Three human monocyte subsets are recognized with different functions in the immune system: CD14++/CD16- classical monocytes (CM), CD14++/CD16+ intermediate monocytes (IM) and CD14+/CD16++ non-classical monocytes (NCM). Increased IM and NCM percentages have been reported under inflammatory conditions, yet little is known about monocyte subsets at the onset of inflammation. The human endotoxemia model is uniquely capable of studying the first phases of acute inflammation induced by intravenous injection of 2 ng/kg bodyweight lipopolysaccharide (LPS) into healthy volunteers. After that, monocyte subset counts, activation/differentiation status and chemokine levels were studied over 24 h. The numbers of all subsets were decreased by >95% after LPS injection. CM numbers recovered first (3- 6 h), followed by IM (6-8 h) and NCM numbers (8-24 h). Similarly, increased monocyte counts were observed first in CM (8 h), followed by IM and NCM (24 h). Monocytes did not display a clear activated phenotype (minor increase in CD11b and CD38 expression). Plasma levels of CCL2, CCL4 and CX3CL1 closely resembled the cell numbers of CM, IM and NCM, respectively. Our study provides critical insights into the earliest stages of acute inflammation and emphasizes the necessity to stain for different monocyte subsets when studying the role of monocytes in disease, as neither function nor kinetics of the subsets overlap.
Background: The assessment of renal function in clinical practice remains challenging. Using creatinine to assess the glomerular filtration rate (GFR) is notoriously inaccurate, and determination of the true GFR, e.g., using inulin or iohexol, is laborious and not feasible in daily practice. Proenkephalin (PENK) is a novel candidate biomarker for kidney function that is filtrated in the glomerulus, has shown to represent steady-state GFR in patients with different severities of renal insufficiency. In this pilot study in non-steady-state critically ill patients, we compared plasma PENK concentrations with creatinine-based GFR assessments and validated both against the “true GFR” measured using a gold standard method: iohexol plasma clearance. Methods: Twenty-three critically ill patients with septic shock were included. Kidney function was determined using the Modification of Diet in Renal Disease formula (eGFR MDRD ), Endogenous Creatinine Clearance (GFR ECC ), and iohexol plasma clearance (GFR iohexol ) during a 6-h window. Plasma PENK concentrations were measured using the penKid immunoassay. Results: The eGFR MDRD and GFR ECC correlated with the GFR iohexol ( R 2 = 0.82, P < 0.0001 and R 2 = 0.82, P < 0.0001 respectively); however, bias and variability were considerable: the eGFR MDRD overestimated the true GFR with 31 ± 35% (95% limits of agreement: −37% to 100%) and the GFR ECC with 37 ± 49% (95% limits of agreement: −59% to 133%). Plasma PENK concentrations showed a very strong inverse correlation with the GFR iohexol ( R 2 = 0.90, P < 0.0001) which tended to be better compared with the correlation of eGFR MDRD ( P = 0.06) and GFR ECC ( P = 0.08) with the GFR iohexol . Conclusions: In this pilot study in non-steady-state critically ill sepsis patients, GFR appears to be more accurately reflected by plasma PENK concentrations compared to conventional creatinine-based methods. Therefore, PENK holds promise as an accurate and feasible biomarker to determine kidney function during non-steady-state conditions in the critically ill.
Aims EA‐230 is a human chorionic gonadotropin hormone‐derived linear tetrapeptide, developed for the treatment of systemic inflammation‐related disorders. EA‐230 has shown promising immunomodulatory and tissue‐protective effects in animals and an excellent safety profile in human phase I studies that we performed. The present phase IIa study follows‐up on these results by investigating the safety, efficacy and pharmacokinetics of EA‐230 under systemic inflammatory conditions induced by experimental human endotoxaemia. Methods In this randomized, double blind, placebo‐controlled phase IIa study, systemic inflammation was induced by intravenous administration of Escherichia coli‐derived lipopolysaccharide (LPS). At t = 0 hours, 36 healthy male volunteers received 2 ng/kg LPS, followed by a 2‐hour continuous infusion of EA‐230 (15, 45 and 90 mg/kg/h, n = 8 per group) or placebo (n = 12). Results EA‐230 was well tolerated and showed a favourable safety profile. Treatment with the highest dose of EA‐230 resulted in a significant attenuation of the LPS‐induced increase in plasma levels of inflammatory mediators interleukin (IL)‐6, IL‐8, IL‐1 receptor antagonist, monocyte chemoattractant protein‐1, macrophage inflammatory proteins‐1α and ‐1β, and vascular cell adhesion protein‐1 (% reduction of 48, 28, 33, 28, 14, 16 and 19 respectively, p < .01), and reduced fever (peak decrease from 1.8 ± 0.1°C to 1.3 ± 0.2°C, P < .05) and symptom scores (peak decrease from 7.4 ± 1.0 to 4.0 ± 1.2 points, P < .05). EA‐230 exhibited a very short elimination half‐life and a large volume of distribution in the highest dosage group (geometric mean and 95% confidence interval: 0.17 [0.12–0.24] hours and 2.2 [1.3–3.8] L/kg, respectively). Conclusion Administration of EA‐230 is safe and results in attenuation of the systemic inflammatory response in humans.
Aims EA‐230 is a newly developed synthetic linear tetrapeptide (AQGV) derived from the chorionic gonadotropin hormone (β‐hCG). We investigated the pharmacokinetics, safety and tolerability of EA‐230 in healthy subjects using different administration strategies. Methods Double‐blind, randomized, placebo‐controlled, dose‐escalating phase I studies in healthy subjects using intravenous administration were conducted. In the single dosage study, 32 subjects were assigned to four single dosage groups (1, 3, 10 or 30 mg/kg). In the multiple dosage study, 24 subjects were assigned to three dosage groups (10, 20 or 30 mg/kg, thrice daily for 3 days). In the continuous dosage study, 24 subjects were assigned to three dosage groups (15, 30, or 90 mg/kg/hour for 2 hours). Pharmacokinetics, safety and tolerability assessments were performed up to 14 days. Results The highest dosage of EA‐230 (continuous infusion of 90 mg/kg/hour for 2 hours) showed more than proportional increases in exposure (Cmax136%; AUC0‐last137%), a large volume of distribution (geometric mean and 95% CI: 13 [3–58] L/kg), a high clearance rate (26 [15–43] L/h/kg), and a short half‐life (0.35 [0.13–1.0] minutes). EA‐230 was well tolerated and no safety concerns were observed. Conclusion These dose‐escalating phase I studies with different administration strategies reveal a pharmacokinetic profile of EA‐230 with a large volume of distribution and a short half‐life. Furthermore, EA‐230 was well tolerated and no safety issues emerged. These results have enabled further clinical development in a phase IIa trial assessing the pharmacodynamics of this compound during systemic inflammation described elsewhere in this issue.
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