Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by abnormal protein aggregation in the motor neurons. Present and earlier proteomic studies to characterize peptides ...in cerebrospinal fluid (CSF) associated with motoneuron pathology did not target low molecular weight proteins and peptides. We hypothesized that specific changes in CSF peptides or low molecular weight proteins are significantly altered in ALS, and that these changes may support deciphering molecular pathophysiology and even guide approaches towards therapeutic interventions.
Cerebrospinal fluid (CSF) from 50 ALS patients and 50 non-ALS controls was collected, centrifuged immediately after collection, aliquoted into polypropylene test tubes, frozen within 30-40 min after the puncture, and stored at -80°C until use. Peptides were sequenced using capillary electrophoresis or liquid chromatography/mass spectrometry (CE-MS/MS or LC-MS/MS).
In the CSF of 50 patients and 50 non-ALS controls 33 peptides were found, of which 14 could be sequenced using a non-lytic single-pot proteomic detection method, CE/MS. ALS deregulated peptides vs. controls included Integral membrane protein 2B, Neurosecretory protein VGF, Osteopontin, Neuroendocrine protein 7B2 (Secretogranin-V), EGF-containing fibulin-like extracellular matrix protein 1, Xylosyltransferase 1 XT-1, Chromogranin-A, Superoxide dismutase SOD-1, Secretogranin-1 (Chromogranin B), NR2F2 Nuclear Receptor Subfamily 2 Group F Member 2 and Collagen alpha-1(VII) chain.
Most striking deregulations in CSF from ALS patients were found in VGF, Osteopontin, SOD-1 and EFEMP1 peptides. No associations of disease severity, duration and region of onset with sequenced peptides were found.
Immunosuppressive treatment in heart transplant (HTx) recipient causes osteoporosis. The urinary proteomic profile (UPP) includes peptide fragments derived from the bone extracellular matrix. Study ...aims were to develop and validate a multidimensional UPP biomarker for osteoporosis in HTx patients from single sequenced urinary peptides identifying the parent proteins.
A single-center HTx cohort was analyzed. Urine samples were measured by capillary electrophoresis coupled with mass spectrometry. Cases with osteoporosis and matching controls were randomly selected from all available 389 patients. In derivation case-control dataset, 1576 sequenced peptides detectable in ≥30 % of patients. Applying statistical analysis on these, an 18-peptide multidimensional osteoporosis UPP biomarker (OSTEO18) was generated by support vector modeling. The 2 replication datasets included 118 and 94 patients. For further validation, the whole cohort was analyzed. Statistical methods included logistic regression and receiver operating characteristic curve (ROC) analysis.
In derivation dataset, the AUC, sensitivity and specificity of OSTEO18 were 0.83 (95 % CI: 0.76–0.90), 74.3 % and 87.1 %, respectively. In replication datasets, results were confirmatory. In the whole cohort (154 osteoporotic patients 39.6 %), the ORs for osteoporosis increased (p < 0.0001) across OSTEO18 quartiles from 0.39 (95 % CI: 0.25–0.61) to 3.14 (2.08–4.75). With full adjustment for known osteoporosis risk factors, OSTEO18 improved AUC from 0.708 to 0.786 (p = 0.0003) for OSTEO18 categorized (optimized threshold: 0.095) and to 0.784 (p = 0.0004) for OSTEO18 as continuously distributed classifier.
OSTEO18 is a clinically meaningful novel biomarker indicative of osteoporosis in HTx recipients and is being certified as in-vitro diagnostic.
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Abstract
Background and Aims
The physiological and related body fluids, urine, plasma and hemodialysis (HD) fluid spent dialysate (a mixture of technical HD fluid and patient´s ultrafiltrate) are ...rich biological sources of information especially in the context of kidney diseases. Of particular relevance are proteins and peptides, as they reflect essentially every biological process. Urine is produced as a result of glomerular plasma filtration and subsequent tubular reabsorption in the kidney. In analogy, HD spent dialysate is a result of ultrafiltration by an artificial kidney (dialysis membrane), but lacking tubular reabsorption and thereby accumulating in huge amounts of > 100 L per session comparable to primary urine. A recent study suggested that tubular reabsorption may be selective for specific proteins, and this process may represent a major difference between “natural” and artificial kidney.
In this study, we aim at gaining insight into the composition of the peptidome/proteome in these body fluids of renal significance in a comprehensive analysis, in order to shed light on the relevant pathophysiological processes that take place in kidney, which may help developing better strategy in advanced-stage chronic kidney disease and detoxification in renal replacement therapies (RRT).
Method
We collected 15 plasma, 15 urine and 13 HD filtrate (spent dialysate during the first 30min of RRT) from age and sex matched subjects with stage 4 or above chronic kidney disease. Peptide identification and quantification were performed with capillary-electrophoresis coupled mass spectrometry and tandem mass spectrometry (CE-MS). The abundance, overlap and differences of the peptidome/proteome of the three body fluids were evaluated.
Results
We were able to detect 6281 urinary peptides, 1750 plasma peptides and 1728 peptides from spent dialysate. Of these we could identify 1764, 452 and 374 sequenced peptides, respectively Among them, there are 318 peptides detectable in both urine and spent dialysate, 307 detectable in both plasma and urine and only 191 detectable in both plasma and spent dialysate. Among the most abundant peptides in plasma were Thymosine-ß4 and fragments from hemoglobin, fibrinogen and collagen. In dialysate, the most abundant proteins detected in these patients were ß-2-microglobuline, Thymosine-ß4, and fragments from fibrinogen, while in urine fragments derived from collagen, albumin, and from alpha-1-antitrypsin were of the highest abundance. When investigating proteins/peptides found in at least 2 body fluids, a strong correlation in peptide abundance between urine and spent dialysate (P=4.2e-27, Rho=0.56), and a moderately strong correlation between HD fluid and plasma (P=3.7e-5, Rho=0.29) were detected. However, there is no significant correlation between peptide abundance in urine and plasma (P=0.22, Rho=0.07). Collagen peptides are the most abundant peptides in all three body fluids.
Conclusion
This dataset will serve as a valid basis to define the protein and peptide contents in blood, urine, and spent dialysate. The data show, as expected, substantial similarity between plasma and spent dialysate, but, surprisingly, very little similarity between urine and plasma. This further supports the hypothesis that tubular reabsorption may be selective for specific proteins and peptides, possibly excluding collagen-derived peptides. A more detailed investigation into the process and relevance of tubular reabsorption appears warranted in the light of the data.
The fact that the samples investigated in this study are derived from advanced stage CKD patients must be taken into account, significant differences exist in comparison to urine produced by healthy kidney.
The identification of molecular differences between urine and dialysate spent may present an opportunity to design future “biologically adapted” removal devices.
Figure: Correlation of the peptide abundance in HD fluid, plasma and urine
Microalbuminuria is an early sign of kidney disease in people with diabetes and indicates increased risk of cardiovascular disease. We tested whether a urinary proteomic risk classifier (CKD273) ...score was associated with development of microalbuminuria and whether progression to microalbuminuria could be prevented with the mineralocorticoid receptor antagonist spironolactone.
In this multicentre, prospective, observational study with embedded randomised controlled trial (PRIORITY), we recruited people with type 2 diabetes, normal urinary albumin excretion, and preserved renal function from 15 specialist centres in ten European countries. All participants (observational cohort) were tested with the CKD273 classifier and classified as high risk (CKD273 classifier score >0·154) or low risk (≤0·154). Participants who were classified as high risk were entered into a randomised controlled trial and randomly assigned (1:1), by use of an interactive web-response system, to receive spironolactone 25 mg once daily or matched placebo (trial cohort). The primary endpoint was development of confirmed microalbuminuria in all individuals with available data (observational cohort). Secondary endpoints included reduction in incidence of microalbuminuria with spironolactone (trial cohort, intention-to-treat population) and association between CKD273 risk score and measures of impaired renal function based on estimated glomerular filtration rate (eGFR; observational cohort). Adverse events (particularly gynaecomastia and hyperkalaemia) and serious adverse events were recorded for the intention-to-treat population (trial cohort). This study is registered with the EU Clinical Trials Register (EudraCT 20120-004523-4) and ClinicalTrials.gov (NCT02040441) and is completed.
Between March 25, 2014, and Sept 30, 2018, we enrolled and followed-up 1775 participants (observational cohort), 1559 (88%) of 1775 participants had a low-risk urinary proteomic pattern and 216 (12%) had a high-risk pattern, of whom 209 were included in the trial cohort and assigned to spironolactone (n=102) or placebo (n=107). The overall median follow-up time was 2·51 years (IQR 2·0-3·0). Progression to microalbuminuria was seen in 61 (28%) of 216 high-risk participants and 139 (9%) of 1559 low-risk participants (hazard ratio HR 2·48, 95% CI 1·80-3·42; p<0·0001, after adjustment for baseline variables of age, sex, HbA
, systolic blood pressure, retinopathy, urine albumin-to-creatinine ratio UACR, and eGFR). Development of impaired renal function (eGFR <60 mL/min per 1·73 m
) was seen in 48 (26%) of 184 high-risk participants and 119 (8%) of 1423 low-risk participants (HR 3·50; 95% CI 2·50-4·90, after adjustment for baseline variables). A 30% decrease in eGFR from baseline (post-hoc endpoint) was seen in 42 (19%) of 216 high-risk participants and 62 (4%) of 1559 low-risk participants (HR 5·15, 95% CI 3·41-7·76; p<0·0001, after adjustment for basline eGFR and UACR). In the intention-to-treat trial cohort, development of microalbuminuria was seen in 35 (33%) of 107 in the placebo group and 26 (25%) of 102 in the spironolactone group (HR 0·81, 95% CI 0·49-1·34; p=0·41). In the safety analysis (intention-to-treat trial cohort), events of plasma potassium concentrations of more than 5·5 mmol/L were seen in 13 (13%) of 102 participants in the spironolactone group and four (4%) of 107 participants in the placebo group, and gynaecomastia was seen in three (3%) participants in the spironolactone group and none in the placebo group. One patient died in the placebo group due to a cardiac event (considered possibly related to study drug) and one patient died in the spironolactone group due to cancer, deemed unrelated to study drug.
In people with type 2 diabetes and normoalbuminuria, a high-risk score from the urinary proteomic classifier CKD273 was associated with an increased risk of progression to microalbuminuria over a median of 2·5 years, independent of clinical characteristics. However, spironolactone did not prevent progression to microalbuminuria in high-risk patients.
European Union Seventh Framework Programme.
Abstract
Background
Risk of kidney function decline in immunoglobulin A (IgA) nephropathy (IgAN) is significant and may not be predicted by available clinical and histological tools. To serve this ...unmet need, we aimed at developing a urinary biomarker-based algorithm that predicts rapid disease progression in IgAN, thus enabling a personalized risk stratification.
Methods
In this multicentre study, urine samples were collected in 209 patients with biopsy-proven IgAN. Progression was defined by tertiles of the annual change of estimated glomerular filtration rate (eGFR) during follow-up. Urine samples were analysed using capillary electrophoresis coupled mass spectrometry. The area under the receiver operating characteristic curve (AUC) was used to evaluate the risk prediction models.
Results
Of the 209 patients, 64% were male. Mean age was 42 years, mean eGFR was 63 mL/min/1.73 m2 and median proteinuria was 1.2 g/day. We identified 237 urine peptides showing significant difference in abundance according to the tertile of eGFR change. These included fragments of apolipoprotein C-III, alpha-1 antitrypsin, different collagens, fibrinogen alpha and beta, titin, haemoglobin subunits, sodium/potassium-transporting ATPase subunit gamma, uromodulin, mucin-2, fractalkine, polymeric Ig receptor and insulin. An algorithm based on these protein fragments (IgAN237) showed a significant added value for the prediction of IgAN progression AUC 0.89; 95% confidence interval (CI) 0.83–0.95, as compared with the clinical parameters (age, gender, proteinuria, eGFR and mean arterial pressure) alone (0.72; 95% CI 0.64–0.81).
Conclusions
A urinary peptide classifier predicts progressive loss of kidney function in patients with IgAN significantly better than clinical parameters alone.
Graphical Abstract
Graphical Abstract
ABSTRACT
Background
Immunoglobulin A nephropathy (IgAN) frequently leads to kidney failure. The urinary proteomics-based classifier IgAN237 may predict disease progression at the time of kidney ...biopsy. We studied whether IgAN237 also predicts progression later in the course of IgAN.
Methods
Urine from patients with biopsy-proven IgAN was analyzed using capillary electrophoresis–mass spectrometry at baseline (IgAN237-1, n = 103) and at follow-up (IgAN237-2, n = 89). Patients were categorized as “non-progressors” (IgAN237 ≤0.38) and “progressors” (IgAN237 >0.38). Estimated glomerular filtration rate (eGFR) and urinary albumin–creatinine ratio slopes were calculated.
Results
Median age at biopsy was 44 years, interval between biopsy and IgAN237-1 was 65 months and interval between IgAN237-1 and IgAN237-2 was 258 days (interquartile range 71–531). IgAN237-1 and IgAN237-2 values did not differ significantly and were correlated (rho = 0.44, P < .001). Twenty-eight percent and 26% of patients were progressors based on IgAN237-1 and IgAN237-2, respectively. IgAN237 inversely correlated with chronic eGFR slopes (rho = –0.278, P = .02 for score-1; rho = –0.409, P = .002 for score-2) and with ±180 days eGFR slopes (rho = –0.31, P = .009 and rho = –0.439, P = .001, respectively). The ±180 days eGFR slopes were worse for progressors than for non-progressors (median –5.98 versus –1.22 mL/min/1.73 m2 per year for IgAN237-1, P < .001; –3.02 vs 1.08 mL/min/1.73 m2 per year for IgAN237-2, P = .0047). In multiple regression analysis baseline progressor/non-progressor according to IgAN237 was an independent predictor of eGFR180days-slope (P = .001).
Conclusion
The urinary IgAN237 classifier represents a risk stratification tool in IgAN also later in the course of the dynamic disease. It may guide patient management in an individualized manner.
Graphical Abstract
Graphical Abstract
Membrane distillation (MD) is a promising process for high-quality water reclamation mainly due to its high capacity to retain non-volatile components and operate without the need for hydraulic ...pressure. However, its low energy efficiency limits its widespread use. With that in mind, this paper critically summarizes the different engineered configurations of membrane distillation coupled with renewable energy sources and waste heat, namely: solar, geothermal, and waste heat, to overcome the limitations associated with low energy efficiency commonly reported. From all sources, solar-driven processes are preferred due to the greater technological maturity related to flat plate collectors (FPCs), evacuated tube collectors (ETCs), compound parabolic concentrators (CPCs), salt-gradient solar ponds (SGSPs), and solar stills. The integration with renewable energy sources represents one of the leading solutions for energy consumption, proving to be a decisive choice for the system's economic viability. The summarized studies suggest membrane distillation's potential to be economically competitive with the classical membrane separation process (ultrafiltration, nanofiltration, and reverse osmosis) when waste heat is considered for wastewater treatment. Even under these conditions, alternative energy sources have a few shortcomings to be investigated in future studies, such as short periods of solar radiation and the intermittence of waste heat sources. These factors still represent obstacles to an uninterrupted and large-scale operation of membrane distillation and must be overcome in a near future. Even so, successful case studies on full-scale systems that integrate membrane distillation and solar energy sources suggest the process's potential for widespread use in the near term.
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•Engineered solutions focused on module set-up and improvement in thermal efficiency.•Renewable energy sources are an alternative to make the MD process viable.•The integration of MD into solar, geothermal, and waste heat is discussed.•Solar-powered systems have greater technological maturity to be employed on a large scale.•MD is economically competitive when waste heat is considered.
Abstract
Acute graft-versus-host disease (aGvHD) contributes to about 50% of transplant-related mortality (non-relapse mortality) after allogeneic hematopoietic stem cell transplantation (HSCT). Here ...the predictive value of a urinary proteomic profile (aGvHD_MS17) was tested together with preemptive prednisolone therapy. Two-hundred and fifty-nine of 267 patients were eligible for analysis. Ninety-two patients were randomized upon aGvHD_MS17 classification factor above 0.1 to receive either prednisolone (2–2.5 mg/kg,
N
= 44) or placebo (
N
= 47;
N
= 1 randomization failure) for 5 days followed by tapering. The remaining 167 patients formed the observation group. The primary endpoint of the randomized trial was incidence of aGvHD grade II between randomization and day +100 post HSCT. Analysis of the short-term preemptive prednisolone therapy in the randomized patients showed no significant difference in incidence or severity of acute GvHD (HR: 1.69, 95% CI: 0.66–4.32,
P
= 0.27). Prednisolone as preemptive treatment did not lead to an increase in relapse (20.2% in the placebo and 14.0% in the prednisolone group (
P
= 0.46)). The frequency of adverse events was slightly higher in the placebo group (64.4% versus 50%, respectively). Taken together, the results of the Pre-GvHD trial demonstrated the feasibility and safety of preemptive prednisolone treatment in the randomized patients.
COVID-19 prediction models based on clinical characteristics, routine biochemistry and imaging, have been developed, but little is known on proteomic markers reflecting the molecular pathophysiology ...of disease progression.
The multicentre (six European study sites) Prospective Validation of a Proteomic Urine Test for Early and Accurate Prognosis of Critical Course Complications in Patients with SARS-CoV-2 Infection Study (Crit-COV-U) is recruiting consecutive patients (≥ 18 years) with PCR-confirmed SARS-CoV-2 infection. A urinary proteomic biomarker (COV50) developed by capillary-electrophoresis-mass spectrometry (CE-MS) technology, comprising 50 sequenced peptides and identifying the parental proteins, was evaluated in 228 patients (derivation cohort) with replication in 99 patients (validation cohort). Death and progression along the World Health Organization (WHO) Clinical Progression Scale were assessed up to 21 days after the initial PCR test. Statistical methods included logistic regression, receiver operating curve (ROC) analysis and comparison of the area under the curve (AUC).
In the derivation cohort, 23 patients died, and 48 developed worse WHO scores. The odds ratios (OR) for death per 1 standard deviation (SD) increment in COV50 were 3·52 (95% CI, 2·02–6·13, p <0·0001) unadjusted and 2·73 (1·25–5·95, p = 0·012) adjusted for sex, age, baseline WHO score, body mass index (BMI) and comorbidities. For WHO scale progression, the corresponding OR were 2·63 (1·80–3·85, p<0·0001) and 3·38 (1·85–6·17, p<0·0001), respectively. The area under the curve (AUC) for COV50 as a continuously distributed variable was 0·80 (0·72–0·88) for mortality and 0·74 (0·66–0·81) for worsening WHO score. The optimised COV50 thresholds for mortality and worsening WHO score were 0·47 and 0·04 with sensitivity/specificity of 87·0 (74·6%) and 77·1 (63·9%), respectively. On top of covariates, COV50 improved the AUC, albeit borderline for death, from 0·78 to 0·82 (p = 0·11) and 0·84 (p = 0·052) for mortality and from 0·68 to 0·78 (p = 0·0097) and 0·75 (p = 0·021) for worsening WHO score. The validation cohort findings were confirmatory.
This first CRIT-COV-U report proves the concept that urinary proteomic profiling generates biomarkers indicating adverse COVID-19 outcomes, even at an early disease stage, including WHO stages 1–3. These findings need to be consolidated in an upcoming final dataset.
The German Federal Ministry of Health funded the study.
Allogeneic stem cell transplantation (HSCT) is a curative treatment for adult patients with hematologic malignancies, but is limited by severe, life-threatening complications such as acute ...graft-versus-host disease (aGvHD). We have developed a proteomic urine pattern “aGvHD_MS17”, consisting of 17 differentially excreted peptides, capable to predict aGvHD grade II or more (1, 2). In 2008, a multicenter, randomized, placebo-controlled, double blind clinical trial (Pre-GvHD) was initiated testing aGvHD_MS17 for prediction of aGvHD and to initiate pre-emptive therapy using prednisolone 2-2.5mg/kg.
Patients and Methods:
Eleven German transplant-centres contributed 267 patients. Urine was collected weekly from day +7 to +35 and on days +50 and +80 (all +/-3 days) frozen, shipped to Hannover and analyzed using capillary electrophoresis coupled on-line to mass spectrometry (CE-MS) within 72h as described (1). aGvHD_MS17 was considered positive, when the dimensionless classification factor (CF) was +0.1 or more. Eight patients were excluded from analyses, either due to no medication (n=5) or protocol violations (n=3) and 92 were randomized according to the positivity of aGvHD-MS17 to receive either prednisolone (2-2.5mg/kg, n=44) or placebo (n=48) for 5 days followed by a taper for 19 days, if no aGvHD occurred. The remaining 167 patients formed the observation group according to pattern negativity.
About half of the patients had acute leukemia (placebo group: n=24/48 (50%), prednisolone group: n=21/44 (50%); observation group: n= 91/167 (54%)) and were in complete remission/chronic phase (CR/CP) (placebo n=23/48 (47%), prednisolone n=27/44 (61%) and observation n=68/167 (41%). The majority was transplanted from matched donors (placebo: n=42/48 (87%); prednisolone: n=37/44 (84%); observation: 146/167 (87%), using reduced intensity conditioning regimens (RIC; 64%), and a calcineurin-inhibitor based GvHD-prophylaxis with MTX or MMF).
Results:
Prospective and blinded evaluation of aGvHD_MS17 revealed that the first analysis time point (day +7; range: 2-17) most accurately predicted aGvHD grade II or more with a sensitivity of 87% and a specificity of 81% prior to clinical signs with a CF of +0.1 (2). Patients with samples positive for aGvHD_MS17 in the early analyses time points had a 21-fold higher risk to develop aGvHD grade II or more ((p<0.0001), Figure 1). By day +28 the predictive value of aGvHD_MS17 was lost. Confounding factors were conditioning with RIC-protocols and early death after HSCT. Patients with one sample positive for aGvHD_MS17 had a 3-fold higher risk to die, 35% of those died prior to day +500, compared to only 10% of the patients with negative samples. Analysis of pre-emptive therapy using prednisolone revealed that the incidence and severity of acute GvHD was not significantly different between the placebo and prednisolone arm suggesting that prednisolone 2-2.5mg/kg was insufficient to prevent aGvHD in this setting. Further analyses of aGvHD according to organ manifestation are ongoing. The occurrence of aGvHD after a positive proteomic pattern test in the placebo group of this trial was lower than in the previous pilot study. Possible reasons include different patient populations (pilot study: 18% of patients transplanted in relapse; current trial: only 4% transplanted in relapse, increasing the risk to develop aGvHD), different intestinal decontamination and GvHD prophylaxis protocols. The frequency of adverse and serious adverse events was not higher in the prednisolone arm than the placebo arm. No specific safety risk of the pre-emptive therapy with prednisolone was identified.
Conclusions:
Taken together our results indicate that pre-emptive treatment of imminent aGvHD based on proteomic-pattern-diagnostic with prednisolone 2-2.5mg/kg appears to be safe, but did not influence severity or incidence of aGvHD grade II or more. The prospective evaluation of aGvHD_MS17 confirms the highly reproducible results in the early analysis time points (day +7 to +21) for prediction of aGvHD (day +7; range 2-17). Patients with aGvHD_MS17 positive samples have a 21-fold risk to develop severe GvHD (grade II-IV). Moreover, patients with one sample positive for aGvHD_MS17have a 3-fold increased risk of death by day +500 after HSCT.
(1) Blood 2007 :109(12):5511-9.
(2) Leukemia, 2014: , 28(4):842-52
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Jochen:Mosaiques GmbH: Employment. Schmid:Jazz: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; MoilMed: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding, Speakers Bureau. Bethge:Miltenyi Biotech GmbH: Consultancy, Honoraria, Research Funding; Neovii GmbH: Honoraria, Research Funding. Raad:Mosaiques GmbH: Employment. Durban:Mosaiques GmbH: Employment.
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