Multicentre evaluation of a second generation point-of-care assay with an extended range for the determination of N-terminal pro-brain natriuretic peptide.

BACKGROUND: In the second generation of the point-of-care (POC) assay Roche CARDIAC proBNP, the upper limit of the measuring range was extended from 3000 to 9000 ng/L. METHODS: A thirteen-site multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP assay and to compare it with a laboratory N-terminal pro-brain natriuretic peptide (NT-proBNP) assay. RESULTS: In method comparisons of six lots of POC NT-proBNP with the lab reference method (Elecsys proBNP) mean bias ranged from -10 to +17%. In lot-to-lot comparisons all six investigated lots of POC NT-proBNP showed excellent agreement, with mean bias between -7% and +2%. The majority of all coefficients of variation obtained from ten-fold measurements using 56 native blood samples were below 8%. No interference was observed with hemolytic blood (hemoglobin concentrations up to 0.12 mmol/L), lipemic blood (triglyceride concentrations up to 14.0 mmol/L) nor icteric blood (bilirubin concentrations up to 63 micromol/L). Hematocrit values between 24% and 51% had no influence on the assay result. High NT-proBNP concentrations above the measuring range of POC NT-proBNP did not lead to false low results due to potential high-dose hook effect. Results with POC NT-proBNP were not influenced by different ambient temperatures (18 degrees C to 32 degrees C), the sample material used, nor by over- or underdosing by 15 microL compared to the regular sample volume of 150 microL. CONCLUSIONS: The POC NT-proBNP assay showed an excellent analytical performance including a good agreement with the laboratory method. The assay is therefore suitable for its intended use in point-of-care settings.

Glutathione peroxidase 1 activity and cardiovascular events in patients with coronary artery disease.

BACKGROUND: Cellular antioxidant enzymes such as glutathione peroxidase 1 and superoxide dismutase have a central role in the control of reactive oxygen species. In vitro data and studies in animal models suggest that these enzymes may protect against atherosclerosis, but little is known about their relevance to human disease. METHODS: We conducted a prospective study among 636 patients with suspected coronary artery disease, with a median follow-up period of 4.7 years (maximum, 5.4) to assess the risk of cardiovascular events associated with base-line erythrocyte glutathione peroxidase 1 and superoxide dismutase activity. RESULTS: Glutathione peroxidase 1 activity was among the strongest univariate predictors of the risk of cardiovascular events, whereas superoxide dismutase activity had no association with risk. The risk of cardiovascular events was inversely associated with increasing quartiles of glutathione peroxidase 1 activity (P for trend <0.001); patients in the highest quartile of glutathione peroxidase 1 activity had a hazard ratio of 0.29 (95 percent confidence interval, 0.15 to 0.58; P<0.001), as compared with those in the lowest quartile. Glutathione peroxidase 1 activity was affected by sex and smoking status but retained its predictive power in these subgroups. After adjustment for these and other cardiovascular risk factors, the inverse association between glutathione peroxidase 1 activity and cardiovascular events remained nearly unchanged. CONCLUSIONS: In patients with coronary artery disease, a low level of activity of red-cell glutathione peroxidase 1 is independently associated with an increased risk of cardiovascular events. Glutathione peroxidase 1 activity may have prognostic value in addition to that of traditional risk factors. Furthermore, increasing glutathione peroxidase 1 activity might lower the risk of cardiovascular events.

Impact of infectious burden on extent and long-term prognosis of atherosclerosis.

BACKGROUND: Recent findings suggest a causative role of infections in the pathogenesis of atherosclerosis. In hypothesizing an association between infectious agents and the development of atherosclerosis, we would expect a correlation to the extent of atherosclerosis. Moreover, this effect could be multiplied by the number of pathogens to which an individual had been exposed. METHODS AND RESULTS: In 572 patients, IgG or IgA antibodies to herpes simplex virus 1 and 2, cytomegalovirus, Epstein-Barr virus, Hemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori were measured. The extent of atherosclerosis was determined by coronary angiography, carotid duplex sonography, and evaluation of the ankle-arm index. Elevated IgA antibodies against C pneumoniae (P<0.04) and IgG antibodies against H pylori (P<0.02), cytomegalovirus (P<0.05), and herpes simplex virus 2 (P<0.01) were associated with advanced atherosclerosis (> or =2 vascular regions), adjusted for age, sex, cardiovascular risk factors, and highly sensitive C-reactive protein. Infectious burden divided into 0 to 3, 4 to 5, and 6 to 8 seropositivities was significantly associated with advanced atherosclerosis, with an odds ratio (95% CI) of 1.8 (1.2 to 2.6) for 4 to 5 (P<0.01) and 2.5 (1.2 to 5.1) for 6 to 8 seropositivities (P<0.02) (adjusted). After a mean follow-up of 3.2 years, cardiovascular mortality rate was 7.0% in patients with advanced atherosclerosis and seropositive for 0 to 3 pathogens compared with 20.0% in those seropositive for 6 to 8 pathogens. CONCLUSIONS: Our results support the hypothesis that infectious agents are involved in the development of atherosclerosis. We showed a significant association between infectious burden and the extent of atherosclerosis. Moreover, the risk for future death was increased by the number of infectious pathogens, especially in patients with advanced atherosclerosis.

Plasma concentrations and genetic variation of matrix metalloproteinase 9 and prognosis of patients with cardiovascular disease.

BACKGROUND: Matrix metalloproteinase (MMP)-9 secretion by macrophages and other inflammatory cells accelerates atherosclerotic progression and destabilizes vulnerable plaque in animal models. However, epidemiological data evaluating the prognostic impact of circulating concentrations and functional genetic variations of MMP-9 are lacking. METHODS AND RESULTS: In a prospective study of 1127 patients with documented coronary artery disease, we measured baseline plasma MMP-9 levels and determined the MMP-9/C-1562T and MMP-9/R279Q genotypes. During the follow-up period (mean of 4.1 years), 97 patients died from cardiovascular (CV) causes. Median concentrations of MMP-9 were significantly higher among patients who experienced a fatal CV event than among those who did not (62.2 versus 47.8 ng/mL; P<0.0001). The crude hazard risk ratio of CV death associated with increasing quartiles of MMP-9 was 1.4 (95% CI, 1.2 to 1.8; P<0.0001), and after adjustment for clinical and therapeutic confounders, it was 1.3 (95% CI, 1.1 to 1.6; P=0.005). Additional adjustment for highly sensitive CRP, interleukin-6, fibrinogen, and interleukin-18 revealed a hazard risk ratio to 1.2 (95% CI, 0.9 to 1.6; P=0.15). The T allele of the C-1562T polymorphism was associated with increased MMP-9 levels in a fairly codominant fashion (P=0.004). Although none of the polymorphisms was significantly related with future CV death, there was a significant association (P=0.02) between the R279Q polymorphism and CV events in patients with stable angina. CONCLUSIONS: Plasma MMP-9 concentration was identified as a novel predictor of CV mortality in patients with coronary artery disease. Whether it provides independent prognostic information compared with other inflammatory markers will have to be additionally assessed.

Prognostic value of lipoproteins and their relation to inflammatory markers among patients with coronary artery disease.

BACKGROUND: Lipoproteins and their subfractions are associated with the incidence of atherosclerotic diseases. In patients with coronary artery disease (CAD), low serum concentrations of high density lipoprotein (HDL) and high low-density lipoproteins (LDL) are correlated to myocardial infarction and cardiovascular death. There is growing evidence indicating that those lipoprotein factors are related to the inflammatory process in atherogenesis. METHODS: We investigated in a median follow up of 3.9 years the association of HDL, apolipoprotein A-I (apoA-I), LDL, apolipoprotein B (apoB), and triglycerides with the incidence of a combined endpoint (myocardial infarction and cardiovascular death) and their relation to markers of inflammation in 1298 patients with angiographically documented CAD. RESULTS: In univariate analysis, serum concentrations of apoA-I were significantly and inversely related to the combined endpoint, whereas serum concentrations of LDL, apoB, and triglycerides were not. HDL was not significantly related to the endpoint in univariate analyses (p=0.057). Multivariate analyses showed that only apoA-I is an independent predictor. ApoA-I (and HDL) was significantly related to markers of inflammation. CONCLUSION: Serum apoA-I levels were an independent predictor for fatal and non-fatal cardiovascular events in patients with CAD. This may be related to its anti-inflammatory effect.

Comparison of the platelet concentrate collection system with the plasma-rich-in-growth-factors kit to produce platelet-rich plasma: a technical report.

PURPOSE: The aim of this study was to compare a new method for the production of platelet-rich plasma (PRP), the plasma-rich-in-growth-factors kit (PRGF kit; G.A.C. Medicale San Antonio, Vitoria, Spain), with an established method, the Platelet Concentrate Collection System (PCCS; 3i/Implant Innovations, Palm Beach Gardens, FL) with respect to resulting cellular and growth factor contents. MATERIALS AND METHODS: Whole blood was drawn from 51 healthy donors (20 men, 31 women) aged 19 to 59 years (mean +/- SD 35.12 +/- 9.65 years), and PRP was prepared by both methods. RESULTS: Platelet counts differed significantly (signed rank test, P < .001 for all) between the donor blood (274,200 +/- 54,050/microL), the PCCS PRP preparation (1,641,800 +/- 426,820/microL), and the PRGF kit PRP preparation (513,630 +/- 139,470/microL). The PCCS concentrated leukocytes (whole blood, 6,992 +/- 2,011/microL; PCCS PRP, 14,153 +/- 7,577/microL), while the PRGF kit produced a leukocyte-poor PRP (65 +/- 108/microL). Higher concentrations of transforming growth factor beta1 (TGF-beta1) and platelet-derived growth factor AB (PDGF-AB) were found in the PCCS PRP (TGF-/beta1, 290 +/- 95 ng/mL; PDGF-AB, 157 +/- 62 ng/mL) than in the Anitua PRGF kit PRP (TGF-beta1, 73 +/- 26 ng/mL; PDGF-AB, 47 +/- 21 ng/mL). Statistical analysis showed significant differences (P < .001 for TGF-beta1 and P < .01 for PDGF-AB). DISCUSSION: The results of this study and some data in the literature indicate that the content of growth factors in PRP can vary tremendously, depending on the system used for the preparation of PRP. CONCLUSION: PCCS collects more platelets and leukocytes than the PRGF kit. This results in significantly higher growth factor levels. Further in vivo studies are needed to determine whether this results in a clinically different biologic effect.

Impact of infectious burden on progression of carotid atherosclerosis.

BACKGROUND AND PURPOSE: Recent findings suggest a causative role of infections in the pathogenesis of atherosclerosis. The extent of atherosclerosis and the prognosis of patients with atherosclerosis seem to be increased by the number of infections to which an individual has been exposed. In a prospective study, we evaluated the effect of 8 pathogens and the aggregate pathogen burden on the progression of carotid atherosclerosis. METHODS: In 504 patients (74.9% men; age, 62.9+/-10 years), we measured intima-media thickness and prevalence of carotid artery stenosis. Follow-up measurements after a mean of 2.5 years were available in 427 patients (85%). Blood samples were taken, and IgG or IgA antibodies to Chlamydia pneumoniae, Helicobacter pylori, Haemophilus influenzae, Mycoplasma pneumoniae, cytomegalovirus, Epstein-Barr virus, and herpes simplex virus types 1 and 2 were measured. Statistical evaluation was performed with logistic regression procedures. RESULTS: Elevated IgA antibodies against C pneumoniae (P<0.04) and IgG antibodies against Epstein-Barr virus (P<0.01) and herpes simplex virus type 2 (P<0.04) were associated with progression of atherosclerosis (increase of intima-media thickness > or =0.1 mm/y or progression of carotid stenosis) after adjustment for age, sex, cardiovascular risk factors, highly sensitive C-reactive protein, and statin intake. Infectious burden, divided into 0 to 3, 4 to 5, and 6 to 8 seropositivities, was significantly associated with progression of atherosclerosis, with odds ratios of 1.8 (95% confidence interval, 1.1 to 2.9) for 4 to 5 and 3.8 (95% CI, 1.6 to 8.8) for 6 to 8 compared with 0 to 3 seropositivities after adjustment. CONCLUSIONS: Our results support the hypothesis that the number of infectious pathogens to which an individual has been exposed independently contributes to the progression of carotid atherosclerosis.

Nickel release after implantation of the Amplatzer occluder.

BACKGROUND: Transcatheter closure of atrial septal defects is a new and less traumatic technique than open heart surgery. In recent years, patients with a patent foramen ovale sustaining potential paradoxical embolism have also become candidates for interventional closure devices. One of the more popular occluding devices is the Amplatzer septal occluder, which, like many other occluders, is made of nitinol. Nitinol-based alloys are widely used in medical products, for example, in orthopedics and orthodontics. However, the clinical use of nitinol, which contains 55% nickel, is still controversial because of concerns about its biocompatibility. Therefore, we examined the systemic nickel release after implantation of the Amplatzer occluder. METHODS AND RESULTS: In 67 patients with no history of nickel sensitivity, blood samples were taken 24 hours before and 24 hours, 1, 3, and 12 months after occluder implantation. Nickel serum concentrations were measured by atomic absorption spectrometry; a value of <2 ng/mL of nickel was considered to be normal. A rise in mean serum levels of nickel was observed, from 0.47 ng/mL before implantation to 1.27 ng/mL (24 hours after), to a maximum of 1.50 ng/mL 1 month after implantation, which was statistically significant (P =.008 and P = 0.022, Wilcoxon Test). During follow-up, the values decreased to those measured before implantation. CONCLUSIONS: Nickel seems to be released from the device, causing a systemic rise in serum levels of nickel, possibly until a calcium-phosphate layer has formed on the passive oxide film of the device or until endothelialization is complete. Possible biological effects should be considered, particularly in young patients or patients with nickel hypersensitivity.

Genetic and environmental influences on the fibrinolytic system: a twin study.

The determination of heritability is a key issue to assess the predictive power of polymorphisms for disease in clinical studies. The aim of this study was to determine the heritability of proteins and activation markers of the fibrinolytic system in a large cohort of healthy twins. Heritability was calculated as 0.76 for thrombin activatable fibrinolysis inhibitor (TAFI), 0.44 for plasminogen activator inhibitor-1 (PAI-1), and 0.43 for tissue plasminogen activator. No significant genetic influence was observed for alpha2-antiplasmin-plasmin-complex and D-dimer. Heritability explained by single gene polymorphisms was 25.2% for TAFI 505G>A, 31.5% for 1542C>G, and 50.0% for combination of both. The influence on TAFI levels of 1542C>G (CC-->GG, median: -80.5%) was considerably stronger than that of 505G>A (GG-->AA, median: +49.3%) and in both cases there seems to be a dose-response relationship. Significant environmental influences on TAFI levels were observed for combined interaction terms (age*sex and bmi*sex). The PAI-1 4G/5G polymorphism explained 56.4% of the calculated heritability. The genetic variables accounting for the 43% heritability of tPA remain unknown. Our data show that the production of several key components of the fibrinolytic system is strongly genetically determined. This genetic influence is accounted for in large part but not completely by a limited number of polymorphisms within the respective genes associated with plasma levels of the gene products.

Serum uric acid as an independent predictor of mortality in patients with angiographically proven coronary artery disease.

It is a matter of controversy as to whether uric acid is an independent predictor of mortality in patients with coronary artery disease (CAD) or whether it represents only an indirect marker of adverse outcome by reflecting the association between uric acid and other cardiovascular risk factors. Therefore, we studied the influence of uric acid levels on mortality in patients with CAD. In 1,017 patients with angiographically proven CAD, classic risk factors and uric acid levels were determined at enrollment. A follow-up over a median of 2.2 years (maximum 3.1) was performed. Death from all causes was defined as an end point of the study. In CAD patients with uric acid levels <303 micromol/L (5.1 mg/dl) (lowest quartile) compared with those with uric acid levels >433 micromol/L (7.1 mg/dl) (highest quartile), the mortality rate increased from 3.4% to 17.1% (fivefold increase). After adjustment for age, both sexes demonstrated an increased risk for death with increasing uric acid levels (female patients: hazard ratio [HR] 1.30, 95% confidence intervals [CI] 1.14 to 1.49, p < or = 0.001; male patients: HR 1.39 [95% CI 1.21 to 1.59], p < or = 0.001). In multivariate Cox regression analysis performed with 12 variables that influence overall mortality-including diuretic use-elevated levels of uric acid demonstrated an independent, significant positive relation to overall mortality (HR 1.23 [95% CI 1.11 to 1.36], p <0.001) in patients with CAD. Thus, uric acid is an independent predictor of mortality in patients with CAD.

Relation of markers of inflammation (C-reactive protein, fibrinogen, von Willebrand factor, and leukocyte count) and statin therapy to long-term mortality in patients with angiographically proven coronary artery disease.

We evaluated a possible interaction between statins and inflammation in 1,246 patients with angiographically diagnosed coronary artery disease. Four different inflammatory markers were determined: high, sensitive C-reactive protein (hs-CRP) (p = 0.001), fibrinogen (p = 0.006), von Willebrand factor (p = 0.006), and leukocyte count (p = 0.03); these levels were significantly higher among the 88 patients who died of cardiac causes during follow-up (median 2.9 years) than among survivors. In a multivariate backward stepwise Cox regression mode, only hs-CRP was evaluated to be a significant predictor of death from coronary artery disease. This prediction was lost in statin-treated patients. Compared with patients receiving statin medication, patients without statins did not have increased cardiac mortality (even when low-density lipoprotein [LDL] levels were >125 mg/dl) when hs-CRP levels were not elevated. In contrast, patients without statins and elevated hs-CRP (top quartile) had a 2.3-fold increase in risk for fatal coronary events, independent of LDL levels. In conclusion, only elevated hs-CRP was selected as an independent predictor of death. Statin therapy is associated with elevated hs-CRP, with a risk reduction for fatal coronary events, independent of LDL levels; this, in part, may be explained by the anti-inflammatory effects on atherosclerosis.

Impact of pathogen burden in patients with coronary artery disease in relation to systemic inflammation and variation in genes encoding cytokines.

The number of infectious pathogens to which an individual has been exposed (pathogen burden) has been linked to the development and the prognosis of coronary artery disease (CAD). The interaction among infection, genetic host susceptibility, and CAD remains unclear. This study was aimed at evaluating the modulation of the association between CAD and pathogen burden, by serum levels of inflammatory markers and polymorphisms of the interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha genes. Immmunoglobulin (Ig) G or IgA antibodies to 8 pathogens were determined in 991 patients with CAD and 333 control subjects. Serum levels of high-sensitivity C-reactive protein, fibrinogen, IL-6, and TNF-alpha were also measured. All subjects were genotyped for the IL-6/G-174C, the TNF/C-851T, and the TNF/G-308A polymorphisms. Analysis of single pathogens demonstrated a positive relation to the presence of CAD for some (Chlamydia pneumoniae, cytomegalovirus, Helicobacter pylori, and herpes virus simplex type 1), but not all pathogens. A strong association between increasing pathogen burden and CAD was confirmed, even after adjustment for risk factors. The prevalence of a high pathogen burden (>/=4 pathogens) was 50% in patients and 21% in controls (p <0.0001). A high pathogen burden was associated with decreased high-density lipoprotein cholesterol levels (p <0.001). The association between CAD and pathogen burden was modulated by the IL6/G-174C polymorphism, the odds ratio being higher in heterozygotes than in both types of homozygotes (p <0.05). This interaction appeared to be mediated by variations in serum IL-6 levels. No such interaction was detected with any of the 2 TNF-alpha polymorphisms.

Release of choline in the isolated heart, an indicator of ischemic phospholipid degradation and its protection by ischemic preconditioning: no evidence for a role of phospholipase D.

The release of choline as a water-soluble product of phospholipid hydrolysis was measured in the perfusate of rat hearts to monitor ischemic membrane degradation and its protection by ischemic preconditioning (IPC). Hearts were subjected to global ischemia (GI; 30 min of no-flow) followed by 60 min of reperfusion. To induce IPC, GI was preceded by four no-flow episodes of 5 min each. Deleterious consequences of GI and reperfusion, namely coronary flow reduction, incidence of arrhythmias and release of cardiac troponin T, were significantly attenuated by IPC. The release of choline increased during reperfusion in a biphasic manner: a first phase peaked immediately after GI and was followed by a second, delayed phase indicating choline release caused during reperfusion. Only the second phase was blocked by both IPC and by AACOCF3 (5 microM), an inhibitor of cytosolic phospholipase A2. The activity of phospholipase D (PLD) was unchanged after GI or IPC or GI plus IPC. In conclusion, choline release into heart perfusate was found to be a useful real-time indicator of phospholipid degradation caused by GI and by reperfusion and its protection by IPC. The results supplement previous observations on the accumulation of fatty acids in the phospholipid pool. There was no evidence for PLD activation by GI or IPC.

Influence of HMG-CoA reductase inhibitors on markers of coagulation, systemic inflammation and soluble cell adhesion.

BACKGROUND: Beneath its lipid-lowering properties additional non-lipid effects of statin therapy are discussed. We therefore examined the impact of statins on laboratory markers of coagulation, inflammation and soluble cell adhesion to further explore these effects in 950 hospitalised patients with angiographically proven CAD. METHODS AND RESULTS: Although no significant differences were found in total cholesterol, LDL and HDL and triglyceride levels a statistically lower value in 277 statin-treated patients was found for von Willebrand factor [162(130/224) vs. 208(154/283)%, P=0.0001], leukocyte count [6.9(5.8/8.4) vs. 7.3(6.1/9.4)/nl, P=0.0005], high sensitive CRP [4.3(1.8/10.8) vs. 7.6(2.8/20.0) mg/dl, P=0.0001], interleukin-6 [9.5(5.1/18.7) vs. 14.4(7.2/28.1) mg/dl, P=0.0001] and soluble p-selectin [112.6(82.0/146.0) vs. 127.8(93.8/162.4) mg/dl, P=0.001] compared to 673 patients without statin therapy. This result was confirmed in a subgroup of 510 patients matched for age, gender and percentage of acute coronary syndromes. CONCLUSIONS: In statin treated patients significantly lower levels of coagulation, systemic inflammation and soluble cell adhesion markers were found. Therefore the effect of statin therapy may also be mediated by additional non-lipid-lowering effects.

An improved assay for the determination of C-reactive protein.

C-reactive protein as the most important acute phase reactant in clinical use provides information about acute as well as chronic inflammatory processes. This application requires an improvement of traditional assays that have been available to the clinical laboratory regarding lipemic interference, precision especially at the lower end, assay and calibration stability as well. In the present study the improved Olympus turbidimetric assay for the determination of C-reactive protein (CRP) was evaluated on the Olympus AU640 analytical system. The assay has a lower detection limit of 1.57 mg/l CRP and is linear from 5 mg/l to 200 mg/l. Prozone hook effect did not occur until 300 mg/l with increased prozone sample detection to 3500 mg/l. Imprecison CV values for within-run of less than 2.25% and between-day of lower than 3.1% were found. On-board stability was extended to 60 days, and calibration stability to 28 days. Method comparison to another automated CRP assay yielded a correlation coefficient of r=0.999. Endogenous substances did not interfere with the test results. There was satisfactory recovery of target values according to CRM 470 standardization. In comparison to the previous assay the improved assay offers more accuracy, precision, and linearity and is free from any known interference, which meets user needs, for rapid and convenient determination of CRP on automated analyzers.

Annexin V does not represent a diagnostic alternative to myoglobin for early detection of myocardial infarction.

Annexin V is a calcium binding protein, which is widely present in various cells and tissues. Due to an early release reaction after myocardial injury the determination of annexin V might be useful for the rapid diagnosis of acute myocardial infarction. An enzyme-linked immunosorbent assay was used to measure annexin V in comparison to myoglobin in samples from healthy individuals, patients suffering from acute or chronic liver, renal, and pulmonary diseases as well as acute coronary syndromes and aortocoronary bypass surgery. Increased myoglobin and annexin V concentrations were observed 80 and 140 (maximum) minutes after myocardial ischemia induced by percutaneous transluminal coronary angioplasty. For the diagnosis of myocardial infarction annexin V (cutoff-level: 5.9 microg/L) showed a slightly higher sensitivity than myoglobin (annexin V: 74.5%; myoglobin: 59.6%), but specificity was much lower (annexin V: 39%; myoglobin: 82.5%). The area under the curve of a ROC analysis demonstrated that annexin V cannot be used as an early marker for the diagnosis of acute coronary syndromes. Increased annexin V levels are induced by several diseases, leading to a low specificity for the diagnosis of a myocardial injury.

Growth factor levels in the platelet-rich plasma produced by 2 different methods: curasan-type PRP kit versus PCCS PRP system.

PURPOSE: Potential treatments using autologous thrombocyte growth factors are an important reason to improve methods for isolating platelet-rich plasma (PRP). Two methods for extracting PRP directly by the surgeon are currently available; this study was conducted to compare the growth factor levels in the resulting PRP. MATERIALS AND METHODS: Whole blood was drawn from 46 healthy donors (17 men, 29 women) aged 20 to 59 years (29.9 +/- 7.8). PRP was then separated from each sample by both the PCCS (3i) and Curasan (PRP Kit, Curasan) methods. RESULTS: The growth factor content differed significantly for TGF-beta1 (PCCS 467.1 ng/mL; Curasan 79.7 ng/mL) (sign test P < .0001) and PDGF-AB (PCCS 251.8 ng/mL; Curasan 314.1 ng/mL) (P < .0001); this was less significant for IGF-I (PCCS 91.0 ng//mL; Curasan 69.5 ng/mL) (P < .02). The higher platelet count in the PCCS PRP (PCCS 2,232,500/microL; Curasan 1,140,500/microL) seemed to correlate with a higher level of TGF-beta1 (Spearman's correlation coefficient, r(s) = 0.7), whereas the higher leukocyte count in the Curasan PRP (PCCS 15,300/microL; Curasan 33,150/pL) had only a minor correlation with higher levels of PDGF-AB (r(s) = 0.46). DISCUSSION: The PCCS end product has both a higher platelet count and a higher total content of the growth factors investigated. Nevertheless, the biologic effect of the evaluated growth factor levels remains unknown. The amount of PRP necessary to achieve the intended biologic effects still remains unclear. CONCLUSION: PRP contains growth factors in high concentrations. Precise predictions of growth factor levels based on the thrombocyte counts of whole blood or PRP appeared limited. There are different sources for growth factors (platelets, leukocytes, plasma).

Growth factor levels in platelet-rich plasma and correlations with donor age, sex, and platelet count.

INTRODUCTION: Platelet-rich plasma contains autologous thrombocyte growth factors and might be promising for acceleration of dentoalveolar bone regeneration. In this study, it was analysed for platelet counts and growth factor concentrations. MATERIAL AND METHOD: Platelet-rich plasma was isolated by discontinuous cell separation from 158 healthy men and 55 women aged 17-62 years. One hundred and fifteen specimens (stratified for age and gender of the donor) were analysed for growth factor concentrations and platelet count. RESULTS: The platelet count in platelet-rich plasma (1,407,640+/-320,100/microl) was 5 times higher than in donor blood (266,040+/-60,530/microl). Platelet-derived growth factor AB (117+/-63 ng/ml), transforming growth factor (TGF) beta -1 (169+/-84 ng/ml), and insulin-like growth factor (IGF) I (84+/-23 ng/ml) were found in large amounts, while platelet-derived growth factor (PDGF) BB (10+/-8 ng/ml) and transforming growth factor beta -2 (0.4+/-0.3 ng/ml) were found in small amounts only. The growth factor content was not well correlated with the platelet count in whole blood nor with the platelet-rich plasma (r(p)=0.35). No influence of gender or age on platelet count or growth factor concentrations was discovered (except IGF-I). CONCLUSIONS: While there was substantial variation in the growth factor content of platelet-rich plasma, the factors influencing this are still worthy of further investigation. Furthermore, a technique whereby the growth factor content could be rapidly assessed in platelet-rich plasma may be of therapeutic benefit.

Prognostic value of troponin T, troponin I, and CK-MBmass in patients with chronic renal failure.

BACKGROUND: In patients with chronic renal failure undergoing long-term hemodialysis, ischemic heart disease accounts for up to 50% of mortality. Cardiac troponins T (TnT) and I (TnI) are frequently elevated in this patient group, but data on the prognostic relevance of these markers, especially TnI, are controversial. The aim of this study was to investigate the prognostic power of a new, sensitive TnI assay in comparison with TnT and other cardiac markers. PATIENTS AND METHODS: 104 ambulatory and in-hospital patients (41 women, median age: 65 years, interquartiles: 48-72.5 years; 63 men, median age: 63 years, interquartiles: 51.3-72.5 years) undergoing long-term hemodialysis were investigated. Patients were followed up for 6 months for all kinds of fatal events and nonfatal cardiac events. Serum levels of cardiac TnT, two TnI assays (ACS:180 and Stratus II), CK (creatine kinase), and CK-MB were measured pre- and post-dialysis. RESULTS: Pre- and post-dialysis results were not different for TnT and TnI, while CK and CK-MB levels were significantly lower post-dialysis. Elevated (pre-)dialysis levels were found in 65.7% of patients for TnT (> 0.1 microg/l), in 32.4% for TnI (ACS:180, > 0.15 microg/l), in 2.9% for TnI (Stratus II, > 0.4 microg/l), in 5.7% for CK (> 170 U/l), and in 2.8% for CK-MB (> 1.0 microg/l). 6-month events were observed in 42 patients (40.4%; 20 fatal, 22 nonfatal). The relative risk for 6-month events was calculated to be 16.0-fold for TnT and 8.5-fold for a known coronary heart disease, while both TnI and CK-MB did not predict 6-month events independently. CONCLUSIONS: TnT and a known coronary heart disease are relevant, independent risk factors in patients with chronic renal failure undergoing long-term hemodialysis.

[Manifestations of atherosclerosis in various vascular regions. Similarities and differences regarding epidemiology, etiology and prognosis]. / Manifestationen der Atherosklerose in verschiedenen Gefässregionen. Gemeinsamkeiten und Unterschiede hinsichtlich Epidemiologie, Atiologie und Prognose.

Pathologic studies have demonstrated that atherosclerosis involves the whole arterial vessel tree. In the Framingham study, cardiovascular risk factors could be defined with different prognostic value for the development of atherosclerosis in various vascular regions. The prognosis of patients with atherosclerosis in coronary, carotid or leg arteries is worse compared to a normal population. Moreover, patients with symptomatic lesions in one vascular bed often have additional asymptomatic atherosclerotic lesions in other vascular regions. Patients with atherosclerosis in multiple vascular regions have a worse prognosis than patients with atherosclerosis in one vascular bed only. In a study of 804 patients, we could show a significantly higher incidence of cardiovascular events (death, myocardial infarction, stroke) in patients with coronary artery disease (CAD) and additional lesions in peripheral arteries (leg, carotid) during a 3.2-year follow-up compared to those with CAD only. Local and systemic inflammatory processes in the arterial vessel wall are considered to play an important role with regard to plaque instability. It has been suggested, that besides the symptomatic atherosclerotic lesion, multiple stable or unstable lesions are present in the whole arterial vessel tree predicting the patient's prognosis. Chronic infections with multiple pathogens ("concept of infectious burden") probably play an important role by triggering these inflammatory processes. Therefore, systemic therapeutic regimes are necessary for the treatment of patients with atherosclerosis. The platelet aggregation inhibitors improve the prognosis of patients with atherosclerosis in all vascular areas. Another important therapeutic regime is the use of statins, which seem to be not only effective in lipid lowering but also in plaque stabilization.