Soluble CD14 and Osteoprotegerin Associate with Ankle-Brachial Index as a Measure of Arterial Stiffness in Patients with Mild-to-Moderate Chronic Kidney Disease in a Five-Year Prospective Study.

INTRODUCTION: Vascular lesions and arterial stiffness appear at early stages of chronic kidney disease (CKD) and follow an accelerated course with disease progression, contributing to high cardiovascular mortality. There are limited prospective data on mechanisms contributing to progression of arterial stiffness in mild-to-moderate CKD (stages 2-3). METHODS: We applied an affinity proteomics approach to identify candidates of circulating biomarkers with potential impact on vascular lesions in CKD and selected soluble cluster of differentiation 14 (sCD14), angiogenin (ANG), and osteoprotegerin (OPG) for further analysis. We studied their association with ankle-brachial index (ABI) and carotid intima-media thickness, as measures of arteriosclerosis and atherosclerosis, respectively, in 48 patients with CKD stages 2-3, who were prospectively followed and intensively treated for 5 years, and 44 healthy controls. RESULTS: Concentrations of sCD14 (p < 0.001), ANG (p < 0.001), and OPG (p < 0.05) were higher in patients with CKD 2-3 at baseline, and sCD14 (p < 0.001) and ANG (p < 0.001) remained elevated in CKD patients at follow-up. There were positive correlations between ABI and sCD14 levels (r = 0.36, p = 0.01) and between ABI and OPG (r = 0.31, p = 0.03) at 5 years. The changes in sCD14 during follow-up correlated to changes in ABI from baseline to 5 years (r = 0.41, p = 0.004). CONCLUSION: Elevated levels of circulating sCD14 and OPG in patients with CKD 2-3 were significantly associated with ABI, a measure of arterial stiffness. An increase in sCD14 over time in CKD 2-3 patients was associated with a corresponding increase in ABI. Further studies are needed to examine if early intensive multifactorial medication to align with international treatment targets may influence cardiovascular outcomes.

Associations of Fibroblast Growth Factor 23 with Markers of Inflammation and Leukocyte Transmigration in Chronic Kidney Disease.

BACKGROUND: Patients with chronic kidney disease (CKD) show elevated levels of inflammatory markers and have an increased risk of infections as well as cardiovascular morbidity. Recent studies have implied effects of fibroblast growth factor 23 (FGF23) on inflammation in CKD. We analyzed potential correlations between levels of FGF23 with pro-inflammatory chemokines and markers of leukocyte transmigration in CKD patients. METHODS: One hundred three patients with CKD 2-5ND and 54 healthy controls, had biochemical markers in blood and urine analyzed according to routine protocol. Pro-inflammatory cytokines were analyzed by Milliplex technique and leukocyte CD11b adhesion molecule expression was measured by flow cytometry. FGF23 levels were measured with ELISA technique. Treatment of leukocytes from healthy blood donors with FGF23 was performed in vitro and effects analyzed by flow cytometry. RESULTS: Tumor necrosis factor-alpha, RANTES and interleukin (IL)-12 levels were significantly higher (p = 0.001, p < 0.001, and p < 0.001) in patients with CKD. Elevated FGF23 levels in the CKD group correlated to glomerular filtration rate, parathyroid hormone, urinary albumin excretion and phosphate as well as to IL-12 and RANTES. CD11b expression on resting granulocytes and monocytes, and on activated monocytes, was associated with FGF23. In vitro treatment of leukocytes with FGF23 reduced CD11b expression in resting as well as in formyl-methyinoyl-leucyl-phenylalanine-stimulated granulocytes (p = 0.03). CONCLUSION: FGF23 levels are associated with various inflammatory markers such as pro-inflammatory cytokines and adhesion molecules on innate immune cells. However, further studies are warranted to define the direct role of FGF23 in modulation of the innate immune system in CKD.

Healthcare costs in chronic kidney disease and renal replacement therapy: a population-based cohort study in Sweden.

OBJECTIVE: To compare healthcare costs in chronic kidney disease (CKD) stage 4 or 5 not on dialysis (estimated glomerular filtration rate <30 mL/min/1.73m2), peritoneal dialysis, haemodialysis and in transplanted patients with matched general population comparators. DESIGN: Population-based cohort study. SETTING: Swedish national healthcare system. PARTICIPANTS: Prevalent adult patients with CKD 4 or 5 (n=1046, mean age 68 years), on peritoneal dialysis (n=101; 64 years), on haemodialysis (n=460; 65 years) and with renal transplants (n=825; 52 years) were identified in Stockholm County clinical quality registers for renal disease on 1 January 2010. 5 general population comparators from the same county were matched to each patient by age, sex and index year. PRIMARY AND SECONDARY OUTCOME MEASURES: Annual healthcare costs in 2009 incurred through inpatient and hospital-based outpatient care and dispensed prescription drugs ascertained from nationwide healthcare registers. Secondary outcomes were annual number of hospital days and outpatient care visits. RESULTS: Patients on haemodialysis had the highest mean annual cost (€87 600), which was 1.49 (95% CI 1.38 to 1.60) times that observed in peritoneal dialysis (€58 600). The mean annual cost was considerably lower in transplanted patients (€15 500) and in the CKD group (€9600). In patients on haemodialysis, outpatient care costs made up more than two-thirds (€62 500) of the total, while costs related to fluids ($29 900) was the largest cost component in patients on peritoneal dialysis (51%). Compared with their matched general population comparators, the mean annual cost (95% CI) in patients on haemodialysis, peritoneal dialysis, transplanted patients and patients with CKD was 45 (39 to 51), 29 (22 to 37), 11 (10 to 13) and 4.0 (3.6 to 4.5) times higher, respectively. CONCLUSIONS: The mean annual costs were ∼50% higher in patients on haemodialysis than in those on peritoneal dialysis. Compared with the general population, costs were substantially elevated in all groups, from 4-fold in patients with CKD to 11, 29 and 45 times higher in transplanted patients and patients on peritoneal dialysis and haemodialysis, respectively.

Early Changes in Monocyte Adhesion Molecule Expression and Tumor Necrosis Factor-α Levels in Chronic Kidney Disease - A 5-Year Prospective Study.

BACKGROUND: Despite the absence of clinical symptoms, patients with chronic kidney disease (CKD) exhibit elevated levels of pro-inflammatory markers. To investigate whether it is possible to detect inflammatory activity and altered monocyte function at an early stage of renal disease, we studied patients with CKD stages 2-3 over 5 years. METHODS: The expression of adhesion molecules on monocytes at resting state and after stimulation with formyl-methionyl-leucyl-phenylalanine (fMLP), as well as oxidative metabolism capacity was measured with flow cytometry in 108 CKD patients and healthy controls. Soluble markers of inflammation, such as cytokines, were analyzed using the Milliplex technique. RESULTS: Patients showed significantly lower CD11b expression after stimulation during the 3rd (p = 0.002) and the 5th year (p < 0.001), together with a lower oxidative burst in response to fMLP over time (p = 0.02). The expression of CD62L on resting monocytes was lower during the 3rd (p = 0.001) and the 5th (p = 0.001) year in patients. Levels of tumor necrosis factor-α and RANTES were significantly increased (p = 0.001, p = 0.006) and interleukin-12 levels were also higher in CKD patients during the 5th year (p = 0.007). CONCLUSION: Monocytes in CKD stages 2-3 show emerging functional abrasions, with altered adhesion molecule expression and impaired fMLP response. These findings suggest that a transformation of monocyte function occurs at an early phase of renal impairment and may together with increased plasma levels of pro-inflammatory cytokines contribute to the higher vulnerability of CKD patients to comorbidities, such as infections and cardiovascular disease.

Dialysis modality and nutritional status are associated with variability of inflammatory markers.

BACKGROUND: Inflammation is a common feature in dialysis patients and is associated with cardiovascular complications and poor outcome. Measuring the variability of inflammatory markers may help in understanding underlying factors triggering inflammation. Whether the inflammatory pattern in hemodialysis (HD) and peritoneal dialysis (PD) patients differs has scarcely been studied. Here we explored factors associated with the magnitude and variability of inflammation markers in HD and PD patients. METHODS: In two 3-month, prospective cohort studies comprising 228 prevalent HD and 80 prevalent PD patients, interleukin-6 (IL-6) and high-sensitivity C-reactive protein (CRP) were measured in blood samples drawn each month and every week, respectively. Information on comorbidity, protein-energy wasting (PEW) and medications was gathered at baseline, and information on symptoms potentially related to inflammation was gathered weekly. A mixed-effect model was used for multivariate analysis of factors linked to CRP and IL-6 variation. RESULTS: IL-6 and CRP levels were higher and showed higher variability in HD versus PD patients [median IL-6 8.3 (interquartile range, IQR, 5.3-14.5) versus 6.7 (IQR 4.2-10.0) pg/mL, P < 0.001 and median CRP 6.1 (IQR 2.5-14.0) versus 5.4 (IQR 1.6-9.0) mg/L, P < 0.001). PEW predicted increased inflammation variability after correcting for age, sex, dialysis vintage, modality and comorbidity. Increased comorbidity predicted IL-6, but not CRP, variability. CONCLUSIONS: Circulating concentrations as well as variability of IL-6 and CRP levels were higher in HD as compared with PD patients. In HD and PD patients, short-term variability of IL-6 and CRP levels associated strongly with PEW, while comorbidity was related to IL-6 but not to CRP variability.

Activation of basophils is a new and sensitive marker of biocompatibility in hemodialysis.

The hemodialysis procedure involves contact between peripheral blood and the surface of dialyzer membranes, which may lead to alterations in the pathways of innate and adaptive immunity. We aimed to study the effect of blood-membrane interaction on human peripheral basophils and neutrophils in hemodialysis with high- and low-permeability polysulfone dialyzers. The surface expression of CD203c (basophil selection marker) and CD63 (activation marker) after activation by the bacterial peptide formyl-methionyl-leucyl-phenylalanine (fMLP) or anti-Fcε receptor I (FcεRI) antibody and the absolute number of basophils was investigated before and after hemodialysis with each of the dialyzers. Moreover, the expression on neutrophils of CD11b, the CD11b active epitope, and CD88 was analyzed in the same groups of individuals. The expression of CD63 in basophils following activation by fMLP was significantly higher in the patient group compared with that in healthy controls, but no differences were observed after activation by anti-FcεRI. During the hemodialysis procedure, the low-flux membrane induced up-regulation of CD63 expression on basophils, while passage through the high-flux membrane did not significantly alter the responsiveness. In addition, the absolute number of basophils was unchanged after hemodialysis with either of the dialyzers and compared with healthy controls. We found no significant differences in the expression of the neutrophil activation markers (CD11b, the active epitope of CD11b, and CD88) comparing the two different dialyzers before and after dialysis and healthy controls. Together, these findings suggest that alterations in basophil activity may be a useful marker of membrane bioincompatibility in hemodialysis.

DNA damage in salivary gland tissue in patients with chronic kidney disease, measured by the comet assay.

OBJECTIVE: The aim of this observational study was to investigate the relationship between DNA damage in minor accessory salivary glands, hyposalivation, and inflammation in patients with chronic kidney disease (CKD). STUDY DESIGN: DNA strand breaks and oxidative DNA lesions in salivary glands, inflammatory markers, and uremic state were measured in 79 patients with CKD and matched controls. RESULTS: CKD patients not yet on dialysis had significantly more, and dialysis patients significantly less, DNA strand breaks in salivary tissue compared with controls. All measured inflammatory markers were higher in patients with CKD compared with controls. Salivary secretion rates were significantly lower in dialysis patients compared with controls. A high level of salivary secretion rate at rest significantly predicted a high level of DNA strand breaks in patients with CKD. CONCLUSIONS: Dialysis patients had fewer DNA strand breaks in minor accessory salivary glands than controls, suggesting that peripheral tissue is differently affected by CKD than leukocytes.

Inflammatory cytokines in saliva: early signs of metabolic disorders in chronic kidney disease. A controlled cross-sectional study.

OBJECTIVE: The aim of this study was to evaluate correlations between levels of cytokines in secreted stimulated saliva in patients with chronic kidney disease (CKD) and hyposalivation. STUDY DESIGN: Seventy patients with clearance <20 mL/min/1.73 m(2) were evaluated; 40 were predialysis, 21 hemodialysis, and 9 peritoneal dialysis, and they were matched with 70 control subjects. Salivary flow rate was measured and submandibular/sublingual saliva collected. Analyses were performed for whole protein content using a protein assay, and levels of tumor necrosis factor (TNF) α, interleukin (IL) 1ß, γ-interferon (γ-INF), IL-6, IL-8, IL-10, monocyte chemotactic protein (MCP) 1, and soluble intercellular adhesion molecule (sICAM) 1, by using Luminex technology. RESULTS: Patients with CKD had lower (P = .03) stimulated salivary secretion rate and higher salivary whole protein concentration (P = .002) than control subjects. Concentrations of IL-8 (P = .03) and MCP-1 (P = .002) were decreased and TNF-α/IL-10 (P = .05) and IL-8/IL10 (P = .03) ratios were decreased in CKD patients. CKD patients with low secretion levels of stimulated saliva expressed decreased levels of TNF-α (P = .04), IL-1ß (P = .02), γ-INF (P = .03), IL-6 (P = .003), IL-8 (P = .005), MCP-1 (P = .006), and sICAM-1 (P = .02). CONCLUSIONS: Salivary cytokines and secretion rates are significantly decreased in CKD patients. Further research is necessary to understand operating mechanisms and clinical implications of the down-regulation of inflammatory markers in saliva.

Biocompatibility and tolerability of a purely bicarbonate-buffered peritoneal dialysis solution.

BACKGROUND: Novel peritoneal dialysis solutions are characterized by a minimal content of glucose degradation products and a neutral pH. Many studies have shown the biocompatibility of neutral lactate-buffered solutions; however, until now, the effect of purely bicarbonate-buffered solutions has not been intensively studied in vivo. METHODS: This study was an open label, prospective, crossover multicenter trial to investigate the biocompatibility of a purely bicarbonate-buffered solution (bicPDF) by measuring biocompatibility parameters such as cancer antigen 125 (CA125) in peritoneal effluent. 55 patients were enrolled in the study. After a 2-week run-in phase, 53 patients could be randomized into 2 groups, starting with either standard lactate-buffered peritoneal dialysis fluid (SPDF) for 12 weeks (phase 1) and then switching to bicPDF for 12 weeks (phase 2), or vice versa. Overnight peritoneal effluents were collected at baseline and at the end of phases 1 and 2 and were tested for CA125, hyaluronic acid, vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), interferon gamma (IFNgamma), and transforming growth factor-beta(1) (TGF-beta1). Total ultrafiltration and residual renal function were also assessed. At the end of the study, pain during fluid exchange and dwell was evaluated using special questionnaires. RESULTS: 34 patients completed the study; 27 of them provided data for analysis of the biocompatibility parameters. CA125 levels in overnight effluent were significantly higher with bicPDF (61.9 +/- 33.2 U/L) than with SPDF (18.6 +/- 18.2 U/L, p < 0.001). Hyaluronic acid levels were significantly lower after the use of bicPDF (185.0 +/- 119.6 ng/mL) than after SPDF (257.4 +/- 174.0 ng/mL, p = 0.013). Both TNF-alpha and TGF-beta1 showed higher levels with the use of bicPDF than with SPDF. No differences were observed for IL-6, VEGF, or IFNgamma levels. We observed an improvement in the glomerular filtration rate with the use of bicPDF but no differences were observed for total fluid loss. Pain scores could be analyzed in 23 patients: there was no difference between the solutions. CONCLUSIONS: The use of a purely bicarbonate-buffered low-glucose degradation product solution significantly changes most of the peritoneal effluent markers measured, suggesting an improvement in peritoneal membrane integrity. Additionally, it seems to have a positive effect on residual renal function.

Prevalence and early detection of oral fungal infection: a cross-sectional controlled study in a group of Swedish end-stage renal disease patients.

OBJECTIVE: Early detection and treatment of local oral fungal infection (OFI) minimize the risk of overgrowth and more serious complications such as invasive infections. Generalized fungal infection increases both morbidity and mortality in end-stage renal disease (ESRD) patients. This study reports the prevalence of ongoing OFI in patients with ESRD and presents correlations with dental microbial plaque formation and mouth dryness. It also describes how oral fungal growth correlates with oral lesions associated with fungal infection. MATERIAL AND METHODS: From March 2007 to October 2008, 93 ESRD patients and 45 age- and gender-matched controls were consecutively asked to participate in the study. In total, 34 patients were treated with peritoneal dialysis (PD) and 59 with haemodialysis (HD). OFI was diagnosed by taking two smear layers from the buccal mucosa. The samples from each side of the mouth were stained with the periodic acid Schiff (PAS) method. The associations between histological findings, age, gender, type of dialysis treatment, tobacco habits, self-experienced mouth dryness, taste disturbances, dental plaque and gingivitis were investigated. The presence of erythematous oral stomatitis, membranous candidiasis and angular cheilitis was noted to clarify how the presence of fungal hyphae correlate with oral lesions associated with OFI. RESULTS: OFI was found in 32% of the ESRD patients and 11% of the controls (p=0.007). An extensive OFI, defined as frequent fungal hyphae formations in oral mucosal smear layers, was found in 3% of the PD and 17% of the HD patients. Oral lesions, defined as clinical signs associated with OFI such as erythematous oral stomatitis, membranous candidiasis or angular cheilitis, were found in 37% of the patients with OFI, while 5% of the patients without findings of fungal infection presented oral lesions associated with OFI (p=0.0002). Furthermore, patients with self-reported mouth dryness were three times more likely (p=0.02) to be diagnosed with OFI. CONCLUSIONS: ESRD patients are found to have significantly more OFI than controls. Patients with ESRD experiencing mouth dryness and dental plaque formation also seem to be at risk of developing OFI. Detection of oral lesions associated with OFI should be combined with a histopathological diagnosis before antifungal treatment.

Clinical findings in oral health during progression of chronic kidney disease to end-stage renal disease in a Swedish population.

OBJECTIVE: Early detection of oral infections plays an important role for dental referral during progression of renal disease and during dialysis treatment in uraemic patients. This study investigated how oral health is related to uraemia in a group of uraemic patients in Stockholm, Sweden. MATERIAL AND METHODS: This cross-sectional study assessed oral diseases in chronic kidney disease (CKD) patients in different stages (n=93) compared with healthy age- and gender-matched controls. Differences in multiple oral outcomes, assessed by a dentist, were investigated in multivariate analyses, adjusted for tobacco habits, diabetes mellitus and uraemia status (predialysis, peritonealdialysis or haemodialysis). RESULTS: Compared with healthy controls, uraemic patients had significantly worse dental status regarding the decayed, missing, filled teeth (DMFT) index (3.3, p=0.003), periodontal loss of attachment (0.9, p=0.00002) and periapical lesions (0.6, p=0.002). For haemodialysis patients DMFT (6.5, p=0.01), periodontal loss of attachment (2.2, p=0.007) and periapical lesions (1.0, p=0.01) were worse compared with controls. The differences between uraemic patients and controls remained after adjustment for age, gender, tobacco habits and diabetes (p<0.05 for all outcomes). CONCLUSIONS: Objective measurements showed that uraemic patients have more dental problems than healthy controls and the patients seem to develop their problems before they have progressed to dialysis. Therefore greater attention to dental problems may be warranted during the progression of uraemia to prevent deterioration of oral health.