Inhibition of Cyclin-Dependent Kinases 8/19 Restricts Bacterial and Virus-Induced Inflammatory Responses in Monocytes

Hyperactivation of the immune system remains a dramatic, life-threatening complication of viral and bacterial infections, particularly during pneumonia. Therapeutic approaches to counteract local and systemic outbreaks of cytokine storm and to prevent tissue damage remain limited. Cyclin-dependent kinases 8 and 19 (CDK8/19) potentiate transcriptional responses to the altered microenvironment, but CDK8/19 potential in immunoregulation is not fully understood. In the present study, we investigated how a selective CDK8/19 inhibitor, Senexin B, impacts the immunogenic profiles of monocytic cells stimulated using influenza virus H1N1 or bacterial lipopolysaccharides. Senexin B was able to prevent the induction of gene expression of proinflammatory cytokines in THP1 and U937 cell lines and in human peripheral blood-derived mononuclear cells. Moreover, Senexin B substantially reduced functional manifestations of inflammation, including clustering and chemokine-dependent migration of THP1 monocytes and human pulmonary fibroblasts (HPF).

Impact of Water Treatment on Anemia in Hemodialysis Patients

Introduction

The microbiological quality of water in the dialysate used in hemodialysis has been suggested as a contributor to inflammation, and a link between dialysate purity, inflammation, and responsiveness to erythropoietin therapy has been suggested in many studies. The level of endotoxin might induce inflammation and resistance to erythropoietin therapy in dialysis patients. We aimed to compare the effect of using the central dialysis fluid delivery system (CDDS) versus the single-patient dialysis fluid delivery system (SPDDS) on anemia in prevalent hemodialysis patients.

Methods

In a prospective cohort study, 100 adult prevalent hemodialysis patients with T-SAT ≥20% were divided into two equal groups: CDDS and SPDDS. Endotoxin in water sample and routine investigations (hemoglobin, serum Ca+, serum Po4-, PTH, and urea level) were done. CRP, erythropoietin resistivity index (ERI), and erythropoietin stimulating agents (ESAs) doses were assessed repeatedly to assess inflammatory and anemia states.

Results

Endotoxin level in the dialysis fluid of the CDDS group was significantly lower compared to the SPDDS group (0.05 vs. 0.11 EU/ml, P = 0.001). CRP level decreased significantly after 3 months in the CDDS group (P < 0.001) compared to the SPDDS group (P = 0.54), with significant improvement in the hemoglobin level and ERI at 3 months in the CDDS group and decrease in ESA requirements.

Conclusion

Improvement in dialysis liquid purity reduces inflammatory markers in prevalent hemodialysis patients, improves ERI, and decreases ESA requirements in renal anemia.

Pyrogen retention: Comparison of the novel medium cut-off (MCO) membrane with other dialyser membranes

Haemodialysis effectively removes small solutes and smaller-sized middle molecules from the blood; however, the clearance of larger middle molecules, which have been associated with negative effects, is poor. The novel medium cut-off (MCO) dialysis membrane has larger pore sizes and a more open structure than other high-flux membranes, providing improved removal of larger middle molecules while retaining albumin. However, larger pore sizes may potentially increase permeability to pyrogens, including endotoxins and other bacterial contaminants, that could be present in the dialysis fluid. In this study, we tested the capacity of low-flux, high-flux, MCO and high cut-off dialyser membranes with different pore sizes to prevent pyrogens crossing from dialysate to the blood side in a closed-loop test system, differentiating among lipopolysaccharides, peptidoglycans and bacterial DNA using a toll-like receptor assay. Even though the bacterial contamination levels in our test system exceeded the acceptable pyrogen dose for standard dialysis fluid, levels of lipopolysaccharides, peptidoglycans and bacterial DNA in the blood-side samples were too low to identify potential differences in pyrogen permeability among the membranes. Our results suggest that MCO membranes are suitable for haemodialysis using ISO standard dialysis fluid quality, and retain endotoxins at a similar level as other membranes.

Effect of ultrapure dialysate on markers of inflammation, oxidative stress, nutrition and anemia parameters: a meta-analysis

BACKGROUND

Markers of inflammation are linked to malnutrition and confer an increased mortality risk in hemodialysis patients. Ultrapure dialysate might have a beneficial effect on markers of inflammation. We conducted a meta-analysis that examined the effect of ultrapure versus standard dialysate on markers of inflammation, oxidative stress, nutrition and anemia parameters.

METHODS

We performed a literature search using MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and scientific abstracts. Single-arm studies, nonrandomized and randomized controlled trials were included. We conducted random effects model meta-analyses to assess changes in the aforementioned outcomes.

RESULTS

We identified 16 single-arm studies, 2 crossover and 3 parallel-arm nonrandomized controlled trials and 5 crossover and 5 parallel-arm randomized controlled trials. In an analysis of 23 study arms or cohorts (n = 2221), ultrapure dialysate resulted in a significant decrease in C-reactive protein (-3.2 mg/L; 95% CI -4.6, -1.8; P < 0.001). Other markers of inflammation and oxidative stress displayed similar significant improvements. Ultrapure dialysate also resulted in a significant increase in serum albumin (0.11 g/dL; 95% CI 0.02, 0.19; P = 0.011) and hemoglobin (0.40 g/dL; 95% CI 0.06, 0.75; P = 0.022), and a decrease in the weekly erythropoietin dose (-273 units; 95% CI -420, -126; P < 0.001). The results remained significant in analyses restricted to controlled trials.

CONCLUSIONS

Use of ultrapure dialysate in hemodialysis patients results in a decrease in markers of inflammation and oxidative stress, an increase in serum albumin and hemoglobin and a decrease in erythropoietin requirement. Although improvement in these surrogate endpoints might confer a cardiovascular benefit, a large trial with hard clinical endpoints is required.