From Active to Non-active Giant Cell Arteritis: Longitudinal Monitoring of Patients on Glucocorticoid Therapy in Combination With Leflunomide

In the present study, we longitudinally monitored leukocyte subsets, expression of neutrophil surface adhesion molecules (CD62L and CD11b) and serum analytes in therapy-naïve patients with active giant cell arteritis (GCA). We collected blood samples at the baseline, and at weeks 1, 4, 12, 24, and 48 of follow-up, and evaluated short- and long-term effects of glucocorticoids (GC) vs. GC and leflunomide. Our aim was to identify candidate biomarkers that could be used to monitor disease activity and predict an increased risk of a relapse. Following high doses of GC, the numbers of CD4+ T-lymphocytes and B-lymphocytes transiently increased and then subsided when GC dose tapering started at week 4. In contrast, the numbers of neutrophils significantly increased during the follow-up time of 12 weeks compared to pre-treatment time. Neutrophil CD62L rapidly diminished after initiation of GC therapy, however its expression remained low at week 48, only in patients under combinatorial therapy with leflunomide. Levels of acute phase reactant SAA and IL-6 decreased significantly after treatment with GC and leflunomide, while levels of IL-8, IL-18, and CHI3L1 did not change significantly during the follow-up period. CHI3L1 was associated with signs of transmural inflammation and vessel occlusion and might therefore serve as a marker of fully developed active GCA, and a promising therapeutic target. Patients with relapses had higher levels of IL-23 at presentation than patients without relapses (p = 0.021). Additionally, the levels of IL-23 were higher at the time of relapse compared to the last follow-up point before relapse. IL-23 might present a promising biomarker of uncontrolled and active disease and could give early indication of upcoming relapses.

Flow Cytometric Determination of Actin Polymerization in Peripheral Blood Leukocytes Effectively Discriminate Patients With Homozygous Mutation in ARPC1B From Asymptomatic Carriers and Normal Controls

Actin nucleators initiate formation of actin filaments. Among them, the Arp2/3 complex has the ability to form branched actin networks. This complex is regulated by members of the Wiscott-Aldrich syndrome protein (WASp) family. Polymerization of actin filaments can be evaluated through flow cytometry by fluorescent phalloidin staining before and after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP). We identified a missense mutation in the gene ARPC1B (Arp2/3 activator subunit) resulting in defective actin polymerization in four patients (three of them were related). All patients (1 male, 3 female) developed microthrombocytopenia, cellular immune deficiency, eczema, various autoimmune manifestations, recurrent skin abscesses and elevated IgE antibodies. Besides four patients with homozygous mutation in ARPC1B, we also identified six heterozygous carriers without clinical disease (3 males, 3 females) within the same family. We developed a functional test to evaluate Arp2/3 complex function, which consists of flow cytometric detection of intracellular polymerized actin after in vitro fMLP stimulation of leukocytes. Median fluorescence intensities of FITC-phalloidin stained actin were measured in monocytes, neutrophils and lymphocytes of patients, carriers, and healthy control subjects. We detected non-efficient actin polymerization in monocytes and neutrophils of homozygous patients compared to carriers or the healthy subjects. In monocytes, the increase in median fluorescence intensities was significantly lower in patients compared to carriers (104 vs. 213%; p < 0.01) and healthy controls (104 vs. 289%; p < 0.01). Similarly, the increase in median fluorescence intensities in neutrophils was significantly increased in the group with carriers (208%; p < 0.01) and healthy controls (238%; p < 0.01) and significantly decreased in the patient's group (94%). Our functional fMLP/phalloidin test can therefore be used as a practical tool to separate symptomatic patients from asymptomatic mutation associated to actin polymerization.

Helicobacter pylori susceptible/resistant to antibiotic eradication therapy differ in the maturation and activation of dendritic cells

BACKGROUND

The natural course of Helicobacter pylori infection, as well as the success of antibiotic eradication is determined by the immune response to bacteria. The aim of the study is to investigate how different Helicobacter pylori isolates influence the dendritic cells maturation and antigen-presenting function in order to elucidate the differences between Helicobacter pylori strains, isolated from the patients with successful antibiotic eradication therapy or repeated eradication failure.

MATERIALS AND METHODS

Dendritic cells maturation and antigen presentation were monitored by flow cytometry analysis of the major histocompatibility complex class II (MHC-II), Toll-like receptor (TLR) and costimulatory molecules expression, and by determining cytokine secretion.

RESULTS

Dendritic cells stimulated with Helicobacter pylori isolated from patients with repeated antibiotic eradication failure expressed less human leukocyte antigen (HLA-DR), CD86, TLR-2, and interleukin-8 (IL-8) compared to Helicobacter pylori strains susceptible to antibiotic therapy; the latter expressed lower production of IL-10. Polymyxin B inhibition of lipopolysaccharide reduces IL-8 secretion in the group of Helicobacter pylori strains susceptible to antibiotic therapy. The differences in IL-8 secretion between both groups are lipopolysaccharide dependent, while the differences in secretion of IL-10 remain unchanged after lipopolysaccharide inhibition. Inhibitor of cathepsin X Mab 2F12 reduced the secretion of IL-6, and the secretion was significantly lower in the group of Helicobacter pylori strains isolated from patients with repeated antibiotic eradication failure.

CONCLUSION

Helicobacter pylori strains, susceptible/resistant to antibiotic eradication therapy, differ in their capability to induce DCs maturation and antigen-presenting function.

Therapeutic electric stimulation does not affect immune status in healthy individuals - a preliminary report

Background

Neuromuscular electric stimulation is widely used for muscle strengthening in clinical practice and for preventative purposes. However, there are few reports on the effects of electric stimulation on the immune response of the organism, and even those mainly describe the changes observed immediately after the electrotherapeutic procedures. The objective of our study was to examine the possible immunological consequences of moderate low-frequency transcutaneous neuromuscular electric stimulation for quadriceps muscle strengthening in healthy individuals.

Methods

The study included 10 healthy volunteers (5 males, 5 females, mean age 37.5 years). At the beginning and after a two-week electric stimulation program, muscle strength was measured and peripheral blood was collected to analyse white blood cells by flow cytometry for the expression of cell surface antigens (CD3, CD19, CD4, CD8, CD4/8, DR/3, NK, Th reg, CD25 + CD3+, CD25 + CD4+, CD25 + CD8+, CD69 + CD3+, CD69 + CD4+, CD69 + CD8+) and phagocytosis/oxidative killing function.

Results

Muscle strength slightly increased after the program on the dominant and the nondominant side. No statistically or clinically significant difference was found in any of the measured blood and immune cells parameters as well as phagocytosis and oxidative burst function of neutrophil granulocytes and monocytes one day after the program.

Conclusions

The program of transcutaneous low-frequency electric stimulation slightly strengthened the quadriceps femoris muscle while producing no changes in measured immunological parameters. Hence, therapeutic low-frequency electric stimulation appears not to be affecting the immune response of healthy persons.

Effect of apoptosis and reactive oxygen species production in human granulosa cells on oocyte fertilization and blastocyst development

PURPOSE

The aim was to establish the impact of human granulosa cell apoptosis and reactive oxygen species (ROS) production on fertilization competence of the oocyte, embryo developmental stage and implantation rate.

METHODS

Thirty women undergoing IVF-ET for tubal factor infertility were included; GnRH antagonists and gonadotrophins were used for ovarian stimulation. Granulosa cells were isolated from each aspirated follicle using gradient centrifugation. Apoptosis was studied by flow cytometry using annexin V and propidium iodide. ROS production was studied with hydroethidine staining and analyzed by flow cytometry.

RESULTS

There were no differences in characteristics of granulosa cells between the follicles with fertilized and non-fertilized oocytes. The analyzed characteristics of granulosa cells in corresponding follicles had no effect on embryo developmental stage on day 5. The percentage of ROS producing granulosa cells was lower in the follicles giving rise to blastocysts that resulted in implantation compared to those that did not (39.9% versus 69.9%, P = 0.031).

CONCLUSIONS

Apoptosis and ROS production in granulosa cells have no significant impact on fertilization and do not correlate with the development of blastocysts. An increased percentage of ROS producing granulosa cells results in fewer oocytes retrieved and diminishes implantation rate.

Specific T cell responses to Helicobacter pylori predict successful eradication therapy

OBJECTIVE

The aim of our prospective study was to test a specific T cell response to Helicobacter pylori before therapy and compare it to the success of H. pylori eradication 12 months later.

METHODS

A total of 14 dyspeptic patients and 10 patients with previous H. pylori eradication failure were recruited into the study; before therapy their gastric samples for H. pylori cultivation and blood samples for dendritic cell cultivation were obtained. H. pylori antigens were produced to prime dendritic cells for stimulation of T lymphocyte response.

RESULTS

The level of cytokine response by T cells was measured and results were compared with the success of H. pylori eradication one year later. There was a significantly increased response in expression of IFN-gamma and IL-4 molecules by DCs stimulated T cells in subjects that successfully eradicated H. pylori compared with those who failed to eradicate the infection. Our results support the hypothesis that successful H. pylori eradication requires established anti-H. pylori immune response besides antibiotic treatment.

CONCLUSION

Effective IFN-gamma cytokine response to H. pylori antigens seems to be of particular importance. Immunisation could be therefore beneficial for H. pylori eradication, while immunodeficiency could cause the failure in H. pylori eradication.

Commensal oral bacteria antigens prime human dendritic cells to induce Th1, Th2 or Treg differentiation

In various immunopathologic conditions, bacterial flora induce an immune response which results in inflammatory manifestations, e.g. periapical granuloma. Dendritic cells provide the main orchestration of specific immune responses. The aim of our study was to test the capacity of distinct oral bacterial antigens (prepared from Streptococcus mitis, Propionibacterium acnes, and Bacteroides spp.) to prime human dendritic cells for stimulation of the T-lymphocyte response. To assess the T-lymphocyte response, the expression of CD25, CD69, intracellular interferon gamma (cIFN-gamma), and intracellular interleukin 4 (cIL-4) was determined. Dendritic cells were prepared from leukocyte buffy coat from healthy blood donors. Monocytes were stimulated with IL-4 and GM-CSF and dendritic cells activated with bacterial lysates. Cell suspensions contained up to 90% dendritic cells, which represented 2-12% of the initial number of mononuclear cells. Lymphocyte subsets that developed in lymphocyte cultures after 1 week of stimulation were analyzed by flow cytometry. Dendritic cells, primed with antigens of Bacteroides fragilis have shown significantly higher activation and expression of intercellular IFN-gamma by T lymphocytes compared to negative controls. The dendritic cells primed with antigens of P. acnes had no effect on T-lymphocyte activation or cytokine production; instead they induced differentiation of T lymphocytes into CD25bright cells (regulatory T cells) with a potentially inhibitory effect on immune response. Dendritic cells primed with antigens of S. mitis induced increased expression of cIL-4. We conclude that commensal oral bacteria antigens prepared from B. fragilis, S. mitis, and P. acnes prime human dendritic cells to induce Th1, Th2, and T(reg) differentiation, respectively. This may advance our understanding of immunopathologic manifestations in the oral cavity and offer new possibilities for redirecting immune responses in mucosal vaccination.

Immune response in lymphocyte cultures stimulated by oral bacteria preparations

Lymphocyte cultures were used as an in vitro experimental model to get a deeper insight into immune response to oral bacteria in periapical granulomas. Lymphocytes isolated from leucocyte concentrate were in lymphocyte cultures stimulated by antigen preparations of oral bacteria. Lymphocyte subsets that have developed in lymphocyte cultures after a week of stimulation were analysed by flow cytometry. A significant increase in expression of INF-gamma molecules in CD3+ cells stimulated by antigen preparations of oral streptococci was found, compared with negative control. On the other hand we observed a significant increase in expression of IL-4 in CD3+ cells stimulated by antigens of anaerobic bacteria, compared with negative control. Our results show that antigens of oral streptococci in in vitro lymphocyte cultures induce the differentiation of T helper cells into Th2 cells and that antigen preparations of anaerobic bacteria induce the differentiation of T helper cells into Th1 cells. Furthermore, an increased expression of HLA-DR molecules on CD8+ T cells stimulated by antigens of oral streptococci was found, compared with negative control.