Serum and intracellular detection of cytokines in patients undergoing chronic hemodialysis

Predictive Markers for Malignant Urothelial Transformation in Balkan Endemic Nephropathy: A Case-Control Study

Simple Summary

Balkan endemic nephropathy (BEN) is chronic kidney disease caused by intoxication with Aristolochia plant. Apart from subtle decline of renal function that eventually results in kidney failure, the patients are at increased risk for urothelial carcinoma (UC) development. Based on the observed UC markers, the aim of this study was to examine urinary and plasma levels of some these markers in BEN patients without carcinoma, in order to potentially identify those with predictive value. Our study revealed either plasma or urinary survivin levels as a potential predictors of future malignant transformation of urothelium.

Abstract

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial disease frequently accompanied by urothelial carcinoma (UC). In light of the increased UC incidence and the markers observed in BEN patients with developed UC, the aim of the current case–control study is to assess survivin, p53 protein, growth factors and receptors (VEGF, VEGFR1, IGF I, IGF-1R and IGFBP5), tumor marker (TF)/CD142, circulating soluble Fas receptor and neopterin, as potentially predictive markers for UC in patients with BEN (52 patients), compared to healthy, age-matched subjects (40). A threefold increase was registered in both circulating and urinary survivin level in BEN patients. Especially noticeable was the ratio of U survivin/U Cr level five times the ratio of BEN patients associated with standard renal markers in multivariate regression models. The concentrations of VEGF, VEGFR1, (TF)/CD142, (sFas) were not significantly different in BEN patients, while urinary/plasma level demonstrated a significant decrease for VEGF. The levels of IGF I, IGFBP5 and IGF-1R were significantly reduced in the urine of BEN patients. Plasma concentration of neopterin was significantly higher, while urinary neopterin value was significantly lower in BEN patients compared to healthy controls, which reflected a significantly lower urine/plasma ratio and low local predictive value. As BEN is a slow-progressing chronic kidney disease, early detection of survivin may be proposed as potential predictor for malignant alteration and screening tool in BEN patients without the diagnosis of UC.

Relations between concentrations of asymmetric dimethylarginine and neopterin as potential risk factors for cardiovascular diseases in haemodialysis-treated patients

OBJECTIVES

To investigate the correlation between concentrations of asymmetric dimethylarginine (ADMA) and neopterin (NP) as potential risk factors for cardiovascular diseases in chronic renal failure patients.

METHOD

In this study, 33 patients with renal failure before and after haemodialysis were compared with healthy control subjects. Serum ADMA and NP levels were measured using high performance liquid chromatography (HPLC).

RESULTS

When ADMA and NP concentrations in renal failure patients were compared before and after dialysis, before dialysis ADMA and NP concentrations were higher than those in the control group. However, ADMA and NP levels showed a falling mean and clear after dialysis. While there is no correlation between ADMA and NP levels before dialysis, there is a mean and positive correlation between ADMA and NP levels after dialysis.

CONCLUSION

Potential risk factors for cardiovascular diseases include high concentrations of both ADMA and NP levels in chronic renal failure patients. A correlation mean between ADMA and NP levels after dialysis was found, but no correlation between ADMA and NP levels before haemodialysis was discovered. These can be evaluated as two different risk factors independent from each other.

Predictive value of serum macrophage colony-stimulating factor for development of aortic calcification in haemodialysis patients: a 6 year longitudinal study

BACKGROUND

Accelerated atherosclerosis is a major complication in patients on haemodialysis (HD). Macrophage colony-stimulating factor (MCSF) is a representative regulator of activation of monocytes and macrophages, and plays important roles in the development of atherosclerosis in HD patients. However, the long-term predictive value of the serum MCSF level for the development of aortic calcification under HD conditions has not been reported.

METHODS

Serum MCSF level was measured in 40 HD patients. The aortic calcification index (ACI) was also calculated on computed tomography once each year for 6 years. Predictive value was examined by logistic regression analysis.

RESULTS

At baseline, there was a significant correlation between serum MCSF and ACI (r = 0.43, P<0.01). A significant increase in ACI was first noted at 4 years post-baseline and the increase was maintained thereafter in the high MCSF group. No such changes were noted in the low MCSF group. Univariate analysis identified high levels of calcium x phosphorus product, triglyceride, C-reactive protein (CRP), MCSF and presence of diabetes mellitus as significant predictors for increased ACI at 6 years. However, among these five factors, high levels of CRP and MCSF were the only independent and significant predictors (odds ratio = 24.0, P = 0.03 and odds ratio = 22.8, P = 0.02, respectively).

CONCLUSIONS

Our results demonstrated that MCSF is associated with the process of atherosclerosis in HD patients. Furthermore, the serum MCSF level is an independent long-term predictor of increased ACI. These results provide useful information for preventive strategies against atherosclerotic disease under HD conditions.

Neopterin measurement in clinical diagnosis

Neopterin is a marker associated with cell-mediated immunity. It is produced in monocytes/macrophages primarily upon stimulation with interferon-gamma. Due to its chemical structure, neopterin belongs to the class of pteridines. It is excreted in an unchanged form via the kidneys. Serum levels above 10 nmol/L are regarded as elevated. The levels of neopterin in body fluids are elevated in infections, autoimmune diseases, malignancies, allograft rejection, cardiac and renal failure, coronary artery disease and myocardial infarction. Neopterin measurements not only provide an insight into the present state of cell-mediated immune response but also allow monitoring and prognosis of disease progression.

Apoptosis of monocytes cultured from long-term hemodialysis patients

Monocyte apoptosis in vitro was studied in patients on long-term hemodialysis, CAPD, and in predialytic uremia to gain insight into the high susceptibility of these patients to infections. Monocytes from dialysis and control subjects were cultured for 24 to 120 hours in vitro to analyze the level and progression of DNA fragmentation as a hallmark of apoptosis. After an incubation time of 48 hours chromatin fragmentation of 48.5 +/- 7.7% was found in monocytes from dialysis patients, which significantly exceeded DNA fragmentation of control monocytes (23.1 +/- 9.1%; N = 12; P < 0.01). Over longer culture periods of up to 5 days, a continuous progression of apoptosis occurred with a similar slope of percent DNA fragmentation in the two studied groups. Monocyte viability was > 95% both in the dialysis and control group. Hemodialysis patients also showed elevated levels of monocyte apoptosis when programmed cell death was evaluated by transmission electron microscopy or DNA electrophoresis of cleaved chromatin. To test the functional relevance of monocyte apoptosis, a significant reduction of Candida growth inhibition by monocytes of dialysis patients was found with a strong linkage between percentage of DNA fragmentation and impaired microbicidal capacity. Monocytes obtained from patients after the hemodialysis session and from CAPD patients showed normal DNA fragmentation levels similar to controls. Differences of monocyte apoptosis between patients on cuprophane and high-flux polysulphone dialysis were not found. Uremic predialytic patients also exerted an increased monocyte DNA fragmentation of 44.2 +/- 1.5% (N = 7; P < 0.05 compared to controls). Enhanced apoptosis of uremic monocytes was accompanied by a reduced formation of TNF-alpha over 48 hours, revealing a significant negative correlation between chromatin fragmentation and monokine synthesis. Supplementation of monocyte cultures from dialysis patients with exogenous TNF-alpha turned increased apoptosis back to baseline levels, suggesting that inflammatory mediators may modulate monocyte senescence. In summary, the elevated degree of monocyte apoptosis in end-stage renal failure may contribute to the impaired cellular host defense seen in these patients.

Levels of serum colony-stimulating factors (CSFs) in patients on long-term haemodialysis

We measured the levels of colony-stimulating factors (G-CSF, M-CSF and GM-CSF) and several cytokines in paired sera obtained from 51 patients (33 males and 18 females; mean age: 53 years) on long-term haemodialysis (HD). The mean pre-HD G-CSF level was 22.7 +/- 21.7 pg/ml and the post-HD level was 40.3 +/- 54.4 pg/ml. The mean pre-HD M-CSF level was 2.4 times higher than normal at 1287 +/- 380 U/ml, and it increased to 1644 +/- 456 U/ml after HD (r = 0.83). GM-CSF was not detectable in any of the serum samples. IL-1 beta was detectable in 38 pre-HD sera at a mean level of 57.1 +/- 21.8 pg/ml, but was rarely detected after HD. TNF-alpha was not usually detected. When the CSF levels were divided by the product of the serum total protein concentration and body weight, the post-HD value for G-CSF was almost always greater than the pre-HD value and there was an improved pre-post correlation (r = 0.69). In the transformed pairs of M-CSF level, the post-HD value did not differ much from the pre-HD value, and a strong pre-post correlation was noted (r = 0.94). These results suggest that the serum G-CSF level is not affected by chronic renal failure, although HD may induce an increase of G-CSF. In the case of M-CSF, however, impaired renal metabolism and/or excretion may increase the serum concentration, but it is not modulated by haemodialysis.(ABSTRACT TRUNCATED AT 250 WORDS)