Włodzimierz Łuczyński

Relationship between circulating endothelial progenitor cells and endothelial dysfunction in children with type 1 diabetes: a novel paradigm of early atherosclerosis in high-risk young patients.

OBJECTIVE The low number of circulating endothelial progenitor cells (EPCs) has emerged as a biomarker of cardiovascular (CV) risk in adults. Data regarding EPCs in paediatric populations with CV risk factors are limited. The aim of the study was to estimate the EPC number and its relationship with vascular function and structure in children with type 1 diabetes mellitus (T1DM). DESIGN AND METHODS We performed a comparative analysis of 52 children with T1DM (mean age 14.5 years; diabetes duration, 6.0 years; HbA1c level, 8.5%) and 36 healthy age- and gender-matched control children. EPCs were identified and analysed by flow cytometry with the use of MABs directed against CD34, CD144 (VE-cadherin) and CD309 (VEGFR-2). sICAM-1, hsCRP, thrombomodulin and adiponectin levels were also assessed. We evaluated vascular function (flow-mediated dilation (FMD)) and structure (carotid intima-media thickness (IMT)) ultrasonographically. RESULTS Frequencies of CD34+ cells were similar in both groups (P=0.30). In contrast, frequencies of CD34+VE-cadherin+ cells were significantly higher in diabetic children compared with the healthy group (P=0.003). Similarly, diabetic patients tended to present with higher frequencies of CD34+VEGFR+ cells (P=0.06). FMD was lower (6.9 vs 10.5%, P=0.002) and IMT was higher (0.50 vs 0.44 mm, P=0.0006) in diabetic children. We demonstrated a significant relationship between CD34+VEGFR-2+ cells and BMI (r=0.3, P=0.014), HDL (r=-0.27, P=0.04), sICAM-1 (r=0.47, P=0.023) and FMD (r=-0.45, P<0.001). Similarly, frequencies of CD34+VE-cadherin+ cells were significantly correlated with BMI (r=0.32, P=0.02) and FMD (r=-0.31, P=0.03). CONCLUSIONS We demonstrated here that increased frequencies of EPCs observed in diabetic children are negatively correlated with endothelial function. Further studies are warranted to assess whether this phenomenon might result from effective mobilisation of EPCs in order to repair damaged endothelium in children at increased risk for atherosclerosis.

Generation of Functional T-Regulatory Cells in Children with Metabolic Syndrome

Recent research implies a role of decreased number and/or function of T-regulatory cells (Tregs) in low-grade inflammation associated with obesity and atherosclerosis. The enhancement of atheroprotective immunity by the expansion of Tregs could serve as a therapeutic strategy in obesity-related immunological disturbances. The aim of our study was an attempt to generate Treg cells in children with risk factors for the development of cardiovascular disease and to compare the results to those obtained in healthy subjects. The study group consisted of 30 children with metabolic syndrome (MS) and 30 controls. Conventional CD4+CD25− cells separated from the peripheral blood were converted into Treg cells with the use of CD3/CD28 antibodies and interleukin (IL)-2/transforming growth factor (TGF)-β stimulation. The expression of critical Treg molecules and cytokines was assessed at mRNA and protein levels. The percentages of Treg cells in the peripheral blood were significantly lower in the children with MS compared to the healthy subjects. After the culture with CD3/CD28 and IL-2/TGF-β we detected a significant increase in the expression of Tregs marker transcription factor FoxP3. The Tregs induced from the children with MS varied from the ones obtained in the controls in the expression of some molecules at mRNA level (e.g. IL-27, LGAL, KLF10 and NRP1) yet not in proliferation studies. For the first time, we have demonstrated the possibility of generating functional Treg cells in children with MS. The results of our study could be used in the design of therapeutic interventions in obesity associated immunologic disturbances.

Upregulation of antigen-processing machinery components at mRNA level in acute lymphoblastic leukemia cells after CD40 stimulation

The development of immunotherapy in hematologic malignancies has been observed in the last few years. One of the approaches is the use of cancer vaccines based on leukemia-derived dendritic cells (DC). Recent studies from our laboratory and other laboratories have shown that CD40 stimulation improves leukemia cells immunogenicity and generates an antitumor immune response. The design of future cancer vaccines requires the knowledge concerning the function of dendritic cells including antigen processing. The aim of our present study was the assessment of antigen-processing machinery (APM) components in acute lymphoblastic leukemia (ALL) cells before and after CD40 stimulation at messenger RNA (mRNA) level. Twenty-five children with ALL were enrolled into the study. Leukemic cells were stimulated (or not) with CD40L and IL-4. Elements of the antigen-processing machinery (MB1, LMP2, LMP7, LMP10, TAP1, TAP2, calnexin, calreticulin, tapasin, ERp57, zeta, delta) were determined by real-time PCR technique. The expression of important costimulatory and adhesion molecules considered as DC markers (CD40, CD54, CD80, CD83, CD86) were determined at the mRNA (PCR) and protein (flow cytometry) levels. The following are the results of our study: (1) We noted an upregulation of all costimulatory and adhesion molecules at the mRNA and protein levels in ALL cells after the culture; (2) the significant rise in expression of nearly all APM components after CD40 stimulation was observed. This confirms specific stimulation of the antigen-processing system in ALL cells by CD40L. Future work should focus on the clinical significance of these findings for immunotherapy in leukemias.

The mRNA expression of pro- and anti-inflammatory cytokines in T regulatory cells in children with type 1 diabetes

Type 1 diabetes mellitus (T1DM) is caused by the autoimmune-mediated destruction of insulin-producing beta cells in the pancreas. T regulatory cells (Tregs) represent an active mechanism of suppressing autoreactive T cells that escape central tolerance. The aim of our study was to test the hypothesis that T regulatory cells express pro- and anti-inflammatory cytokines, elements of cytotoxicity and OX40/4-1BB molecules. The examined group consisted of 50 children with T1DM. Fifty two healthy individuals (control group) were enrolled into the study. A flow cytometric analysis of T-cell subpopulations was performed using the following markers: anti-CD3, anti-CD4, anti-CD25, anti-CD127, anti-CD134 and anti-CD137. Concurrently with the flow cytometric assessment of Tregs we separated CD4+CD25+CD127dim/- cells for further mRNA analysis. mRNA levels for transcription factor FoxP3, pro- and anti-inflammatory cytokines (interferon gamma, interleukin-2, interleukin-4, interleukin-10, transforming growth factor beta1 and tumor necrosis factor alpha), activatory molecules (OX40, 4-1BB) and elements of cytotoxicity (granzyme B, perforin 1) were determined by real-time PCR technique. We found no alterations in the frequency of CD4+CD25highCD127low cells between diabetic and control children. Treg cells expressed mRNA for pro- and anti-inflammatory cytokines. Lower OX40 and higher 4-1BB mRNA but not protein levels in Treg cells in diabetic patients compared to the healthy children were noted. Our observations confirm the presence of mRNA for pro- and anti-inflammatory cytokines in CD4+CD25+CD127dim/- cells in the peripheral blood of children with T1DM. Further studies with the goal of developing new strategies to potentiate Treg function in autoimmune diseases are warranted.

Cardiovascular risk in nonobese hypertensive adolescents: a study based on plasma biomarkers and ultrasonographic assessment of early atherosclerosis.

The objective of this study was to investigate the vascular status, left-ventricular mass and biomarkers of endothelial activation in hypertensive (HT) adolescents, with particular attention to comparing nonobese with obese patients. Seventy-nine newly diagnosed HT adolescents aged 15.1±2.1 years (divided into 34 nonobese and 45 obese) were compared with 35 healthy volunteers. Intima–media thickness (IMT), flow-mediated dilation (FMD) and left-ventricular mass index (LVMi) were determined using ultrasound. Adhesion molecules and inflammatory interleukins (ILs), together with lipids and insulin resistance (HOMA), were also studied. HT obese adolescents had higher triglycerides, HOMA, and elevated levels of interleukin-6, tumor necrosis factor-α, soluble intercellular adhesion molecule-1 and soluble E-selectin compared with controls and nonobese HT patients. FMD was lower in HT groups (8.5±4.5% in nonobese, P=0.004; 8.1±4.9%, P=0.01 in obese vs 12.5±4.9%; in control), and IMT was higher (0.52±0.06 mm, P<0.001 in nonobese; 0.54±0.05 mm, P<0.001 in obese vs 0.42±0.05 mm in control). Higher LVMi was found in both HT groups, with the highest value in the nonobese group being 37.8±5.3 g m−2.7 vs 28.4±5.3 g m−2.7 in controls (P=0.003). In conclusion, nonobese HT adolescents had the same early cardiovascular deteriorations assessed ultrasonographically as their obese HT peers, although metabolic alterations and endothelial activation measured as plasma biomarkers were more pronounced in obese individuals. The potential mechanisms of early atherosclerosis in nonobese HT adolescents need further evaluation in prospective studies because these factors may differ considerably from those found in young obese individuals with HT.

Disturbances in some Gene Expression in T Regulatory Cells Separated from Children with Metabolic Syndrome

The metabolic syndrome (MS) is defined as a cluster of risk factors, including abdominal obesity, dyslipidaemia, glucose intolerance and hypertension, which increase the risk for coronary heart disease. The immunological aspects of obesity and MS, including the role of T regulatory cells, have been intensively investigated. The aim of this study was to determine whether there is any disturbance in T regulatory cells number and/or function in children with MS. The percentages of T regulatory cells in the peripheral blood of children fulfilling the International Diabetes Federation criteria of the disease (n = 47) were assessed. Treg cells were also separated for further analysis of multiple genes important in their function with the use of real‐time RT‐PCR. We did not observe any difference in Treg percentages between study and control group but there was lower expression of some molecules including transforming growth factor‐β and interleukin‐12 family members in Treg cells separated from children with MS compared to the healthy subjects. Our study is the first to report significant disturbances in some gene expression in T regulatory cells separated from children with MS. The results should be useful for further research in this field, including immunotherapeutic interventions.

Subclinical Cardiovascular System Changes in Obese Patients with Juvenile Idiopathic Arthritis

Objective. We aimed to determine the prevalence of excess body mass in juvenile idiopathic arthritis (JIA) children and to investigate the influence of obesity into the early, subclinical changes in cardiovascular system in these patients. Methods. Fifty-eight JIA patients, aged median 13 years, were compared to 36 healthy controls. Traditional cardiovascular risk factors and inflammatory markers (hsCRP, IL-6, TNFα, adiponectin) were studied together with IMT (intima-media thickness), FMD (flow mediated dilation), and LVMi (left ventricle mass index) as surrogate markers of subclinical atherosclerosis. Results. Thirteen JIA children (22%) were obese and had increased systolic blood pressure, cholesterol, triglycerides, insulin, HOMA, hsCRP, and IL-6 compared to nonobese JIA and controls. FMD was decreased compared to nonobese JIA and controls, whereas IMT and LVMi were increased. In multivariate regression analysis, TNFα, SDS-BMI, and systolic blood pressure were independent predictors of early CV changes in JIA. Conclusions. Coincident obesity is common in JIA children and is associated with insulin resistance, dyslipidemia, and increased levels of inflammatory markers leading to early changes in cardiovascular system. Thus, medical care of children with JIA should include strategies preventing cardiovascular disease by maintenance of adequate body weight.

Elevated levels of Th17 cells in children with central obesity

Abstract Background. It is believed that the recently discovered interleukin 17-producing Th17 cells play a role in the pathogenesis of chronic inflammation in the course of obesity and diabetes. Objectives. The purpose of our study was to complete data on this subject in children. Methods. We assessed Th17 cell levels in the peripheral blood of children diagnosed with central obesity (n = 14) and compared the results with data obtained in patients with newly diagnosed (n = 11) and long-term type 1 diabetes mellitus (n = 18), and in a control group as well (n = 24). Results. (i) Children with central obesity were characterized by higher percentages of Th17 cells as compared to children from the control group; (ii) in the peripheral blood of patients with long-term type 1 diabetes the Th17 cell counts were higher compared to the control group; (iii) total plasma cholesterol concentration correlated positively with Th17/Treg cells ratio; and (iv) among patients with long-term diabetes, disease duration correlated positively with Th17 cell count and Th17/Th1 cell ratio. Conclusion. The results of our study indicate that Th17 cells may be involved in chronic inflammation accompanying obesity and type 1 diabetes mellitus in children.

Polymorphism of the FTO Gene Influences Body Weight in Children with Type 1 Diabetes without Severe Obesity

The objective was to compare the impact of clinical and genetic factors on body mass index (BMI) in children with type 1 diabetes (T1DM) without severe obesity. A total of 1,119 children with T1DM (aged 4–18 years) were qualified to take part in the study. All children were genotyped for variants of FTO, MC4R, INSIG2, FASN, NPC1, PTER, SIRT1, MAF, IRT1, and CD36. Results. Variants of FTO showed significant association with BMI-SDS in the T1DM group. The main factors influencing BMI-SDS in children with T1DM included female gender (P = 0.0003), poor metabolic control (P = 0.0001), and carriage of the A allele of the FTO rs9939609 gene (P = 0.02). Conclusion. Our research indicates, when assessing, the risk of overweight and obesity carriage of the A allele in the rs9939609 site of the FTO gene adds to that of female gender and poor metabolic control. This trial is registered with ClinicalTrials.gov (NCT01279161).

Organ-specific autoimmunity in relation to clinical characteristics in children with long-lasting type 1 diabetes

Abstract Background: The aim of this study was to assess the prevalence of diabetes and other organ-specific autoantibodies (Ab) associated with various autoimmune conditions, in Polish children with type 1 diabetes mellitus (T1DM). Methods: In this study 114 patients, aged 13.4 years, with mean diabetes duration 5.2 years were included. Ab to islet cell antigens: glutamic acid decarboxylase (GAD), insulinoma antigen 2 (IA-2), zinc transporter 8 (ZnT8), together with thyroid peroxidase Ab (TPO Ab), thyroglobulin Ab (Tg Ab), tissue transglutaminase Ab (tTG Ab) and 21-hydroxylase Ab (21-OH Ab) were measured. Results: The prevalence of at least one diabetes associated Ab was found in 87%, with the highest prevalence of 64% for ZnT8 Ab. In patients with disease duration <5 years, at least one antibody was present in 90%, the most prevalent was ZnT8 Ab (72%). In patients with duration >10 years, 50% had at least one antibody. The prevalence of other than islet cell autoimmunity was high (34%). Thyroid Ab were detected in 26% patients, 42% in girls vs. 8% in boys, p<0.001. tTG Ab were found in 11% patients, with a greater prevalence in children with early onset (p=0.01). 21-OH Ab were found in 2.6% T1DM patients. Conclusions: Islet Ab were found in most T1DM children and remained positive even 10 years after onset. ZnT8 Ab emerged as an important marker for the diagnosis of T1DM in the Polish children. Screening for non-diabetes Ab in T1DM may be helpful in identifying subclinical cases of autoimmune thyroid, celiac or Addison’s disease (AD).