BACKGROUND:Several studies point towards the involvement of the immune system (especially the monocyte-macrophage system) in the pathophysiology of Complex Regional Pain Syndrome (CRPS), as shown by increased levels of the cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6. These cytokines are primarily released from pro-inflammatory M1 macrophages, but are difficult to measure in a clinical setting. Investigating the activity of tissue-resident macrophages by measuring soluble CD163 (sCD163) in serum is much more clinically applicable. sCD163 could potentially be a biomarker for determining inflammation in CRPS and would have direct consequences for the choice of therapy. The aim of this study is to investigate the tissue-resident macrophage activation in CRPS with sCD163 and explore the relationship between soluble IL-2R, which is a marker for T-cell activation, and sCD163. METHODS:The sCD163 levels were determined in this retrospective cohort study (MEC-2020-0716) in serum of CRPS patients (n = 22) and healthy controls (n = 27). ELISA kits were used to measure the levels of these markers. Data on demographics, pain scores (11-point Numeric Rating Scale: NRS), sIL-2R levels, signs and symptoms, and CRPS disease severity were also recorded. RESULTS:The median serum sCD163 level was significantly higher in CRPS patients (CRPS 960.5 pg/mL [Q3-Q1: 1211.5-623.9] than in healthy controls 677.0 pg/mL [Q3-Q1: 828.0-469.5], p = 0.008). There was a statistically significant positive correlation between sCD163 and sIL-2R in the CRPS group (rs = 0.577; p = 0.005), but not in the healthy control group (rs = 0.359; p = 0.066). CONCLUSION:Our findings indicate that pro-inflammatory activation of tissue-resident macrophages and thus the monocyte-macrophage system is part of CRPS pathogenesis. The monocyte-macrophage system is an interesting new target for future research into the pathogenesis of CRPS, but also has potential for diagnosis, particularly for assessing the involvement of the immune system and choice of therapy in the individual CRPS patient. Measurement of the sCD163 could be a potential biomarker for inflammation in CRPS. TRIAL REGISTRATION:This retrospective cohort study was approved by the Medical Ethics Committee of the Erasmus MC University Medical Center (MEC-2020-0716).

Background: Obesity is a multifactorial, chronic, progressive disease associated with decreased health-related quality of life, comorbidities, and increased mortality risk. Lifestyle interventions, focusing on dietetics, physical exercise, and behavioral therapy, are a cornerstone of therapy. Despite this very multidisciplinary treatment approach, the definition of treatment success is often based only on a weight loss of ≥ 5%. However, the heterogeneous nature of obesity may necessitate a more comprehensive approach to assessing treatment effects. Objectives: Here, we describe changes in physiological, psychological, and behavioral health after a multidisciplinary combined lifestyle intervention (CLI). Additionally, we investigated whether these changes were related to weight loss. Methods: This prospective observational longitudinal study comprised 96 adults with obesity (73 women, 81 Caucasian) participating in a CLI at the Obesity Center CGG, Erasmus University Medical Center, Rotterdam, the Netherlands. The 1.5-year intervention comprised multidisciplinary professional guidance towards a healthy diet, increased physical activity, and included cognitive behavioral therapy. Physiological health outcomes, psychological well-being, eating behavior, and physical activity were assessed after ten weeks and 1.5 years and compared to baseline. Results: An average of 5.2% weight loss (-6.0 kg) was accompanied by a mean 9.8% decrease in fat mass (-5.9 kg; both P < 0.001) and significant improvements in metabolism, hormonal status, and immune parameters (all P < 0.05). Moreover, we observed decreased psychopathology, increased quality of life, and decreased disordered eating (all P < 0.05). Weight loss correlated with most metabolic changes (all P < 0.05) but not with most psychological/behavioral changes. Conclusions: Combined lifestyle intervention in patients with obesity was accompanied by significant improvements in body weight and body composition along with cardiometabolic, endocrine, immunological, psychological, and behavioral improvements. Interestingly, most changes in psychological and behavioral health occurred independently of weight loss. Obesity treatment success should be evaluated based on a combination of physical and patient-reported outcomes rather than weight loss alone.

BACKGROUND:Indolent systemic mastocytosis (ISM) is characterized by pathologic accumulation of mast cells. The mechanism behind its phenotypic heterogeneity is not well understood. Interaction of mast cells with other immune cells might cause systemic inflammation and thereby associated symptoms. OBJECTIVE:We investigated peripheral leukocyte compartments and serum immune proteome in ISM. METHODS:Peripheral blood leukocyte phenotyping using flow cytometry in a cohort of 18 adults with ISM and 12 healthy controls. Targeted proteomics was performed to measure 169 proteins associated with inflammation on serum of another 20 ISM patients and 20 healthy controls. RESULTS:Proportions of plasmacytoid dendritic cells and monocytes were significantly decreased while TH2 cells were increased in peripheral blood of ISM patients. Furthermore, a shift from naive to memory T cells was observed. Hierarchical clustering of the serum proteome revealed 2 distinct subgroups within ISM patients. In subgroup A (n = 8), 62 proteins were significantly overexpressed, whereas those of subgroup B (n = 12) were comparable to healthy controls. Patients in subgroup A displayed upregulated signaling pathways downstream of Toll-like receptor 4, TNF-α, and IFN-γ. Fatigue was more often present in subgroup A compared to B (75% vs 33% respectively, P = .06). CONCLUSIONS:Altered distribution of leukocyte subsets and a proinflammatory proteome were observed in subsequent 2 cohorts of ISM patients. We hypothesize that neoplastic mast cells recruit and activate plasmacytoid dendritic cells, monocytes, and T cells, leading to a vicious cycle of inflammation.

Background: The macrophage theory of depression states that macrophages play an important role in Major Depressive Disorder (MDD). Methods: MDD patients (N = 140) and healthy controls (N = 120) participated in a cross-sectional study investigating the expression of apoptosis/growth and lipid/cholesterol pathway genes (BAX, BCL10, EGR1, EGR2, HB-EGF, NR1H3, ABCA1, ABCG1, MVK, CD163, HMOX1) in monocytes (macrophage/microglia precursors). Gene expressions were correlated to a set of previously determined and reported inflammation-regulating genes and analyzed with respect to various clinical parameters. Results: MDD monocytes showed an overexpression of the apoptosis/growth/cholesterol and the TNF genes forming an inter-correlating gene cluster (cluster 3) separate from the previously described inflammation-related gene clusters (containing IL1 and IL6). While upregulation of monocyte gene cluster 3 was a hallmark of monocytes of all MDD patients, upregulation of the inflammation-related clusters was confirmed to be found only in the monocytes of patients with childhood adversity. The latter group also showed a downregulation of the cholesterol metabolism gene MVK, which is known to play an important role in trained immunity and proneness to inflammation. Conclusions: The upregulation of cluster 3 genes in monocytes of all MDD patients suggests a premature aging of the cells, i.e. mitochondrial apoptotic dysfunction and TNF "inflammaging", as a general feature of MDD. The overexpression of the IL-1/IL-6 containing inflammation clusters and the downregulation of MVK in monocytes of patients with childhood adversity indicates a shift in this condition to a more severe inflammation form (pyroptosis) of the cells, additional to the signs of premature aging and inflammaging.

Abstract In previous work, we showed the prominence of the T cell response in the formation of brain metastases of primary ER-negative breast cancers. We also showed that prior co-cultured breast cancer cells with stimulated T lymphocytes bear an overexpression of Guanylate-binding protein 1 (GBP1) and possess an increased trespassing ability through an in vitro blood-brain barrier (BBB) model. In addition, we demonstrated a predilection for metastasizing to the brain of breast cancer cells that were co-cultured with activated T cells in a mouse model. In the present work, we show that activated CD8+ cytotoxic T lymphocytes, rather than CD4+ lymphocytes, are the main cause of increasing the ability of breast cancer cells to cross the BBB. While synthetic IFNγ does not change the ability of breast cancer cells to cross the BBB, this study shows that the T lymphocyte-secreted IFNγ activates the STAT1-dependent IFNγ pathway in breast cancer cells, enabling them to cross the in vitro BBB. Direct inhibition of soluble IFNγ or blocking of the IFNγ-specific receptor in breast cancer cells significantly decreases their ability to cross the BBB. The results illustrate that IFNγ signaling pathway is one of the crucial pathways in the formation of brain metastasis of ER- breast cancer. The interference with the IFNγ pathway will develop preventive strategies against the formation of brain metastases of breast cancer.

Although extensive angiogenesis takes place in glial tumors, antiangiogenic therapies have remained without the expected success. In the peripheral circulation of glioma patients, increased numbers of endothelial precursor cells (EPCs) are present, potentially offering targets for antiangiogenic therapy. However, for an antiangiogenic therapy to be successful, the therapy should specifically target glioma-related EPC subsets and secreted factors only. Here, we compared the EPC subsets and plasma factors in the peripheral circulation of patients with gliomas to acute myocardial infarctions. We investigated the five most important EPC subsets and 21 angiogenesis-related plasma factors in peripheral blood samples of 29 patients with glioma, 14 patients with myocardial infarction, and 20 healthy people as controls, by FACS and Luminex assay. In GBM patients, all EPC subsets were elevated as compared to healthy subjects. In addition, HPC and KDR+ cell fractions were higher than in MI, while CD133+ and KDR+CD133+ cell fractions were lower. There were differences in relative EPC fractions between the groups: KDR+ cells were the largest fraction in GBM, while CD133+ cells were the largest fraction in MI. An increase in glioma malignancy grade coincided with an increase in the KDR+ fraction, while the CD133+ cell fraction decreased relatively. Most plasma angiogenic factors were higher in GBM than in MI patients. In both MI and GBM, the ratio of CD133+ HPCs correlated significantly with elevated levels of MMP9. In the GBM patients, MMP9 correlated strongly with levels of all HPCs. In conclusion, the data demonstrate that EPC traffic in patients with glioma, representing neoplasia, is different from that in myocardial infarction, representing tissue regeneration. Glioma patients may benefit from therapies aimed at lowering KDR+ cells and HPCs.

PURPOSE:To analyse intraocular cytokine levels and prevalence of intraocular antiretinal antibodies (ARAs) in patients with retinitis pigmentosa (RP), age-related macular degeneration (AMD), glaucoma and cataract, and correlate the results to clinical manifestations.METHODS:We collected intraocular fluid samples from patients with RP (n = 25), AMD (n = 12), glaucoma (n = 28) and cataract (n = 22), and serum samples paired with the intraocular fluids from patients with RP (N = 7) and cataract (n = 10). Interleukin (IL)-1β, IL-1ra, IL-2, IL-6, IL-6rα, IL-7, IL-8, IL-10, IL-17A, IL-23, thymus- and activation-regulated chemokine (TARC), monocyte chemoattractant protein-1 (MCP-1), tumour necrosis factor-alpha (TNF-α), placental growth factor (PlGF) and vascular endothelial growth factor (VEGF) were measured using a multiplex assay. Antiretinal antibodies (ARA) detection was performed by indirect immunofluorescence.RESULTS:Increasing age was associated with increasing levels of IL-6, IL-8, TNF-α and VEGF. All patient groups exhibited distinct profiles of intraocular cytokines. Intraocular levels of IL-8 were highest in patients with AMD and glaucoma. Cataract patients exhibited high intraocular levels of IL-23. Intraocular levels of IL-2, IL-6, MCP-1 and PlGF in RP patients exceeded the levels of serum, indicating intraocular production. Intraocular ARAs were found in only one patient with AMD.CONCLUSION:Increased levels of inflammatory cytokines in intraocular fluid of patients with originally noninflammatory ocular diseases show that intraocular inflammation is involved in their pathogenesis of these entities. Moreover, we show that increasing age is associated with increasing levels of intraocular cytokines and conclude that future studies on intraocular mediators should be corrected for age of patients.

OBJECTIVE:Complex regional pain syndrome (CRPS) is characterized by continued pain disproportional to the inciting event, sensory abnormalities, vasomotor and sudomotor disturbances, and motor and trophic changes. Inflammatory involvement has been demonstrated in past CRPS studies resulting in pain, swelling, and warmth. Currently, it is unknown whether spinal cord stimulation (SCS) has immunomodulatory properties. The aim of this study was to determine whether SCS has immunomodulatory properties in CRPS patients.METHODS:The primary outcome parameters are cytokines (IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-15, IL-17, TNF-α, IFN-γ), chemokines (IP-10 and Eotaxin), and growth factors (VEGF, PDGFbb, and basic FGF) from interstitial fluid of artificial skin blisters before (T0-baseline without SCS) and after SCS therapy (T1-40 Hz standard frequency stimulation and T2-preferred frequency stimulation). Secondary outcome parameters were baseline demographics, CRPS signs, symptoms, and phenotype (inflammatory, vasomotor, dystonia, or neuropathic). Results were analyzed by means of a MANOVA repeated measures design.RESULTS:After SCS, the expression of both pro- and anti-inflammatory cytokines decreased over time in both the CRPS affected extremity and the contralateral extremity. The levels of IP-10, Eotaxin, VEGF, and PDGFbb were also significantly reduced bilaterally. There were no significant changes in IL-6 and TNF-α before and after SCS. The sensory signs, symptoms, and phenotype improved after SCS.DISCUSSION:SCS in CRPS patients attenuates T-cell activation, improves peripheral tissue oxygenation and decreases anti-angiogenetic activity which results in diminished endothelial dysfunction and improved bloodflow. The possible immunomodulatory effects of SCS opens new therapeutic possibilities in diseases with the involvement of the immune system and vasomotor disturbances, and requires further research on these mechanisms of action.

Around 1960, observations of lymphocytic insulitis and the presence of islet cell autoantibodies in patients with type 1 diabetes led to the concept of type 1 diabetes being an organ-specific autoimmune disease. Much work has since been done to unravel the mechanisms behind the aberrant self-directed immune response and to predict disease progression, as it appeared that the autoimmune reaction preceded clinical diabetes, often for many years. Research focused on the identification of the primary autoantigen(s) to which the antibodies were directed. Important targets, such as insulin, GAD65, and IA-2, were discovered. However, research into the pathogenic mechanisms was hampered because the pancreas tissue of patients in the initial phases was rarely available. For that reason, animal models, such as the NOD mouse and the diabetes-prone BioBreeding (BBDP) rat, that developed autoimmune diabetes spontaneously were used to study prestages of the disease and to test therapeutic interventions. Studies in these animal models have mainly focused on autoreactive T-cell–mediated inflammatory destructive reactions to the islets of Langerhans, and balances between a multitude of regulatory and effector mechanisms became gradually apparent (1). However, translation of these animal data to the human disease was a controversial issue. Nevertheless, from all this work the view developed that the central pathogenic mechanism is an antigen-driven T lymphocyte–mediated inflammatory reaction of the islets, which specifically affects the β-cells disappearing in the reaction. This excessive reaction is allowed by defective tolerance mechanisms, and particular emphasis has been on the population of thymus-derived CD4+CD25+FOXP3+ T regulatory cells (excellently reviewed in ref. 1). However, many questions remained (1), among which were, “What are the initiating factors?” and “How are innate immune responses involved?”A consortium of research groups (Network for Pancreatic Organ Donors with Diabetes [nPOD]) embarked on collecting relevant tissues from organ donors …

BACKGROUND Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) induce effector memory T-cell expansions, which are variable and potentially depend on the age at primary exposure and coinfections. We evaluated the T-cell compartment and herpesvirus infections in 6-year-old children. METHODS T-cell subsets and immunoglobulin G seropositivity for CMV, EBV, herpes-simplex virus 1, and varicella-zoster virus were studied in 1079 6-year-old children. A random subgroup of 225 children was evaluated for CMV and EBV seropositivity before 2 years of age and for vaccination responses against measles and tetanus. RESULTS CMV and EBV infections were associated with significant expansions of CD27(-) and CD27(+) effector memory T cells, respectively. These expansions were enhanced in CMV-EBV-coinfected children and were independent of varicella-zoster virus or herpes-simplex virus 1 coinfection. Naive and central memory T-cell numbers were not affected, nor were anti-tetanus and anti-measles immunoglobulin G levels. Children infected before 2 years of age showed smaller effector memory T-cell expansions than those infected between 2 and 6 years of age. CONCLUSIONS CMV- and EBV-related T-cell expansions do not impair naive T-cell numbers or maintenance of protective responses against nonrelated pathogens. Duration of infection was not directly related to larger expansions of effector memory T cells in children, suggesting that other mechanisms affect these expansions at later age.