Binding and detoxification efficiency of albumin decline after haemodialysis

BACKGROUND

Albumin, as the most abundant plasma protein, represents a target structure for both drug and physicochemical therapeutic approaches to eliminate uraemic toxins more efficiently. Potentially, this approach could reduce mortality of haemodialysis patients. However, little is known about albumin functional properties in these patients and its alteration by haemodialysis treatment.

METHODS

The binding and detoxification efficiency of albumin were assessed by electron paramagnetic resonance spectroscopy using a spin-labelled fatty acid. Binding efficiency (BE) reflects strength and amount of bound fatty acids under certain ethanol concentration. Detoxification efficiency (DTE) reflects the molecular flexibility of the patient's albumin molecule, thus the ability to change the conformation depending on ethanol concentration. Percentage of BE and DTE are depicted in relation to healthy individuals (100%).

RESULTS

Fifty-eight patients (59% male, median age 68 years, median time on haemodialysis 32 months) were included in the study. Before haemodialysis treatment, albumin binding and detoxification efficiency were substantially below healthy individuals [median BE 52% (interquartile range, IQR, 45%-59%); median DTE 38% (IQR 32-49%)]. After haemodialysis treatment, median BE and DTE significantly decreased [BE 28% (IQR 20-41%); DTE 11% (IQR 7%-27%; P < .001)]. BE and DTE decline after haemodialysis was not dependent on age, sex or treatment modalities, but was to a certain extent on the level of non-esterified fatty acids.

CONCLUSION

Albumin binding and detoxification efficiency of fatty acids in maintenance haemodialysis patients were substantially below those in healthy individuals and even declined after dialysis treatment. These findings might be helpful when considering new therapeutic approaches in maintenance haemodialysis patients.

Comparing Flow Cytometry and ELISpot for Detection of IL-10, IL-6, and TNF Alpha on Human PBMCs

ELISpot and flow cytometry are two methods often utilized side-by-side for detecting secreted and intracellular cytokines, respectively. Each application has its own advantages and challenges. ELISpot is more sensitive compared to ELISA and appears to be more consistent in detecting IL-10 production than flow cytometry. ELISpot can be used for detecting the secretion of multiple cytokines but not from the same cells simultaneously, whereas flow cytometry allows for the concurrent detection of multiple intracellular cytokines by the same cells. Flow cytometry is a convenient technique allowing for the detection of many cytokines at the same time in a population of cells. The restimulation cocktails used for cytokine detection in flow cytometry are hard on cells and lead to decreased cell viability. Using a live dead dye allows for the exclusion of dead cells when analyzing data. We illustrated the differences between ELISpot and flow cytometry by stimulating cells with two toll-like receptor (TLR) agonists, LPS or Pam3CSK4. Both activators increase production of various cytokines, including IL-10, IL-6, and TNF-alpha. The TLR2 antagonist, MMG-11, was used to inhibit this increased cytokine production. We observed some inhibition of IL-6 and IL-10 from Pam3CSK4 stimulation in the presence of MMG-11 by flow cytometry. TNF-α remains largely unchanged as its basal expression is high, but there is some reduction in the presence of MMG-11 for both methods. However, IL-10 was difficult to detect by ELISpot given the low seeding density. Overall, both ELISpot and flow cytometry are good methods for detecting secreted and intracellular cytokines, respectively, and should be used as complimentary assays.

Effect of serum creatinine difference between the Jaffe and the enzymatic method on kidney disease detection and staging

Background

Serum creatinine (SCr), mainly determined by the Jaffe or an enzymatic method, is the central marker to assess kidney function. Deviations between these two methods may affect the diagnosis and staging of acute kidney injury (AKI) and chronic kidney disease (CKD).

Methods

The results of the first parallel SCr measurement (Jaffe and enzymatic method) of adult in- and outpatients in the same serum sample at the University Hospital Essen (Essen, Germany) between 2020-2022 were retrospectively evaluated. A Bland-Altman plot with 95% limits of agreement (LoAs) was used to assess the difference between the Jaffe and the enzymatic SCr (eSCr) method. We used the 2009 Chronic Kidney Disease Epidemiology Collaboration equation for determination of estimated glomerular filtration rate (eGFR) according to the Kidney Disease: Improving Global Outcomes guidelines.

Results

A total of 41 144 parallel SCr measurements were evaluated. On average, Jaffe SCr was 0.07 mg/dl higher than eSCr (LoA -0.12; 0.25 mg/dl). In 19% of all cases there was a different CKD stage when comparing eGFR between both SCr methods, of which 98% resulted in a more severe CKD stage determined with Jaffe SCr. In 1.6% of all cases Jaffe SCr was ≥0.3 mg/dl higher than eSCr.

Conclusion

The present study showed that methods of SCr measurement may affect both the diagnosis and staging of AKI and CKD. This must be taken into account when interpreting measurements of renal function in everyday clinical practice, but also when planning and comparing studies on renal diseases. One should therefore stay with one method for SCr measurement, preferably with the enzymatic method.

Single-Nucleotide Polymorphism in Genes Encoding G Protein Subunits GNB3 and GNAQ Increase the Risk of Cardiovascular Morbidity among Patients Undergoing Renal Replacement Therapy

Single-nucleotide polymorphisms in G protein subunits are linked to an increased risk of cardiovascular events among the general population. We assessed the effects of GNB3 c.825C > T, GNAQ -695/-694GC > TT, and GNAS c.393C > T polymorphisms on the risk of cardiovascular events among 454 patients undergoing renal replacement therapy. The patients were followed up for a median of 4.5 years after the initiation of dialysis. Carriers of the TT/TT genotype of GNAQ required stenting because of coronary artery stenosis (p = 0.0009) and developed cardiovascular events involving more than one organ system (p = 0.03) significantly earlier and more frequently than did the GC/TT or GC/GC genotypes. Multivariate analysis found that the TT/TT genotype of GNAQ was an independent risk factor for coronary artery stenosis requiring stent (hazard ratio, 4.5; p = 0.001), cardiovascular events (hazard ratio, 1.93; p = 0.04) and cardiovascular events affecting multiple organs (hazard ratio, 4.9; p = 0.03). In the subgroup of male patients left ventricular dilatation with abnormally increased LVEDD values occurred significantly more frequently in TT genotypes of GNB3 than in CT/CC genotypes (p = 0.007). Our findings suggest that male dialysis patients carrying the TT genotype of GNB3 are at higher risk of left ventricular dilatation and that dialysis patients carrying the TT/TT genotype of GNAQ are prone to coronary artery stenosis and severe cardiovascular events.

Albumin redox state of maintenance haemodialysis patients is positively altered after treatment

BACKGROUND AND AIM

Maintenance haemodialysis patients have increased morbidity and mortality which is mainly driven by an elevated inflammation level due to the uraemic milieu. A major part of this increased inflammation level is the degree of oxidative stress which can be assessed by albumin redox state (ARS). Aim of this study was to evaluate how the ARS is affected by a haemodialysis treatment and different dialyzer properties.

METHODS

ARS was determined before and after haemodialysis treatment by fractionating it into reduced human mercaptalbumin (HMA), reversibly oxidized human non-mercaptalbumin 1 (HNA-1), and irreversibly oxidized human non-mercaptalbumin 2 (HNA-2) by high-performance liquid chromatography. In healthy individuals, albumin circulates in the following proportions: HMA 70-80%, HNA-1 20-30% and HNA-2 2-5%. High flux (FX 100 [Fresenius Medical Care], BG 1.8 [Toray], Xevonta Hi 18 [B. Braun], CTA-2000 [Kawasumi]) and low flux FX10 [Fresenius Medical Care] dialyzers were used.

RESULTS

58 patients (59% male, median age 68 years, median time on haemodialysis 32 month) were included in the study. Before haemodialysis treatment, HMA (median 55.9%, IQR 50.1-61.2%) was substantially lower than in healthy individuals. Accordingly, oxidized albumin fractions were above the level of healthy individuals (median HNA-1 38.5%, IQR 33.3-43.2%; median HNA-2 5.8%, IQR 5.1-6.7%). Before haemodialysis treatment HMA was significantly higher in patients usually treated with high flux membranes (p < 0.01). After haemodialysis treatment there was a significant increase of HMA and a decrease of HNA-1 and HNA-2 (p < 0.01). These effects were more pronounced in patients treated with high flux dialyzers (p < 0.01). There were no differences of ARS alteration with regard to the dialyzer´s sterilization mode or the presence of diabetes.

CONCLUSION

The study confirms that the ARS is positively altered by haemodialysis and shows for the first time that this effect depends on dialyzer properties.

Expression of Interferon Regulatory Factor 8 (IRF8) and Its Association with Infections in Dialysis Patients

Patients on dialysis have dysfunctions of innate and adaptive immune system responses. The transcriptional factor IRF8 (interferon regulatory factor 8) is primarily expressed in plasmacytoid cells (pDCs) and myeloid dendritic cells (mDCs), playing a crucial role in the maturation of dendritic cells, monocytes, and macrophages, and contributing to protection against bacterial infections. The current study analyzed the expression patterns of IRF8 and assessed its association with the risk of infections in 79 dialysis patients compared to 44 healthy controls. Different subsets of leukocytes and the intracellular expression of IRF8 were measured using flow cytometry. Compared to the healthy controls, the dialysis patients showed significantly reduced numbers of pDCs and significantly increased numbers of natural killer cells and classical and intermediate monocytes. The dialysis patients exhibited decreased numbers of IRF8-positive dendritic cells (pDC p < 0.001, mDC1 p < 0.001, mDC2 p = 0.005) and increased numbers of IRF8-positive monocytes (p < 0.001). IRF8 expression in pDC, mDC, and classical monocytes was lower in the dialysis patients than in the controls. Dialysis patients who required hospitalization due to infections within one year of follow-up displayed significantly reduced IRF8 expression levels in pDCs compared to patients without such infections (p = 0.04). Our results suggest that reduced IRF8 expression in pDCs is a potential risk factor predisposing dialysis patients to serious infections.

Impact of first-line use of caplacizumab on treatment outcomes in immune thrombotic thrombocytopenic purpura

BACKGROUND

The von Willebrand factor-directed nanobody caplacizumab has greatly changed the treatment of immune thrombotic thrombocytopenic purpura (iTTP) in recent years. Data from randomized controlled trials established efficacy and safety.

OBJECTIVES

This study aims to address open questions regarding patient selection, tailoring of therapy duration, obstacles in prescribing caplacizumab in iTTP, effect on adjunct treatment, and outcomes in the real-world setting.

METHODS

We report retrospective, observational cohorts of 113 iTTP episodes treated with caplacizumab and 119 historical control episodes treated without caplacizumab. We aggregated data from the caplacizumab phase II/III trials and real-world data from France, the United Kingdom, Germany, and Austria (846 episodes, 396 treated with caplacizumab, and 450 historical controls).

RESULTS

Caplacizumab was efficacious in iTTP, independent of the timing of therapy initiation, but curtailed the time of active iTTP only when used in the first-line therapy within 72 hours after diagnosis and until at least partial ADAMTS13-activity remission. Aggregated data from multiple study populations showed that caplacizumab use resulted in significant absolute risk reduction of 2.87% for iTTP-related mortality (number needed to treat 35) and a relative risk reduction of 59%.

CONCLUSION

Caplacizumab should be used in first line and until ADAMTS13-remission, lowers iTTP-related mortality and refractoriness, and decreases the number of daily plasma exchange and hospital stay. This trial is registered at www.

CLINICALTRIALS

gov as #NCT04985318.

[Staging of kidney disease today and tomorrow]

Since September 2022, there is a new, German-language glossary for the nomenclature of renal function and renal disease, aligned with international technical terms and KDIGO guidelines for a more precise and uniform description of the facts. Terms such as "renal disease," "renal insufficiency," or "acute renal failure" should be avoided and replaced with "disease" or "functional impairment."The KDIGO guideline recommends in patients with CKD stage G3a, in addition to the determination of serum creatinine, the additional determination of cystatin to confirm the CKD stage. A combination of serum creatinine and cystatin C to estimate GFR without taking into account the so-called race coefficient seems to be more accurate in African Americans than the previous eGFR formulas. However, there is no recommendation on this in international guidelines yet. For Caucasians, the formula does not change.Renal function impairment lasting more than 7 days but less than 3 months is called acute kidney disease (AKD). The AKD stage is the critical time window for therapeutic interventions to reduce the risk of progression in kidney disease.A future, expanded AKI definition incorporating biomarkers will allow patients to be divided into subclasses according to functional and structural limitations, thus mapping the two-dimensionality of AKI. By using artificial intelligence, large amounts of data from clinical parameters, blood and urine samples, histopathological and molecular markers (including proteomics and metabolomics data) can be used integratively for the graduation of CKD and thus contribute significantly to individualized therapy.

Effect of intraoperative haemoadsorption therapy on cardiac surgery for active infective endocarditis with confirmed Staphylococcus aureus bacteraemia

OBJECTIVES

Sepsis caused by infective endocarditis (IE), due to Staphylococcus aureus, is associated with significant morbidity and mortality. Blood purification using haemoadsorption (HA) may attenuate the inflammatory response. We investigated the effect of intraoperative HA on postoperative outcomes in S. aureus IE.

METHODS

Patients with confirmed S. aureus IE undergoing cardiac surgery were included in a dual-centre study between January 2015 and March 2022. Patients treated with intraoperative HA (HA group) were compared to patients not treated with HA (control group). The primary outcome was vasoactive-inotropic score within the first 72 h postoperatively and secondary outcomes were sepsis-related mortality (SEPSIS-3 definition) and overall mortality at 30 and 90 days.

RESULTS

No differences in baseline characteristics were observed between groups (haemoadsorption group, n = 75, control group, n = 55). Significantly decreased vasoactive-inotropic score was observed in the haemoadsorption group at all time points [6 h: 6.0 (0-17) vs 17 (3-47), P = 0.0014; 12 h: 2 (0-8.3) vs 5.9 (0-37), P = 0.0138; 24 h: 0 (0-5) vs 4.9 (0-23), P = 0.0064; 48 h: 0 (0-2.1) vs 0.1 (0-13), P = 0.0192; 72 h: 0 (0) vs 0 (0-5), P = 0.0014]. Importantly, sepsis-related mortality (8.0% vs 22.8%, P = 0.02) and 30-day (17.3% vs 32.7%, P = 0.03) and 90-day overall mortality (21.3% vs 40%, P = 0.03) were also significantly lower with haemoadsorption.

CONCLUSIONS

Intraoperative HA during cardiac surgery for S. aureus IE was associated with significantly lower postoperative vasopressor and inotropic requirements and resulted in lower sepsis-related and overall 30- and 90-day mortality. In this high-risk population, improved postoperative haemodynamic stabilization by intraoperative HA appears to improve survival and should be further tested in future randomized trials.

Early Treatment with Monoclonal Antibodies or Convalescent Plasma Reduces Mortality in Non-Vaccinated COVID-19 High-Risk Patients

Vulnerable patients such as immunosuppressed or elderly patients are at high risk for a severe course of COVID-19 upon SARS-CoV-2 infection. Immunotherapy with SARS-CoV-2 specific monoclonal antibodies (mAb) or convalescent plasma represents a considerable treatment option to protect these patients from a severe or lethal course of infection. However, monoclonal antibodies are not always available or less effective against emerging SARS-CoV-2 variants. Convalescent plasma is more commonly available and may represent a good treatment alternative in low-income countries. We retrospectively evaluated outcomes in individuals treated with mAbs or convalescent plasma and compared the 30-day overall survival with a patient cohort that received supportive care due to a lack of SARS-CoV-2 specific therapies between March 2020 and April 2021. Our data demonstrate that mAb treatment is highly effective in preventing severe courses of SARS-CoV-2 infection. All patients treated with mAb survived. Treatment with convalescent plasma improved overall survival to 82% compared with 61% in patients without SARS-CoV-2 targeted therapy. Our data indicate that early convalescent plasma treatment may be an option to improve the overall survival of high-risk COVID-19 patients. This is especially true when other antiviral drugs are not available or their efficacy is significantly reduced, which may be the case with emerging SARS-CoV-2 variants.

Phenotyping of M1 and M2a Macrophages and Differential Expression of ACE-2 on Monocytes by Flow Cytometry: Impact of Cell Culture Conditions and Sample Processing

Macrophages are ubiquitously distributed throughout the various tissues of the body and perform many functions including the orchestration of inflammatory responses against pathogens by classically activated M1 macrophages and the regulation of wound healing and tissue remodeling by anti-inflammatory, alternatively activated M2 macrophages. The responsibility for these pleiotropic functions lies in the expression of a myriad of surface receptors unique to given subsets of macrophages. Much of what we know about the function of human macrophage subsets has been gleaned by studying in vitro generated macrophages matured in the presence of GM-CSF or M-CSF and polarized with different cytokines. Oftentimes, culture conditions, such as the type of serum used, the duration of the culture, and the use of polarizing cytokines, vary between studies making direct comparisons difficult. Sample preparation and processing (e.g., Ficoll^® enrichment of leukocytes from whole blood) can also influence gene expression on human monocytes. Furthermore, overlap in surface marker expression can make it difficult to distinguish between different macrophage subsets.We directly compared the expression of over 20 different surface markers on M1 and M2a macrophages cultured in either serum-free media or in the presence of fetal bovine serum or human AB serum and found that the presence or type of serum used affected the expression of several markers such as CD200R1 and CD32. Moreover, we compared the expression of these surface markers on polarized and unpolarized macrophages and determined that polarization was critical to the expression of several of these markers including CD38 and SLAM F7. Differences in sample processing can alter the expression of surface markers, such as ACE-2, on monocytes. We observe that ACE-2 expression is higher on human whole blood CD14⁺ monocytes versus Ficoll^®-enriched CD14⁺ monocytes derived from PBMCs (peripheral blood mononuclear cells), where expression can be reduced by up to 50%. These results indicate that differences in serum, culture media, and sample processing can alter gene expression in both human macrophages and monocytes. Importantly, the results of these studies significantly expand our knowledge of the phenotypic differences between human M1 and M2a macrophages and demonstrate the importance of culture conditions in generating these phenotypes.

Intraoperative hemoadsorption in high-risk patients with infective endocarditis

Background

Postoperative sepsis is an important cause of morbidity and mortality in patients with infective endocarditis undergoing surgical therapy. Blood purification using hemoadsorption therapy shows promising results in the treatment of sepsis. In this study, the clinical effects of intraoperative hemoadsorption in high-risk patients with infective endocarditis were evaluated.

Methods

Eligible candidates were high-risk patients with infective endocarditis undergoing cardiac surgery between January 2014 and December 2019. Patients with intraoperative hemoadsorption (hemoadsorption) were compared to patients without hemoadsorption (control). The endpoints were the incidence of postoperative sepsis, sepsis-associated death and in-hospital mortality. Additionally, postoperative vasopressor need, systemic vascular resistance indices and Sequential Organ Failure Assessment (SOFA) scores were compared.

Results

After propensity score matching, 70 high-risk patients were included. Postoperative sepsis occurred in 14 patients in the hemoadsorption group and in 16 patients in the control group, p = 0.629. Four patients died due to postoperative sepsis in the hemoadsorption group, while 11 postoperative septic patients died in the control group, p = 0.041. In-hospital mortality was 34% in the hemoadsorption group versus 43% in the control group, p = 0.461. On ICU-admission and the first postoperative day, the cumulative vasopressor need was 0.17 versus 0.25 μg/kgBW/min, p = 0.123 and 0.06 versus 0.11 μg/kgBW/min, p = 0.037, and the systemic vascular resistance index was 1448 versus 941 dyn·s·cm-5, p = 0.013 and 1156 versus 858 dyn·s·cm-5, p = 0.110 in the hemoadsorption versus control group, respectively. Postoperative course of SOFA score normalized significantly (p = 0.01) faster in the hemoadsorption group.

Conclusions

In high-risk cardiac surgical patients with infective endocarditis, intraoperative hemoadsorption significantly reduced sepsis-associated mortality. Furthermore, intraoperative hemoadsorption resulted in significant faster recovery of hemodynamics and organ function. Intraoperative hemoadsorption seems to attenuate the severity of postoperative sepsis.

Severe and long-lasting alteration of albumin redox state by plasmapheresis

Plasmapheresis (PE) is an established form of therapeutic apheresis (TA). Purpose of this longitudinal prospective single center study was to investigate the effect of PE on albumin redox state (ARS), as infusion of commercial albumin during PE may alter albumin oxidation which has an impact on its functional properties and oxidative stress level. 43 subjects with autoimmune-mediated neurological disorders were included. 20 subjects in the experimental group received five treatments of PE. 13 subjects received five treatments of immunoadsorption and 10 subjects received no TA as controls. ARS was determined before and after TA and 12 days after the last TA by fractionating it into human mercaptalbumin (HMA), human non-mercaptalbumin 1 (HNA-1), and human non-mercaptalbumin 2 (HNA-2) by high-performance liquid chromatography. Irreversibly oxidised HNA-2 increased over the course of five PE treatments from 2.8% (IQR 1.3–3.7%) to 13.6% (IQR 10.9–15.9) (P < 0.01) and remained elevated 12 days after the last PE procedure (7.7% IQR 7.1–10.5, P < 0.05). The study showed for the first time that PE exerts a severe and long-lasting alteration on ARS indicating a new adverse effect of PE, that may influence oxidative stress level.

[Treatment and progression management of acute kidney injury]

Acute kidney injury (AKI) represents one of the greatest global health challenges and is associated with high mortality. The often multifactorial etiology and complex pathophysiological mechanisms have so far hampered the development of causal therapeutic options. The treatment should be stage-adapted according to the current KDIGO guideline: avoid nephrotoxicity, optimize volume status and perfusion pressure, monitor serum creatinine, urine output and proteinuria. New insights into the influence of mitochondrial dysfunction and cellular senescence in AKI, well-defined study endpoints, and innovations through nanotechnology may enable targeted drug-based AKI therapy in the future. Especially the weeks following an AKI are a vulnerable phase and crucial for progression management.

Pathological findings in rotation thromboelastometry associated with thromboembolic events in COVID-19 patients

Background

Severe thromboembolic events are one of the major complications associated with COVID-19 infection, especially among critically ill patients. We analysed ROTEM measurements in COVID-19 patients with a severe disease course and in patients with severe sepsis.

Methods

In this study, data obtained by extended analysis of haemostasis with standard laboratory tests and thromboelastometry of 20 patients with severe course of COVID-19 were retrospectively analysed and compared with similar data from 20 patients with severe sepsis but no COVID-19.

Results

The thromboelastometry values obtained from 20 sepsis patients contained a maximum clot firmness above the normal range but among COVID-19 patients, hypercoagulability was much more pronounced, with significantly higher maximum clot firmness (FIBTEM: 38.4 ± 10.1 mm vs. 29.6 ± 10.8 mm; P  = 0.012; EXTEM: 70.4 ± 10.4 mm vs. 60.6 ± 14.8 mm; P  = 0.022). Additionally, fibrinogen levels were significantly higher among COVID-19 patients (757 ± 135 mg/dl vs. 498 ± 132 mg/dl, P < 0.0001). Furthermore, thromboelastometry showed fibrinolysis shutdown among COVID-19 patients with significantly lower maximum of lysis than among sepsis patients (EXTEM: 0.6 ± 1.2 % vs. 3.3 ± 3.7 %; P  = 0.013). Seven of 20 COVID-19 patients experienced thromboembolic events, whereas no patient in the sepsis group experienced such events.

Conclusions

ROTEM analysis showed significantly different pathological findings characterized by hypercoagulability and fibrinolysis shutdown among COVID-19 patients with a severe disease course compared to patients with severe sepsis. These abnormalities seem to be associated with thromboembolic events.

Extracorporeal cytokine adsorption: Significant reduction of catecholamine requirement in patients with AKI and septic shock after cardiac surgery

Background

Extracorporeal cytokine adsorption is an option in septic shock as an additional measure to treat a pathological immune response. Purpose of this study was to investigate the effects of extracorporeal cytokine adsorption on hemodynamic parameters in patients with acute kidney injury (AKI) on continuous renal replacement therapy (CRRT) and septic shock after cardiac surgery.

Methods

In this retrospective study, a total of 98 patients were evaluated. Hemoadsorption was performed by the CytoSorb® adsorber. In all patients cytokine adsorption was applied for at least 15 hours and at least one adsorber was used per patient. To compare cumulative inotrope need in order to maintain a mean arterial pressure (MAP) of ≥ 65 mmHg, we applied vasoactive score (VAS) for each patient before and after cytokine adsorption. A paired t-test has been performed to determine statistical significance.

Results

Before cytokine adsorption the mean VAS was 56.7 points. This was statistically significant decreased after cytokine adsorption (27.7 points, p< 0.0001). Before cytokine adsorption, the mean noradrenalin dose to reach a MAP of ≥ 65 mmHg was 0.49 μg/kg bw/min, the mean adrenalin dose was 0.12 μg/kg bw/min. After cytokine adsorption, significantly reduced catecholamine doses were necessary to maintain a MAP of ≥ 65 mmHg (0.24 μg/kg bw/min noradrenalin; p< 0.0001 and 0.07 μg/kg bw/min adrenalin; p < 0.0001). Moreover, there was a significant reduction of serum lactate levels after treatment (p< 0.0001). The mean SOFA-score for these patients with septic shock and AKI before cytokine adsorption was 16.7 points, the mean APACHE II-score was 30.2 points. The mean predicted in-hospital mortality rate based on this SOFA-score of 16.7 points was 77,0%, respectively 73,0% on APACHE II-score, while the all-cause in-hospital mortality rate of the patients in this study was 59.2%.

Conclusion

In patients with septic shock and AKI undergoing cardiac surgery, extracorporeal cytokine adsorption could significantly lower the need for postoperative inotropes. Additionally, observed versus SOFA- and APACHE II-score predicted in-hospital mortality rate was decreased.

Intraperitoneal ampicillin treatment for peritoneal dialysis- related peritonitis with Listeria monocytogenes - a case report

BACKGROUND

Peritoneal dialysis (PD)-related peritonitis is a rare but serious complication and is associated with increased morbidity and mortality rates. It is most commonly caused by Staphylococcus aureus or Staphylococcus epidermidis, but infection with Listeria monocytogenes may also occur. Recommendations for antibiotic treatment of a Listeria infection are currently based on a small number of case reports and suggest the administration of ampicillin. But unlike vancomycin or gentamicin, for ampicillin the route of application, the dosage, and the duration of treatment have not yet been established. We report a case in which PD-associated peritonitis due to Listeria infection was treated with ampicillin administered intravenously and intraperitoneally, separately and in combination.

CASE PRESENTATION

A 72-year-old man with chronic kidney disease stage 5 dialysis (CKDG5D) secondary to hypertension and diabetes was hospitalised in April 2020 because of PD-related peritonitis caused by a Listeria infection. In accordance with the results of resistance tests, the patient was treated with intravenous ampicillin at a dosage of 6 g twice daily. After initial treatment the leukocyte count in the PD effluent had decreased substantially, but it was permanently reduced only with the addition of intraperitoneal ampicillin (4 g daily). Efficient serum concentrations of ampicillin were determined for both routes of administration, intravenous and intraperitoneal.

CONCLUSION

This is the first case report demonstrating that PD-related peritonitis due to Listeria monocytogenes infection can be treated with intraperitoneal ampicillin and monitored by the determination of peripheral serum concentrations of ampicillin.

P1065EXTRACORPOREAL CYTOKINE ADSORPTION IN PATIENTS WITH AKI AND SEPTIC SHOCK AFTER CARDIAC SURGERY

Background and Aims

Extracorporeal cytokine adsorption is a new option in septic shock as an additional measure to prevent severe cytokinaemia. The purpose of this study was to investigate the effects of extracorporeal cytokine adsorption on hemodynamics in patients with acute kidney injury (AKI) and septic shock after cardiac surgery.

Method

In this retrospective study 64 patients with AKI and septic shock after cardiac surgery were investigated for the effect of extracorporeal cytokine adsorption by CytoSorb® columns on hemodynamics. In all patients CytoSorb®-treatment was applied in addition to continuous renal replacement therapy (CRRT) with citrate anticoagulation. A paired t-test has been performed to determine statistical significance.

Results

Before treatment, the mean noradrenalin dose to reach a mean arterial pressure (MAP) &gt; 65 mmHg was 0.49 µg/kg bw/min, the mean adrenalin dose was 0.1 µg/kg bw/min. 24 h after treatment, significantly reduced catecholamine doses were necessary to maintain a MAP &gt; 65 mmHg (0.23 µg/kg bw/min noradrenalin; p***&lt; 0.0002 and 0.06 µg/kg bw/min adrenalin; p* &lt; 0.02). The mean SOFA-score for these patients with AKI and septic shock 24 h before CytoSorb®- treatment was 16.6 points. The mean predicted in-hospital mortality rate based on this SOFA-score of 16.6 points was 77 % while the all-cause mortality rate of the patients in this study was 59.4 %.

Conclusion

In patients with AKI and septic shock after cardiac surgery, 24 h after extracorporeal cytokine adsorption by CytoSorb® the catecholamine dose required to maintain a MAP &gt; 65 mmHg was halved. Additionally, observed in-hospital mortality was lower than SOFA-score predicted mortality.

Does dimeric melittin occur in aqueous solutions?

Melittin, a peptide from bee venom, is known to undergo a monomer / tetramer conversion in aqueous solutions. We have studied the possible participation of dimers in the association equilibrium of melittin by sedimentation equilibrium experiments in the analytical ultracentrifuge and subsequent mathematical analysis of the concentration distributions obtained. It was found that the dimeric state is not significantly populated, the contribution of dimer to the total peptide weight probably being below 0.5%.

Cell saver efficacy for routine coronary artery bypass surgery

A retrospective study was conducted to determine the effect of intraoperative Haemonetics Cell Saver (HCS) usage on postoperative homologous blood product requirements in CABG patients. From 1 January to 31 December 1993, 516 patients without renal disease or postoperative surgical or gastrointestinal haemorrhage had elective, first-time CABG surgery. The HCS was utilized in 435 of these patients (Group CS) and in 81 patients the HCS was excluded (Group NCS). Preoperative patient variables were similar in the group. We evaluated the HCS effect on blood product transfusion by comparing -x units of red blood cells (RBC), fresh frozen plasma (FFP) and platelets (PLTS) transfused per patient between groups CS and NCS. There were no differences in the -x units of RBC (1.9 +/- 2.7 CS vs. 1.8 +/- 1.5 NCS) or in the RBC transfusion rate (48% CS vs 50% NCS). There were also no significant differences between the groups in -x units of FFP (0.9 +/- 0.8 CS vs 0.4 +/- 0.9 NCS) or PLTS (0.7 +/- 3.1 CS vs 0.4 +/- 2.5 NCS), or in the percentage of patients receiving these products (12% CS vs 8% NCS). These data provide no evidence that the use of the HCS decreases the amount of homologous blood bank products required postoperatively in patients having routine first-time CABG surgery. The current era of aggressive blood conservation may have limited the role of the HCS in routine CABG surgery.

A comparison of the IgG isotype expression in the so-called thymus-independent immune responses to alpha(1----3) and alpha(1----6) dextran

This paper presents data on the IgG antibody response against two "thymus-independent" dextran (Dex) antigens from Leuconostoc mesenteroides, alpha(1----3) Dex B 1355S and alpha(1----6) Dex B 512F in BALB/c and C57BL/6 mice, which are considered to be responders or low responders to the respective antigen. The data point toward three common rules governing the two anti-Dex responses despite immunogenetic and antigenic disparities: (1) age dependency of the IgG isotype regulation of the response; (2) down-regulation of IgG isotype expression by T cells; and (3) individually determined preposition for IgG isotype formation in a given animal.

An ultracentrifuge study on the self-association of glucose dehydrogenase from Bacillus megaterium

The self-association of glucose dehydrogenase (beta-D-glucose:NAD(P) 1-oxidoreductase, EC 1.1.1.47) from Bacillus megaterium was studied by analytical ultracentrifugation. The pH and composition of the buffer used were such that, owing to a reversible partial dissociation of the tetrameric enzyme, enzyme activity was reduced. It was found that under these conditions the protein exists in a monomer/dimer/tetramer association equilibrium.

The nature of the stable noncovalent dimers of band 3 protein from erythrocyte membranes in solutions of Triton X-100

Stable noncovalent dimers of band 3 protein from human erythrocyte membranes, in which state the protein is thought to exist after solubilization by the nonionic detergent Triton X-100, do not occur when purified batches of the detergent are used. Instead, the protein is in a monomer/dimer/tetramer association equilibrium. The stable dimers do appear, however, when the detergent has been 'aged'. They thus seem to be artifacts.

Band 3 protein-cholesterol interactions in erythrocyte membranes. Possible role in anion transport and dependency on membrane phospholipid

Band 3 protein of the human erythrocyte membrane, the anion transport protein, possesses a high affinity steroid binding site. In mixed phospholipid-cholesterol monolayers, the state of occupancy of this site is positively correlated with their cholesterol and sphingomyelin content and negatively with their glycerophospholipid content. We suggest that, in the erythrocyte membrane, the binding site is an inhibitory site of anion transport and that the modulation of its state of occupancy by the membrane lipid is responsible for the negative correlation of anion transport with the membrane's content of cholesterol and sphingomyelin and the positive correlation with the phosphatidylcholine content.