Helen Graf

Dr. Helen Graf

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Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 June 2024 in Annals of Intensive Care
Verified
Journal Article
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HGHelen Graf
Helen Graf
CGCaroline Gräfe
Caroline Gräfe
MBMathias Bruegel
Mathias Bruegel
MZMichael Zoller
Michael Zoller
NMNils Maciuga
Nils Maciuga
CSChristina Scharf
Christina Scharf
Rhabdomyolysis is a serious condition that can lead to acute kidney injury with the need of renal replacement therapy (RRT). The cytokine adsorber Cytosorb® (CS) can be used for extracorporeal myoglobin elimination in patients with rhabdomyolysis. However, data on adsorption capacity and saturation kinetics are still missing. The prospective Cyto-SOLVE study (NCT04913298) included 20 intensive care unit patients with severe rhabdomyolysis (plasma myoglobin > 5000 ng/ml), RRT due to acute kidney injury and the use of CS for myoglobin elimination. Myoglobin and creatine kinase (CK) were measured in the patient´s blood and pre- and post-CS at defined time points (ten minutes, one, three, six, and twelve hours after initiation). We calculated Relative Change (RC, %) with: $$1 - \left( {concentration(pre - post)\,/\,concentration\left( {pre} \right)} \right)*100$$ . Myoglobin plasma clearances (ml/min) were calculated with: $$\left( {bloodflow*\left( {1 - hematocrit} \right)} \right)*\left( {concentration\left( {pre - post} \right)\,/\,concentration\left( {pre} \right)} \right)$$ There was a significant decrease of the myoglobin plasma concentration six hours after installation of CS (median (IQR) 56,894 ng/ml (11,544; 102,737 ng/ml) vs. 40,125 ng/ml (7879; 75,638 ng/ml) (p < 0.001). No significant change was observed after twelve hours. Significant extracorporeal adsorption of myoglobin can be seen at all time points (p < 0.05) (ten minutes, one, three, six, and twelve hours after initiation). The median (IQR) RC of myoglobin at the above-mentioned time points was − 79.2% (-85.1; -47.1%), -34.7% (-42.7;-18.4%), -16.1% (-22.1; -9.4%), -8.3% (-7.5; -1.3%), and − 3.9% (-3.9; -1.3%), respectively. The median myoglobin plasma clearance ten minutes after starting CS treatment was 64.0 ml/min (58.6; 73.5 ml/min), decreasing rapidly to 29.1 ml/min (26.5; 36.1 ml/min), 16.1 ml/min (11.9; 22.5 ml/min), 7.9 ml/min (5.5; 12.5 ml/min), and 3.7 ml/min (2.4; 6.4 ml/min) after one, three, six, and twelve hours, respectively. The Cytosorb® adsorber effectively eliminates myoglobin. However, the adsorption capacity decreased rapidly after about three hours, resulting in reduced effectiveness. Early change of the adsorber in patients with severe rhabdomyolysis might increase the efficacy. The clinical benefit should be investigated in further clinical trials. ClinicalTrials.gov NCT04913298. Registered 07 May 2021, https//clinicaltrials.gov/study/NCT04913298.

1 October 2025 in Scientific Reports
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Journal Article
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HGHelen Graf
Helen Graf
CGCaroline Gräfe
Caroline Gräfe
MPMichael Paal
Michael Paal
KHKatarina Habler
Katarina Habler
AEAlice Ewert
Alice Ewert
CSChristina Scharf
Christina Scharf
Angiopoietin 2 (Ang-2) is a growth factor in angiogenesis, causing pericyte migration and vascular regression, leading to increased vascular permeability. Inflammatory mediators, hypoxia, hyperglycaemia and cancer stimulate its secretion. Particularly in sepsis, high Ang-2 levels appear to be a prognostic marker for morbidity and mortality in the critically ill. As an important trigger for endothelial damage one therapeutic option in these patients might be the removal of Ang-2. The Cyto-SOLVE trial included patients with septic shock or rhabdomyolsis treated with the adsorber Cytosorb (CS) (included in continuous kidney replacement therapy) for the removal of cytokines and myoglobin. Ang-2 was measured in the patient´s blood and pre- and post-CS at defined time points (ten minutes, one, three, six, and twelve hours after initiation). Ang-2 extracorporeal clearances (ml/min) were calculated with: $$\:\left(bloodflow*\left(1-hematocrit\right)\right)*\left(\frac{concentration\:\left(pre-post\right)}{concentration\:\left(pre\right)}\right).$$ U-Test was used to compare different subgroups. 26 patients were included (17 with rhabdomyolsis and 9 with septic shock, median Ang-2 concentration prior to CS-application: 21,653 pg/ml). We observed a low Ang-2 adsorption in the first hour of CS application, resulting in a median Ang-2 extracorporeal clearance of 8.2 ml/min and 1.7 ml/min after 10 min and 1 h, respectively. There was no significant change in Ang-2 plasma concentrations at any time point. No significant difference in Ang-2 levels was observed between patients with septic shock (median: 31,916 pg/ml) and rhabdomyolysis (median 18,379 pg/ml, p = 0.241). The Cytosorb adsorber does not decrease Ang-2 concentrations by adsorption. Therefore, Ang-2 can be considered a reliable biomarker for endothelial dysfunction even in the presence of Cytosorb therapy in critically ill patients. Further studies should be conducted to determine whether the removal of Ang-2 could be beneficial when utilizing an appropriate device.

23 October 2024 in Biomedicines
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Journal Article
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VBVeronika Bucher
Veronika Bucher
HGHelen Graf
Helen Graf
JZJohannes Zander
Johannes Zander
ULUwe Liebchen
Uwe Liebchen
DHDanilo Hackner
Danilo Hackner
CSChristina Scharf
Christina Scharf
Introduction: Angiopoietin II (Ang-II) plays a pivotal role in the development of microcirculatory dysfunction as it provokes endothelial barrier disruption in patients with sepsis or septic shock. In particular, those with acute kidney injury show high Ang-II concentrations. So far, it is unclear which covariates influence Ang-II concentration in the early phase of sepsis, especially if extracorporeal therapies also do. Methods: Ang-II concentrations were measured in 171 patients with sepsis after the first day of antibiotic treatment between 03/2013 and 01/2015. Ang-II was correlated with potential influencing factors (Spearman correlation). A multivariate model was established including the significant correlating parameters. The Mann–Whitney U test and the Kruskal–Wallis test were used to detect significant differences in Ang-II concentration. Results: The median Ang-II concentration was 8015 pg/mL (interquartile range (IQR): 5024–14,185). A total of forty patients were treated with kidney replacement therapy (KRT) and 20 were supported by venovenous extracorporeal membrane oxygenation (vv-ECMO). Sequential organ failure assessment (SOFA) score (r = 0.541), creatinine clearance (r = −0.467), urinary output (r = −0.289), interleukin (IL)-6 (r = 0.529), C-reactive protein (CRP) (r = 0.241), platelet count (r = −0.419), bilirubin (r = 0.565), lactate (r = 0.322), KRT (r = 0.451), and fluid balance (r = 0.373) significantly correlated with Ang-II concentration and were included in the multivariate model. There, creatinine clearance (p < 0.01, b = −26.3, 95% confidence interval (CI) −41.8–−10.8), fluid balance (p = 0.002, b = 0.92, 95% CI 0.33–1.51), and CRP (p = 0.004, b = 127.6, 95% CI 41.6–213.7) were associated with Ang-II concentration. Furthermore, patients with KRT (median: 15,219 pg/mL, IQR: 10,548–20,270) had significantly (p < 0.01) higher Ang-II concentrations than those with vv-ECMO support (median: 6412 pg/mL, IQR: 5246–10,257) or those without extracorporeal therapy (median: 7156 pg/mL, IQR: 4409–12,741). Conclusion: Increased CRP, positive fluid balance, and impaired kidney function were associated with higher Ang-II concentrations in critically ill patients in the early stage of sepsis in this post hoc analysis. In particular, patients with KRT had very high Ang-II concentrations, whereas the use of vv-ECMO was not related to higher Ang-II concentrations. The significance for clinical practice should be clarified by a prospective study with standardized measurements.

10 February 2025 in Biomedicines
Verified
Journal Article
Open access
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VWVassilissa Wustrow
Vassilissa Wustrow
CGCaroline Gräfe
Caroline Gräfe
HGHelen Graf
Helen Graf
PSPatrick Scheiermann
Patrick Scheiermann
MPMichael Paal
Michael Paal
CSChristina Scharf
Christina Scharf
Background/Objectives: Patients with shock suffer from hyperlactatemia, which can lead to endothelial dysfunction. The use of the adsorber Cytosorb® (CS) is recommended in these patients as it may contribute to higher lactate clearance and hemodynamic stabilization. However, it is unclear whether CS can directly adsorb lactate and can therefore increase lactate clearance. Methods: The Cyto-SOLVE trial included patients undergoing continuous kidney replacement therapy combined with CS application. Patients with a lactate concentration > 2 mmol/L and measurements of lactate pre- and post-adsorber, as well as measurements in the blood 10 min and 1, 3, 6, and 12 h after initiation were selected. Lactate clearance was calculated using the following formula: bloodflow(mL/min) × concentrationpre−post/concentrationpre. A t-test was used with the collected samples. Changes in the lactate concentration and vasopressor requirement were recorded before initiation and at the end of therapy. Results: Sixty-five lactate concentrations were measured pre- and post-CS application, as well as in patients’ blood, in a total of 14 patients (median age of 52 years, 10 males, median SAPS-II 67). There was no significant change in the lactate concentration pre- and post-CS application (mean pre-CS: 6.7 mmol/L, mean post-CS: 6.9 mmol/L, RR: −0.2, 95% confidence interval (CI): −0.4–0.1, p = 0.13, Cohen’s d: 0.90). The mean lactate clearance was −6 mL/min (standard deviation (SD): 21 mL/min), with no correlation with the initial lactate concentration or blood flow. In contrast, the mean lactate clearance measured using the dialyzer was 39 mL/min (SD: 28 mL/min). When comparing values before and after treatment, no significant change was observed in the lactate blood concentrations (mean of 9.0 vs. 8.5 mmol/L), nor in the requirement for vasopressin (median of 1.9 vs. 1.8 IE/h) or norepinephrine (mean of 2.7 vs. 2.6 mg/h). Conclusions: The adsorber CS cannot directly adsorb lactate, unlike kidney replacement therapy. Therefore, it is not suitable for achieving faster extracorporeal lactate elimination. Understanding the adsorption spectrum is of great relevance and should be considered when using CS in clinical practice.