neutrophils and in some lymphocytes. In this study we report that HNPs-1, -2, and -3 are also expressed in renal cell carcinomas (RCCs). Several RCC lines were found to express mRNA as well as the specific peptides of HNP-1, -2, and -3 demonstrated by reverse transcriptase-polymerase chain reaction, mass spectrometric, and flow cytometric analyses. At physiological concentrations HNPs-1, -2, and -3 stimulated cell proliferation of selected RCC lines in vitro but at high concentrations were cytotoxic for all RCC lines tested. As in RCC lines, alpha-defensins were also detected in vivo in malignant epithelial cells of 31 RCC tissues in addition to their expected presence in neutrophils. In most RCC cases randomly, patchy immunostaining of alpha-defensins on epithelial cells surrounding neutrophils was seen, but in six tumors of higher grade malignancy all tumor cells were diffusely stained. Cellular necrosis observed in RCC tissues in association with extensive patches of HNP-1, -2, and -3, seemed to be related to high concentrations of alpha-defensins. The in vitro and in vivo findings suggest that alpha-defensins are frequent peptide constituents of malignant epithelial cells in RCC with a possible direct influence on tumor proliferation.

Elevated Levels of α-Defensins in Plasma and BAL Fluid of Patients With Active Pulmonary Tuberculosis

To investigate the role of neutrophil peptides named alpha-defensins in patients with pulmonary tuberculosis (TB). Thirty-seven patients with TB and 25 healthy subjects. Concentrations of alpha-defensins (human neutrophil peptide [HNP]-1, HNP-2, and HNP-3) were measured by radioimmunoassay in plasma and BAL fluid (BALF). Concentrations of alpha-defensins were significantly higher in plasma and BALF of patients with TB than in healthy subjects. In BALF of patients with TB, the concentration of alpha-defensins correlated positively with the levels of interleukin 8, and higher concentrations of alpha-defensins in BALF were also detected in patients with cavitary lesions. There was an inverse relationship between plasma alpha-defensins and FEV(1)/FVC ratio before treatment, and between plasma concentrations of alpha-defensins before treatment and the improvement in percentage of vital capacity after treatment. Plasma alpha-defensin concentrations returned to the normal range after treatment. Our data suggest that alpha-defensins released from neutrophils may play an important role in the pathogenesis of TB, and that plasma alpha-defensin concentration may be a useful marker of disease severity and deterioration of pulmonary function.