Cerebrospinal fluid CXCL13 concentration for diagnosis and monitoring of neurosyphilis in people with HIV

OBJECTIVES

The study aimed to assess and compare cerebrospinal fluid (CSF)-CXCL13 levels in People with HIV (PWH) with suspected neurosyphilis (NS), those with syphilis but without NS, and patients without treponema infection. Additionally, it aimed to evaluate changes in CSF-CXCL13 concentrations before and after antibiotic treatment.

DESIGN

This was a prospective cohort study involving 93 PWH suspected of NS. All participants underwent lumbar puncture, with CSF-CXCL13 levels measured at baseline and during follow-up in patients diagnosed with NS.

METHODS

CSF-CXCL13 levels were quantified using ELISA. The Mann-Whitney U test was used to analyze differences between groups, while the Wilcoxon test assessed within subject changes. ROC curve analysis determined the diagnostic efficacy of CSF-CXCL13 for NS.

RESULTS

Significantly higher CSF-CXCL13 levels were observed in patients with NS compared to those with syphilis without NS and non-syphilis patients. Posttreatment, a decline in CSF-CXCL13 levels was noted in all NS cases. A CSF-CXCL13 threshold exceeding 60.0 pg/ml, in conjunction with reactive CSF-FTA-ABS, yielded a sensitivity of 88.9% and a specificity of 97.6% for NS diagnosis.

CONCLUSIONS

CSF-CXCL13 emerges as a valuable adjunctive biomarker for detecting NS in PWH, especially in cases with nonreactive CSF-VDRL. Monitoring CSF-CXCL13 levels also appears effective in evaluating therapeutic response in PWH undergoing NS treatment.

The temporal course of T- and B-cell responses to vaccination with BNT162b2 and mRNA-1273

OBJECTIVES

To investigate the response of the immune system (and its influencing factors) to vaccination with BNT162b2 or mRNA-1273.

METHODS

531 vaccinees, recruited from healthcare professionals, donated samples before, in between, and after the administration of the two doses of the vaccine. T- and B-cell responses were examined via interferon-γ (IFN-γ) release assay, and antibodies against different epitopes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (S1 and NCP) were detected via ELISA and surrogate neutralization assay. Results were correlated with influencing factors such as age, sex, prior infection, vaccine received (BNT162b2 or mRNA-1273), and immunosuppression. Furthermore, antinuclear antibodies (ANAs) were measured to screen for autoimmune responses following vaccination with an mRNA vaccine.

RESULTS

No markers of immunity against SARS-CoV-2 were found before the first vaccination. Two weeks after it, specific responses against SARS-CoV-2 were already measurable (median ± median absolute deviation (MAD): anti-S1 IgG 195.5 ± 172.7 BAU/mL; IgA 6.7 ± 4.9 OD; surrogate neutralization 39 ± 23.7%), and were significantly increased two weeks after the second dose (anti-S1 IgG 3744 ± 2571.4 BAU/mL; IgA 12 ± 0 OD; surrogate neutralization 100 ± 0%, IFN-γ 1897.2 ± 886.7 mIU/mL). Responses were stronger for younger participants (this difference decreasing after the second dose). Further influences were previous infection with SARS-CoV-2 (causing significantly stronger responses after the first dose compared to unexposed individuals (p ≤ 0.0001)) and the vaccine received (significantly stronger reactions for recipients of mRNA-1273 after both doses, p < 0.05-0.0001). Some forms of immunosuppression significantly impeded the immune response to the vaccination (with no observable immune response in three immunosuppressed participants). There was no significant induction of ANAs by the vaccination (no change in qualitative ANA results (p 0.2592) nor ANA titres (p 0.08) from pre-to post-vaccination.

CONCLUSIONS

Both vaccines elicit strong and specific immune responses against SARS-CoV-2 which become detectable one week (T-cell response) or two weeks (B-cell response) after the first dose.

Differences in Immunogenicity of Three Different Homo- and Heterologous Vaccination Regimens against SARS-CoV-2

Background: Due to findings on adverse reactions and clinical efficacy of different vaccinations against SARS-CoV-2, the administration of vaccination regimens containing both adenoviral vector vaccines and mRNA-based vaccines has become common. Data are still needed on the direct comparison of immunogenicity for these different regimens. Methods: We compared markers for immunogenicity (anti-S1 IgG/IgA, neutralizing antibodies, and T-cell response) with three different vaccination regimens (homologous ChAdOx1 nCoV-19 (n = 103), or mixture of ChAdOx1 nCoV-19 with mRNA-1273 (n = 116) or BNT162b2 (n = 105)) at two time points: the day of the second vaccination as a baseline and 14 days later. Results: All examined vaccination regimens elicited measurable immune responses that were significantly enhanced after the second dose. Homologous ChAdOx1 nCoV-19 was markedly inferior in immunogenicity to all other examined regimens after administration of the second dose. Between the heterologous regimens, mRNA-1273 as second dose induced greater antibody responses than BNT162b2, with no difference found for neutralizing antibodies and T-cell response. Discussion: While these findings allow no prediction about clinical protection, from an immunological point of view, vaccination against SARS-CoV-2 with an mRNA-based vaccine at one or both time points appears preferable to homologous vaccination with ChAdOx1 nCoV-19. Whether or not the demonstrated differences between the heterologous regimens are of clinical significance will be subject to further research.

B-cell-responses to vaccination with BNT162b2 and mRNA-1273 six months after second dose

Objectives

To examine the state of B-cell immunity 6 months after the second vaccination against SARS-CoV-2 in comparison to the state observed 2 weeks after vaccination.

Methods

Sera of 439 participants, whose immune responses to two doses of an mRNA-based vaccine (BNT162b2 or mRNA-1273) were previously characterized, was examined for anti-S1 IgG and IgA, anti-NCP IgG and neutralizing antibodies (nAb), and antinuclear antibodies (ANA).

Results

Levels of all examined markers decreased significantly from 2 weeks to 6 months after second vaccination (anti-S1 IgG: 3744 ± 2571.4 vs. 253 ± 144 binding antibody units (BAU)/mL; anti-S1 IgA: 12 ± 0 vs. 1.98 ± 1.75 optical density (OD) ratio; nAb: 100% ± 0% vs. 82% ± 19.3%), the vast majority of participants retaining reactive levels of anti-S1 IgG (436/439) and anti-S1 IgA (334/439) at 6 months. Immune responses were stronger for mRNA-1273 compared with BNT162b2 (anti-S1 IgG: 429 ± 289 vs. 243 ± 143 BAU/mL; anti-S1 IgA: 5.38 ± 3.91 vs. 1.89 ± 1.53 OD ratio; nAb: 90.5% ± 12.6% vs. 81% ± 19.3%). There was no meaningful influence of sex and age on the examined markers. There was a strong correlation between anti-S1 IgG and the surrogate neutralization assay (rho = 0.91, p <0.0001), but not for for IgA and the surrogate neutralization assay (rho = 0.52, p <0.0001). There was a ceiling effect for the association between anti-S1 IgG titres and the inhibition of binding between S1 and ACE2. ANA prevalence was unchanged from 2 weeks to 6 months after the second vaccination (87/498 vs. 77/435), as were the median ANA titres (1:160 vs. 1:160).

Discussion

Although the clinical consequences of decreasing anti-SARS-CoV-2 antibody titres cannot be estimated with certainty, a lowered degree of clinical protection against SARS-CoV-2 is possible. Persistently stronger responses to mRNA-1273 suggest that it might confer greater protection than BNT162b2, even 6 months after the second vaccination. Neither examined vaccinations induced ANA within the examined time frame.

Kinetics of the Antibody Response to Boostering With Three Different Vaccines Against SARS-CoV-2

Background

Heterologous vaccinations against SARS-CoV-2 with ChAdOx1 nCoV-19 and a second dose of an mRNA-based vaccine have been shown to be more immunogenic than homologous ChAdOx1 nCoV-19. In the current study, we examined the kinetics of the antibody response to the second dose of three different vaccination regimens (homologous ChAdOx1 nCoV-19 vs. ChAdOx1 nCoV-19 + BNT162b2 or mRNA-1273) against SARS-CoV-2 in a longitudinal manner; whether there are differences in latency or amplitude of the early response and which markers are most suitable to detect these responses.

Methods

We performed assays for anti-S1 IgG and IgA, anti-NCP IgG and a surrogate neutralization assay on serum samples collected from 57 participants on the day of the second vaccination as well as the following seven days.

Results

All examined vaccination regimens induced detectable antibody responses within the examined time frame. Both heterologous regimens induced responses earlier and with a higher amplitude than homologous ChAdOx1 nCoV-19. Between the heterologous regimens, amplitudes were somewhat higher for ChAdOx1 nCoV-19 + mRNA-1273. There was no difference in latency between the IgG and IgA responses. Increases in the surrogate neutralization assay were the first changes to be detectable for all regimens and the only significant change seen for homologous ChAdOx1 nCoV-19.

Discussion

Both examined heterologous vaccination regimens are superior in immunogenicity, including the latency of the response, to homologous ChAdOx1 nCoV-19. While the IgA response has a shorter latency than the IgG response after the first dose, no such difference was found after the second dose, implying that both responses are driven by separate plasma cell populations. Early and steep increases in surrogate neutralization levels suggest that this might be a more sensitive marker for antibody responses after vaccination against SARS-CoV-2 than absolute levels of anti-S1 IgG.

First amyloid β1-42 certified reference material for re-calibrating commercial immunoassays

INTRODUCTION

Reference materials based on human cerebrospinal fluid were certified for the mass concentration of amyloid beta (Aβ)1-42 (Aβ₄₂ ). They are intended to be used to calibrate diagnostic assays for Aβ₄₂ .

METHODS

The three certified reference materials (CRMs), ERM-DA480/IFCC, ERM-DA481/IFCC and ERM-DA482/IFCC, were prepared at three concentration levels and characterized using isotope dilution mass spectrometry methods. Roche, EUROIMMUN, and Fujirebio used the three CRMs to re-calibrate their immunoassays.

RESULTS

The certified Aβ₄₂ mass concentrations in ERM-DA480/IFCC, ERM-DA481/IFCC, and ERM-DA482/IFCC are 0.45, 0.72, and 1.22 μg/L, respectively, with expanded uncertainties (k = 2) of 0.07, 0.11, and 0.18 μg/L, respectively. Before re-calibration, a good correlation (Pearson's r > 0.97), yet large biases, were observed between results from different commercial assays. After re-calibration the between-assay bias was reduced to < 5%.

DISCUSSION

The Aβ₄₂ CRMs can ensure the equivalence of results between methods and across platforms for the measurement of Aβ₄₂ .

Serum uromodulin-a marker of kidney function and renal parenchymal integrity

Background

An ELISA to analyse uromodulin in human serum (sUmod) was developed, validated and tested for clinical applications.

Methods

We assessed sUmod, a very stable antigen, in controls, patients with chronic kidney disease (CKD) stages 1-5, persons with autoimmune kidney diseases and recipients of a renal allograft by ELISA.

Results

Median sUmod in 190 blood donors was 207 ng/mL (women: men, median 230 versus 188 ng/mL, P = 0.006). sUmod levels in 443 children were 193 ng/mL (median). sUmod was correlated with cystatin C (rs = -0.862), creatinine (rs = -0.802), blood urea nitrogen (BUN) (rs = -0.645) and estimated glomerular filtration rate (eGFR)-cystatin C (rs  =  0.862). sUmod was lower in systemic lupus erythematosus-nephritis (median 101 ng/mL), phospholipase-A2 receptor- positive glomerulonephritis (median 83 ng/mL) and anti-glomerular basement membrane positive pulmorenal syndromes (median 37 ng/mL). Declining sUmod concentrations paralleled the loss of kidney function in 165 patients with CKD stages 1-5 with prominent changes in sUmod within the 'creatinine blind range' (71-106 µmol/L). Receiver-operating characteristic analysis between non-CKD and CKD-1 was superior for sUmod (AUC 0.90) compared with eGFR (AUC 0.39), cystatin C (AUC 0.39) and creatinine (AUC 0.27). sUmod rapidly recovered from 0 to 62 ng/mL (median) after renal transplantation in cases with immediate graft function and remained low in delayed graft function (21 ng/mL, median; day 5-9: relative risk 1.5-2.9, odds ratio 1.5-6.4). Immunogold labelling disclosed that Umod is transferred within cytoplasmic vesicles to both the apical and basolateral plasma membrane. Umod revealed a disturbed intracellular location in kidney injury.

Conclusions

We conclude that sUmod is a novel sensitive kidney-specific biomarker linked to the structural integrity of the distal nephron and to renal function.

Urinary uromodulin independently predicts end-stage renal disease and rapid kidney function decline in a cohort of chronic kidney disease patients

Data on risk factors predicting rapid progression to end-stage renal disease (ESRD) or short-term kidney function decline (i.e., within 1 year) in chronic kidney disease (CKD) are rare but urgently needed to plan treatment. This study describes the association and predictive value of urinary uromodulin (uUMOD) for rapid progression of CKD.We assessed uUMOD, demographic/treatment parameters, estimated glomerular filtration rate (eGFR), and proteinuria in 230 CKD patients stage I-V. ESRD and 25% decline of eGFR was documented at the end of follow-up period and used as a composite endpoint. Association between logarithmic uUMOD and eGFR/proteinuria was calculated using linear regression analysis, adjusting for age, gender, and body mass index. We performed multivariable Cox proportional hazard regression analysis to evaluate the association of uUMOD with the composite endpoint. Therefore, patients were categorized into quartiles. The predictive value of uUMOD for the above outcomes was assessed using receiver-operating characteristic (ROC) curve analysis.Follow-up was 57.3 ± 18.7 weeks, baseline age was 60 (18;92) years, and eGFR was 38 (6;156) mL/min/1.73 m. Forty-seven (20.4%) patients reached the composite endpoint. uUMOD concentrations were directly associated with eGFR and inversely associated with proteinuria (β = 0.554 and β = -0.429, P < .001). In multivariable Cox regression analysis, the first 2 quartiles of uUMOD concentrations had a hazard ratio (HR) of 3.589 [95% confidence interval (95% CI) 1.002-12.992] and 5.409 (95% CI 1.444-20.269), respectively, in comparison to patients of the highest quartile (≥11.45 μg/mL) for the composite endpoint. In ROC-analysis, uUMOD predicted the composite endpoint with good sensitivity (74.6%) and specificity (76.6%) at an optimal cut-off at 3.5 μg/mL and area under the curve of 0.786 (95% CI 0.712-0.860, P < .001).uUMOD was independently associated with ESRD/rapid loss of eGFR. It might serve as a robust predictor of rapid kidney function decline and help to better schedule arrangements for future treatment.

Comparison of elevated phosphorylated neurofilament heavy chains in serum and cerebrospinal fluid of patients with amyotrophic lateral sclerosis

OBJECTIVE

Phosphorylated neurofilament heavy chain (pNfH) levels are elevated in cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). Instead of CSF, we explored blood as an alternative source to measure pNfH in patients with ALS.

METHODS

In this single centre retrospective study, 85 patients with ALS, 215 disease controls (DC) and 31 ALS mimics were included. Individual serum pNfH concentrations were correlated with concentrations in CSF and with several clinical parameters. The performance characteristics of pNfH in CSF and serum of patients with ALS and controls were calculated and compared using receiver operating characteristic (ROC) curves.

RESULTS

CSF and serum pNfH concentrations in patients with ALS correlated well (r=0.652, p<0.0001) and were significantly increased compared with DC (p<0.0001) and ALS mimics (p<0.0001). CSF pNfH outperformed serum pNfH in discriminating patients with ALS from DC and ALS mimics (difference between area under the ROC curves: p=0.0001 and p=0.0005; respectively). Serum pNfH correlated inversely with symptom duration (r=-0.315, p=0.0033). CSF and serum pNfH were lower when the disease progression rate was slower (r=0.279, p<0.01 and r=0.289, p<0.01; respectively). Unlike CSF, serum pNfH did not correlate with the burden of clinical and electromyographic motor neuron dysfunction.

CONCLUSIONS

CSF and serum pNfH concentrations are elevated in patients with ALS and correlate with the disease progression rate. Moreover, CSF pNfH correlates with the burden of motor neuron dysfunction. Our findings encourage further pursuit of CSF and serum pNfH concentrations in the diagnostic pathway of patients suspected to have ALS.

Optimized Standard Operating Procedures for the Analysis of Cerebrospinal Fluid Aβ42 and the Ratios of Aβ Isoforms Using Low Protein Binding Tubes

Background: Reduced cerebrospinal fluid (CSF) concentration of amyloid-β_1-42 (Aβ_1-42) reflects the presence of amyloidopathy in brains of subjects with Alzheimer’s disease (AD).

Objective: To qualify the use of Aβ_1-42/Aβ_1-40 for improvement of standard operating procedures (SOP) for measurement of CSF Aβ with a focus on CSF collection, storage, and analysis.

Methods: Euroimmun ELISAs for CSF Aβ isoforms were used to set up a SOP with respect to recipient properties (low binding, polypropylene), volume of tubes, freeze/thaw cycles, addition of detergents (Triton X-100, Tween-20) in collection or storage tubes or during CSF analysis. Data were analyzed with linear repeated measures and mixed effects models.

Results: Optimization of CSF analysis included a pre-wash of recipients (e.g., tubes, 96-well plates) before sample analysis. Using the Aβ_1-42/Aβ_1-40 ratio, in contrast to Aβ_1-42, eliminated effects of tube type, additional freeze/thaw cycles, or effect of CSF volumes for polypropylene storage tubes. ‘Low binding’ tubes reduced the loss of Aβ when aliquoting CSF or in function of additional freeze/thaw cycles. Addition of detergent in CSF collection tubes resulted in an almost complete absence of variation in function of collection procedures, but affected the concentration of Aβ isoforms in the immunoassay.

Conclusion: The ratio of Aβ_1-42/Aβ_1-40 is a more robust biomarker than Aβ_1-42 toward (pre-) analytical interfering factors. Further, ‘low binding’ recipients and addition of detergent in collection tubes are able to remove effects of SOP-related confounding factors. Integration of the Aβ_1-42/Aβ_1-40 ratio and ‘low-binding tubes’ into guidance criteria may speed up worldwide standardization of CSF biomarker analysis.

Recommendations for cerebrospinal fluid collection for the analysis by ELISA of neurogranin trunc P75, α-synuclein, and total tau in combination with Aβ(1-42)/Aβ(1-40)

BACKGROUND

The pathophysiology of neurodegeneration is complex. Its diagnosis requires an early identification of sequential changes in several hallmarks in the brains of affected subjects. The presence of brain pathology can be visualized in the cerebrospinal fluid (CSF) by protein profiling. It is clear that the field of Alzheimer's disease (AD) will benefit from an integration of algorithms including CSF concentrations of individual proteins, especially as an aid in clinical decision-making or to improve patient enrolment in clinical trials. The protein profiling approach requires standard operating procedures for collection and storage of CSF which must be easy to integrate into a routine clinical lab environment. Our study provides recommendations for analysis of neurogranin trunc P75, α-synuclein, and tau, in combination with the ratio of β-amyloid Aβ(1-42)/Aβ(1-40).

METHODS

Protocols for CSF collection were compared with CSF derived from subjects with normal pressure hydrocephalus (n = 19). Variables included recipient type (collection, storage), tube volume, and addition of detergents at the time of collection. CSF biomarker analysis was performed with enzyme-linked immunosorbent assays (ELISAs). Data were analyzed with linear repeated measures and mixed effects models.

RESULTS

Adsorption to recipients is lower for neurogranin trunc P75, α-synuclein, and tau (<10%), as compared to Aβ(1-42). For neurogranin trunc P75 and total tau, there is still an effect on analyte concentrations as a function of the tube volume. Protocol-related differences for Aβ(1-42) can be normalized at the (pre-)analytical level using the ratio Aβ(1-42)/Aβ(1-40), but not by using the ratio Aβ(1-42)/tau. The addition of detergent at the time of collection eliminates differences due to adsorption.

CONCLUSIONS

Our study recommends the use of low protein binding tubes for quantification in CSF (without additives) of all relevant CSF biomarkers. Pre-analytical factors have less effect on α-synuclein, neurogranin trunc P75, and total tau, as compared to Aβ(1-42). The ratio of Aβ(1-42)/Aβ(1-40), but not Aβ(1-42)/tau, can be used to adjust for pre-analytical differences in analyte concentrations. Our study does not recommend the inclusion of detergents at the time of collection of CSF. The present results provide an experimental basis for new recommendations for parallel analysis of several proteins using one protocol for collection and storage of CSF.

Serum uromodulin predicts graft failure in renal transplant recipients

OBJECTIVE AND METHODS

Test the ability of serum uromodulin concentrations 1-3 months after renal transplantation to predict all-cause mortality (ACM) and graft loss (GL) in 91 patients.

RESULTS

uromodulin predicted GL equivalently to the other markers studied: the risk for GL was reduced by 0.21 per one standard deviation (SD) increase (cystatin C: hazard ratio [HR] 4.57, creatinine: HR 4.53, blood-urea-nitrogen [BUN]: HR 2.50, estimated glomerular filtration rate [eGFR]: HR 0.10). In receiver-operating-characteristic (ROC) analysis, uromodulin predicted GL with an area-under-the curve of 0.782 at an optimal cut-off (OCO) of 24.0 ng/ml with a sensitivity of 90.0% and a specificity of 70.2%.

CONCLUSION

Serum uromodulin predicted GL equivalently compared to conventional biomarkers of glomerular filtration.

Prospective longitudinal course of cognition in older subjects with mild parkinsonian signs

Background

Mild parkinsonian signs (MPS) are common in older people and are associated with an increased risk of different neurodegenerative diseases. This study prospectively evaluates the longitudinal course of cognitive performance in older individuals with MPS.

Methods

From the TREND study, 480 individuals neurologically healthy at baseline, aged between 50 and 80 years, with complete follow-up data for three assessments within a mean of 43.8 months, were included in this analysis. Participants underwent a detailed cognitive test battery, evaluation of prodromal markers for neurodegenerative diseases and history of vascular diseases at each study visit. In addition, plasma levels of amyloid-beta (Aβ)_1–40 and Aβ_1–42 were evaluated longitudinally.

Results

In 52 (11 %) of the 480 participants, MPS could be detected at baseline. These individuals had cognitive deficits significantly more often compared with controls at each time point and their cognitive performance showed a steeper decline during follow-up. In addition, their levels of plasma Aβ_1–42 were significantly lower than those of controls, and declined more rapidly over time.

Conclusions

This longitudinal study shows that MPS are associated with cognitive decline and decrease in plasma Aβ_1–42, possibly indicating an ongoing neurodegenerative process.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-016-0209-7) contains supplementary material, which is available to authorized users.

Plasma Uromodulin Correlates With Kidney Function and Identifies Early Stages in Chronic Kidney Disease Patients

Uromodulin, released from tubular cells of the ascending limb into the blood, may be associated with kidney function. This work studies the relevance of plasma uromodulin as a biomarker for kidney function in an observational cohort of chronic kidney disease (CKD) patients and subjects without CKD (CKD stage 0). It should be further evaluated if uromodulin allows the identification of early CKD stages.Plasma uromodulin, serum creatinine, cystatin C, blood-urea-nitrogen (BUN) concentrations, and estimated glomerular filtration rate (eGFR CKD-EPIcrea-cystatin) were assessed in 426 individuals of whom 71 were CKD stage 0 and 355 had CKD. Besides descriptive statistics, univariate correlations between uromodulin and biomarkers/eGFR were calculated using Pearson-correlation coefficient. Multiple linear regression modeling was applied to establish the association between uromodulin and eGFR adjusted for demographic parameters and pharmacologic treatment. Receiver-operating-characteristic (ROC) analysis adjusted for demographic parameters was performed to test if uromodulin allows differentiation of subjects with CKD stage 0 and CKD stage I.Mean uromodulin plasma levels were 85.7 ± 60.5 ng/mL for all CKD stages combined. Uromodulin was correlated with all biomarkers/eGFR in univariate analysis (eGFR: r = 0.80, creatinine: r = -0.76, BUN: r = -0.72, and cystatin C: r = -0.79). Multiple linear regression modeling showed significant association between uromodulin and eGFR (coefficient estimate β = 0.696, 95% confidence interval [CI] 0.603-0.719, P < 0.001). In ROC analysis uromodulin was the only parameter that significantly improved a model containing demographic parameters to differentiate between CKD 0° and I° (area under the curve [AUC] 0.831, 95% CI 0.746-0.915, P = 0.008) compared to creatinine, cystatin C, BUN, and eGFR (AUC for creatinine: 0.722, P = 0.056, cystatin C: 0.668, P = 0.418, BUN: 0.653, P = 0.811, and eGFR: 0.634, P = 0.823).Plasma uromodulin serves as a robust biomarker for kidney function and uniquely allows the identification of early stages of CKD. As a marker of tubular secretion it might represent remaining nephron mass and therefore intrinsic "kidney function" rather than just glomerular filtration, the latter only being of limited value to represent kidney function as a whole. It therefore gives substantial information on the renal situation in addition to glomerular filtration and potentially solves the problem of creatinine-blind range of CKD, in which kidney impairment often remains undetected.

Multimodal evoked potential monitoring in asleep patients versus neurological evaluation in awake patients during carotid endarterectomy: a single-centre retrospective trial of 651 patients

BACKGROUND

A controversy exists regarding which monitoring technique is superior in cases in which general anesthesia (GA) is necessary for carotid endarterectomy (CEA). Multimodal evoked potential (mEP) monitoring was investigated under GA during CEA and compared with a historical control group undergoing neurological evaluations awake under loco-regional anesthesia (LA).

METHODS

We retrospectively studied 651 patients undergoing elective CEA. In groupHISTORY (N.=349; 1997-1999) LA was provided using superficial or deep/superficial cervical plexus blocks. In groupmEP, (N.=302; 2009-2013) GA was performed by administering remifentanil/propofol infusion. The multimodal EPs included the median-nerve-somatosensory and motor evoked potentials. The primary outcome was the rate of technical failure. The arterio-arterial shunt rate and immediate postoperative motor outcomes were also compared.

RESULTS

GroupmEP showed a significantly lower rate of technical failure (OR 0.17; CI 0.03-0.6; P=0.002). Because the groups differed systematically, logistic regression analysis was used to compare shunt rates and motor outcomes. Since shunt rates were 8.3% (groupmEP) versus 8.2% (groupHISTORY), but logistic regression model showed significant differences (OR 3.77; CI 1.67-8.95; P=0.001) correct comparison was impossible. Immediate postoperative deficits were 4.3% (groupmEP) and 4.9% (groupHISTORY); logistic regression analysis: transient OR 0.77, CI 0.28 to 0.22, P=0.61 and permanent OR 0.37, CI 0.02-7.74, P=0.49.

CONCLUSION

Monitoring mEPs was associated with less technical failure than awake evaluation and showed similar motor outcomes. Because the groups differed systematically, the interpretation of shunt rates was impossible. Monitoring mEP should be considered to detect intraoperative ischemia in cases in which patients undergo CEA under GA.

[Diagnostic value of the determination of total testosterone in the serum and free biologically active testosterone in the saliva in men]

The study was undertaken to provide evidence that the salivary concentration of free testosterone (FT) well correlates with the serum level of unbound testosterone in men. Recent articles demonstrate that the results obtained by the use of especially automatic systems are incorrect. Anew luminescence enzyme immunoassay has been now put into practice. Its high analytical (6.2 pmol/l) and functional (17.3 pmol/l) sensitivities allow the quantification of minor salivary concentrations. In healthy males, the morning salivary concentration was 369 pl/lmo (median) with a range of 263-544 pmol/l, which is statistically higher than that in males with androgen deficiency (215 pl/lmol/I (median) with a range of 51-249 pmol/l. Once-weekly remeasurement of salivary FT during 5 weeks showed the high stability of results over time with a variation coefficient of 9% (range 5-23%). The study indicated that FT in the morning salivary sample well correlates with the calculated FR in the blood of both healthy males (R = 0.754; p = 0.001) and patients with androgen deficiency (R = 0.889; p = 0.0001).

Diagnostic significance of free salivary testosterone measurement using a direct luminescence immunoassay in healthy men and in patients with disorders of androgenic status

The accurate measurement of testosterone remains a challenge. The determination of the blood testosterone concentrations in serum by conventional immunoassays is inaccurate in men and even more so in females and children. A new luminescence enzyme immunoassay (LIA) has been developed and validated. The high analytical (8.7 pmol/L) and functional (17.3 pmol/L) sensitivity allows the quantification of the very low concentration in saliva, as well as in serum, after 1/40 dilution. This study measured salivary testosterone levels and compared the results with the free levels calculated from total testosterone and sex hormone-binding globulin in eugonadal and hypogonadal men. Salivary testosterone concentrations in healthy men in morning hours were 369 pmol/L (mean), range 263-544 pmol/L, which was statistically significantly higher than that in men with androgen deficiency, 215 pmol/L (mean), range 51-249 pmol/L. Repetitive determination of free testosterone concentrations in saliva (once a week for 5 weeks) showed high stability of results over time, with coefficient of variation 9% (range 5-23%). In this study we showed that free salivary testosterone levels in morning samples correlated well with calculated free testosterone in blood, both in healthy men (R = 0.754, P = 0.001), and in patients with androgen deficiency (R = 0.889, P = 0.0001), though in cases with very low testosterone, salivary concentrations were systematically higher than calculated free testosterone levels in blood.

Determination of cortisol in saliva and serum by a luminescence-enhanced enzyme immunoassay

A new luminescence-enhanced enzyme immunoassay (LEIA) has been developed and validated for the direct measurement of cortisol in saliva and serum. It has been demonstrated that this LEIA has a very good analytical and functional sensitivity. There was a good correlation to a commercial RIA. The assessment of diurnal cortisol profiles of healthy persons are discussed. Cortisol monitoring is indicated in diseases with abnormal glucocorticoid production such as Cushing's syndrome and Addison's disease. Because of the diurnal fluctuation of cortisol levels it is necessary to take several samples for an individual cortisol profile or during dynamic tests like the dexamethasone-suppression or ACTH stimulation. Salivary sample collection is an alternative method without the stress of repeated venipuncture. The measurement of cortisol in saliva is advisable in patients with abnormal cortisol-binding-globulin (CBG) levels such as pregnancy, hypothyroidism, nephrotic syndrome or marked adipositas and during the administration of certain drugs, especially oral contraceptives.

[Water pollution, self-purification and restoration possibilities]

Organic pollution is still the most important anthropogenic stress factor influencing the usability of ground and surface water as drinking water for cattle. Organic pollution is decomposed in several distinct heterotrophic processes that cause oxygen deficit, and finally end in the production of ammonia, hydrogen sulphide or methane. Even after the oxygen balance being restored higher nutrient concentrations (eutrophication) will remain. Eutrophication itself often leads to secondary pollution processes that adversely affect oxygen availability. Toxins may be generated by certain bluegreen bacteria growing under highly eutrophic conditions. Due to the concentrations of organic substances bacterial growth is forced, sometimes including faecal indicators and pathogenic species originating from the effluents of most of the communal sewage treatment works. Another kind of man made pollution concerns certain toxic substances. Disregarding the effects of accidental spills, the industrial production and use of pesticides in agriculture as well as other industrial chemicals or heavy metals may cause concentrations beyond acceptable limits. The use of surface water for cattle may become a problem for this reason. Accidental spills must be reckoned with as well, so the technical equipment for providing alternative sources of drinking water in emergencies must be available. Whereas the use of groundwater is normally not affected by toxic substance or pathogenic bacteria, high concentrations of iron, humic acids or salination may affect the suitability of water for cattle.

Lymphocytic angiitis following streptokinase therapy

A palpable, purpuric, nonpruritic eruption occurred in a 64-year-old man nine days after he received intravenous streptokinase therapy, which was successful in treating acute myocardial infarction. Perivascular mononuclear and eosinophilic infiltration was noted on routine staining of skin biopsy specimens: immune complexes, fibrin, and complement deposition in the skin microvasculature were demonstrated on immunofluorescent studies. These findings confirm the diagnosis of lymphocytic angiitis induced by streptokinase. Intermediate-type hypersensitivity reactions to streptokinase apparently have variable levels of severity. Clinicians who use streptokinase as a therapeutic agent should be aware of this potentially serious complication.