The efficacy of haemoperfusion combined with continuous venovenous haemodiafiltration in the treatment of severe viral encephalitis in children

BACKGROUND

This study investigated the efficacy of the integrated blood purification mode of early haemoperfusion (HP) combined with continuous venovenous haemodiafiltration (CVVHDF) in children with severe viral encephalitis, and evaluated the correlation of cerebrospinal fluid (CSF) neopterin (NPT) levels with prognosis.

METHODS

The records of children with viral encephalitis who received blood purification treatment in the authors' hospital from September 2019 to February 2022 were retrospectively analysed. According to the blood purification treatment mode, they were divided into the experimental group (HP + CVVHDF, 18 cases), control group A (CVVHDF only, 14 cases), and control group B (16 children with mild viral encephalitis who did not receive blood purification treatment). The correlation between the clinical features, severity of the disease and the extent of lesions on brain magnetic resonance imaging (MRI) and the CSF NPT levels was analysed.

RESULTS

The experimental group and control group A were comparable with respect to age, gender and hospital course (P > 0.05). There was no significant difference in speech and swallowing functions between the two groups after treatment (P > 0.05) and no significant difference in 7 and 14-day mortality (P > 0.05). The CSF NPT levels in the experimental group before treatment were significantly higher compared with control group B (P < 0.05). The extent of brain MRI lesions correlated positively with CSF NPT levels (P < 0.05). In the experimental group (14 cases), the serum NPT levels decreased after treatment, whereas the CSF NPT levels increased after treatment, and the differences were statistically significant (P < 0.05). Dysphagia and motor dysfunction correlated positively with CSF NPT levels (P < 0.05).

CONCLUSION

Early HP combined with CVVHDF in the treatment of severe viral encephalitis in children may be a better approach than CVVHDF only for improving prognosis. Higher CSF NPT levels indicated the likelihood of a more severe brain injury and a greater possibility of residual neurological dysfunction.

Plasmapheresis adjusts inflammatory responses in potential kidney transplant recipients

BACKGROUND

Plasmapheresis (PP) has been used in the treatment of various immunologic disorders, and its efficacy has mainly been attributed to the removal of humoral factors and autoantibodies. Besides these effects, PP may induce modifications of the cellular immunologic status, contributing to the restoration of impaired immunologic function. The effect of PP on lymphocyte subpopulations, plasma neopterin, and cytokines in renal transplant recipients was investigated in this study.

METHODS

We compared pre-PP and post-PP lymphocyte subpopulations and plasma neopterin in 37, and cytokine plasma levels in 30, potential renal transplant recipients. Plasma neopterin and cytokines were measured by enzyme-linked immunosorbent assay kits, lymphocyte subsets were determined using four-color fluorescence flow cytometry.

RESULTS

Lymphocyte subpopulation counts and ratios including CD45:μL (P=0.005), CD3:μL (P=0.02), CD4DR:μL (P=0.002), CD8:μL (P=0.01), and CD8DR:μL (P=0.005) T cells; CD4DR:CD4 (P=0.009) and CD8DR:CD8 (P=0.0004) ratios; DR cells:μL (P=0.003); CD19 B lymphocytes:μL (P=0.001); and plasma levels of neopterin (P<;0.0001), soluble interleukin-1 receptor antagonist (P<;0.0001), IL-8 (P=0.0001), and tumor necrosis factor-α (P=0.008) were significantly decreased after PP as compared with before PP. The results indicate a decrease of activated DR, CD4, and CD8 T lymphocytes and B lymphocytes, and a decrease of monocyte and macrophage activation as a result of PP.

CONCLUSION

Based on these results, we conclude that PP not only removes antibodies from the plasma but, in addition, modulates T-lymphocyte activation and the inflammatory response by decreasing plasma proinflammatory cytokines.

Anticoagulant potential of regioselective derivatized cellulose

Regioselective derivatization was carried out introducing sulfate, phosphate or quaternary ammonia groups in C2-, C3- and C6-position of the anhydroglycose unit of cellulose. The anticoagulant potential of these derivatives was estimated with common clotting assays, such as thrombin time and partial thromboplastin time. It was found that a pronounced anticoagulant activity of cellulose derivatives could be achieved if the degree of substitution (DS) with sulfate was above 1.0. The anticoagulant activity was maximal at a DS of about 1.5 and then decreased again. Further, it was detected that particularly sulfation in C2-position resulted in a pronounced anticoagulant activity of cellulose derivatives. Development and application of assays specific for thrombin and factor Xa indicated that the anticoagulant potential of these cellulose derivatives was mainly due to anti-thrombin activity. The comparison of cellulose sulfates and cellulose derivatized with phosphate and quaternary ammonium groups demonstrated that the negative charge and type of the substituent is an important prerequisite for the anticoagulant activity of cellulose derivatives. Indeed, derivatization with sulfate produced superior activity in comparison with phosphate.

Adsorption of complement, cytokines, and proteins by different dialysis membrane materials: evaluation by confocal laser scanning fluorescence microscopy

The membranes tested in the present study were cellulose triacetate (CTA), polymethylmethacrylate (PMMA), and polyacrylonitrile (PAN). The adsorption by each membrane of albumin, IgG, C3a, interleukin-1beta (IL-1beta), interleukin-6 (IL-6), human neutrophil elastase (HNE), and tumor necrosis factor alpha (TNFalpha) was examined and semiquantitatively graded by confocal laser scanning fluorescence microscopy (CLSFM). After clinical use the dialyzers were treated with antibodies for these proteins and cytokines. Then the samples were incubated with fluorescein isothiocyanate-labeled anti-IgG antibody and observed by CLSFM. The changes in the blood levels of C3a and cytokines were also studied. In the CTA membrane, the adsorption of these substances, except for albumin and HNE, was less than in the synthetic membranes. The PAN membrane revealed the most abundant adsorption, especially for IL-1beta, IL-6, and TNFalpha. Although a marked elevation of C3a in the blood was observed in the CTA membrane, considerable adsorption was evident in the PMMA and the PAN membranes. Because the changes in the blood levels could be affected by membrane adsorption, both the blood levels and the adsorption of the biocompatibility parameters should be evaluated when membrane biocompatibility is discussed.

Inhibition of the tissue reaction to a biodegradable biomaterial by monoclonal antibodies to IFN-gamma

Biomaterials are increasingly used for clinical applications. However, loss of function may occur owing to tissue reactions, which are mainly caused by a variety of inflammatory reactions. Recently, we demonstrated that macrophages (MO) and T cells play key roles in these reactions. Since immunological studies showed that the T cell-derived cytokine interferon-gamma (IFN-gamma) activates MO, the aim of this study was to investigate the possibility of modulating tissue reactions to biodegradable biomaterials by inactivating IFN-gamma. Dermal sheep collagen (DSC) was used as a test biomaterial. DSC impregnated with anti-IFN-gamma or phosphate-buffered saline (control) was implanted in rats. The results showed that cellular ingrowth and formation and function of giant cells were strongly delayed by anti-IFN-gamma. Also, MHC class II expression was strongly inhibited. In the treated DSC, some huge giant cells were formed at the interface but association with the DSC bundles did not occur. Finally, in both the control and treated DSC, T cells and NK cells were rarely detected. This study demonstrates that IFN-gamma plays an important role in the inflammatory reaction to biomaterials. This reaction can be modulated by anti-IFN-gamma, which warrants further studies of anti-IFN-gamma for clinical application to prevent unwanted tissue reactions to biomaterials.

Soluble interleukin 2 receptor in dialyzed patients

Azotemic patients are usually characterized by a state of so-called preactivation resulting in excessive expression of interleukin 2 receptors (IL-2R) on T lymphocytes. The etiological mechanism of this preactivation is, however, still speculative. We studied the serum level of the soluble form of IL-2R (sIL-2R) in azotemic patients on either hemodialysis (HD) (n = 49) or continuous ambulatory peritoneal dialysis (CAPD) (n = 45). Both patient groups had significantly higher sIL-2R levels (1,750+/-664 U/ml in the HD group and 1,769+/-647 U/ml in the CAPD group, respectively) p < 0.00001 as compared to the normal control group (511+/-436 U/ml). However, there was no significant difference between the levels of the HD and CAPD group patients. When clinical parameters were studied for their influence on sIL-2R levels, none of the following caused any significant changes: blood transfusion, type of dialyzer used, type of dialysis fluid used, treatment with erythropoietin, hepatitis B infection, or liver function profile. We conclude that chronic renal failure per se is the major cause of the preactivation of T lymphocytes. The modes of treatment and various clinical variables in these patients have no significant influence on sIL-2R levels.

Clinical study of high-flux cuprammonium rayon hemodialysis membranes

The aim of this crossover clinical study was to gain basic information on the hemocompatibility and effectiveness of recently developed high-flux membranes made of cuprammonium rayon with ultrafiltration coefficients of 10, 17, and 19 ml/mm Hg/h (S12W, SU12W, and SS12W dialyzers, respectively), and to identify any possible differences from a conventional membrane made of the same material with an ultrafiltration coefficient of 6 ml/mm Hg/h (C12W dialyzer). All the tested membranes led to an abrupt drop in leukocyte count in the initial phase of hemodialysis. In high-flux membranes, C5a anaphylatoxin would pass into the dialysate, but mean C5a anaphylatoxin concentrations in the dialysate were lower by orders of magnitude than its plasma concentrations, which behaved, in high- and low-flux membranes alike, typically of those made of nonsubstituted cellulose with no intermembrane differences. As judged by the concentrations of the thrombin-antithrombin III complex, the coagulation system was activated--again, without differences between membranes. The reduction rates for urea, creatinine, and phosphates were comparable for all the tested membranes. Compared with baseline, the post-dialysis serum concentrations of beta 2-microglobulin in high-flux membranes, unlike the low-flux membrane, were significantly lower. We conclude that there are no significant differences between the tested high- and low-flux membranes made of cuprammonium rayon in the monitored hemocompatibility parameters, and that high-flux membranes are capable of reducing serum beta 2-microglobulin concentrations.