Predictive performance of two types of urinary biomarkers for renal non-recovery in sepsis-associated acute kidney injury: a prospective observational study

BACKGROUND AND PURPOSE

Renal non-recovery is known to have negative prognostic implications in patients suffering from acute kidney injury (AKI). Nevertheless, the identification of biomarkers for predicting renal non-recovery in sepsis-associated AKI (SA-AKI) within clinical settings remains unresolved. This study aims to evaluate and compare the predictive ability for renal non-recovery, use of kidney replacement therapy (KRT) in the Intensive Care Unit (ICU), and 30-day mortality after SA-AKI by two urinary biomarkers, namely C-C motif chemokine ligand 14 (CCL14) and [TIMP-2]•[IGFBP7].

METHODS

We prospectively screened adult patients who met the criteria for AKI stage 2-3 and Sepsis-3.0 in two ICUs from January 2019 to May 2022. Patients who developed new-onset SA-AKI after ICU admission were enrolled and urinary biomarkers including [TIMP-2]•[IGFBP7] and CCL14 were detected at the time of SA-AKI diagnosis. The primary endpoint was non-recovery from SA-AKI within 7 days. The secondary endpoints were the use of KRT in the ICU and 30-day mortality after SA-AKI. The individual discriminative ability of [TIMP-2]•[IGFBP7] and CCL14 to predict renal non-recovery were evaluated by the area under receiver operating characteristics curve (AUC).

RESULTS

141 patients with stage 2-3 SA-AKI were finally included, among whom 54 (38.3%) experienced renal non-recovery. Urinary CCL14 exhibited a higher predictive capability for renal non-recovery compared to [TIMP-2]•[IGFBP7], with CCL14 showing an AUC of 0.901, versus an AUC of 0.730 for [TIMP-2]•[IGFBP7] (P = 0.001). Urinary CCL14 and [TIMP-2]•[IGFBP7] demonstrated a moderate predictive value for the need for KRT in ICU, with AUC values of 0.794 and 0.725, respectively; The AUC of [TIMP-2]•[IGFBP7] combined with CCL14 reached up to 0.816. Urinary CCL14 and [TIMP-2]•[IGFBP7] exhibited poor predictive power for 30-day mortality, with respective AUC values of 0.623 and 0.593.

CONCLUSION

Urinary CCL14 had excellent predictive value for renal non-recovery in SA-AKI patients. For predicting the use of KRT in the ICU, the predictive capability of urinary [TIMP-2]•[IGFBP7] or CCL14 was fair. However, a combination of [TIMP-2]•[IGFBP7] and CCL14 showed good predictive ability for the use of KRT.

Biomarker Enrichment in Sepsis-Associated Acute Kidney Injury: Finding High-Risk Patients in the Intensive Care Unit

BACKGROUND

Sepsis-associated acute kidney injury (AKI) is a leading comorbidity in admissions to the intensive care unit. While a gold standard definition exists, it remains imperfect and does not allow for the timely identification of patients in the setting of critical illness. This review will discuss the use of biochemical and electronic biomarkers to allow for prognostic and predictive enrichment of patients with sepsis-associated AKI over and above the use of serum creatinine and urine output.

SUMMARY

Current data suggest that several biomarkers are capable of identifying patients with sepsis at risk for the development of severe AKI and other associated morbidity. This review discusses these data and these biomarkers in the setting of sub-phenotyping and endotyping sepsis-associated AKI. While not all these tests are widely available and some require further validation, in the near future we anticipate several new tools to help nephrologists and other providers better care for patients with sepsis-associated AKI.

KEY MESSAGES

Predictive and prognostic enrichment using both traditional biomarkers and novel biomarkers in the setting of sepsis can identify subsets of patients with either similar outcomes or similar pathophysiology, respectively. Novel biomarkers can identify kidney injury in patients without consensus definition AKI (e.g., changes in creatinine or urine output) and can predict other adverse outcomes (e.g., severe consensus definition AKI, inpatient mortality). Finally, emerging artificial intelligence and machine learning-derived risk models are able to predict sepsis-associated AKI in critically ill patients using advanced learning techniques and several laboratory and vital sign measurements.

Urinary C3 levels associated with sepsis and acute kidney injury-A pilot study

Acute kidney injury (AKI) is an abrupt deterioration of renal function often caused by severe clinical disease such as sepsis, and patients require intensive care. Acute-phase parameters for systemic inflammation are well established and used in routine clinical diagnosis, but no such parameters are known for AKI and inflammation at the local site of tissue damage, namely the nephron. Therefore, we sought to investigate complement factors C3a/C3 in urine and urinary sediment cells. After the development of a C3a/C3-specific mouse monoclonal antibody (3F7E2), urine excretion from ICU sepsis patients was examined by dot blot and immunoblotting. This C3a/C3 ELISA and a C3a ELISA were used to obtain quantitative data over 24 hours for 6 consecutive days. Urine sediment cells were analyzed for topology of expression. Patients with severe infections (n = 85) showed peak levels of C3a/C3 on the second day of ICU treatment. The majority (n = 59) showed C3a/C3 levels above 20 μg/ml at least once in the first 6 days after admission. C3a was detectable on all 6 days. Peak C3a/C3 levels correlated negatively with peak C-reactive protein (CRP) levels. No relationship was found between peak C3a/C3 with peak leukocyte count, age, or AKI stage. Analysis of urine sediment cells identified C3a/C3-producing epithelial cells with reticular staining patterns and cells with large-granular staining. Opsonized bacteria were detected in patients with urinary tract infections. In critically ill sepsis patients with AKI, urinary C3a/C3 inversely correlated with serum CRP. Whether urinary C3a/C3 has a protective function through autophagy, as previously shown for cisplatin exposure, or is a by-product of sepsis caused by pathogenic stimuli to the kidney must remain open in this study. However, our data suggest that C3a/C3 may function as an inverse acute-phase parameter that originates in the kidney and is detectable in urine.

A panel of urine-derived biomarkers to identify sepsis and distinguish it from systemic inflammatory response syndrome

Sepsis is a potentially fatal condition caused by infection. It is frequently difficult to distinguish sepsis from systemic inflammatory response syndrome (SIRS), often resulting in poor prognoses and the misuse of antibiotics. Hence, highly sensitive and specific biomarkers are needed to differentiate sepsis from SIRS. Urine samples were collected and segregated by group (a sepsis group, a SIRS group, and a healthy control group). iTRAQ was used to identify the differentially expressed proteins among the three groups. The identified proteins were measured by ELISA in urine samples. Finally, all the acquired data were analyzed in SPSS. C-reactive protein, leucine-rich alpha glycoprotein-1 and serum amyloid A (SAA) protein were differentially expressed among the three groups. The adjusted median concentrations of urinary C-reactive protein were 1337.6, 358.7, and 2.4 in the sepsis, SIRS, and healthy control groups, respectively. The urinary leucine-rich alpha glycoprotein-1 levels in these three groups were 1614.4, 644.5, and 13.6, respectively, and the levels of SAA were 6.3, 2.9, and 0.07, respectively. For all three of these measures, the sepsis group had higher levels than the SIRS group (P < 0.001), and the SIRS group had higher levels than the healthy control group. When combined, the three biomarkers had a sensitivity of 0.906 and a specificity of 0.896 in distinguishing sepsis from SIRS. Urinary C-reactive protein, urinary leucine-rich alpha glycoprotein-1 and urinary SAA have diagnostic value in cases of sepsis. This initial study suggests the possibility of improved differential diagnosis between sepsis and systemic inflammatory response syndrome; additional confirmation is necessary to corroborate the findings.

Feasibility of Embedding a Scalable, Virtually Enabled Biorepository in the Electronic Health Record for Precision Medicine

Importance

A cornerstone of precision medicine is the identification and use of biomarkers that help subtype patients for targeted treatment. Such an approach requires the development and subsequent interrogation of large-scale biobanks linked to well-annotated clinical data. Traditional means of creating these data-linked biobanks are costly and lengthy, especially in acute conditions that require time-sensitive clinical data and biospecimens.

Objectives

To develop a virtually enabled biorepository and electronic health record (EHR)-embedded, scalable cohort for precision medicine (VESPRE) and compare the feasibility, enrollment, and costs of VESPRE with those of a traditional study design in acute care.

Design, Setting, and Participants

In a prospective cohort study, the EHR-embedded screening alert was generated for 3428 patients, and 2199 patients (64%) were eligible and screened. Of these, 1027 patients (30%) were enrolled. VESPRE was developed for regulatory compliance, feasibility, internal validity, and cost in a prospective cohort of 1027 patients (aged ≥18 years) with sepsis-3 within 6 hours of presentation to the emergency department. The VESPRE infrastructure included (1) automated EHR screening, (2) remnant blood collection for creation of a virtually enabled biorepository, and (3) automated clinical data abstraction. The study was conducted at an academic institution in southwestern Pennsylvania from October 17, 2017, to June 6, 2019.

Main Outcomes and Measures

Regulatory compliance, enrollment, internal validity of automated screening, biorepository acquisition, and costs.

Results

Of the 1027 patients enrolled in the study, 549 were included in the proof-of-concept analysis (305 [56%] men); median (SD) age was 59 (17) years. VESPRE collected 12 963 remnant blood and urine samples and demonstrated adequate feasibility for clinical, biomarker, and microbiome analyses. Over the 20-month test, the total cost beyond the existing operations infrastructure was $39 417.50 ($14 880.00 project management, $22 717.50 laboratory supplies/staff, and $1820.00 data management)-approximately $39 per enrolled patient vs $239 per patient for a traditional cohort study.

Conclusions and Relevance

Results of this study suggest that, in a large US health system that collects data using a common EHR platform and centralized laboratory system, VESPRE, a large-scale, inexpensive EHR-embedded infrastructure for precision medicine can be used. Tested in the sepsis setting, VESPRE appeared to capture a high proportion of eligible patients at low incremental cost.

Urinary orosomucoid: validation of an automated immune turbidimetric test and its possible clinical use

INTRODUCTION

Besides routine serum markers of inflammatory diseases, the diagnostic potential of selected urinary proteins has not been fully exploited yet. Former studies revealed that urinary orosomucoid (u-ORM) might have complementary information in inflammatory disorders. Our aim was to develop and validate a fully automated method for u-ORM measurements and to evaluate its potential clinical impact on systemic inflammatory diseases.

MATERIALS AND METHODS

A particle-enhanced immune turbidimetric assay was validated for a Cobas 8000/c502 analyzer to determine u-ORM levels. Spot urine samples from 72 healthy individuals, 28 patients with Crohn's disease and 30 septic patients were studied.

RESULTS

Our assay time was 10 minutes and the detection limit of u-ORM was 0.02 mg/L. The intra- and inter-assay imprecision expressed as CV was less than 5%, and the recovery ranged between 95-103%. Within 10 to 60 years of age, a preliminary reference range for urinary orosomucoid/creatinine ratio (u-ORM/u-CREAT) was found to be 0.08 (0.01-0.24) mg/mmol [median (2.5-97.5 percentiles)]. Compared to controls, a five-fold increase of u-ORM/u-CREAT values in Crohn's disease and approximately a 240-fold increase in sepsis were observed.

CONCLUSIONS

We set up a fast, sensitive and precise turbidimetric approach for automated u-ORM determination. Our highly sensitive assay is ideal for routine u-ORM measurements and might be a potential novel laboratory test in the management of systemic inflammatory processes.

Increased levels of phthalates in very low birth weight infants with septicemia and bronchopulmonary dysplasia

Very low birth weight infants (VLBW; birth weight<1500g) are exposed to potentially harmful phthalates from medical devices during their hospital stay. We measured urinary phthalate concentrations among hospitalized VLBW infants participating in a nutritional study. Possible associations between different phthalates and birth weight (BW), septicemia and bronchopulmonary dysplasia (BPD) were evaluated. Forty-six VLBW infants were enrolled in this randomized controlled nutritional study. The intervention group (n=24) received increased quantities of energy, protein, fat, essential fatty acids and vitamin A, as compared to the control group (n=22). The concentrations of 12 urinary phthalate metabolites were measured, using high-performance liquid chromatography coupled to tandem mass spectrometry, at 3 time points during the first 5weeks of life. During this study, the levels of di (2-ethylhexyl) phthalate (DEHP) metabolites decreased, whereas an increasing trend was seen regarding metabolites of di-iso-nonyl phthalate (DiNP). Significantly higher levels of phthalate metabolites were seen in infants with lower BW and those diagnosed with late onset septicemia or BPD. A significant positive correlation between the duration of respiratory support and DEHP metabolites was observed (p≤0.01) at 2.9weeks of age. Birth weight was negatively associated with urinary phthalate metabolite concentrations. Infants with lower BW and those diagnosed with septicemia or BPD experienced prolonged exposure from medical equipment containing phthalates, with subsequent higher levels of phthalate metabolites detected. Clinical Trial Registration no.: NCT01103219.

Prognosis Biomarkers of Severe Sepsis and Septic Shock by 1H NMR Urine Metabolomics in the Intensive Care Unit

Early diagnosis and patient stratification may improve sepsis outcome by a timely start of the proper specific treatment. We aimed to identify metabolomic biomarkers of sepsis in urine by ¹H-NMR spectroscopy to assess the severity and to predict outcomes. Urine samples were collected from 64 patients with severe sepsis or septic shock in the ICU for a ¹H NMR spectra acquisition. A supervised analysis was performed on the processed spectra, and a predictive model for prognosis (30-days mortality/survival) of sepsis was constructed using partial least-squares discriminant analysis (PLS-DA). In addition, we compared the prediction power of metabolomics data respect the Sequential Organ Failure Assessment (SOFA) score. Supervised multivariate analysis afforded a good predictive model to distinguish the patient groups and detect specific metabolic patterns. Negative prognosis patients presented higher values of ethanol, glucose and hippurate, and on the contrary, lower levels of methionine, glutamine, arginine and phenylalanine. These metabolites could be part of a composite biopattern of the human metabolic response to sepsis shock and its mortality in ICU patients. The internal cross-validation showed robustness of the metabolic predictive model obtained and a better predictive ability in comparison with SOFA values. Our results indicate that NMR metabolic profiling might be helpful for determining the metabolomic phenotype of worst-prognosis septic patients in an early stage. A predictive model for the evolution of septic patients using these metabolites was able to classify cases with more sensitivity and specificity than the well-established organ dysfunction score SOFA.

Impaired systemic tetrahydrobiopterin bioavailability and increased dihydrobiopterin in adult falciparum malaria: association with disease severity, impaired microvascular function and increased endothelial activation

Tetrahydrobiopterin (BH₄) is a co-factor required for catalytic activity of nitric oxide synthase (NOS) and amino acid-monooxygenases, including phenylalanine hydroxylase. BH4 is unstable: during oxidative stress it is non-enzymatically oxidized to dihydrobiopterin (BH₂), which inhibits NOS. Depending on BH₄ availability, NOS oscillates between NO synthase and NADPH oxidase: as the BH₄/BH₂ ratio decreases, NO production falls and is replaced by superoxide. In African children and Asian adults with severe malaria, NO bioavailability decreases and plasma phenylalanine increases, together suggesting possible BH₄ deficiency. The primary three biopterin metabolites (BH₄, BH₂ and B₀ [biopterin]) and their association with disease severity have not been assessed in falciparum malaria. We measured pterin metabolites in urine of adults with severe falciparum malaria (SM; n=12), moderately-severe malaria (MSM, n=17), severe sepsis (SS; n=5) and healthy subjects (HC; n=20) as controls. In SM, urinary BH₄ was decreased (median 0.16 ¼mol/mmol creatinine) compared to MSM (median 0.27), SS (median 0.54), and HC (median 0.34)]; p<0.001. Conversely, BH₂ was increased in SM (median 0.91 ¼mol/mmol creatinine), compared to MSM (median 0.67), SS (median 0.39), and HC (median 0.52); p<0.001, suggesting increased oxidative stress and insufficient recycling of BH2 back to BH4 in severe malaria. Overall, the median BH₄/BH₂ ratio was lowest in SM [0.18 (IQR: 0.04-0.32)] compared to MSM (0.45, IQR 0.27-61), SS (1.03; IQR 0.54-2.38) and controls (0.66; IQR 0.43-1.07); p<0.001. In malaria, a lower BH₄/BH₂ ratio correlated with decreased microvascular reactivity (r=0.41; p=0.03) and increased ICAM-1 (r=-0.52; p=0.005). Decreased BH4 and increased BH₂ in severe malaria (but not in severe sepsis) uncouples NOS, leading to impaired NO bioavailability and potentially increased oxidative stress. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria.

[In the search for effective and safe dose of amikacin in patients with chronic kidney disease]

The aim of the study was to asses safe and effective amikacin (AMK) doses in patients with different stages of chronic kidney disease.

MATERIAL AND METHODS

The study included 25 patients, among them was 12 (48%) men and 13 (52%) women, aged 73.1 +/- 11.9 (38-89) years. AMK was applied in intravenous infusion during 10 days. The dosage was dependent on the stage of chronic kidney disease (CKD). Patients in stage 3A CKD (GFR 59--40 ml/min/1.73 m2) received 7.5 mg/kg/day, in stage 3B (GFR 39--30 ml/min/1.73 m2) received 4 mg/ kg m.c./day, in stage 4 (GFR 29--15 ml/min/1,73 m2) received 4 mg/ kg/day or 6.0 mg/kg every two days, in stage 5 treated with hemodialysis received 5 mg/kg every two days, in stage 5 treated with continuous ambulatory peritoneal dialysis received 4 mg/kg every two days. Trough levels of the drug (minimal level, before the next dose) and maximal levels (one hour after beginning of the infusion) were measured on day 3, 5, 9. Hearing tests were done twice, on day 1 and 9. Urine cultures were tested on day 1 and 5. Complicated urinary tract infections were the reasons of antibiotic treatment in 22 patients (88%). Other reasons were: sepsis (2 patients) and neutropenic fever (1 patient).

RESULTS

Average maximal level of the drug was 25.5 +/- 8.8 (9.6-50.4) microg/ml, average trough level was 3.1 +/- 2.9 (0.4-14.1) microg/ml. Bacterial eradication confirmed by negative culture was observed in 14 patients (56%). In patients with stage 4 CKD eradication was observed more often when AMK was used every day than every two days. Mean trough level was 6.9 +/- 5.5 microg/ml for every day dosage in comparison with 1.9 +/- 0.5 microg/ml for dosage every two days. Mean maximal level was 24.1 +/- 7.2 microg/ml for every day dosage and 21.8 +/- 5.8 microg/ml for every two days dosage.

CONCLUSION

Amikacin usage in described, lowered doses with prolonged interval between them is safe in terms of ototoxicity and nephrotoxicity in patients with chronic kidney disease. Every two days dosage is less effective than every day dosage in patients with stage 4 CKD. It can be a result of too lower minimal (trough) levels of the drug in serum. AMK trough levels are associated with effective therapy in patients with chronic kidney disease.

Urinary (1)H-NMR and GC-MS metabolomics predicts early and late onset neonatal sepsis

The purpose of this article is to study one of the most significant causes of neonatal morbidity and mortality: neonatal sepsis. This pathology is due to a bacterial or fungal infection acquired during the perinatal period. Neonatal sepsis has been categorized into two groups: early onset if it occurs within 3-6 days and late onset after 4-7 days. Due to the not-specific clinical signs, along with the inaccuracy of available biomarkers, the diagnosis is still a major challenge. In this regard, the use of a combined approach based on both nuclear magnetic resonance ((1)H-NMR) and gas-chromatography-mass spectrometry (GC-MS) techniques, coupled with a multivariate statistical analysis, may help to uncover features of the disease that are still hidden. The objective of our study was to evaluate the capability of the metabolomics approach to identify a potential metabolic profile related to the neonatal septic condition. The study population included 25 neonates (15 males and 10 females): 9 (6 males and 3 females) patients had a diagnosis of sepsis and 16 were healthy controls (9 males and 7 females). This study showed a unique metabolic profile of the patients affected by sepsis compared to non-affected ones with a statistically significant difference between the two groups (p = 0.05).

[Protective effect of sodium ferulate magnetic nanoparticle in septic kidney injury rats]

OBJECTIVE

To investigate the renal protective effect of sodium ferulate magnetic nanoparticle targeting therapy in septic rats receives norepinephrine treatment.

METHODS

First we constructed sodium ferulate magnetic nanoparticle, Wistar male rats were randomly divided into 4 groups (n = 6): control group, septic group, norepinephrine treatment group (NE treatment group) and NE plus sodium ferulate magnetic nanoparticle treatment group (NE + SF group), septic rat model was reproduced by intravenous injection of lipolysaccharide (IPS) in rats in NE treatment group norepinephrine were used to elevate the blood pressure of septic rats, in NE + SF group sodium ferulate magnetic nanoparticle was injected via tail vein, magnetic field was placed near renal region. Urinary concentration of N-acetyl-beta-D-glucosaminidase (NAG), kidney injury molecule (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), renal tissue concentration of malonaldehyde (MDA), superoxide dismutase (SOD), and serum concentration of blood urea nitrogen (BUN), creatinine (Cr), alanine aminotransferase (ALT), aspartate aminotransferase (AST) were measured 3 hours after treatment.

RESULTS

After injected LPS via tail vein, systolic blood pressure, pH value, PaO2 and PaCO2 of arterial blood of septic rats decreased significantly. Systolic blood pressure, pH value, PaO2 and PaCO2 of arterial blood returned to baseline approximately after norepinephrine treatment, sodium ferulate magnetic nanoparticle targeting therapy did not change hemodynamic effects of norepinephrine. Compared with control group, urine NAG, KIM-1 and NGAL of sepsis group were increased significantly (P < 0.01), after treatment with norepinephrine, urine NAG, KIM-1 and NGAL of NE treatment group were elevated rapidly compared with those of sepsis group (P < 0.01), combined with sodium ferulate magnetic nanoparticles targeting treatment, urine NAG, KIM-1 and NGAL of NE + SF group were decreased significantly compared with those of sepsis group and NE treatment group (P < 0.01). Compared with control group, renal tissue MDA levels of septic rats increased significantly (P < 0.01), NE treatment could notably raise MDA levels compared with those of sepsis group (P < 0.01), renal tissue MDA levels of NE + SF group were decreased significantly compared with those of sepsis group and NE treatment group (P < 0.01). Compared with control group, renal tissue activities of SOD of sepsis group and NE treatment group were decreased significantly (P < 0.01), after targeted treatment with sodium ferulate magnetic nanoparticle, renal tissue SOD activities of NE + SF group increased significantly compared with those of sepsis group and NE treatment group (P < 0.01 vs sepsis group and NE treatment group). Serum BUN, Cr, ALT, AST levels did not significantly change in each groups.

CONCLUSION

Sodium ferulate magnetic nanoparticle targeting therapy can effectively decrease urine NAG, KIM-1, NGAL and renal tissue MDA level, increase tissue SOD activity of sepsis group and NE treatment group rats, thus protect renal function of septic rats.

Identification of novel biomarkers for sepsis prognosis via urinary proteomic analysis using iTRAQ labeling and 2D-LC-MS/MS

OBJECTIVES

Sepsis is the major cause of death for critically ill patients. Recent progress in proteomics permits a thorough characterization of the mechanisms associated with critical illness. The purpose of this study was to screen potential biomarkers for early prognostic assessment of patients with sepsis.

METHODS

For the discovery stage, 30 sepsis patients with different prognoses were selected. Urinary proteins were identified using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS. Mass spec instrument analysis were performed with Mascot software and the International Protein Index (IPI); bioinformatic analyses were used by the algorithm of set and the Gene Ontology (GO) Database. For the verification stage, the study involved another 54 sepsis-hospitalized patients, with equal numbers of patients in survivor and non-survivor groups based on 28-day survival. Differentially expressed proteins were verified by Western Blot.

RESULTS

A total of 232 unique proteins were identified. Proteins that were differentially expressed were further analyzed based on the pathophysiology of sepsis and biomathematics. For sepsis prognosis, five proteins were significantly up-regulated: selenium binding protein-1, heparan sulfate proteoglycan-2, alpha-1-B glycoprotein, haptoglobin, and lipocalin; two proteins were significantly down-regulated: lysosome-associated membrane proteins-1 and dipeptidyl peptidase-4. Based on gene ontology clustering, these proteins were associated with the biological processes of lipid homeostasis, cartilage development, iron ion transport, and certain metabolic processes. Urinary LAMP-1 was down-regulated, consistent with the Western Blot validation.

CONCLUSION

This study provides the proteomic analysis of urine to identify prognostic biomarkers of sepsis. The seven identified proteins provide insight into the mechanism of sepsis. Low urinary LAMP-1 levels may be useful for early prognostic assessment of sepsis.

TRIAL REGISTRATION

ClinicalTrial.gov NCT01493492.

[Clinical study of kidney injury molecule-1 in the treatment of sepsis patients]

OBJECTIVE

To investigate the relationship between kidney injury molecule-1 (KIM-1) in urine and acute physiology and chronic health evaluation II (APACHEII) score, and the prognosis in the patients suffered from sepsis.

METHODS

In the perspective study, 56 patients in intensive care unit (ICU) from March 2010 to September 2011 suffered from sepsis were enrolled and treated according to the early goal-directed therapy (EGDT). The patients were divided into two groups according to the perform in EGDT or not within 6 hours (groupI, group II). Monitoring included APACHEII score, KIM-1, blood urea nitrogen (BUN) and creatinine (Cr) at before resuscitation (T0), 6 hours after resuscitation (T6 h), and 1 day (T1 d), 2 days (T2 d), 3 days (T3 d), 4 days (T4 d) and 5 days (T5 d) after ICU admission. According to the 28-day prognosis, all the patients were divided into survival group or death group.

RESULTS

The value of APACHEII score, urine KIM-1, BUN and Cr in groupI(n=30), decreased after fluid resuscitation and decreased to the lowest at T5 d. The value of APACHEII score, urine KIM-1, BUN and Cr in groupII(n=26), increased after failure of fluid resuscitation and increased to the highest at T5 d. The value of APACHEII score at T2 d and urine KIM-1 at T1 d in groupII were significantly higher than those in groupI (APACHEII score: 26.35±6.18 vs. 13.25±4.72, urine KIM-1: 4.721±1.432 μg/L vs. 0.909±0.325 μg/L, both P<0.05). The mortality in groupI was significantly lower than that in group II [10.0% (3/30) vs. 73.1% (19/26), P<0.05]. The value of APACHEII score, urine KIM-1, BUN and Cr in survival group (n=34) decreased with the clinical condition improved and decreased to the lowest at T5 d, while the value of APACHEII score, urine KIM-1, BUN and Cr in death group (n=22) increased and increased to the highest at T5 d. The value of APACHEII score at T1 d, and urine KIM-1 at T6 d in death group were significantly higher than those in survival group (APACHEII score:26.39±8.95 vs. 14.27±5.11, urine KIM-1:3.134±1.117 μg/L vs. 1.447±0.472 μg/L, both P<0.05).

CONCLUSIONS

KIM-1 in urine could be a good index for evaluation of sepsis, and it is helpful to understand the disease development by continuous surveillance. It is very important for the appraisal of prognosis, development and prognosis in sepsis, combined with APACHEII score.

Point-of-care urine albumin:creatinine ratio is associated with outcome in emergency department patients with sepsis: a pilot study

OBJECTIVES

Sepsis is characterized by an initial systemic proinflammatory response leading to endothelial damage and increased capillary permeability. The authors conducted a pilot study to determine if microalbuminuria, measured by the urine albumin:creatinine ratio (ACR), was associated with outcome in emergency department (ED) sepsis patients.

METHODS

This was an observational cohort study of a convenience sample of adult patients presenting to two EDs over 10 months with sepsis (two or more systemic inflammatory response syndrome [SIRS] criteria and suspected infection). Those who received a urinalysis were prospectively enrolled. Patients with anuria, grossly contaminated specimens, or concurrent noninfectious diagnoses were excluded. Urine ACR was measured on a point-of-care (POC) device. The primary study outcome was ED disposition (three groups): treated and discharged, admitted to the floor, or admitted to the intensive care unit (ICU). Kruskal-Wallis testing was used to compare ACR based on disposition. Variables associated with ACR were identified by Spearman rank correlation or Mann-Whitney rank-sum testing. A post hoc subgroup analysis of patients with and without a genitourinary (GU) source of infection was also performed.

RESULTS

A total of 121 patients were screened, and 29 (24%) were excluded; 92 patients met criteria (mean ± SD age, 51.2 ± 17.0 years; 51 [55%] had severe sepsis, three [3%] had septic shock). There were three in-hospital deaths. Median ACR for patients treated and discharged (n = 22), admitted to floor (n = 50), and admitted to ICU (n = 20) was 2.54 (interquartile range [IQR] = 0.89 to 6.16) versus 2.8 (IQR = 1.69 to 8.8) versus 12.15 (IQR = 4.76 to 20.95), respectively (p = 0.0049). Age, serum creatinine, and GU source of infection were associated with ACR. ACR was significantly associated with disposition among patients without a GU source of infection (p = 0.003), but not among patients with a GU source (p = 0.3744).

CONCLUSIONS

In this pilot study, microalbuminuria measured by POC ACR was associated with disposition in ED patients with sepsis or severe sepsis. Larger studies using more robust outcomes comparing ACR with validated sepsis biomarkers are needed to elaborate on these results.

Urine abnormalities in acute kidney injury and sepsis

Acute kidney injury (AKI) is a common complication of critical illness. While the etiology of AKI in critically ill patients is likely often multifactorial, sepsis has consistently been found an important contributing factor and has been associated with high attributable morbidity and mortality. Accordingly, the timely identification of septic AKI in critically ill patients is clearly a clinical priority. The diagnosis of AKI has traditionally depended upon biochemical measurements such as serum creatinine, urea, and urine output. In addition, several urinary biochemical tests, derived indices and microscopy have also been widely cited as valuable in the diagnosis and classification of AKI. However, the value of these urinary tests in the diagnosis, classification, prognosis and clinical management in septic AKI remains unclear, due in part to a lack of kidney morphologic changes and histopathology in human studies of septic AKI. This review will summarize the urinary biochemistry and microscopy in septic AKI.

[A study of urine lactulose/mannitol ratio and intestinal fatty acid binding protein as the indexes of intestinal damage in sepsis]

OBJECTIVE

To assess urine lactulose/mannitol ratio (LMR), and intestinal fatty acid binding protein (IFABP) concentration as the indexes of intestinal damage in septic patients, and to evaluate the clinical severity and mortality of septic patients by use of these indexes.

METHODS

Thirty-eight patients with sepsis were consecutively selected in Beijing Friendship Hospital intensive care unit (ICU) from June 2007 to February 2008, according to the inclusions and exclusions criteria. Urine samples were taken in 72 hours after ICU admission. Urine LMR was determined by high performance liquid chromatography by use of pulsed electrochemical detection (HPLC-PED), and urine IFABP concentration was determined by enzyme-linked immunosorbent assays (ELISA). The results of LMR and IFABP were analyzed with acute physiology and chronic health evaluation II (APACHE II) score, with multiple organ dysfunction syndrome (MODS) or not and outcome on day 28. The relationship between the two indexes and the patients' gastrointestinal function score was analyzed.

RESULTS

Thirty-eight patients included had significantly higher urine level of IFABP concentration and LMR. Urine LMR were higher in patients with APACHE II score > 20 than in patients with APACHE II score < or =20 (P = 0.056), and the values were significantly higher in patients who with MODS and in nonsurvivors than those in patients who without MODS and in survivors (both P < 0.05). Urine IFABP concentration was not found significantly difference in patients with APACHE II score > 20, those with MODS and nonsurvivors, compared with patients with APACHE II score < or = 20, those without MODS and survivors. Patients with stress ulcer had higher urine IFABP concentration than patients without stress ulcer (P < 0.05). There was no correlation among LMR, IFABP and gastrointestinal function score.

CONCLUSION

This study reveals that patients with sepsis have intestinal mucosal damage and increased intestinal permeability. Increased LMR in urine is associated with clinical severity and prognosis; urine IFABP concentration is not associated with clinical severity and prognosis. Patients with stress ulcer have higher urine IFABP concentration. There is no correlation among IFABP, LMR and gastrointestinal function score.

Sepsis-related acute kidney injury: a protective effect of drotrecogin alpha (activated) treatment?

BACKGROUND

Drotrecogin alpha activated (DrotAA) is licensed for treatment of patients with severe sepsis and organ failure. Among the latter, acute kidney injury (AKI), defined as the persistence of oligo-anuria following adequate resuscitation, is one of the most apprehended. We conducted a prospective, observational, and controlled study to test the hypothesis that DrotAA beneficially affected the evolution and outcome of AKI, complicating acute sepsis-induced cardiopulmonary failure.

METHODS

Forty-six patients were studied. Thirty subjects received standard treatment for sepsis without DrotAA. In the remaining 16 patients, DrotAA was added as a continuous infusion of 24 microg/kg/h for 96 h.

RESULTS

Mean age, causes of sepsis, and severity/organ failure scores were comparable between patients treated with or without DrotAA. Mortality at 28 days was high and comparable between both treatment groups (56% vs. 69%, DrotAA vs. no DrotAA; P=0.5). When oligo-anuria was present at the start of the study, it persisted during treatment in all patients, with no significant difference between groups. Both treatment groups presented with baseline mean daily fractional excretion of sodium values >2% that remained high during the observation period, regardless of whether DrotAA was given or not. Kidney histology showed a preserved renal architecture with tubular necrosis in all specimens. Similar glomerular, tubulo-interstitial, and vascular alterations were present in both treatment groups.

CONCLUSION

In this small cohort of patients with severe sepsis who received adjuvant DrotAA treatment, no effect on urine output, tubular function, or mortality could be demonstrated.

Urine neutrophil gelatinase-associated lipocalin is an early marker of acute kidney injury in critically ill children: a prospective cohort study

Introduction

Serum creatinine is a late marker of acute kidney injury (AKI). Urine neutrophil gelatinase-associated lipocalin (uNGAL) is an early marker of AKI, where the timing of kidney injury is known. It is unknown whether uNGAL predicts AKI in the general critical care setting. We assessed the ability of uNGAL to predict AKI development and severity in critically ill children.

Methods

This was a prospective cohort study of critically ill children. Children aged between 1 month and 21 years who were mechanically ventilated and had a bladder catheter inserted were eligible. Patients with end-stage renal disease or who had just undergone kidney transplantation were excluded. Patients were enrolled within 24 to 48 hours of initiation of mechanical ventilation. Clinical data and serum creatinine were collected daily for up to 14 days from enrollment, and urine was collected once daily for up to 4 days for uNGAL measurement. AKI was graded using pRIFLE (pediatric modified Risk, Injury, Failure, Loss, End Stage Kidney Disease) criteria. Day 0 was defined as the day on which the AKI initially occurred, and pRIFLEmax was defined as the worst pRIFLE AKI grade recorded during the study period. The χ² test was used to compare associations between categorical variables. Mann-Whitney and Kruskal-Wallis tests were used to compare continuous variables between groups. Diagnostic characteristics were evaluated by calculating sensitivity and specificity, and constructing receiver operating characteristic curves.

Results

A total of 140 patients (54% boys, mean ± standard deviation Pediatric Risk of Mortality II score 15.0 ± 8.0, 23% sepsis) were included. Mean and peak uNGAL concentrations increased with worsening pRIFLEmax status (P < 0.05). uNGAL concentrations rose (at least sixfold higher than in controls) in AKI, 2 days before and after a 50% or greater rise in serum creatinine, without change in control uNGAL. The parameter uNGAL was a good diagnostic marker for AKI development (area under the receiver operating characteristic curve [AUC] 0.78, 95% confidence interval [CI] 0.62 to 0.95) and persistent AKI for 48 hours or longer (AUC 0.79, 95% CI 0.61 to 0.98), but not for AKI severity, when it was recorded after a rise in serum creatinine had occurred (AUC 0.63, 95% CI 0.44 to 0.82).

Conclusion

We found uNGAL to be a useful early AKI marker that predicted development of severe AKI in a heterogeneous group of patients with unknown timing of kidney injury.

A systematic review of urinary findings in experimental septic acute renal failure

OBJECTIVE

In experimental septic acute renal failure, urinary analysis is used to help diagnose and classify renal injury. However, the scientific basis for such use has not been systematically evaluated. Thus, we appraised the value of common urinary findings for the diagnosis and classification of experimental septic acute renal failure.

DESIGN

Systematic review.

SETTING

Academic medical center and university-based research laboratory.

SUBJECTS

Experimental studies describing urinary biochemistry, derived indexes, and microscopy in septic acute renal failure.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Twenty-seven articles fulfilled all inclusion criteria. Due to heterogeneity, no formal quantitative analysis was possible. The methods for induction of sepsis and models were variable. The urinary sodium, fractional excretion of sodium, and urine osmolality were reported in only four (15%), 21 (78%), and seven (26%) studies, respectively. The fractional excretion of sodium exhibited a decrease, no change, or an increase from baseline in 11 (52%), five (24%), and five (24%) studies, respectively. The urine osmolality decreased from baseline in all endotoxin-induced models but showed an early transient increase in six (22%) studies of cecal-ligation perforation. Proteinuria or urinary enzymuria was reported in only seven (26%) studies. Urinary microscopy was described in one study. Only ten studies (37%) simultaneously reported on histopathology. In all these studies, histology either was normal or showed minor ultrastructural changes on electron microscopy.

CONCLUSIONS

No conclusions are possible on how several urinary tests perform in diagnosing or classifying acute renal failure or in predicting the presence of acute tubular necrosis in experimental sepsis. Additional research is necessary to define the diagnostic and prognostic value of urinalysis in experimental sepsis.

Leukocyte counts in urine reflect the risk of concomitant sepsis in bacteriuric infants: a retrospective cohort study

BACKGROUND

When urine infections are missed in febrile young infants with normal urinalysis, clinicians may worry about the risk--hitherto unverified--of concomitant invasion of blood and cerebrospinal fluid by uropathogens. In this study, we determine the extent of this risk.

METHODS

In a retrospective cohort study of febrile 0-89 day old infants evaluated for sepsis in an urban academic pediatric emergency department (1993-1999), we estimated rates of bacteriuric sepsis (urinary tract infections complicated by sepsis) after stratifying infants by urine leukocyte counts higher, or lower than 10 cells/hpf. We compared the global accuracy of leukocytes in urine, leukocytes in peripheral blood, body temperature, and age for predicting bacteruric sepsis. The global accuracy of each test was estimated by calculating the area under its receiver operating characteristic curve (AUC). Chi-square and Fisher exact tests compared count data. Medians for data not normally distributed were compared by the Kruskal-Wallis test.

RESULTS

Two thousand two hundred forty-nine young infants had a normal screening dipstick. None of these developed bacteremia or meningitis despite positive urine culture in 41 (1.8%). Of 1516 additional urine specimens sent for formal urinalysis, 1279 had 0-9 leukocytes/hpf. Urine pathogens were isolated less commonly (6% vs. 76%) and at lower concentrations in infants with few, compared to many urine leukocytes. Urine leukocytes (AUC: 0.94) were the most accurate predictors of bacteruric sepsis. Infants with urinary leukocytes < 10 cells/hpf were significantly less likely (0%; CI:0-0.3%) than those with higher leukocyte counts (5%; CI:2.6-8.7%) to have urinary tract infections complicated by bacteremia (N = 11) or bacterial meningitis (N = 1)--relative risk, 0 (CI:0-0.06) [RR, 0 (CI: 0-0.02), when including infants with negative dipstick]. Bands in peripheral blood had modest value for detecting bacteriuric sepsis (AUC: 0.78). Cases of sepsis without concomitant bacteriuria were comparatively rare (0.8%) and equally common in febrile young infants with low and high concentrations of urine leukocytes.

CONCLUSION

In young infants evaluated for fever, leukocytes in urine reflect the likelihood of bacteriuric sepsis. Infants with urinary tract infections missed because of few leukocytes in urine are at relatively low risk of invasive bacterial sepsis by pathogens isolated from urine.

[Microbiological investigation of blood, urine, cerebrospinal fluid, and soft tissue material from corpses with purulent and inflammatory foci]

A microbiological investigation conducted by the author allowed her to formulate differential-diagnostic signs of the time of death in persons who die of pyoinflammatory complications of polytrauma: up to 24 hours ago or more than 24 hours. Differences in the count of the pathogens depending on the time of death are demonstrated.

Urinary biomarker of oxidative stress correlating with outcome in critically septic patients

OBJECTIVE

To determine whether urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), an in vivo parameter of oxidative stress, is correlated with the outcome of critically septic patients.

DESIGN AND SETTING

Clinical outcome study in an adult medical intensive care unit (ICU).

PATIENTS

85 consecutive septic patients (59 men, 26 women).

MEASUREMENTS AND RESULTS

Patient characteristics and the clinical course were examined. Urinary 8-OHdG was analyzed using isotope-dilution liquid chromatography with tandem mass spectrometry (LC/MS/MS). ICU mortality was 25.9% (22/85) and hospital mortality 38.8% (33/85). Survivors' APACHEII scores on days 1 and 3 and the difference between them differed significantly from those of nonsurvivors (day 1, 21.0+/-7.1 vs. 25.9+/-8.0; day 3, 15.0+/-5.8 vs. 23.2+/-8.3; difference, 6.0+/-5.5 vs. 1.7+/-6.6). Urinary 8-OHdG was significantly lower in survivors than in nonsurvivors on day 1 (1.8+/-2.4 vs. 3.0+/-2.4). The area under receiver operating characteristic curve analysis for the association between day 1 urinary 8-OHdG and ICU mortality was 0.71. The comparison performed upon discharge from hospital revealed similar results.

CONCLUSIONS

This is a preliminary study. Excretion of urinary 8-OHdG, as measured using isotope-dilution LC/MS/MS, and the APACHE II score were correlated with the outcome of critically septic patients in medical ICU.

Urinary Biochemistry and Microscopy in Septic Acute Renal Failure: A Systematic Review

BACKGROUND

Biochemistry and microscopy of urine are widely published diagnostic activities in patients with acute renal failure (ARF). However, their scientific basis in patients with septic ARF has not been assessed systematically.

METHODS

We performed a systematic review of MEDLINE, EMBASE, CINHAL, and PubMed databases and bibliographies of retrieved articles for all studies describing urinary biochemistry, indices, and microscopy in patients with septic ARF.

RESULTS

We identified 27 articles (1,432 patients). Because of substantial heterogeneity, no formal quantitative analysis could be performed. Urinary biochemistry or derived indices were reported in 24 articles (89%), and microscopy, in 7 articles (26%). The majority were small single-center reports and had serious limitations. For example, only 52% of patients were septic, only 54% of patients had ARF, many studies failed to include a control group, time from diagnosis of sepsis or ARF to measure of urinary tests was variable, and there were numerous potential confounders. Urinary sodium, fractional excretion of sodium, urinary-plasma creatinine ratio, urinary osmolality, urinary-plasma osmolality ratio, and serum urea-creatinine ratio showed variable and inconsistent results. Low-molecular-weight proteinuria was described in only 22% of articles. A few reports of urinary microscopy described muddy brown/epithelial cell casts and renal tubular cells in patients with septic ARF, whereas others described normal urinary sediment.

CONCLUSION

The scientific basis for the use of urinary biochemistry, indices, and microscopy in patients with septic ARF is weak. More research is required to describe their accuracy, pattern, and time course in patients with septic ARF.

Low-dose hydrocortisone during severe sepsis: effects on microalbuminuria

OBJECTIVE

The aim of this study was to investigate the effect of low-dose hydrocortisone on glomerular permeability measured by the microalbuminuria to creatinine ratio (MACR) and on other markers of sepsis in severe septic patients.

DESIGN

Randomized prospective study.

SETTING

University intensive care unit.

PATIENTS

The study involved 40 patients with severe sepsis randomized into the hydrocortisone group (n = 20) and the standard therapy group (n = 20).

INTERVENTIONS

The hydrocortisone group received standard therapy plus a continuous infusion of hydrocortisone for 6 days, whereas the standard therapy group received only standard therapy.

MEASUREMENTS AND MAIN RESULTS

MACR, serum C-reactive protein, and procalcitonin concentrations were recorded every day from the day before the steroid therapy (T(0)) until the 6 days after (T(1), T(2), T(3), T(4), T(5), and T(6)). Concentrations in the hydrocortisone group and the standard therapy group were compared using Mann-Whitney test at each time. We also compared with Wilcoxon signed rank test the values determined in each group at T(0) with those at each subsequent time. Median MACR decreased from T(0) to T(6) in both patient groups; however, values were significantly lower in the hydrocortisone group from T(3) through to T(6). Median serum C-reactive protein also decreased from T(0) in both patient groups, with significantly lower values in the hydrocortisone group from T(3) through to T(6). There were no significant differences in procalcitonin between groups compared with baseline values or at any individual time point.

CONCLUSIONS

Low-dose hydrocortisone seems to reduce MACR and serum C-reactive protein but not procalcitonin in patients with severe sepsis. Further studies are needed to confirm these results and to understand the underlying molecular mechanisms.

Urinary biochemistry in experimental septic acute renal failure

BACKGROUND

Several biochemical urine tests and derived indices are reported as useful in the diagnosis of acute renal failure (ARF) and its classification in prerenal (hypoperfusion) or intrarenal (acute tubular) necrosis. However, they have not been adequately studied in sepsis, the most frequent cause of ARF in ICU.

METHODS

In 10 female Merino ewes, we implanted flow probes around the pulmonary and renal arteries to measure cardiac output and renal blood flow (RBF) continuously. Cardiovascular variables were monitored and urine samples collected during a 48 h control period and one week later during a 48 h period of hyperdynamic sepsis induced by an infusion of live Escherichia coli.

RESULTS

Infusion of live E. coli induced systemic hyperdynamic sepsis with renal vasodilatation and increased RBF. Serum creatinine increased from 73.3 +/- 15.1 to 276.9 +/- 156.3 micromol/l (P < 0.05) and creatinine clearance decreased from 84.6 +/- 21.4 to 27.5 +/- 21.4 ml/min (P < 0.05). Urine sodium concentration (UNa) decreased significantly from 164.5 +/- 50.4 to 14.6 +/- 14.3 mmol/l, fractional excretion of sodium (FeNa) from 1.5 +/- 0.17 to 0.12 +/- 0.11%, fractional excretion of urea nitrogen (FeUn) from 62.7 +/- 9.5 to 11.5 +/- 15.4%, and urine osmolality from 724.8 +/- 277.1 mosmol/l to 329.0 +/- 52.1 mosmol/l. The u/p creatinine ratio did not change.

CONCLUSION

Sustained Gram-negative sepsis induced a hyperdynamic state and hyperaemic ARF. Despite increased renal perfusion, UNa, FeNa and FeUn decreased significantly. Our findings suggest that, in sepsis, these urinary biochemical changes are not reliable markers of renal hypoperfusion.

Biomarker and drug-target discovery using proteomics in a new rat model of sepsis-induced acute renal failure

Sepsis is one of the common causes of acute renal failure (ARF). The objective of this study was to identify new biomarkers and therapeutic targets. We present a new rat model of sepsis-induced ARF based on cecal ligation and puncture (CLP). We used this model to find urinary proteins which may be potential biomarkers and/or drug targets. Aged rats were treated with fluids and antibiotics after CLP. Urinary proteins from septic rats without ARF and urinary proteins from septic rats with ARF were compared by difference in-gel electrophoresis (DIGE). CLP surgery elevated interleukin (IL)-6 and IL-10 serum cytokines and blood nitrite compared with sham-operated rats. However, there was a range of serum creatinine values at 24 h (0.4-2.3 mg/dl) and only 24% developed ARF. Histology confirmed renal injury in these rats. Forty-nine percent of rats did not develop ARF. Rats without ARF also had less liver injury. The mortality rate at 24 h was 27% but was increased by housing the post-surgery rats in metabolic cages. Creatinine clearance and urine output 2-8 h after CLP was significantly reduced in rats which died within 24 h. Using DIGE we identified changes in a number of urinary proteins including albumin, brush-border enzymes (e.g., meprin-1-alpha) and serine protease inhibitors. The meprin-1-alpha inhibitor actinonin prevented ARF in aged mice. In summary, we describe a new rat model of sepsis-induced ARF which has a heterogeneous response similar to humans. This model allowed us to use DIGE to find changes in urinary proteins and this approach identified a potential biomarker and drug target - meprin-1-alpha.

Monitoring Urinary Orosomucoid in Acute Inflammation: Observations on Urinary Excretion of Orosomucoid, Albumin, α1-Microglobulin, and IgG

Background: Inflammation-associated proteinuria in acute, nonrenal disease is a common but poorly understood phenomenon. We performed an observational study of the urinary excretion of orosomucoid (α1-acid glycoprotein), albumin, α1-microglobulin (protein HC), and IgG to obtain quantitative and temporal data on these 4 proteins.

Methods: Urine samples were collected at daily intervals for up to 23 days from 6 patients with surgery-induced inflammation and at hourly intervals for a 24-h period from 7 sepsis patients. Urinary protein concentrations were assessed by immunoturbidimetry.

Results: During surgery-induced inflammation, the increase and decrease in orosomucoid excretion mirrored changes in plasma C-reactive protein. Values for all 4 urinary proteins were increased in sepsis patients. The observed maximum increases in urinary protein excretion relative to the upper reference values were 280-fold for orosomucoid, 98-fold for α1-microglobulin, 33-fold for albumin, and 26-fold for IgG.

Conclusions: Orosomucoid, usually present in plasma and urine in much lower concentrations than albumin, is increased in urine to concentrations equal to or higher than albumin in proteinuria associated with acute inflammation. The pathophysiologic mechanisms responsible for this markedly increased excretion are unknown. Monitoring of urinary excretion of orosomucoid and other specific proteins, expressed as protein/creatinine ratios, may provide a window for clinically relevant real-time observation of changes in acute inflammatory processes. Orosomucoid in urine may be a more informative marker than albumin for inflammation.

Effects of polymyxin B immobilized fiber on urinary N-acetyl-beta-glucosaminidase in patients with severe sepsis

Severe sepsis is known to cause multiple organ failure, including renal dysfunction. During sepsis, endotoxin targets the renal proximal tubular cells, the function of which can be evaluated on the basis of urinary N-acetyl-beta-glucosaminidase (NAG). We investigated whether urinary NAG activity is altered in patients with severe sepsis and whether treatment with polymyxin B immobilized fibers (PMX-F) affects this activity. Subjects of this study were 120 patients with severe sepsis and 60 healthy volunteers matched for age and gender. Patients were randomly assigned to one of two treatments: PMX-F treatment (n = 70) or conventional treatment (n = 50). The plasma endotoxin level was significantly reduced, from 34.6 +/- 10.2 to 6.8 +/- 2.4 pg/ml (p < 0.01) in patients treated with PMX-F, and the urinary NAG/creatinine ratio was reduced from 46.5 +/- 26.8 U/gm to 18.6 +/- 13.6 U/gm (p < 0.01). The plasma endotoxin level and urinary NAG/creatinine ratio were unchanged in patients who received conventional treatment. The increased urinary NAG/creatinine ratio in patients with severe sepsis may reflect proximal tubular dysfunction. PMX-F is effective in reducing proximal tubular dysfunction, in part owing to reduced plasma endotoxin levels.

A patient with E. coli-induced pyelonephritis and sepsis who transiently exhibited symptoms associated with primary biliary cirrhosis

A 28-year-old woman had chief complaints of headache and a 40 degrees C fever. At this time, findings indicative of inflammation including elevated CRP and increased WBC were observed, and E. coli was detected on blood and urine culture. As a result, the patient was diagnosed with pyelonephritis and sepsis. Furthermore, markedly increased hepatobiliary enzymes and elevated anti-mitochondrial antibody were confirmed. The administration of antimicrobial agents resulted in improvement of the pyelonephritis and sepsis and normalization of hepatobiliary enzyme and anti-mitochondrial antibody levels. It has been documented that the incidence of urinary tract infection is high among patients with primary biliary cirrhosis (PBC). The findings obtained from the present patient are of considerable interest in elucidating the mechanism of onset in PBC.

Cytokines and chemokines in serum and urine as early predictors to identify septic patients on intensive care unit

The aim of this prospective cohort study was to address the feasibility of measuring cytokines in serum and urine as early predictor tests for the identification of septic Intensive Care Unit (ICU) patients. The study group consisted of 10 septic and 5 non-septic patients at the onset of sepsis according to modified definitions by the American College of Chest Physicians (ACCP)/Society of Critical Care Medicine (SCCM). Serum and urine samples were taken from septic patients at the onset of sepsis and from non-septic patients, every 12 h for 3 days and thereafter every 24 h until day 10. Levels of TNF-alpha, IL-1beta, IL-6, IL-10, IL-18, IFN-gamma, MCP-1, and PCT (procalcitonin) were measured by ELISA. Apart from serum IL-18 and PCT levels, which were elevated in septic patients (p<0.05), levels of all other cytokines and chemokines in the serum of septic patients did not exceed those of the control group. In urine, in contrast with TNF-alpha, IL-1beta, IL-6, IL-10, IFN-gamma, and MCP-1 in which no differences between the two groups were observed, a distinct trend of elevated IL-18 levels was observed only in the septic group. Whereas elevated serum IL-18 and PCT are clear candidate markers for sepsis criteria, the present data indicating elevated urine IL-18 levels albeit from a limited number of septic patients is an interesting observation. The profile of inflammatory mediators in serum and urine from septic patients herein warrants further investigations in a larger group of patients at the onset of sepsis driven by different infectious foci.

Analysis of the efficacy of urine culture as part of sepsis evaluation in the premature infant

BACKGROUND

Premature infants have a higher incidence of urinary tract infection (UTI) than full term infants. UTI in premature infants can present with signs of sepsis: poor weight gain; temperature instability; metabolic acidosis; poor feeding; and abdominal distention.

OBJECTIVE

The purpose of this study was to determine the usefulness of routine urine culture as part of a sepsis evaluation in the preterm infants.

METHODS

We conducted a retrospective review of all infants with birth weight <1500 g (very low birth weight) who underwent sepsis evaluation at MetroHealth Medical Center between January 1991 and February 1998. All infants from whom urine and blood specimens were collected concomitantly for culture as part of a sepsis evaluation were included.

RESULTS

Included were 538 infants. Their mean gestational age was 28.5 +/- 2.7 weeks, and mean birth weight was 1072 +/- 276 g. Blood and urine specimens for culture were taken from 349 infants on admission or in the first 24 h of life (Group A), their mean birth weight was 1147 +/- 244 g, and mean gestational age was 28.9 +/- 2.6 weeks. None of these infants had positive urine cultures; 8 infants (2%) had positive blood cultures. Blood and urine specimens were obtained from 189 infants later between Days 6 and 150 of life (Group B); their mean birth weight was 933 +/- 278 g, and mean gestational age was 27.5 +/- 2.5 weeks. Forty-eight infants (25.3%) in Group B had positive urine cultures, and 79 infants (41.7%) had positive blood cultures. Eighteen infants (38%) with positive urine cultures had positive blood cultures, and 30 infants (62%) had negative blood cultures.

CONCLUSIONS

There is minimal benefit in obtaining urine cultures from very low birth weight infants as part of a sepsis evaluation in the first 24 h of life. It is important to obtain urine cultures from older infants with signs of sepsis to identify patients with UTI with or without bacteremia.

Hemoperfusion with polymyxin B-immobilized fiber in septic patients with methicillin-resistant Staphylococcus aureus-associated glomerulonephritis

BACKGROUND/AIMS

We investigated whether urinary podocytes are present in septic patients with methicillin-resistant Staphylococcus aureus (MRSA)-associated glomerulonephritis and whether polymyxin B-immobilized fiber (PMX-F) treatment affects proteinuria and urinary podocyte excretion in these patients.

METHODS

Twenty septic patients with MRSA-associated glomerulonephritis (mean age: 63.7 years) and 80 septic patients whose MRSA infection was not followed by glomerulonephritis (mean age: 60.5 years) were included in this study. All septic patients were treated with fosfomycin sodium, beta-lactams, arbekacin sulfate, and teicoplanin, or a combination of these. Twenty septic patients with MRSA-associated glomerulonephritis were randomly assigned to one of two treatments: PMX-F treatment (group A, n = 10) and conventional treatment (group B, n = 10). PMX-F treatment was repeated twice.

RESULTS

Urinary podocytes and urinary protein excretion were not detected in MRSA septic patients without glomerulonephritis. However, urinary podocytes (1.7 +/- 0.6 cells/ml) and proteinuria (2.6 +/- 0.6 g/d) were detected in the 20 septic patients with MRSA-associated glomerulonephritis. Plasma endotoxin levels were decreased from 13.6 +/- 4.6 pg/ml to 6.6 +/- 2.2 pg/ml (p < 0.05) in group A. Levels in group B, however, showed little difference after treatment. Urinary podocytes were reduced in group A (from 1.8 +/- 0.6 cells/ml to 0.4 +/- 0.2 cells/ml, p < 0.01) as was urinary protein excretion (from 3.0 +/- 0.5 g/d to 0.8 +/- 0.4 g/d, p < 0.01) but urinary podocytes and protein excretion levels showed little difference after treatment in group B.

CONCLUSION

PMX-F treatment may be effective in reducing urinary protein and urinary podocyte excretion in septic patients with MRSA-associated glomerulonephritis.

TNF-alpha elimination with high cut-off haemofilters: a feasible clinical modality for septic patients?

BACKGROUND

Renal replacement therapies with high cut-off haemofilters are new approaches in the adjuvant therapy of sepsis. We analysed the cytokine elimination capacity of a newly developed polyflux high cut-off haemofilter. Different renal replacement therapies are compared and tested for their clinical feasibility.

METHODS

Blood from healthy volunteers (n=15) was incubated for 4 h with 1 mg of endotoxin and then circulated through a closed extracorporeal circuit. A newly developed polyflux haemofilter (P2SX) was used. Haemofiltration, haemodialysis and albumin dialysis were tested. IL-1ra (17 kDa), interleukin-6 (IL-6) (28 kDa), tumour necrosis factor alpha (TNF-alpha) (51 kDa), albumin (64 kDa), creatinkinase (CK) (80 kDa) and IgG (140 kDa) were measured in blood and filtrates prior to the initiation and after 5 min, 1, 2 and 4 h.

RESULTS

Haemofiltration was superior to haemodialysis in the clearance capacity of all substances when applied in the 1 l/h ultrafiltration mode. Increasing the ultrafiltration rate/dialysate flow from 1 to 3 l/h led to a significant increase in cytokine clearances (P<0.001). At 3 l/h the differences between haemofiltration and haemodialysis vanished and both techniques achieved comparable cytokine clearances. Median clearance values ranged between 25 and 54 ml/min for interleukin-1 receptor antagonist (IL-1ra), 23 and 42 ml/min for IL-6 and 15 and 28 ml/min for TNF-alpha. Albumin loss was highest in the haemofiltration group with albumin clearances ranging between 7 and 13 ml/min. Using diffusion instead of convection significantly reduced the loss of albumin (P<0.01 for 1 l/h, P<0.05 for 3 l/h). Albumin dialysis was able to completely inhibit albumin loss but cytokine clearance capacity was limited.

CONCLUSIONS

High cut-off haemofilters achieve high clearances for inflammatory IL-6 and TNF-alpha. Due to the high protein loss in haemofiltration, dialysis in combination with balanced protein substitution seems to be a suitable approach for clinical trials.

Hemoperfusion with polymyxin B immobilized fibers for urinary albumin excretion in septic patients with trauma

We investigated whether microalbuminuria/urinary creatinine ratio (MACR) is increased in septic patients with trauma and whether polymyxin B immobilized fiber (PMX-F) treatment decreases MACR. Twelve trauma patients without sepsis, 18 trauma patients with sepsis, and 10 healthy controls were included in this study. The 18 trauma patients with sepsis were randomly assigned to one of two groups, PMX-F treatment or conventional treatment. Urinary microalbumin and creatinine were measured before and after treatment. Plasma endotoxin levels were determined by endospecy test. Hemoperfusion with PMX-F was carried out twice, for 2 hours, at a flow rate of 100 ml/min. MACR increased in the 30 trauma patients (5.2+/-2.2 mg/mmol) in comparison to that in the healthy controls (1.0+/-0.6 mg/mmol, p < 0.01). In the 18 trauma patients with sepsis, MACR after sepsis (16.6+/-4.8 mg/mmol) was significantly greater than that before sepsis (5.5+/-2.3 mg/mmol, p < 0.01). There was a significant correlation between plasma endotoxin levels and MACR in septic trauma patients (p < 0.001). MACR was reduced from 17.0+/-5.0 mg/mmol to 4.2+/-1.5 mg/mmol (p < 0.01) with PMX-F, and plasma endotoxin levels were also reduced from 34.5+/-18.5 pg/ml to 10.8+/-6.6 pg/ml (p < 0.01). Neither MACR nor plasma endotoxin levels were affected by conventional treatment, however. In summary, trauma patients with sepsis appear to show increased MACR, and PMX-F therapy may be effective for attenuating the increase in MACR.

Urinary excretion of 8-iso-PGF(2 alpha) in three patients during sepsis, recovery and state of health

Sepsis is known to be associated with oxidative stress. Novel markers of oxidative stress are now believed to be F2-isoprostanes which are produced in situ in phospholipids and subsequently released into circulation and excreted in the urine. This study, therefore, sought to investigate whether the excretion of the isoprostane, 8-iso-PGF(2 alpha), is elevated during sepsis. The excretion of 8-iso-PGF(2 alpha), in the 24 h urine of three patients was studied in the septic stage, during mobilisation and in the state of health by a radioimmunological method. Extrapolating the urinary excretion of 8-iso-PGF(2 alpha) over time showed an insignificant variation in the excretion values during 24 h. The amount of mean 24 h urinary 8-iso-PGF(2 alpha) was about similar in the septic stage and in the state of health but increased remarkably during mobilisation in two of the patients. We suggest that mobilisation of septic patients can be associated with an increase of oxidative stress which may stem from an increase in oxygen consumption and/or from a depletion of antioxidants leading to the enhanced formation of free radicals.

Green urine in a critically ill patient

The development of discolored urine in the critically ill patient, although uncommon, may have many possible causes, with the most likely source related to medication administration. Studies were undertaken in a 39-year-old man who developed dark green urine while in the intensive care unit for neutropenic sepsis. Although the patient had developed prior nonoliguric renal failure stemming from his sepsis, his renal function at the time of presentation of urine discoloration was considered normal. Review of his medications and intravenous infusions suggested the most likely cause was the food dye placed in his enteral tube feedings. Spectrophotometric evaluation of the urine confirmed the presence of Food Dye and Color Blue Number 1 (FD&C Blue No. 1). This case shows that significant gastrointestinal absorption of FD&C Blue No. 1 can occur. FD&C Blue No. 1 should be considered in the differential diagnosis of dark green discolored urine.

EAU guidelines for the management of urinary and male genital tract infections. Urinary Tract Infection (UTI) Working Group of the Health Care Office (HCO) of the European Association of Urology (EAU)

A short version of the UTI Guidelines elaborated by the Urinary Tract Infection Working Group of the Health Care Office of the European Association of Urology is presented. The topics include classification, diagnosis, treatment and follow-up of uncomplicated UTI, UTI in children, UTI in diabetes mellitus, renal insufficiency, renal transplant recipients and immunosuppression, complicated UTI due to urological disorders, sepsis syndrome, urosepsis, urethritis, prostatitis, epididymitis, orchitis and principles of perioperative prophylaxis in urology.

Degradation of albumin in meningococcal sepsis

We postulate that the proteolytic degradation of albumin into fragments could link the rapidity of the shock, rash, and hypocalcaemia associated with meningococcal sepsis. We examined urine of children with meningococcal disease and urine from control children with no sepsis and found albumin fragments of about 45 kDa, 25 kDa, and less than 20 kDa only in the urine of children with meningococcal sepsis and associated purpura. Exogenous or endogenous proteases, or both, may be released in severe meningococcal sepsis and, in association with an inadequate antiprotease response, result in albumin degradation. This may be a contributory factor to the rapid shock, hypocalcaemia, and rash seen in meningococcal sepsis.

Continuous venovenous hemofiltration improves intensive care unit, but not hospital survival rate, in nonoliguric septic patients

PURPOSE

The purpose of this study was to assess the effect of the early institution of continuous veno-venous hemofiltration on survival rates of nonoliguric, septic patients.

MATERIALS AND METHODS

A retrospective study of 48 nonoliguric septic patients with PaO(2)/FIO(2) < or = 250, who were admitted to the General Intensive Care of the Soroka Medical Center. Twenty-six patients were treated with continuous venovenous hemofiltration (CVVH group) and 22 were treated by conventional therapy. The end point of treatment was weaning from mechanical ventilation, adequate oxygenation, and the need for minimal cardiocirculatory support.

RESULTS

The study groups were similar in terms of age, gender, percentage of surgical or nonsurgical patients, APACHE II scores, and the Therapeutic Intervention Scoring System (TISS). Baseline serum urea and creatinine levels were similar in the groups, but the PAO(2)/FIO(2) ratio was significantly lower in the CVVH group (150.6 +/- 86 vs. 214.2 +/- 8.9). Twenty of the CVVH patients and 10 of the patients receiving conventional therapy were discharged from the intensive care unit (P =.03), but the hospital discharge rate was only slightly higher in the CVVH group (12 of 26) compared with the conventional therapy group (7 of 22) (P =.145).

CONCLUSIONS

In this retrospective uncontrolled study, the mortality rate was considerably lower in nonoliguric septic patients who received continuous venovenous hemofiltration early in the course of the disease. The improved survival rate may be due to the ability of CVVH to eliminate mediators involved in the septic process, thus averting the multiple system organ failure consequent to septic insult.

Release of urokinase plasminogen activator receptor during urosepsis and endotoxemia

BACKGROUND

The urokinase receptor (uPAR; CD87) is a multifunctional molecule involved in fibrinolysis, in proteolysis, in renal tubular functions, and in migration and adhesion of inflammatory cells to the site of infection.

METHODS

To gain insight into systemic and local release of uPAR and into its regulation during urosepsis, which is one of the leading causes of chronic renal failure, uPAR was measured in urine and plasma of healthy human controls (N = 20), patients with culture-proven urosepsis (N = 30), and healthy human volunteers intravenously injected with endotoxin (N = 7).

RESULTS

Patients had elevated uPAR levels in both plasma and urine. Three hours after endotoxin challenge in volunteers, there was also a significant increase of uPAR in plasma and in urine. The urine/plasma ratio for uPAR was highly elevated during urosepsis and experimental endotoxemia, suggesting local production in the kidney. Accordingly, damaged tubuli strongly expressed uPAR during pyelonephritis. Moreover, tubular epithelial cells produced uPAR in vitro, and this secretion was strongly up-regulated after stimulation with interleukin-1 beta or tumor necrosis factor-alpha.

CONCLUSIONS

We found that uPAR is released systemically and in the urinary tract during urosepsis and experimental endotoxemia. This systemic and renal production of uPAR during pyelonephritis may play a central role in eliminating the infection and protecting renal function.

Amino acid kinetics in patients with sepsis

BACKGROUND

In patients with sepsis and systemic inflammatory response syndrome, amino acid extraction by the liver is enhanced, resulting in decreased plasma amino acid concentrations. Systematic investigations of the elimination of intravenously infused amino acids have not been performed.

OBJECTIVE

The objective of this study was to compare the elimination of 17 amino acids in patients with sepsis and in healthy control subjects.

DESIGN

Elimination of amino acids was evaluated in 9 patients with sepsis and in 8 healthy control subjects by using a combined loading and maintenance infusion of 375 mg amino acids/kg body wt for 60 min. Pharmacokinetic variables were analyzed from plasma curves.

RESULTS

With the exception of lysine, methionine, glutamate, ornithine, phenylalanine, and tyrosine, plasma concentrations of amino acids were lower in the patients with sepsis than in the control subjects; phenylalanine was the only amino acid whose plasma concentration increased (P < 0.001). In patients with sepsis, whole-body clearance (Cl(tot)) of total amino acids was 74% higher than in control subjects (x +/- SEM: 13,161 +/- 1659 and 7566 +/- 91 mL/min, respectively; P < 0.01), the Cl(tot) of essential amino acids was 64% higher (P < 0.02), that of nonessential amino acids was 82% higher (P < 0.01), and that of both branched-chain amino acids and glucogenic amino acids was 97% higher (P < 0.001). With the exception of phenylalanine, ornithine, proline, and glutamate, the Cl(tot) of all amino acids was elevated. The Cl(tot) of phenylalanine and ornithine decreased slightly (NS).

CONCLUSIONS

In patients with sepsis, plasma concentrations of most amino acids are greatly decreased and the elimination of amino acids from the intravascular space during intravenous infusion is greatly enhanced.

Increased urinary excretion of bilirubin oxidative metabolites in septic patients: a new marker for oxidative stress in vivo

BACKGROUND

Bilirubin oxidative metabolites (BOMs) are generated from bilirubin as a result of its scavenging action against free radicals. During sepsis, excess amounts of free radicals are produced, and they play an important role in the pathophysiological process. We studied whether urinary excretion of BOMs would increase under septic conditions in humans and compared BOM levels with other well-established clinical parameters of inflammation.

METHODS

In 19 septic patients and 28 nonseptic control patients, the BOM concentrations in urine were measured by enzyme-linked immunosorbent assay with an anti-bilirubin antibody.

RESULTS

Urinary BOM levels in septic patients were much higher than those in control patients (21.6 +/- 2.5 vs 1.4 +/- 0.4 micromol/g creatinine, P < 0.001). Although there was a linear correlation between urinary BOM and serum total bilirubin levels (r = 0.392, P = 0.008), serum bilirubin levels were not significantly higher in the septic group than in the control group (P = 0.072). BOM levels correlated with body temperature (r = 0.801, P < 0.001), white blood cell counts in the peripheral blood (r = 0.590, P < 0.001), serum C-reactive protein (r = 0.653, P < 0.001), and the acute physiological and chronic health evaluation (APACHE II) score (r = 0.467, P = 0.003).

CONCLUSIONS

These results demonstrated a urinary increase in BOMs in septic patients. This increase indicates that urinary BOM level is a possible marker for continuous monitoring of sepsis severity in clinical practice.