Increased whole blood chemiluminescence in patients with chronic renal failure independent of hemodialysis treatment

Kidney Transplant Recipients Show Limited Lung Diffusion Capacity but Similar Hydrogen Peroxide Exhalation as Healthy Matched Volunteers: A Pilot Study

Patients with end-stage chronic kidney disease show higher systemic oxidative stress and exhale more hydrogen peroxide (H2O2) than healthy controls. Kidney transplantation reduces oxidative stress and H2O2 production by blood polymorphonuclear leukocytes (PMNs). Kidney transplant recipients (KTRs) may be predisposed to an impairment of lung diffusing capacity due to chronic inflammation. Lung function and H2O2 concentration in the exhaled breath condensate (EBC) were compared in 20 KTRs with stable allograft function to 20 healthy matched controls. Serum interleukin eight (IL-8) and C-reactive protein (CRP), blood cell counts, and spirometry parameters did not differ between groups. However, KTRs showed lower total lung diffusing capacity for carbon monoxide, corrected for hemoglobin concentration (TLCOc), in comparison to healthy controls (92.1 ± 11.5% vs. 102.3 ± 11.9% of predicted, p = 0.009), but similar EBC H2O2 concentration (1.63 ± 0.52 vs. 1.77 ± 0.50 µmol/L, p = 0.30). The modality of pre-transplant renal replacement therapy had no effect on TLCOc and EBC H2O2. TLCOc did not correlate with time after transplantation. In this study, TLCOc was less reduced in KTRs in comparison to previous reports. We suggest this fact and the non-elevated H2O2 exhalation exhibited by KTRs, may result perhaps from the evolution of the immunosuppressive therapy.

Exhaustive Exercise Increases Spontaneous but Not fMLP-Induced Production of Reactive Oxygen Species by Circulating Phagocytes in Amateur Sportsmen

Strenuous exercise alters the oxidative response of blood phagocytes to various agonists. However, little is known about spontaneous post exercise oxidant production by these cells. In this cross-over trial, we tested whether an exhaustive treadmill run at a speed corresponding to 70% of VO2max affects spontaneous and fMLP-provoked oxidant production by phagocytes in 18 amateur sportsmen. Blood was collected before, just after, and 1, 3, 5 and 24 h post exercise for determination of absolute and normalized per phagocyte count spontaneous (a-rLBCL, rLBCL) and fMLP-induced luminol-enhanced whole blood chemiluminescence (a-fMLP-LBCL, fMLP-LBCL). a-rLBCL and rLBCL increased by 2.5- and 1.5-times just after exercise (p < 0.05) and then returned to baseline or decreased by about 2-times at the remaining time-points, respectively. a-fMLP-LBCL increased 1.7- and 1.6-times just after and at 3 h post-exercise (p < 0.05), respectively, while fMLP-LBCL was suppressed by 1.5- to 2.3-times at 1, 3, 5 and 24 h post-exercise. No correlations were found between elevated post-exercise a-rLBCL, a-fMLP-LBCL and run distance to exhaustion. No changes of oxidants production were observed in the control arm (1 h resting instead of exercise). Exhaustive exercise decreased the blood phagocyte-specific oxidative response to fMLP while increasing transiently spontaneous oxidant generation, which could be a factor inducing secondary rise in antioxidant enzymes activity.

Decreased integrity of exercise-induced plasma cell free nuclear DNA - negative association with the increased oxidants production by circulating phagocytes

Strenuous exercise increases circulating cell free DNA (cfDNA) and stimulates blood phagocytes to generate reactive oxygen species (ROS) which may induce DNA strand breaks. We tested whether: (A) elevated cfDNA in response to three repeated bouts of exhaustive exercise has decreased integrity; (B) each bout of exercise increases luminol enhanced whole blood chemiluminescence (LBCL) as a measure of ROS production by polymorphonuclear leukocytes. Eleven men performed three treadmill exercise tests to exhaustion separated by 72 hours of resting. Pre- and post-exercise concentrations and integrity of cf nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) and resting (r) and fMLP (n-formyl-methionyl-leucyl-phenylalanine)-stimulated LBCL were determined. Each bout increased concentrations of cf n-DNA by more than 10-times which was accompanied by about 2-times elevated post-exercise rLBCL and fMLP-LBCL. Post-exercise cf n-DNA integrity (integrity index, I_229/97) decreased after the first (0.59 ± 0.19 vs. 0.48 ± 0.18) and second (0.53 ± 0.14 vs. 0.44 ± 0.17) bout of exercise. There were negative correlations between I_229/97 and rLBCL (ƍ = –0.37), and I_229/97 and fMLP-LBCL (ƍ = –0.40) – analysis of pooled pre- and post-exercise data (n = 66). cf mt- DNA integrity (I_218/78) did not alter in response to exercise. This suggests an involvement of phagocyte ROS in cf n-DNA strand breaks in response to exhaustive exercise.

Apple intake improves antioxidant parameters in hemodialysis patients without affecting serum potassium levels

Oxidative stress (OS) is associated with increased morbidity and mortality in hemodialysis (HD) patients, and the consumption of fruits seems to improve OS due to their antioxidant properties. Therefore, we hypothesized that Fuji apple intake improves OS markers in HD patients due to its polyphenolic compounds without increasing serum potassium levels. This trial was a 1-group, pre- and posttest comparison between 16 patients who had been on hemodialysis for at least 3 months without any acute illness or hyperkalemia. Each volunteer consumed 2 Fuji apples (~360 g) per day for 1 week. Blood samples were collected at the baseline period and after 8 days for the measurement of total antioxidant status, ascorbic acid, catalase, glutathione peroxidase, superoxide dismutase, reduced glutathione, total oxidant status, oxidative stress index, potassium, phosphorus, uric acid, glucose, and fructosamine. For tolerance evaluation, participants were asked about their bowel habits. Apple intake increased glutathione peroxidase (P = .006) and superoxide dismutase activities (P = .006) and ascorbic acid levels (P = .002). No significant changes were observed in uric acid, potassium, phosphorus, glucose, and fructosamine levels. Additionally, there was a decrease in the catalase activity (P = .021) and in the total antioxidant status values (P = .004). However, increased total oxidant status (P = .003) and oxidative stress index (P = .033) levels were observed after apple intake. In conclusion, the intake of 2 Fuji apples per day for 1 week was well tolerated and improved antioxidant parameters in HD patients without affecting serum potassium levels.

Using chemiluminescence to determine whole blood antioxidant capacity in rheumatoid arthritis and Parkinson's disease patients

The consequences of oxidative stress and inflammation are implicated in a wide range of diseases, including rheumatoid arthritis and Parkinson's disease. The status of antioxidant capacity in rheumatoid arthritis and Parkinson's disease remains unclear, in part due to common practice of assaying erythrocytes separately to plasma. This method removes any synergistic interactions between plasma and erythrocyte-based antioxidants. The experiments in this report tested antioxidant capacity in whole blood, erythrocytes and plasma by group and disease stage. Medically diagnosed patients were recruited along with appropriate control group participants. Fasting venous blood was assayed using chemiluminescence methods for: time to maximum light emitted, maximum light emitted, and plasma antioxidant capacity in vitamin E analogue units. Here we demonstrate that whole blood exhibits higher antioxidant capacity than either plasma or erythrocytes assayed separately. We report increased oxidative stress in the blood of rheumatoid arthritis patients by group (p = 0.018, p = 0.049). We show increased antioxidant capacity in Parkinson's disease patients by group (p < 0.001). For later stage Parkinson's disease patients, we report reduced oxidative stress (p = 0.025), and increased antioxidant capacity and for erythrocytes (p < 0.001, p = 0.004) and whole blood (p < 0.001, p = 0.003). Early stage Parkinson's disease showed higher antioxidant capacity on only one measure (p = 0.008). Whole blood chemiluminescence is a useful technique for determining redox status in disease and might help clarify the role of oxidative stress in rheumatoid arthritis and Parkinson's disease.

Do HDL and LDL subfractions play a role in atherosclerosis in end-stage renal disease (ESRD) patients?

BACKGROUND

Significantly increased cardiovascular mortality in patients with chronic kidney (CKD) disease cannot be explained by traditional risk factors. Recent studies revealed that the quality of HDL and LDL cholesterol may be more important than their serum levels. The aim of this study was to assess which LDL and HDL subfractions were more abundant in end-stage renal disease (ESRD) patients and to analyse whether subfraction distribution could be associated with accelerated atherosclerotic processes.

METHODS

This study included 50 ESRD patients undergoing dialysis and 20 healthy volunteers. LDL and HDL subfractions were analysed in serum with the use of Lipoprint system. All patients had intima-media thickness (IMT) measured.

RESULTS

Statistically significant differences in subfractions between control and study group were observed in case of: HDL1 (p < 0.0001), HDL2 (p = 0.009), HDL3 (p < 0.0001), HDL4 (p = 0.003), HDL5 (p = 0.01), HDL7 (p < 0.0001), HDL8 (p < 0.0001), HDL9 (p < 0.0001), HDL10 (p < 0.0001), large HDL (p < 0.0001), HDL Small (p < 0.0001) as well as IDL-B (p = 0.014), IDLA (p = 0.011), LDL2 (p = 0.007). Significant differences were also observed in HDL and LDL subfraction distribution between haemodialysis patients with normal and increased IMT: HDL6 (p = 0.020), HDL Large (HDL1-3) (p = 0.017), HDL Intermediate (HDL4-7) (p = 0.017).

CONCLUSIONS

This study revealed that ESRD influenced HDL subfractions. In HD patients, large HDL subfractions are more abundant while small HDL fraction is more frequent in healthy persons. It failed to show the influence of end-stage disease on LDL subfraction levels. Shift in HDL subfractions might be responsible for the increased risk of atherosclerosis in CKD patients.

Addition of strawberries to the usual diet decreases resting chemiluminescence of fasting blood in healthy subjects-possible health-promoting effect of these fruits consumption

OBJECTIVE

Regular strawberry consumption augmented plasma antioxidant activity and decreased lipid peroxidation suggests preventive potential of these fruits against oxidative stress-dependent disorders. Blood phagocytes are important source of oxidants that may contribute to systemic oxidative stress. We examined the effect of strawberry consumption on the luminol enhanced whole blood chemiluminescence (LBCL) reflecting oxidants generation by circulating phagocytes in healthy subjects.

METHODS

Thirty-one healthy subjects (being on their usual diet) consumed 500 g of strawberry pulp daily (between 11.00-14.00) for 30 days (1st strawberry course) and after 10 day wash-out the cycle was repeated (2nd strawberry course). Fasting blood and spot morning urine samples were collected before and after each strawberry course for measuring resting and agonist (fMLP)-induced LBCL, various phenolics and plasma antioxidant activity. Twenty subjects served as a control in respect to LBCL changes over the study period.

RESULTS

Strawberry consumption decreased median resting LBCL and this effect was more evident after the 1st course (by 38.2%, p < 0.05) than after the the 2nd one (18.7%), while fMLP-induced LBCL was constant. No changes in LBCL were noted in controls. Strawberries increased fasting plasma levels of caffeic acid and homovanillic acid as well as urolithin A and 4-hydroxyhippuric acid in spot urine. Plasma antioxidant activity and the number of circulating phagocytes did not change over the study period. Resting LBCL correlated positively with the number of circulating polymorphonuclear leukocytes at all occasions and negative correlation with plasma 4-hydroxyhippuric acid was noted especially after the first strawberry course (r = -0.46, p < 0.05).

CONCLUSIONS

The decrease in resting LBCL suggests that regular strawberry consumption may suppress baseline formation of oxidants by circulating phagocytes. This may decrease the risk of systemic imbalance between oxidants and anti-oxidants and be one of mechanisms of health-promoting effect of these fruits consumption.

The influence of uremic high cystatin C concentration on neutrophil apoptosis and selected neutrophil functions isolated from healthy subjects

Background

Cystatin C (cC) is a cysteine protease inhibitor that may influence immune response. Our aim was to test the effect of a high concentration of cC, characteristic for uremic patients, on neutrophil (PMN) apoptosis and respiratory burst, as well as the cC secretion from PMNs stimulated with proinflammatory cytokines.

Material/Methods

PMNs from 35 healthy volunteers aged 27–61 years were cultured in presence of cC, IL-1β or TNF-α. The percentage of apoptotic cells based on DNA depletion, Fas, FasL and caspase -3 expression were assessed. CC concentrations were determined by ELISA test. The influence of cC on spontaneous, fMLP-, PMA- or OZ-induced burst response of PMNs was tested using chemiluminescence.

Results

PMN cultured in the presence of cC resulted in a significant drop in apoptotic cell percentage (38% [11%; 65%]) compared both to control (70% [29%; 92%], and to the cells cultured with TNF-α (58% [24%; 85%]). These differences were not accompanied by Fas, FasL and caspase-3 expression changes. Spontaneous, fMLP- and PMA-stimulated oxidative burst of PMNs preincubated with cC were significantly downregulated. IL-1β markedly diminished and TNF-α significantly increased cC concentration in culture supernatants.

Conclusions

The presented results suggest that antiapoptotic activity of cC results from its inhibitory effect on ROS production. Thus, the higher concentration of cC characteristic for uremic patients may modulate acute inflammation through maintaining PMN longevity and inhibiting their respiratory burst and proinflammatory cytokine-related changes in cC release from PMNs.

Evaluation of selected parameters of the antioxidative system in patients with type 2 diabetes in different periods of metabolic compensation

Introduction:

The aim of the study was to evaluate some selected parameters of the antioxidative system in patients with type 2 diabetes.

Materials and Methods:

Eighty-one type 2 diabetes patients took part in the study (39 patients with metabolically balanced and 42 with metabolically unbalanced diabetes). The control group consisted of 30 healthy people. The total antioxidant capacity of plasma was measured fluorometrically using phycoerythrin. To calculate the low-molecular-weight antioxidant concentration in the plasma samples, the duration of Trolox activity as a function of its concentration in the sample was measured. The activity of antioxidative enzymes in red blood cells was determined using the Misra and Fridovich method and Beers and Sizer method.

Results:

The total plasma antioxidant capacity and the low-molecular-weight antioxidant concentration in the group of patients with metabolically compensated type 2 diabetes were statistically significantly higher than in the group of patients with metabolically uncontrolled diabetes. The activity of antioxidative enzymes was found to be higher in the group of type 2 diabetes patients at the stage of metabolic balance.

Conclusions:

The obtained results confirm the thesis of glucose toxicity and intensification of oxidative stress in patients with diabetes.