Assessment of EN-RAGE, sRAGE and EN-RAGE/sRAGE as potential biomarkers in patients with autoimmune hepatitis

Exploring the role of CD13 and inflammatory factors in radiation enteritis: insights from high-throughput proteomics and Mendelian randomization analysis

BACKGROUND

Radiation enteritis (RE) is an unavoidable complication during radiotherapy for pelvic malignancies, characterized by chronic inflammation, fibrosis, and vascular injury in the intestinal tissue. Currently, there is a lack of research that delves into the relationship between inflammatory factors and key proteins in RE.

METHODS

This study employed high-throughput proteomics to analyze intestinal tissues from RE rats and healthy controls, identifying differentially expressed key proteins. The degree of intestinal damage was validated through HE staining. Furthermore, five Mendelian randomization methods were used to analyze the causal relationship between 70 serum circulating inflammatory factors and CD13 levels. Sensitivity analyses, including heterogeneity tests, leave-one-out tests, and horizontal pleiotropy tests, were performed to ensure the robustness and reliability of the results.

RESULTS

CD13 was identified as a key differentially expressed protein, with its expression significantly upregulated in RE rats and positively correlated with disease severity. Bidirectional Mendelian randomization analysis revealed causal relationships between CD13 and four inflammatory factors: increased levels of CCL28 and EN-RAGE may promote the rise in CD13, while increased levels of TAM-binding protein may be associated with decreased CD13 levels. Additionally, higher CD13 levels were found to be associated with increased levels of interleukin-12. Sensitivity analyses indicated good consistency and reliability in terms of heterogeneity and pleiotropy for these exposure variables.

CONCLUSION

This study reveals the potential mechanistic role of CD13 in RE. Moreover, the identified CD13-associated inflammatory factors offer potential targets for the development of new prevention and treatment strategies, with significant clinical implications.

Assessment of EN-RAGE, sRAGE, and its isoforms: cRAGE, esRAGE in obese patients treated by moderate caloric restriction combined with physical activity conducted in hospital condition

BACKGROUND

AGEs, their receptor (RAGE), and the extracellular newly identified receptor for AGEs product-binding protein (EN-RAGE) are implicated in the pathogenesis of inflammation.

AIM

We analyzed serum EN-RAGE, soluble RAGE (sRAGE), and their isoforms: endogenous secretory - esRAGE and cleaved - cRAGE concentrations in lean controls (n = 74) and in patients with obesity (n = 71) treated for three weeks with moderate calorie restriction (CR) combined with physical activity in a hospital condition.

METHODS

Using the ELISA method, serum sRAGE, esRAGE, and EN-RAGE were measured before and after CR.

RESULTS

The serum level of sRAGE and esRAGE in patients with obesity was lower than that in non-obese individuals, contrary to cRAGE. EN-RAGE concentration was about three times higher in obese patients. Gradually, a rise in BMI resulted in sRAGE, esRAGE reduction, and EN-RAGE increase. The sRAGE concentration was sex-dependent, indicating a higher value in lean men. A moderate negative correlation was observed between BMI and all RAGE isoforms, whereas EN-RAGE displays a positive correlation. CR resulted in an expected decrease in anthropometric, metabolic, and proinflammatory parameters and EN-RAGE, but no RAGE isoforms. The ratio EN-RAGE/sRAGE was higher in obese humans than in control and was not modified by CR.

CONCLUSION

Obesity decreases sRAGE and esRAGE and increases EN-RAGE concentration. Moderate CR and physical activity by decreasing inflammation reduces EN-RAGE but is insufficient to increase sRAGE and esRAGE to the extent observed in lean patients. EN-RAGE instead of sRAGE could be helpful to indicate a better outcome of moderate dietary intervention in obese subjects.

Stretch Causes cffDNA and HMGB1-Mediated Inflammation and Cellular Stress in Human Fetal Membranes

Danger-associated molecular patterns (DAMPs) are elevated within the amniotic cavity, and their increases correlate with advancing gestational age, chorioamnionitis, and labor. Although the specific triggers for their release in utero remain unclear, it is thought that they may contribute to the initiation of parturition by influencing cellular stress mechanisms that make the fetal membranes (FMs) more susceptible to rupture. DAMPs induce inflammation in many different tissue types. Indeed, they precipitate the subsequent release of several proinflammatory cytokines that are known to be key for the weakening of FMs. Previously, we have shown that in vitro stretch of human amnion epithelial cells (hAECs) induces a cellular stress response that increases high-mobility group box-1 (HMGB1) secretion. We have also shown that cell-free fetal DNA (cffDNA) induces a cytokine response in FM explants that is fetal sex-specific. Therefore, the aim of this work was to further investigate the link between stretch and the DAMPs HMGB1 and cffDNA in the FM. These data show that stretch increases the level of cffDNA released from hAECs. It also confirms the importance of the sex of the fetus by demonstrating that female cffDNA induced more cellular stress than male fetuses. Our data treating hAECs and human amnion mesenchymal cells with HMGB1 show that it has a differential effect on the ability of the cells of the amnion to upregulate the proinflammatory cytokines and propagate a proinflammatory signal through the FM that may weaken it. Finally, our data show that sulforaphane (SFN), a potent activator of Nrf2, is able to mitigate the proinflammatory effects of stretch by decreasing the levels of HMGB1 release and ROS generation after stretch and modulating the increase of key cytokines after cell stress. HMGB1 and cffDNA are two of the few DAMPs that are known to induce cytokine release and matrix metalloproteinase (MMP) activation in the FMs; thus, these data support the general thesis that they can function as potential central players in the normal mechanisms of FM weakening during the normal distension of this tissue at the end of a normal pregnancy.

Proteomic profiling identifies biomarkers of COVID-19 severity

SARS-CoV-2 infection remains a major public health concern, particularly for the aged and those individuals with co-morbidities at risk for developing severe COVID-19. Understanding the pathogenesis and biomarkers associated with responses to SARS-CoV-2 infection remain critical components in developing effective therapeutic approaches, especially in cases of severe and long-COVID-19. In this study blood plasma protein expression was compared in subjects with mild, moderate, and severe COVID-19 disease. Evaluation of an inflammatory protein panel confirms upregulation of proteins including TNFβ, IL-6, IL-8, IL-12, already associated with severe cytokine storm and progression to severe COVID-19. Importantly, we identify several proteins not yet associated with COVID-19 disease, including mesothelin (MSLN), that are expressed at significantly higher levels in severe COVID-19 subjects. In addition, we find a subset of markers associated with T-cell and dendritic cell responses to viral infection that are significantly higher in mild cases and decrease in expression as severity of COVID-19 increases, suggesting that an immediate and effective activation of T-cells is critical in modulating disease progression. Together, our findings identify new targets for further investigation as therapeutic approaches for the treatment of SARS-CoV-2 infection and prevention of complications of severe COVID-19.

Markers of inflammation predict survival in newly diagnosed cirrhosis: a prospective registry study

The inflammatory activity in cirrhosis is often pronounced and related to episodes of decompensation. Systemic markers of inflammation may contain prognostic information, and we investigated their possible correlation with admissions and mortality among patients with newly diagnosed liver cirrhosis. We collected plasma samples from 149 patients with newly diagnosed (within the past 6 months) cirrhosis, and registered deaths and hospital admissions within 180 days. Ninety-two inflammatory markers were quantified and correlated with clinical variables, mortality, and admissions. Prediction models were calculated by logistic regression. We compared the disease courses of our cohort with a validation cohort of 86 patients with cirrhosis. Twenty of 92 markers of inflammation correlated significantly with mortality within 180 days (q-values of 0.00-0.044), whereas we found no significant correlations with liver-related admissions. The logistic regression models yielded AUROCs of 0.73 to 0.79 for mortality and 0.61 to 0.73 for liver-related admissions, based on a variety of modalities (clinical variables, inflammatory markers, clinical scores, or combinations thereof). The models performed moderately well in the validation cohort and were better able to predict mortality than liver-related admissions. In conclusion, markers of inflammation can be used to predict 180-day mortality in patients with newly diagnosed cirrhosis. Prediction models for newly diagnosed cirrhotic patients need further validation before implementation in clinical practice.Trial registration: NCT04422223 (and NCT03443934 for the validation cohort), and Scientific Ethics Committee No.: H-19024348.

Multivariate analyses of immune markers reveal increases in plasma EN-RAGE in first-episode psychosis patients

Immune cells and cytokines are largely recognized as significant factors in the pathophysiology of neuropsychiatric disorders. The possible role of other blood cells such as leukocytes in events of acute psychosis is in contrast only emerging. To study blood-born markers in acute psychosis we here evaluated plasma proteins in drug-naive first-episode psychosis (FEP) patients and healthy controls using a multiplex proximity extension assay technique. We analyzed a panel of 92 immune markers and plasma samples from 60 FEP patients and 50 controls and evaluated the changes obtained using multivariate statistical methods followed by protein pathway analyses. Data showed that 11 proteins are significantly different between FEP patients and healthy controls We observed increases in pro-inflammatory proteins such as interleukin-6, oncostatin-M, and transforming growth factor-alpha in FEP patients compared with controls. Likewise, the extracellular newly identified RAGE-binding protein (EN-RAGE) that regulates the expression of various cytokines was also elevated in the plasma of FEP patients. The results indicate that neutrophil-derived EN-RAGE could play an important role during the early phase of acute psychosis by stimulating cytokines and the immune response targeting thereby likely also the brain vasculature.

RAGE deficiency ameliorates autoimmune hepatitis involving inhibition of IL-6 production via suppressing protein Arid5a in mice

Activation of T cells and pro-inflammatory cytokines are essential for human autoimmune hepatitis. RAGE is one of the receptors for the inflammatory alarm molecule high mobility group box 1 (HMGB1), and it is involved in autoimmune hepatitis. However, the molecular mechanism of RAGE in the context of autoimmune hepatitis remains elusive. This study aimed to identify the function and mechanism of RAGE in autoimmune hepatitis. The role and underlying mechanisms of RAGE signaling-driven immune inflammatory response in ConA-induced experimental hepatitis were examined using the RAGE-deficient mice. We found that the RAGE deficiency protected the mouse from liver inflammatory injury caused by the ConA challenge. mRNA expression of VCAM-1, IL-6, and TNF-α within the livers is markedly decreased in RAGE-deficient mice compared to wild-type mice. In parallel, RAGE deficiency leads to reduced levels of the serum pro-inflammatory cytokines IL-6 and TNF-α as compared with wild-type control mice. RAGE-deficient mice exhibit increased hepatic NK cells and decreased CD4+ T cells compared with wild-type control mice. Notably, in vivo blockade of IL-6 in wild-type mice significantly protected mice from ConA-induced hepatic injury. Furthermore, RAGE deficiency impaired IL-6 production and was associated with decreased expression of Arid5a in liver tissues, a half-life IL-6 mRNA regulator. RAGE signaling is important in regulating the development of autoimmune hepatitis. Immune regulation of RAGE may represent a novel therapeutic strategy to prevent immune-mediated liver injury.

Sterile inflammation in liver transplantation

Sterile inflammation is the immune response to damage-associated molecular patterns (DAMPs) released during cell death in the absence of foreign pathogens. In the setting of solid organ transplantation, ischemia-reperfusion injury results in mitochondria-mediated production of reactive oxygen and nitrogen species that are a major cause of uncontrolled cell death and release of various DAMPs from the graft tissue. When properly regulated, the immune response initiated by DAMP-sensing serves as means of damage control and is necessary for initiation of recovery pathways and re-establishment of homeostasis. In contrast, a dysregulated or overt sterile inflammatory response can inadvertently lead to further injury through recruitment of immune cells, innate immune cell activation, and sensitization of the adaptive immune system. In liver transplantation, sterile inflammation may manifest as early graft dysfunction, acute graft failure, or increased risk of immunosuppression-resistant rejection. Understanding the mechanisms of the development of sterile inflammation in the setting of liver transplantation is crucial for finding reliable biomarkers that predict graft function, and for development of therapeutic approaches to improve long-term transplant outcomes. Here, we discuss the recent advances that have been made to elucidate the early signs of sterile inflammation and extent of damage from it. We also discuss new therapeutics that may be effective in quelling the detrimental effects of sterile inflammation.

Does the Use of the "Proseek® Multiplex Inflammation I Panel" Demonstrate a Difference in Local and Systemic Immune Responses in Endometriosis Patients with or without Deep-Infiltrating Lesions?

Endometriotic lesions are able to infiltrate surrounding tissue. This is made possible partly by an altered local and systemic immune response that helps achieve neoangiogenesis, cell proliferation and immune escape. Deep-infiltrating endometriosis (DIE) differs from other subtypes through the invasion of its lesions over 5 mm into affected tissue. Despite the invasive nature of these lesions and the wider range of symptoms they can trigger, DIE is described as a stable disease. This elicits the need for a better understanding of the underlying pathogenesis. We used the "Proseek^® Multiplex Inflammation I Panel" in order to simultaneously detect 92 inflammatory proteins in plasma and peritoneal fluid (PF) of controls and patients with endometriosis, as well as in particular patients with DIE, in order to gain a better insight into the systemically and locally involved immune response. Extracellular newly identified receptor for advanced gycation end-products binding protein (EN-RAGE), C-C motif Chemokine ligand 23 (CCL23), Eukaryotic translation initiation factor 4-binding protein 1 (4E-BP1) and human glial cell-line derived neurotrophic factor (hGDNF) were significantly increased in plasma of endometriosis patients compared to controls, whereas Hepatocyte Growth factor (HGF) and TNF-related apoptosis inducing ligand (TRAIL) were decreased. In PF of endometriosis patients, we found Interleukin 18 (IL-18) to be decreased, yet Interleukin 8 (IL-8) and Interleukin 6 (IL-6) to be increased. TNF-related activation-induced cytokine (TRANCE) and C-C motif Chemokine ligand 11 (CCL11) were significantly decreased in plasma, whereas C-C motif Chemokine ligand 23 (CCL23), Stem Cell Factor (SCF) and C-X-C motif chemokine 5 (CXCL5) were significantly increased in PF of patients with DIE compared to endometriosis patients without DIE. Although DIE lesions are characterized by increased angiogenetic and pro-inflammatory properties, our current study seems to support the theory that the systemic immune system does not play a major role in the pathogenesis of these lesions.

Alarmins and Related Molecules in Elective Surgery

Surgery is associated with alterations of alarmins' and related molecules' levels. The aim of this study was to investigate which biomarkers are most involved in surgery. The studied group consisted of 58 patients with inguinal or umbilical hernia or cholecystolithiasis and 21 healthy controls for compa-rison. We also added seven acute patients with appendicitis, cholecystitis and incarcerated hernia. Serum concentrations of soluble receptor of advanced glycation end-products (sRAGE), extracellular newly identified receptor for advanced glycation end-products binding protein (EN-RAGE), calprotectin, high mobility group box 1 (HMGB1) and interleukin 6 (IL-6) were analysed by ELISA before and after surgery. Preoperative concentrations of calprotectin were significantly decreased while concentrations of sRAGE were significantly increased in patients compared to controls; the concentrations of EN-RAGE and HMGB1 did not differ significantly. IL-6 levels were undetectable in elective patients preoperatively and in controls. Postoperatively, there was a significant increase of EN-RAGE, calprotectin, HMGB1, and IL-6 and a significant decrease of sRAGE compared to preoperative levels. In acute patients, all tested molecules except for sRAGE were significantly increased preoperatively, and sRAGE was significantly decreased. In contrast, after surgery, we could observe a further increase in IL-6; the other biomarkers did not differ significantly. We can conclude that the concentrations of all tested biomarkers are significantly influenced by elective surgery. The postoperative levels of all tested molecules increase except for sRAGE, whose level is significantly decreased after surgery. In acute states, these molecules are already increased, and the influence of surgery is, apart from IL-6, insignificant.

Gastrodin ameliorates Concanavalin A-induced acute hepatitis via the IL6/JAK2/STAT3 pathway

AIMS

Gastrodin, the main active ingredient of Gastrodia elata Blume, has been shown to protect against many inflammatory diseases. Our study aimed to investigate the anti-inflammatory role of gastrodin in concanavalin A (ConA)-induced acute hepatitis in mice and to explore its precise mechanism.

METHODS

C57BL/6 mice were administered with gastrodin (50 or 100mg/kg) for 3 days prior to intravenous injection of ConA to induce acute autoimmune hepatitis (AIH). Serum aminotransferases levels and cytokine levels were measured. Liver tissue histology was conducted to assess the degree of liver injury. Splenocytes pretreated with gastrodin were stimulated with ConA to observe splenocyte proliferation.

RESULTS

Gastrodin greatly reduced the level of serum aminotransferases, inflammatory cytokine such as IL-6 and TNF-α and histopathological damage in ConA-induced hepatitis. Besides, gastrodin had an inhibitory effect on liver apoptosis, and autophagy. Furthermore, gastrodin inhibited the proliferation of splenocytes in vitro. The protein expression of p-JAK2 and p-STAT3 was markedly affected by gastrodin pretreatment.

CONCLUSIONS

The present study indicated that gastrodin pretreatment exerted protective effects against ConA-induced acute hepatitis, partly through the inhibition of the IL6/JAK2/STAT3 pathway. Further studies are recommended to determine the potential therapeutic role of gastrodin in acute AIH.

Reduced Circulating Soluble Receptor for Advanced Glycation End-products in Chronic Hepatitis B Are Associated with Hepatic Necroinflammation

The diagnosis and disease management of chronic hepatitis B (CHB) remain challenging due to the elusive assessment of disease severity. Recently, soluble receptor for advanced glycation end-products (sRAGE) has been implicated in the inflammatory-immune response initiated by liver injury. Nonetheless, its natural behavior and clinical importance in CHB remain elusive. One hundred and twenty CHB patients and forty healthy controls (HCs) were enrolled, and the serum sRAGE as well as RAGE expression in biopsy specimens from these subjects was analyzed, and correlation of sRAGE with clinical features as well as its potential predictive value for monitoring the CHB was also evaluated. Reduced serum sRAGE levels and decreased tissular RAGE expression were observed in CHB patients. sRAGE and RAGE were inversely correlated with gradually increased grades of hepatic necroinflammation as well as the routine indicator ALT. Furthermore, receiver operating characteristic (ROC) analysis showed that combination of ALT and sRAGE exerted better predictive power (area under the ROC curve (AUC) of 0.86) for hepatic necroinflammation than that of ALT (AUC of 0.82), sRAGE (AUC of 0.81), or sRAGE-to-ALT ratio (sRAGE/ALT) (AUC of 0.85) alone. More importantly, circulating sRAGE alone exerted valuable predictive power for hepatic moderate-to-severe necroinflammation in CHB patients but with normal ALT (AUC of 0.81) or minimally elevated ALT (AUC of 0.85). In conclusion, reduced serum sRAGE levels may imply an increased severity for necroinflammation, and it may serve as a potential alternative biomarker for monitoring hepatic necroinflammation in CHB.

RAGE against the Machine: Can Increasing Our Understanding of RAGE Help Us to Battle SARS-CoV-2 Infection in Pregnancy?

The receptor of advanced glycation end products (RAGE) is a receptor that is thought to be a key driver of inflammation in pregnancy, SARS-CoV-2, and also in the comorbidities that are known to aggravate these afflictions. In addition to this, vulnerable populations are particularly susceptible to the negative health outcomes when these afflictions are experienced in concert. RAGE binds a number of ligands produced by tissue damage and cellular stress, and its activation triggers the proinflammatory transcription factor Nuclear Factor Kappa B (NF-κB), with the subsequent generation of key proinflammatory cytokines. While this is important for fetal membrane weakening, RAGE is also activated at the end of pregnancy in the uterus, placenta, and cervix. The comorbidities of hypertension, cardiovascular disease, diabetes, and obesity are known to lead to poor pregnancy outcomes, and particularly in populations such as Native Hawaiians and Pacific Islanders. They have also been linked to RAGE activation when individuals are infected with SARS-CoV-2. Therefore, we propose that increasing our understanding of this receptor system will help us to understand how these various afflictions converge, how forms of RAGE could be used as a biomarker, and if its manipulation could be used to develop future therapeutic targets to help those at risk.

Serum Biomarkers for Autoimmune Hepatitis Type 1: the Case for CD48 and a Review of the Literature

In autoimmune hepatitis (AIH), the persisting inflammation contributes to fibrosis progression, for which conventional biochemical markers manifest relatively unsatisfactory prediction. Herein, we assessed the value of serum CD48 (sCD48) as an indicator for inflammation and fibrosis in AIH type 1. The levels of sCD48 were detected first in an exploratory cohort using ELISA. In this cohort, compared with healthy controls (4.90 ng/mL, P < 0.0001), primary biliary cholangitis (7.32 ng/mL, P < 0.0001), and non-alcoholic fatty liver disease (7.76 ng/mL, P < 0.0001), sCD48 levels were elevated in AIH (12.81 ng/mL) and correlated with histological inflammation and fibrosis. Further using multivariate logistic regression analysis, sCD48 was identified as an independent predictor for both significant inflammation (G3-4) and advanced fibrosis (S3-4). Two predictive scores, based on sCD48, were constructed for diagnosing significant inflammation and advanced fibrosis (sCD48-AIH-SI and sCD48-AIH-AF, respectively). Using these data as a premise, predictive abilities were subsequently evaluated and verified in a validation cohort. In the exploratory cohort, the area under the receiver operating characteristic curve of sCD48 and sCD48-AIH-SI, for significant inflammation, were 0.748 and 0.813, respectively. Besides, during treatment follow-up, sCD48 levels gradually decreased from immunosuppression initiation to re-evaluation biopsy, in parallel with aspartate transaminase, total sera IgG, and fibrosis-4 score. For AIH patients in a re-evaluation biopsy cohort, sCD48 could predict significant fibrosis (S2-4). Further using immunohistochemistry, hepatic CD48 expression was elevated in AIH patients and decreased after treatment. In conclusion, sCD48 and sCD48-based predictive scores predict histological inflammation and fibrosis in AIH-1. Detecting sCD48 might help in the clinical management of AIH.

Targeting Scavenger Receptors in Inflammatory Disorders and Oxidative Stress

Oxidative stress and inflammation cannot be considered as diseases themselves; however, they are major risk factors for the development and progression of the pathogenesis underlying many illnesses, such as cancer, neurological disorders (including Alzheimer's disease and Parkinson's disease), autoimmune and metabolic disorders, etc. According to the results obtained from extensive studies, oxidative stress-induced biomolecules, such as advanced oxidation protein products, advanced glycation end products, and advanced lipoxidation end products, are critical for an accelerated level of inflammation and oxidative stress-induced cellular damage, as reflected in their strong affinity to a wide range of scavenger receptors. Based on the limitations of antioxidative and anti-inflammatory molecules in practical applications, targeting such interactions between harmful molecules and their cellular receptors/signaling with advances in gene engineering technology, such as CRISPR or TALEN, may prove to be a safe and effective alternative. In this review, we summarize the findings of recent studies focused on the deletion of scavenger receptors under oxidative stress as a development in the therapeutic approaches against the diseases linked to inflammation and the contribution of advanced glycation end products (AGEs), advanced lipid peroxidation products (ALEs), and advanced oxidation protein products (AOPPs).

Increased Production of Interleukin-10 and Tumor Necrosis Factor-Alpha in Stimulated Peripheral Blood Mononuclear Cells after Inhibition of S100A12

Sepsis may induce immunosuppression and result in death. S100A12 can bind to the receptor for advanced glycation end-products (RAGE) and Toll-like receptor (TLR)4 following induction of various inflammatory responses. It is unclear whether S100A12 significantly influences the immune system, which may be associated with sepsis-related mortality. We measured plasma S100A12 levels and cytokine responses (mean ± standard error mean) of lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) after S100A12 inhibition in healthy controls and patients with sepsis on days one and seven. Day one plasma soluble RAGE (sRAGE) and S100A12 levels in patients with sepsis were significantly higher than those in controls (2481.3 ± 295.0 vs. 1273.0 ± 108.2 pg/mL, p < 0.001; 530.3 ± 18.2 vs. 310.1 ± 28.1 pg/mL, p < 0.001, respectively). Day seven plasma S100A12 levels in non-survivors were significantly higher than those in survivors (593.1 ± 12.7 vs. 499.3 ± 23.8 pg/mL, p = 0.002, respectively). In survivors, plasma sRAGE levels were significantly decreased after 6 days (2297.3 ± 320.3 vs. 1530.1 ± 219.1 pg/mL, p = 0.009, respectively), but not in non-survivors. Inhibiting S100A12 increased the production of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in stimulated PBMCs for both controls and patients. Therefore, S100A12 plays an important role in sepsis pathogenesis. S100A12 may competitively bind to TLR4 and RAGE, resulting in decreased IL-10 and TNF-α production.

Serum Levels of Soluble Receptor for Advanced Glycation End Products Are Reduced in Euthyroid Children with Newly Diagnosed Hashimoto's Thyroiditis: A Pilot Study

OBJECTIVE

No data are available on advanced glycation end products (AGEs) and their soluble receptor (sRAGE) in pediatric patients with Hashimoto's thyroiditis (HT). The present study was aimed to simultaneously evaluate serum levels of sRAGE, AGEs, and advanced oxidation protein products (AOPPs) and investigate the relationships between these oxidative stress markers and clinical and biochemical parameters of thyroid function in euthyroid children with HT.

DESIGN

This is a case-control study carried out in a single university hospital center.

METHODS

We enrolled 19 newly diagnosed euthyroid HT pediatric patients (3 M, 16 F; median age 12.44 years, range 6.54-15.81 years) and 16 age-, sex-, and BMI-matched healthy controls (5 M, 11 F; median age 12.83 years, range 5.68-15.07 years). None was on levothyroxine treatment. The exclusion criteria were autoimmune, inflammatory, and infection comorbidities. Patients did not differ significantly from controls with regard to lipid or for anthropometric parameters.

RESULTS

sRAGE levels were significantly lower in HT patients (median 414.30 pg/mL, range 307.30-850.30 pg/mL) than in controls (561.30, 273.20-1121.60 pg/mL; p = 0.034). No differences emerged between patients and controls with regard to serum AGEs (124.25 AU/g prot, 71.98-186.72 vs. 133.90, 94.06-200.78 AU/g prot, p = 0.707) and AOPPs (1.13 nmol/mL, 0.62-1.83 vs. 1.17, 0.76-1.42 nmol/mL, p = 0.545).

CONCLUSIONS

sRAGE levels were decreased in euthyroid children/adolescents at the onset of HT, suggesting that autoimmunity per se seems to play an important role in such a reduction of sRAGE, irrespective of any functional alteration. Children and adolescents suffering from HT may exhibit increased susceptibility to oxidative damage, even when in euthyroid status.