Estimation of Urinary Creatinine Excretion and Prediction of Renal Function in Morbidly Obese Patients: New Tools from Body Composition Analysis.

BACKGROUND/AIMS: In obese subjects the accuracy of prediction of renal function is quite low. The aim of this study was to obtain a more accurate estimate of urinary creatinine excretion (UCr), creatinine clearance (CCr), and GFR from body cell mass (BCM). METHODS: Seventy-three adult morbidly obese patients (BMI 35.2-64.5 kg/m2) were examined. BCM was calculated from body impedance analysis. CCr was measured (mCCr) and was predicted from BCM and antropometric data (MR-BCMCCr), with Cockcroft and Gault (C&GCCr) and Salazar and Corcoran (S&CCCr) formulas. GFR was predicted from BCM (BCM GFR) and with MDRD and CKD-EPI formulas. RESULTS: Multiple regression (MR) indicated a strict linear correlation between UCr, BCM and anthropometric data. UCr predicted from MR equation (MR-BCMUCr) was very similar to measured UCr. MR-BCMCCr (168±46 mL/min) and mCCr (167±51 mL/min) were also similar, while significant differences were found between mCCr, C&GCCr and S&CCCr. The correlation and the agreement between MR-BCMCCr and mCCr were closer and prediction error was lower than the other formulas. BCM GFR (125±32 mL/min) had close correlations and agreements with MDRD GFR and CKD EPI formulas. CONCLUSIONS: In morbidly obese patients the measurement of BCM meliorates the prediction of UCr and CCr, and allows the prediction of GFR.

High-Flux Dialysis: Clinical, Biochemical, and Proteomic Comparison with Low-Flux Dialysis and On-Line Hemodiafiltration.

Hemodiafiltration on-line (on-line HDF) is a more efficient treatment than low-flux hemodialysis (HD). Unfortunately, it cannot be proposed to all patients. The aim of this study was to evaluate the safety, efficiency, and mechanisms of removal of toxins with high-flux HD vs. low-flux HD and on-line HDF. Randomized cross-over study designed to evaluate efficiency and tolerability of high-flux HD vs. low-flux HD in aged patients; to compare by means of biochemical and proteomic analyses the efficiency and mechanisms of removal of toxins with high-flux HD vs. on-line HDF. The removal of small toxins was similar with high-flux and low-flux HD. ß2-microglobulin was removed only with high-flux HD, which had an excellent tolerability. The efficiency of high-flux HD was similar to on-line HDF. Proteomic analysis demonstrated that only high-flux membranes remove and adsorb small proteins. High-flux HD may be an efficient alternative to on-line HDF.

ß-trace protein is highly removed during haemodialysis with high-flux and super high-flux membranes.

BACKGROUND: Serum ß-trace protein (ßTP, MW 23-29 kDa) is a marker of GFR impairment in renal patients. Recent papers propose to predict residual renal function (RRF) in maintenance haemodialysis (MHD) patients from serum concentrations of ßTP and other small proteins, avoiding the collection of urine. Few data are available on the removal of ßTP in patients treated with dialysis membranes with different flux characteristics. The aim of this study was to evaluate the effects of haemodialysis with low-flux, high-flux and super high-flux membranes on serum concentrations of ßTP in MHD patients with null RRF. METHODS: Serum ßTP concentrations were measured before and after the first dialysis of the week in 51 MDH patients treated by low-flux (n = 24), high-flux (n = 17), or super high-flux (n = 10) membranes. The removal of ß2-microglobulin (ß2M, MW 11.8), cystatin C (Cys, MW 13.3), urea and creatinine was also analyzed. RESULTS: Low-flux membranes did not remove ßTP, ß2M and Cys whose concentration increased at the end of dialysis. High-flux membrane removed more efficiently ß2M and Cys than ßTP. Super high-flux membrane had the highest efficiency to remove ßTP: mean reduction ratio (RR) 53.4%, similar to ß2M (59.5%), and Cys (62.0%). CONCLUSIONS: In conclusion, the plasma clearance of small proteins and particularly of ßTP is dependent from the permeability of the dialysis membranes Therefore, the reliability of the formulas proposed to predict RRF from serum ßTP and other LMWP may be affected by the different permeability of the dialysis membranes.

Impact of hyperhydration on the mortality risk in critically ill patients admitted in intensive care units: comparison between bioelectrical impedance vector analysis and cumulative fluid balance recording.

BACKGROUND: Studies have demonstrated a positive correlation between fluid overload (FO) and adverse outcomes in critically ill patients. The present study aims at defining the impact of hyperhydration on the Intensive Care Unit (ICU) mortality risk, comparing Bioelectrical Impedance Vector Analysis (BIVA) assessment with cumulative fluid balance (CFB) recording. METHODS: We performed a prospective, dual-centre, clinician-blinded, observational study of consecutive patients admitted to ICU with an expected length of ICU stay of at least 72 hours. During observational period (72-120 hours), CFB was recorded and cumulative FO was calculated. At the admission and daily during the observational period, BIVA was performed. We considered FO between 5% and 9.99% as moderate and a FO ≥ 10% as severe. According to BIVA hydration scale of lean body mass, patients were classified as normohydrated (>72.7%-74.3%), mild (>71%-72.7%), moderate (>69%-71%) and severe (≤ 69%) dehydrated and mild (>74.3%-81%), moderate (>81%-87%) and severe (>87%) hyperhydrated. Two multivariate logistic regression models were performed: the ICU mortality was the response variable, while the predictor variables were hyperhydration, measured by BIVA (BIVA model), and FO (FO model). A p-value <0.05 was considered to indicate statistical significance. RESULTS: One hundred and twenty-five patients were enrolled (mean age 64.8 ± 16.0 years, 65.6% male). Five hundred and fifteen BIVA measurements were performed. The mean CFB recorded at the end of the observational period was 2.7 ± 4.1 L, while the maximum hydration of lean body mass estimated by BIVA was 83.67 ± 6.39%. Severe hyperhydration measured by BIVA was the only variable found to be significantly associated with ICU mortality (OR 22.91; 95% CI 2.38-220.07; p < 0.01). CONCLUSIONS: The hydration status measured by BIVA seems to predict mortality risk in ICU patients better than the conventional method of fluid balance recording. Moreover, it appears to be safe, easy to use and adequate for bedside evaluation. Randomized clinical trials with an adequate sample size are needed to validate the diagnostic properties of BIVA in the goal-directed fluid management of critically ill patients in ICU.

Outcomes of Vascular Access Care and Surgery Managed by Interventional Nephrologists: A Twelve-Year Experience.

BACKGROUND: Optimizing vascular access outcomes is still a challenge, since 30-60% of arteriovenous fistulas fail or do not mature and catheters are widely used in contemporary patients. METHODS: This study reports on strategies and outcomes in a single center in which access planning, surgery and maintenance are managed by a team of nephrologists. We retrospectively analyzed 305 fistulas and 61 grafts created in 270 consecutive patients between 2002 and 2013. RESULTS: The percentage of patients receiving a fistula or graft who initiated hemodialysis with a mature access was 68.6%. Among prevalent patients, 71.7% used a fistula, 15.7% a graft and 12.6% a catheter. Rates of primary failure and revision before cannulation were 14.4 and 1.6% for fistulas vs. 4.9 and 3.3% for grafts. After maturation, complications (1.040 vs. 0.188 per patient-year (py)) and interventions (0.743 vs. 0.066 per py) were greater for grafts than for fistulas (p < 0.001). Secondary patency did not significantly differ between grafts and fistulas (median survival 34.8 vs. 57.3 months, p = 0.36), unless primary failures were excluded from Kaplan-Meier analysis (median survival 34.9 vs. 70.9 months, p = 0.03). CONCLUSIONS: High fistula prevalence, low access-related morbidity and catheter dependence were achieved using individualized strategies, including mid-forearm or perforating vein fistula creation and selective graft placement in high risk patients. Direct involvement of nephrologists throughout all steps of access care can improve access outcomes, by promoting a patient-centered approach.

Effect of glomerular filtration rate impairment on diagnostic performance of neutrophil gelatinase-associated lipocalin and B-type natriuretic peptide as markers of acute cardiac and renal failure in chronic kidney disease patients.

INTRODUCTION: Cardio-renal syndromes are characterized by the impairment of cardiac and renal functions. Plasma and urinary neutrophil gelatinase-associated lipocalin (NGAL), and plasma B-type natriuretic peptide (BNP) are markers of acute kidney injury (AKI) and heart failure (HF), respectively. METHODS: GFR (99mTc-DTPA), plasma BNP, and plasma and urinary concentrations of NGAL were measured in 310 clinically stable CKD patients, at functional stages from 1 to 5. Serum and urinary low-molecular-weight proteins cystatin C and ß2-microglobulin, and urinary tubular enzymes were measured for comparison. Plasma BNP, NGAL, cystatin C and ß2-microglobulin were measured also in 31 maintenance hemodialysis patients. RESULTS: Plasma NGAL increased with the reduction of GFR in CKD patients from stage 2. In the different CKD stages modest differences were found for BNP values. Urinary NGAL increased slightly but significantly in patients at CKD stages 4 and 5, similarly to urinary cystatin C and ß2-microglobulin. In maintenance hemodialysis patients, plasma NGAL and BNP were markedly increased, and high-flux hemodialysis significantly decreased their plasma concentrations. CONCLUSIONS: Plasma NGAL increases markedly with the reduction in GFR, generating a very high number of false positive diagnoses of AKI in stable CKD patients. The grade of GFR impairment and the cause of kidney disease have a lower effect on urinary NGAL and on plasma BNP. In any case, specific reference values of NGAL and BNP should be used in chronic kidney disease patients, according to their functional stage, when assessing acute kidney injury, heart failure, and cardio-renal syndromes in patients with impaired GFR.

Reflectance confocal microscopy features of seborrheic dermatitis for plaque psoriasis differentiation.

BACKGROUND: Plaque psoriasis (PP) and seborrheic dermatitis (SD) are chronic inflammatory skin diseases with similar clinical and pathological features. Differential diagnosis can be difficult, especially when particular skin areas of the face are involved. Reflectance confocal microscopy (RCM) has been demonstrated to be useful for 'real-time' diagnosis of skin inflammatory diseases. OBJECTIVE: To define distinctive confocal criteria of SD and to evaluate the usefulness of this technique for noninvasive differential diagnosis with PP. METHODS: A total of 40 patients affected by PP and 19 patients by SD involving the face were recruited and subjected to RCM evaluation. Univariate and adjusted odds ratios were calculated. Discriminant functions were used to plot ROC curves. RESULTS: The results disclosed specific patterns for SD and PP. The following distinctive confocal features for SD have been identified: spongiosis, dermal inflammation and horizontal orientation of dilated blood vessels. CONCLUSION: SD has a specific and easily recognizable confocal pattern supporting clinical differentiation with PP.

A new green protocol for the identification of microplastics and microfibers in marine sediments, a case study from the Vesuvian Coast, Southern Italy.

Microplastics (MP; 1 µm-5 mm) and microfibers (MF; thin, elongated particles with a high-length-to-width ratio) have become a major global environmental issue due to their ubiquity in the oceans and possess complex physicochemical properties that vary their mobility, bioavailability, and toxicity toward organisms and interactions with their surrounding pollutants. Nonetheless, a reliable methodology that would facilitate and automate the monitoring of MP is still lacking. Intending to select practical and standardized methods and considering the challenges in MPs detection, a new analysis protocol based on optical microscopy for the counting and morphological analysis of the particles has been developed. This method overcomes some issues related to the lack of practicality and standardization of the others currently applied, and does not involve sieving, washing, heating, or density separation and digestion processes. Our method is green and requires a minimum quantity of sediment, i.e., 1.5 g, and shortened timeframes. Future research efforts may need to develop and implement new analytical tools and combinations of technologies to complement respective detection limitations and yield reliable characterization of both MFs and MPs. We tested our protocol to study, for the first time, both marine and land sediment in the Vesuvian area of the Gulf of Naples (Italy).

Concordance between in vivo reflectance confocal microscopy and optical histology of lymphomatoid papulosis.

BACKGROUND: Lymphomatoid papulosis is a primary cutaneous CD30+ T-cell lymphoma clinically characterized by a benign, chronic, recurrent course with self-limited papulo-nodular skin lesion eruption. In vivo Reflectance Confocal Microscopy is a non-invasive technique for real-time imaging of the superficial layers of the skin down to the superficial dermis with cellular-level resolution close to conventional histopathology. RCM has been previously reported to be useful in the in vivo evaluation of inflammatory diseases, skin tumours and also cutaneous lymphomas. Only two articles have been published on cutaneous lymphomas and none detailing confocal features of LyP. The aim of this manuscript was to describe the confocal features of LyP and their histological correlation to evaluate the possible application of this non-invasive tool in this T-cell lymphoma subtype clinical management. METHODS: Five patients with histological diagnosis of LyP were imaged with RCM, followed by a skin biopsy on a clinically selected lesion. RESULTS: High grade of correspondence between RCM and histopathology of LyP was observed, disclosing the potential rule of RCM at least for biopsy site selection. CONCLUSION: Future studies on RCM for LyP vs. other cutaneous T-cells lymphomas and inflammatory skin diseases are needed to assess specificity and sensibility of our preliminary data.

Prediction of glomerular filtration rate from serum concentration of cystatin C: comparison of two analytical methods.

BACKGROUND: The aim of this study was to compare two methods used to measure serum cystatin C (Cys) and their accuracy to predict glomerular filtration rate (GFR). METHODS: Three hundred and sixty-seven adult chronic kidney disease (CKD) patients with different functional impairments participated in this study. GFR was determined as the renal clearance of 99mTc-DTPA. Serum concentrations of cystatin C (SCys) were determined with an immunonephelometric method and with an immunoturbidimetric method. RESULTS: A very high linear correlation was found between the two measurements of SCys (r=0.929). The mean difference of SCysTurb-SCysNeph was 0.02±0.43 mg/L (not significant). A high logarithmic correlation was also found between SCys and GFR (r was 0.919 for SCysNeph and 0.937 for SCysTurb). By means of multiple regression analysis, we developed formulae to predict GFR from SCysNeph, SCysTurb and SCr. For comparison, GFR was predicted using published formulae. A good agreement was found between predicted GFR and measured GFR. The results showed that the accuracy of SCysNeph, SCysTurb and SCr and of the different prediction formulae were quite similar. CONCLUSIONS: The immunoturbidimetric method seems adequate to measure SCys and to predict GFR and its impairment in CKD, at least similar to the immunonephelometric method. The accuracy of SCys and of derived formulae was not higher than that of SCr and SCr-based formulae.

Morpho-bathymetric acoustic surveys as a tool for mapping traces of anthropogenic activities on the seafloor: The case study of the Taranto area, southern Italy.

In this study, an investigation procedure for mapping the traces of anthropogenic activities on the seafloor is proposed. Analyses are based on the interpretation of acoustic data (Multibeam Echosounder and Side Scan Sonar) acquired in the Taranto coastal area. Specific GIS tools supported the acoustic data analysis, interpretation, and mapping. These analyses highlighted that the seafloor of both coastal basins included in the investigated area is affected by a high distribution of traces related to different anthropogenic activities such as dredging, shipping, and mussel farming activities. Such kind of traces resulted efficiently detectable from morpho-bathymetric acoustic data. In particular, groove traces resulted highly distributed in both basins, while sunken mussel farm facilities are widely distributed in the Mar Grande basin. The results highlight as acoustic surveys represent a useful tool for orienting effective coastal management actions. This study points out how geophysical surveys support the geo-environmental characterization of highly urbanized coastal sectors.

Direct evidence that late Neanderthal occupation precedes a technological shift in southwestern Italy.

OBJECTIVES: During the middle-to-upper Paleolithic transition (50,000 and 40,000 years ago), interaction between Neanderthals and Homo sapiens varied across Europe. In southern Italy, the association between Homo sapiens fossils and non-Mousterian material culture, as well as the mode and tempo of Neanderthal demise, are still vividly debated. In this research, we focus on the study of two human teeth by using 3D geometric morphometric approaches for a reliable taxonomical attribution as well as obtaining new radiometric dates on the archeological sequence. MATERIAL AND METHODS: This work presents two lower deciduous molars uncovered at Roccia San Sebastiano (Mondragone-Caserta, Italy), stratigraphically associated with Mousterian (RSS1) and Uluzzian (RSS2) artifacts. To obtain a probabilistic attribution of the two RSS teeth to each reference taxa group composed of Neanderthals and Homo sapiens, we performed and compared the performance of three supervised learning algorithms (flexible discriminant analysis, multiadaptive regression splines, and random forest) on both crown and cervical outlines obtained by virtual morphometric methods. RESULTS: We show that RSS1, whose Mousterian context appears more recent than 44,800-44,230 cal BP, can be attributed to a Neanderthal, while RSS2, found in an Uluzzian context that we dated to 42,640-42,380 cal BP, is attributed to Homo sapiens. DISCUSSION: This site yields the most recent direct evidence for a Neanderthal presence in southern Italy and confirms a later shift to upper Paleolithic technology in southwestern Italy compared to the earliest Uluzzian evidence at Grotta del Cavallo (Puglia, Italy).

A vitamin E-coated polysulfone membrane reduces serum levels of inflammatory markers and resistance to erythropoietin-stimulating agents in hemodialysis patients: results of a randomized cross-over multicenter trial.

BACKGROUND: Oxidative stress is prevalent in dialysis patients and has been implicated in the pathogenesis of cardiovascular disease and anemia. Vitamin E is a fat-soluble antioxidant that plays a central role in reducing lipid peroxidation and inhibiting the generation of reactive oxygen species. The aim of this cross-over randomized study was to compare the effects of a vitamin E-coated polysulfone (Vit E PS) membrane and a non-vitamin E-coated polysulfone (PS) membrane on inflammatory markers and resistance to erythropoietin-stimulating agents (ESAs). METHODS: After a 1-month run-in period of standard bicarbonate dialysis with a synthetic membrane, 62 patients of both genders, and older than 18 years, dialysis vintage 48 ± 27 months, BMI 22 ± 3 (from 13 different dialysis units) were randomized (A-B or B-A) in a cross-over design to Vit E PS (treatment A) and to PS (treatment B) both for 6 months. C-reactive protein (CRP) and interleukin-6 (IL-6) concentrations were determined by a sandwich enzyme immunoassay at baseline and every 2 months; red blood cell count, ESA dose and ESA resistance index (ERI) were assessed monthly. RESULTS: Hemoglobin (Hb) levels significantly increased in the Vit E PS group from 11.1 ± 0.6 g/dl at baseline to 11.5 ± 0.7 at 6 months (p < 0.001) and remained unchanged in the PS group. Although ESA dosage remained stable during the observation periods in both groups, ERI was significantly reduced in the Vit E PS group from 10.3 ± 2.2 IU-dl/kg/g Hb week at baseline to 9.2 ± 1.7 at 6 months (p < 0.001). No significant variation of ERI was observed in the PS group. A significant reduction in plasma CRP and IL-6 levels was observed in the Vit E PS group: CRP from 6.7 ± 4.8 to 4.8 ± 2.2 mg/l (p < 0.001) and IL-6 from 12.1 ± 1.4 to 7.5 ± 0.4 pg/ml (p < 0.05). In the PS group, CRP varied from 6.2 ± 4.0 to 6.4 ± 3.7, and IL-6 from 10.6 ± 2.1 to 9.6 ± 3.5 (p = n.s.). CONCLUSIONS: Treatment with Vit E PS membranes seems to lead to a reduction in ESA dosage in HD patients; in addition, a low chronic inflammatory response may contribute to a sparing effect on exogenous ESA requirements.

A novel approach to the classification of terrestrial drainage networks based on deep learning and preliminary results on solar system bodies.

Several approaches were proposed to describe the geomorphology of drainage networks and the abiotic/biotic factors determining their morphology. There is an intrinsic complexity of the explicit qualification of the morphological variations in response to various types of control factors and the difficulty of expressing the cause-effect links. Traditional methods of drainage network classification are based on the manual extraction of key characteristics, then applied as pattern recognition schemes. These approaches, however, have low predictive and uniform ability. We present a different approach, based on the data-driven supervised learning by images, extended also to extraterrestrial cases. With deep learning models, the extraction and classification phase is integrated within a more objective, analytical, and automatic framework. Despite the initial difficulties, due to the small number of training images available, and the similarity between the different shapes of the drainage samples, we obtained successful results, concluding that deep learning is a valid way for data exploration in geomorphology and related fields.

Serum and urinary markers of early impairment of GFR in chronic kidney disease patients: diagnostic accuracy of urinary ß-trace protein.

The screening for chronic kidney diseases (CKD) patients with impaired GFR needs the measurement of serum creatinine (SCr) or cystatin C (SCys). GFR can also be predicted from SCr or SCys with different formulas. The aim of this study, performed in a group of CKD patients with different levels of GFR, was to evaluate the possibility to select the patients with a GFR <90 ml·min(-1)·1.73 m(-2) by means of serum levels and urinary excretion of different low-molecular-weight proteins (LMWP), cystatin C (Cys), ß2-microglobulin (ß2M), retinol-binding protein (RBP), ß-trace protein (BTP), and derived prediction equations for GFR. In the 295 CKD patients (137 women), at all stages of GFR impairment a very high correlation was found between GFR ((99m)Tc-DTPA) and serum Cr, Cys, ß2M, and BTP. All these serum markers showed a similar accuracy as indicators of different GFR impairments. RBP had the lowest correlation with GFR and was also significantly less accurate. The different prediction formulas derived from gender, anthropometric data and SCr or S-LMWP had a diagnostic accuracy similar to that of serum Cr, Cys, ß2M, and BTP. Urinary albumin was inadequate as an indicator of any level of GFR impairment. Urinary excretion of Cys and ß2M increased significantly only in patients with a GFR <30 ml·min(-1)·1.73 m(-2), while urinary BTP increased already at GFR <90 ml·min(-1)·1.73 m(-2). In this selected group of CKD patients, the positive predictive value of urinary BTP for a GFR <90 ml·min(-1)·1.73 m(-2) was 85%, indicating that, in CKD patients, a urine-based test can predict a slight GFR impairment.

Sediment contamination by heavy metals and ecological risk assessment: The case of Gulf of Pozzuoli, Naples, Italy.

Heavy metal concentrations in sediments of the Gulf of Pozzuoli, GoP, and northwest of the Gulf beyond Monte di Procida, MdP, were determined. The enrichment factor, EF, revealed in GoP strong pollution with peaks for Cr and Cu of 61.1 and 96.9. High EF Cr, Cu, and Ni values were observed for MDP. Geoaccumulation index, Igeo, rates GoP extremely polluted by Cr and Cu, Igeo > 5, and MdP heavily polluted by Cr, moderately to heavily polluted by Cu, and heavily to extremely polluted by Ni. Contamination factor, Cf, was high in GoP and varied: Cu > Cr > Ni > Cd > Hg > Zn > Pb > As, and those of Cr, Cu and Ni largely surpassed the thresholds in MdP. The ecological and comprehensive ecological risk placed Cr, Cu, Hg and Ni at high or serious risk level in the Gulf, with a peak of 465 for Cu and at a moderate level in MdP except for a very high risk for Ni.

Dose individualization can minimize nephrotoxicity due to carboplatin therapy in patients with ovarian cancer.

Carboplatin (Carbo-Pt), an alkylating agent cleared from the plasma through glomerular filtration, is commonly used for the treatment of ovarian cancer. When administered at high dosage or to patients with reduced renal function, Carbo-Pt may be nephrotoxic. The dose of Carbo-Pt is calculated with Calvert formula, using the value of 24-hour creatinine clearance (24h Ccr) as an estimate of glomerular filtration rate (GFR). The aim of this study was to evaluate the possibility of individualizing the dose of Carbo-Pt using an alternative method to estimate GFR, based on body composition analysis, and then to assess the nephrotoxicity of Carbo-Pt therapy individualized with this new method. First, we evaluated the agreement between GFR (renal clearance of diethylene triamine pentaacetic acid (99mTc-DTPA)), 24h Ccr, and the new estimate of GFR (BCMGFR) calculated on the basis of individual values of body cell mass (BCM) and plasma creatinine. BCMGFR gave a better estimate of GFR than 24h Ccr. Then, we evaluated the nephrotoxicity of a combination chemotherapy based on Carbo-Pt (AUC(5-6)) in 23 patients affected by ovarian cancer. The dose of Carbo-Pt was adjusted to residual renal function of patients, evaluated as BCMGFR. No case of acute renal failure was observed with this treatment regimen. Urinary excretion of proteins (albumin, beta2-microglobulin, and retinol-binding protein) and tubular enzymes, measured as markers of tubular damage, increased significantly and transiently only in the first days after chemotherapy, whereas no evidence of chronic nephrotoxic effect was documented. Dose individualization, using the value of BCMGFR, may minimize nephrotoxicity due to Carbo-Pt therapy.

Serum albumin fragmentation in end-stage renal disease patients--a pilot study.

BACKGROUND: The goal of this study was to detect modification in the expression of plasma proteins and/or post-translational modifications of their structure in patients with end stage renal disease. METHODS: Serum samples from 19 adult patients treated by maintenance hemodialysis (MHD) were analyzed in comparison to sera from six healthy controls using sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2DE). Spots of interest were identified by mass spectrometry analysis. In addition, the 2DE maps were incubated with a human anti-albumin polyclonal antibody. RESULTS: SDS-PAGE gels, 2DE maps and matrix-assisted laser desorption/ionization time of flight analysis indicated over-expression of low-molecular weight proteins (LMWP) in sera from patients. Unexpectedly, another 15 spots with estimated M(r) of 12.5-29 kDa from the 2DE maps of six patients were identified as fragments of albumin. 2D immunoblotting of sera from 12 other patients detected numerous albumin fragments. CONCLUSIONS: These results indicate that in addition to increased expression of LMWP, a relevant amount of albumin fragments are detectable in the serum of patients undergoing MHD. Uremia appears to facilitate the fragmentation of albumin and/or the retention of albumin fragments in blood.