Serum YKL-40: a potential biomarker for psoriasis or endothelial dysfunction in psoriasis?

Significance of chitinase-3-like protein 1 in the pathogenesis of inflammatory diseases and cancer

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly upregulated by various inflammatory and immunological diseases, including several cancers, Alzheimer's disease, and atherosclerosis. Several studies have shown that CHI3L1 can be considered as a marker of disease diagnosis, prognosis, disease activity, and severity. In addition, the proinflammatory action of CHI3L1 may be mediated via responses to various proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 may contribute to a vast array of inflammatory diseases. However, its pathophysiological and pharmacological roles in the development of inflammatory diseases remain unclear. In this article, we review recent findings regarding the roles of CHI3L1 in the development of inflammatory diseases and suggest therapeutic approaches that target CHI3L1.

The Impact of Treatment with IL-17/IL-23 Inhibitors on Subclinical Atherosclerosis in Patients with Plaque Psoriasis and/or Psoriatic Arthritis: A Systematic Review

Accumulating evidence considers psoriasis a systemic inflammatory disorder that is associated with comorbidities such as psoriatic arthritis, cardiovascular disease, and metabolic syndrome. Although the precise pathogenetic links between psoriasis and atherosclerosis warrants further investigation, it is believed that chronic systemic inflammation along with the T helper (Th)-1 and Th17 polarization are associated with endothelial dysfunction and subsequent acceleration of atherosclerosis. Considering the above, several studies have evaluated if optimal control of the inflammation in psoriasis by inhibiting interleukins targeting the Interleukin (IL)-23/Th17 axis could subsequently reduce the atherosclerotic process during anti-psoriatic treatment by using a variety of surrogate markers of subclinical atherosclerosis. This systematic review summarizes current knowledge on the pathogenetic mechanisms and diagnostic evaluation of atherosclerosis in the context of psoriasis and provides a systematic review of the literature on the impact of treatment with biologics targeting the IL-23/Th17 axis on subclinical atherosclerosis in patients with plaque psoriasis and/or psoriatic arthritis.

Psoriasis a Cause of Cardiovascular Diseases: A Review Article

Psoriasis is a severe, chronic inflammatory disease characterized by erythematous plaques across the extensor surfaces of the skin. Psoriasis has been linked to a higher threat of vascular events like myocardial infarction and stroke. Other associated cardiovascular disorders in the case of psoriasis include building up atherosclerosis, non-ischemic dilated cardiomyopathy, and psoriatic arthritis. Individuals can use International Classification of Diseases (ICD-9) codes to identify cardiovascular disease/comorbidities and related risk factors. The relation between pathophysiology and mechanism of psoriasis and the building up of fat and cholesterol in or on the arterial walls makes the association between psoriasis and cardiovascular diseases more obvious. There is very little research on the adverse effect of systemic treatment of psoriasis on cardiovascular events. Treatment of psoriasis includes mainly biologics and systemic therapy, including methotrexate as a first-line drug. An indirect relation between psoriasis-arthritis and cardiovascular diseases is being noted. Various risk factors contribute to psoriasis and are associated with cardiovascular disease, including smoking, hypertension, and obesity. Personal management to decrease the threat to the cardiovascular system in case of psoriasis can be achieved by changing lifestyle, which includes exercising and avoiding smoking. The criteria for identifying metabolic syndrome are discussed in this review article. Figure Rating Scales (FRS) were used for studying the risk prediction of various cardiovascular diseases. Individuals with atherosclerosis, hypertension and diabetes mellitus type-2 are at a higher risk of developing cardiovascular events and multiple chronic conditions in the case of psoriasis; hence they are part of the population at risk.

Oxidative Stress Induced by High Salt Diet—Possible Implications for Development and Clinical Manifestation of Cutaneous Inflammation and Endothelial Dysfunction in Psoriasis vulgaris

Although oxidative stress is recognized as an important effector mechanism of the immune system, uncontrolled formation of reactive oxygen and nitrogen species promotes excessive tissue damage and leads to disease development. In view of this, increased dietary salt intake has been found to damage redox systems in the vessel wall, resulting in endothelial dysfunction associated with NO uncoupling, inflammation, vascular wall remodeling and, eventually, atherosclerosis. Several studies have reported increased systemic oxidative stress accompanied by reduced antioxidant capacity following a high salt diet. In addition, vigorous ionic effects on the immune mechanisms, such as (trans)differentiation of T lymphocytes are emerging, which together with the evidence of NaCl accumulation in certain tissues warrants a re-examination of the data derived from in vitro research, in which the ionic influence was excluded. Psoriasis vulgaris (PV), as a primarily Th17-driven inflammatory skin disease with proven inflammation-induced accumulation of sodium chloride in the skin, merits our interest in the role of oxidative stress in the pathogenesis of PV, as well as in the possible beneficial effects that could be achieved through modulation of dietary salt intake and antioxidant supplementation.

Defining imaging sub-phenotypes of psoriatic arthritis: integrative analysis of imaging data and gene expression in a PsA patient cohort

OBJECTIVES

To define imaging sub-phenotypes in patients with PsA; determine their association with whole blood gene expression and identify biological pathways characterizing the sub-phenotypes.

METHODS

Fifty-five patients with PsA ready to initiate treatment for active disease were prospectively recruited. We performed musculoskeletal ultrasound assessment of the extent of inflammation in the following domains: synovitis, peritenonitis, tenosynovitis and enthesitis. Peripheral whole blood was profiled with RNAseq, and gene expression data were obtained. First, unsupervised cluster analysis was performed to define imaging sub-phenotypes that reflected the predominant tissue involved. Subsequently, principal component analysis was used to determine the association between imaging-defined sub-phenotypes and peripheral blood gene expression profile. Pathway enrichment analysis was performed to identify underlying mechanisms that characterize individual sub-phenotypes.

RESULTS

Cluster analysis revealed three imaging sub-phenotypes: (i) synovitis predominant [n = 31 (56%)]; (ii) enthesitis predominant [n = 13 (24%)]; (iii) peritenonitis predominant [n = 11 (20%)]. The peritenonitis-predominant sub-phenotype had the most severe clinical joint involvement, whereas the enthesitis-predominant sub-phenotype had the highest tender entheseal count. Unsupervised clustering of gene expression data identified three sub-phenotypes that partially overlapped with the imaging sub-phenotypes suggesting biological and clinical relevance of these sub-phenotypes. We therefore characterized enriched differential pathways, which included: immune system (innate system, B cells and neutrophil degranulation), complement system, platelet activation and coagulation function.

CONCLUSIONS

We identified three sub-phenotypes based on the predominant tissue involved in patients with active PsA. Distinct biological pathways may underlie these imaging sub-phenotypes seen in PsA, suggesting their biological and clinical importance.

Biomarkers of subclinical atherosclerosis in patients with psoriasis

Psoriasis is linked with increased risk of cardiovascular disease (CVD) that is underestimated by traditional risk stratification. We conducted a large-scale plasma proteomic analysis by use of a proximity extension assay in 85 patients with a history of moderate-to-severe psoriasis with or without established atherosclerotic CVD. Differentially expressed proteins associated with CVD were correlated with subclinical atherosclerotic markers including vascular inflammation determined by 18F-fluorodeoxyglucose positron emission tomography/computed tomography, carotid intima-media thickness (CIMT), carotid artery plaques, and coronary artery calcium score (CCS) in the patients without CVD and statin treatment. We also examined the association between the neutrophil-to-lymphocyte ratio (NLR) and subclinical atherosclerosis. In unadjusted analyses, growth differentiation factor-15 (GDF-15) levels and NLR were increased, while tumor necrosis factor (TNF)-related activation-inducing ligand (TRANCE) and TNF-related apoptosis-induced ligand (TRAIL) levels were decreased in patients with established CVD compared to those without CVD. Among patients with psoriasis without CVD and statin treatment, GDF-15 levels were negatively associated with vascular inflammation in the ascending aorta and entire aorta, and positively associated with CIMT and CCS. NLR was positively associated with vascular inflammation in the carotid arteries. Our data suggest that circulating GDF-15 levels and NLR might serve as biomarkers of subclinical atherosclerosis in patients with psoriasis.

Molecular Pathogenesis of Psoriasis and Biomarkers Reflecting Disease Activity

Psoriasis is a chronic inflammatory skin disease induced by multifactorial causes and is characterized by bothersome, scaly reddish plaques, especially on frequently chafed body parts, such as extensor sites of the extremities. The latest advances in molecular-targeted therapies using biologics or small-molecule inhibitors help to sufficiently treat even the most severe psoriatic symptoms and the extra cutaneous comorbidities of psoriatic arthritis. The excellent clinical effects of these therapies provide a deeper understanding of the impaired quality of life caused by this disease and the detailed molecular mechanism in which the interleukin (IL)-23/IL-17 axis plays an essential role. To establish standardized therapeutic strategies, biomarkers that define deep remission are indispensable. Several molecules, such as cytokines, chemokines, antimicrobial peptides, and proteinase inhibitors, have been recognized as potent biomarker candidates. In particular, blood protein markers that are repeatedly measurable can be extremely useful in daily clinical practice. Herein, we summarize the molecular mechanism of psoriasis, and we describe the functions and induction mechanisms of these biomarker candidates.

Relationship between Serum YKL-40 Level and Forearm Arterial Patency after Repair

BACKGROUND

The study aimed to assess the effects of serum YKL-40 level on patency at the repair site in patients who underwent arterial repair at the level of the forearm.

METHODS

The study included 58 subjects, including 29 patients (aged 18-50 years) who had ulnar or radial artery injury secondary to cut injury to wrist between June 2015 and November 2019 and no comorbid disease and 29 age- and sex-matched healthy controls. The vascular patency was assessed using Doppler sonography in patients who underwent arterial repair at the level of the forearm. The patients were defined as flow failure if the blood flow was ≤50%, and sufficient flow if the blood flow was >50% of those in the synonymous artery on the intact extremity. The YKL-40 level differences in the patient and control groups were compared to those in the sufficient and insufficient flow groups.

RESULTS

The patients were stratified into 2 groups based on the presence of sufficient flow. The mean YKL level was 11.96 ± 8.87 in the sufficient flow groups, whereas it was 32.22 ± 15.43 in the insufficient flow groups (p= 0.038). Besides, it was found that each unit of increase in the YKL-40 level increased the likelihood of having flow failure by 1.128.

CONCLUSION

Based on our results, it was observed that over-expression of the YKL-40 level has adverse effects on patency following arterial repair.

Serum YKL-40 and IL 17 in Psoriasis: Reliability as prognostic markers for disease severity and responsiveness to treatment

YKL-40, a mammalian chitinase 3- like protein that was associated with multiple inflammatory and immune diseases. Previous studies have suggested a role for YKL-40 in psoriasis based on its significantly higher levels in the serum of psoriatic patient compared with healthy controls. The aim of this study was to determine the correlation between serum YKL-40, psoriasis severity using PASI score and serum levels of IL-17 before and after narrow-band UVB therapy. 28 patients with moderate to severe plaque psoriasis, as defined by PASI scores, were enrolled in this prospective cohort study. All cases received NB-UVB phototherapy twice weekly for 3 months. Serum YKL-40 and IL-17 levels were evaluated before and after 3 months of treatment. Clinical photographs were taken both at baseline and after 3 months. There was a statistical positive correlation between serum levels of YKL-40 and serum IL-17 levels as well as PASI score in patients with moderate to severe psoriasis before and after treatment. YKL-40 represents a reliable marker for psoriasis severity estimated by PASI and positively correlated with IL 17 as an inflammatory marker in psoriasis.

Assessment of seminal YKL-40 in infertile men with varicocele

Several studies attempted to explain the negative impact of varicocele on spermatogenesis and fertilisation processes. YKL-40 is a novel glycoprotein biomarker that had been associated with several diseases. This quasi-interventional study aimed to assess the seminal levels of YKL-40 in infertile men with varicocele before and after varicocelectomy. Overall, 50 men were included in this study divided into 20 healthy fertile men and 30 infertile oligoasthenoteratozoospermic (OAT) men with varicocele that underwent varicocelectomy. All participants were subjected to history taking, clinical examination and scrotal Doppler. Also, semen analysis and seminal YKL-40 assessment were carried out in the start and 6 months after varicocele surgical repair. The results showed a significant increase in the mean seminal YKL-40 level in infertile OAT men with varicocele compared with the healthy fertile men. Six months post-varicocelectomy, the mean seminal KYL-40 level exhibited significant decreases correlated with improved sperm parameters. Overall, seminal levels of YKL-40 showed significant negative correlations with sperm concentration, total sperm motility and sperm normal morphology. It could be concluded that seminal YKL-40 is elevated in infertile OAT men with varicocele where varicocelectomy induces decreased seminal YKL-40 levels correlated with improved semen parameters.

Plasm YKL-40 Levels Are Associated with Hypertension in Patients with Obstructive Sleep Apnea

Background

Obstructive sleep apnea (OSA) is a common disease. It can cause many serious complications. OSA may increase the risk of hypertension. However, the exact mechanism of OSA causing hypertension is not fully understood. YKL-40/chitinase-3-like protein-1 plays an important role in vascular injury, repair, and generation. We sought to explore the role of YKL-40 in endothelial dysfunction and hypertension in OSA patients.

Methods

All subjects were examined by polysomnography (PSG) and the expression of YKL-40 in the plasm of the subjects was measured by luminex. Carotid intima-media thickness (CIMT) was measured by B-mode ultrasound.

Results

According to the conditions of OSA and hypertension, we studied four groups of 157 subjects, including OSA group (OSA, N=77), OSA with hypertension group (OSA+HT, N=37), hypertension group (HT, N=20), and healthly group (Con, N=23). YKL-40 levels were significantly elevated in OSA, OSA+HT, and HT group compared to Con groups. We used the ROC to predict the sensitivity and specificity of YKL-40 in all OSA patients or all hyperpietic patients. For OSA patients, the AUC of YKL-40 is 0.807 (95% confidence interval 0.725–0.888; p<0.01). For hyperpietic patients, the AUC of YKL-40 is 0.656 (95% confidence interval 0.570–0.742, p=0.01). There was a significant correlation between the parameter of OSA and hypertension and YKL-40 (P<0.05) and a significant correlation between Max-CIMT and YKL-40 (P<0.05).

Conclusion

Elevated circulating levels of YKL-40 are associated with hypertension in OSA patients. The specificity of YKL-40 suggests that it could be a potential biomarker for OSA and hypertension.

Psoriasis as a cardiovascular risk factor: updates and algorithmic approach

Although psoriasis is predominantly a chronic inflammatory skin disorder, it has been known to be associated with cardiovascular disease. Patients with psoriasis, particularly with moderate to severe forms, present an increased rate of cardiovascular mortality, myocardial infarction and stroke. However the pathophysiology of the relationship between psoriasis and cardiovascular risk and comorbidities has not yet completely known. Chronic inflammation may be considered a solid link between psoriasis and related cardiovascular events. Several cytokines and inflammatory cells play a pivotal role in the development of psoriatic lesions, resulting in angiogenesis and endothelial dysfunction. Furthermore, the imbalance between oxidative stress and antioxidant mechanisms in psoriatic patients may contribute to explain the pathogenesis of increased reactive oxygen species and the formation of atherosclerotic plaque. Other mechanistic pathways which may be involved in this relationship include cardiovascular effects of medications, a common genetic background and a higher prevalence of cardiovascular risk factors, which are often under-diagnosed and under-treated in psoriatic patients. Indeed, the early detection of specific markers of cardiovascular impairment, such as N-terminal pro B-type natriuretic peptide, homocysteine and YKL-40, may enable psoriatic patients at higher cardiovascular risk to be identified as soon as possible. This review examines the increased cardiovascular risk profile and high prevalence of cardiovascular disease associated with psoriasis, focusing on pathogenic links between psoriasis and atherosclerosis, serological markers of cardiovascular involvement and the implications of antipsoriatic therapies on cardiovascular risk and proposes a flow chart, that every dermatologist should follow to screen psoriatic patients.

Endothelial dysfunction marker YKL-40 is elevated in male patients with idiopathic infertility

Metabolic syndrome represents a collection of cardiovascular risk factors, including overweight, hypertension, dyslipidemia and impaired glucose metabolism, with insulin resistance. In recent years, the potential relationship between metabolic syndrome and male factor infertility has been studied. As endothelial dysfunction is the hallmark of metabolic syndrome, the aim of this work was to assess serum levels of YKL-40 as a marker of endothelial dysfunction in male patients with idiopathic infertility. The study revealed that YKL-40 levels were elevated in patients than controls denoting that endothelial dysfunction might play a role in the pathogenesis of idiopathic infertility and that YKL-40 as a marker of endothelial dysfunction could be a useful marker of idiopathic infertility.

Biomarkers and personalized medicine: current status and further perspectives with special focus on dermatology

Biomarkers are of increasingly high importance in medicine, particularly in the realm of 'personalized medicine'. They are valuable for predicting prognosis and dose selection. Moreover, they may be helpful in detecting therapeutic and adverse responses and in patient stratification based on efficacy or safety prediction. Thus, biomarkers are essential tools for the selection of appropriate patients for treatment with certain drugs to and enable personalized medicine, that is 'providing the right treatment to the right patient, at the right dose at the right time'. Currently, there are six drugs approved for dermatological indications with recommended or mandatory biomarker testing. Most of them are used to treat melanoma and human immunodeficiency virus infection. In contrast to the few fully validated biomarkers, many exploratory biomarkers and biomarker candidates have potential applications. Prognostic biomarkers are of particular significance for malignant conditions. Similarly, diagnostic biomarkers are important in autoimmune diseases. Disease severity biomarkers are helpful tools in the treatment for inflammatory skin diseases. Identification, qualification and implementation of the different kinds of biomarkers are challenging and frequently necessitate collaborative efforts. This is particularly true for stratification biomarkers that require a companion diagnostic marker that is co-developed with a certain drug. In this article general definitions and requirements for biomarkers as well as for the impact of biomarkers in dermatology are reviewed and opportunities and challenges are discussed.

Atherosclerosis is exacerbated by chitinase-3-like-1 in amyloid precursor protein transgenic mice

Although the important role of amyloid precursor protein (APP) in vascular diseases associated with Alzheimer's disease (AD) has been demonstrated, the underlying molecular mechanisms and physiological consequences are unclear. We aimed to evaluate vascular inflammation and atherosclerosis in Swedish mutant of human APP transgenic (APPsw-Tg) and ApoE^-/-/APPsw-Tg mice. We also aimed to explore the mechanisms underlying any changes observed in these mice compared with non-Tg controls. Methods: The transgenic and non-Tg mouse strains were subjected to partial ligation of the left carotid artery to induce atherosclerotic changes, which were measured using histological approaches, immunohistochemistry, quantitative polymerase chain reaction, and gene expression microarrays. Results: Our results showed increased vascular inflammation, arterial wall thickness, and atherosclerosis in APPsw-Tg and ApoE^-/-/APPsw-Tg mice. We further found that the expression of chitinase-3-like-1 (Chi3l1) is increased in the APPsw-Tg mouse artery and Chi3l1 mediates endothelial cell (EC) inflammation and vascular smooth muscle cell (VSMC) activation, which in turn exacerbates atherosclerosis. In addition, using two publicly available microarray datasets from the dorsolateral prefrontal cortex of people with AD and unaffected controls as well as inflamed human umbilical vein endothelial cells, we found that Chi3l1 and associated inflammatory gene were significantly associated with AD, evaluated by co-expression network analysis and functional annotation. Knockdown of Chi3l1 in the arterial endothelium in vivo suppressed the development of atherosclerosis. We also show that microRNA 342-3p (miR-342-3p) inhibits EC inflammation and VSMC activation through directly targeting Chi3l1, and that APPsw increased Chi3l1 expression by reducing miR-342-3p expression in the arterial endothelium, promoting atherosclerosis. Conclusion: Our findings suggest that targeting Chi3l1 might provide new diagnostic and therapeutic strategies for vascular diseases in patients with AD.

Chitinase-3-Like Protein 1 (YKL-40) Is a New Biomarker of Inflammation in Psoriasis

Purpose

The evaluation of new inflammatory biomarkers in psoriasis could determine therapeutic decisions. Chitinase-3-like protein 1 (YKL-40) plays a role in inflammation. The study was undertaken to check whether YKL-40 is a reliable biomarker of inflammation in psoriasis.

Materials and Methods

55 psoriatic patients were enrolled, including 21 men and 34 women, aged from 18 to 88 years. The PASI and body surface area were calculated for all patients. Blood samples were taken to evaluate serum concentration of YKL-40, as well as other inflammatory parameters, including CRP, ESR, white blood cell count, and neutrophil count. The measurements of YKL-40 level were performed by enzyme-linked immunosorbent assay (ELISA).

Results

YKL-40 serum concentration was significantly higher in psoriatic patients than in the control group. No correlations were found between YKL-40 levels and other clinical or laboratory parameters. Serum YKL-40 level was elevated in 81.8% patients, whereas CRP and WBC in 20% and 7.3% of patients, respectively.

Conclusions

YKL-40 could be considered as a useful biomarker of inflammation in psoriasis and is more sensitive than CRP or WBC. Increased YKL-40 may indicate psoriatic patients with a higher level of systemic inflammation, which may determine disease management.

Serum YKL-40 as a potential biomarker of inflammation in psoriasis

OBJECTIVE

YKL-40 is an inflammatory glycoprotein associated with atherosclerosis, cardiovascular disease, diabetes or metabolic syndrome which are common comorbidities in psoriasis. The aim of the study was to assess serum YKL-40 level in psoriasis and elucidate possible associations with disease activity, inflammatory or metabolic parameters and treatment.

METHODS

A total of 37 individuals with active plaque-type psoriasis and 15 healthy controls were enrolled. Blood samples were collected before and after 2 weeks of therapy. Serum YKL-40 concentrations were evaluated by enzyme-linked immunosorbent assay (ELISA). The results were correlated with Psoriasis Area and Severity Index (PASI), body mass index (BMI), inflammatory and biochemical markers, lipid profile and topical therapy.

RESULTS

Median YKL-40 serum levels were significantly increased in psoriatic patients in comparison to the controls (p < .0001). No significant correlations between investigated protein and metabolic parameters as BMI (p = .19), glucose (p = .32) nor lipids levels were found. Significant positive relation with CRP (p = .003) or alanine aminotransferase (p = .04) and no correlation with PASI (p = .2) were noted. Serum YKL-40 level remained unchanged (p = .5) after topical treatment, despite clinical improvement.

CONCLUSIONS

YKL-40 might be a biomarker of psoriasis and inflammation in psoriatic patients, but not a reliable indicator of metabolic conditions, severity of psoriasis nor efficacy of the treatment.

Clinical significance of serum YKL-40 in Behçet disease

BACKGROUND

Serum YKL-40 is an inflammatory biomarker of endothelial dysfunction and may play a role in the inflammatory process of Behçet disease (BD).

OBJECTIVES

Serum YKL-40 levels were evaluated in patients with BD in order to identify associations with other inflammatory cytokines and establish laboratory parameters. Serum YKL-40 levels were also compared with BD clinical features and disease activity.

METHODS

In total, 112 patients with BD and 45 age- and sex-matched healthy volunteers were included. Disease activity was assessed with BD Current Activity Form score and Electronic Medical Record-based Activity Index (EMRAI) score.

RESULTS

Serum YKL-40 levels were significantly higher in patients with BD (median 41·88, range 12·52-171·30 ng mL(-1) ) than in healthy volunteers (median 20·92, range 5·01-64·20 ng mL(-1) ; P < 0·01). The cut-off value for YKL-40 (30·005 ng mL(-1) ) was determined from the receiver operating characteristic curve. EMRAI scores and the proportion of patients in the active phase of BD presenting with two or more major criteria were significantly higher in patients with elevated YKL-40 levels (P = 0·04 and P = 0·04, respectively). A statistically significant elevation in YKL-40 levels was observed in patients with active BD compared with patients with inactive BD (P = 0·05). Serum YKL-40 values were positively correlated with interleukin-6 and EMRAI scores (both P = 0·04), indicating that serum YKL-40 levels are increased in patients with BD and positively correlate with disease activity.

CONCLUSIONS

YKL-40 may play a role in the pathophysiology of BD and provide a useful marker for monitoring patients with BD.

Psoriasis, non-alcoholic fatty liver disease, and cardiovascular disease: Three different diseases on a unique background

Psoriasis is a chronic inflammatory immune-mediated skin disease, frequently associated with systemic comorbidities. According to recent data, patients with psoriasis show a greater prevalence of metabolic syndrome, which confers a higher cardiovascular risk. The link between these pathological conditions appears to be a chronic low-grade inflammatory status. The aim of this review is to focus on the multiple epidemiological and physio-pathogenetic aspects linking non-alcoholic fatty liver disease, psoriasis, and cardiovascular disease.

YKL-40 level in gingival crevicular fluid from patients with periodontitis and type 2 diabetes

OBJECTIVE

YKL-40 is a chitin-binding glycoprotein, the level of which increases in inflammatory diseases, diabetes mellitus (DM), cardiovascular diseases, and tumors. Gingival crevicular fluid (GCF) contains many proteins and markers of periodontitis. The purpose of this study was to investigate YKL-40 level in GCF from patients with periodontitis and DM and the association between YKL-40 level and chronic periodontitis (CP) or DM.

SUBJECTS AND METHODS

The subjects were 121 patients with DM, CP, DM and periodontitis (DM-P), and healthy subjects (H). GCF was collected using paper strips after the sites for GCF collection were clinically evaluated for probing depth (PD), gingival index (GI), and bleeding on probing (BOP). YKL-40 in GCF was identified by Western blotting, and its level was determined by ELISA.

RESULTS

YKL-40 was contained in GCF samples from H, DM, CP, and DM-P sites, and its levels (amount and concentration) in CP and DM-P were significantly higher than those in H and DM. GCF YKL-40 level significantly correlated with PD and GI, and its level in BOP-positive sites was significantly higher than that in BOP-negative ones.

CONCLUSIONS

GCF YKL-40 level was elevated in periodontitis, but not DM. YKL-40 in GCF may be an inflammatory marker for periodontitis.