CHI3L1 polymorphisms associate with asthma in a Taiwanese population

The role of the Chitinase 3-Like 1 (CHI3L1) genes in the preeclampsia pathophysiology

OBJECTIVE

The aim of this study was to investigate the relationship between Chitinase 3-Like 1 gene polymorphisms and the occurrence of preeclampsia in a selected cohort of pregnant women.

METHODS

A total of 75 pregnant women participated in the study, 35 of whom were diagnosed with preeclampsia, while 40 served as healthy controls. The preeclamptic group was subdivided based on severity. Real-time polymerase chain reaction was employed to analyze the serum samples for variations in Chitinase 3-Like 1 gene polymorphisms.

RESULTS

The rs880633 polymorphism was found to be significantly more frequent in the control group (80%) compared with the overall preeclamptic group (60%) (p<0.05). In the severity-based subgroups, rs880633 appeared in 57.1% of non-severe and 61.9% of severe preeclamptics. Contrarily, the heterozygous form of rs7515776 polymorphism showed a significantly higher prevalence in the preeclamptic cohort (p<0.05), without distinctions in severity subgroups.

CONCLUSION

The study suggests that the rs880633 polymorphism may serve a protective role against the development of preeclampsia, whereas the rs7515776 polymorphism may be associated with an elevated risk. Further research is warranted to elucidate the clinical implications of these findings.

The potential roles and mechanisms of Chitinase-3-like-1 in the pathogenesis of type 2-biased airway diseases

The immune modulation in the epithelium is a protective feature of the epithelial function in the mucosal airways. Dysfunction of the epithelium can lead to chronic allergic airway inflammatory diseases, such as chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. Chitinase-3-like-1 (CHI3L1) is a key modulator in the epithelium against irritants, pathogens, and allergens and is involved in cancers, autoimmune diseases, neurological disorders, and other chronic diseases. Induction of epithelial cell-derived CHI3L1 is also confirmed to be implicated in the pathogenesis of Th2-related airway diseases like CRSwNP, AR, and allergic asthma, triggering a cascade of subsequent inflammatory reactions leading to the disease development. The techniques that block the biological function of CHI3L1 include small interfering RNA, neutralizing antibodies, and microRNAs and these methods proved to be successful in preclinical and clinical investigation in cancers, autoimmune diseases, asthma, and chronic obstructive pulmonary disease. Therefore, treatment with CHI3L1-blocking methods could open up therapeutic options for allergic airway diseases. This review article discusses the role of epithelial cell-derived CHI3L1 in the development of CRSwNP, AR, and allergic asthma and examines the use of CHI3L1 as a potential therapeutic agent for allergic airway diseases.

Functional variants of the chitinase 3-like 1 gene are associated with clinicopathologic outcomes and progression of prostate cancer

Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in advanced stages of several cancer types, including prostate cancer (PCa). Impacts of genetic variants of CHI3L1 on PCa development have not yet been investigated. The most common well-studied genetic variations are single-nucleotide polymorphisms (SNPs). Therefore, the objective of this study was to explore associations of CHI3L1 SNPs with both the susceptibility to PCa and its clinicopathological development. Three promoter SNPs, rs6691378 (-1371, G>A), rs10399805 (-247, G>A) and rs4950928 (-131, C>G), and one non-synonymous SNP, rs880633 (+2950, T>C), were analysed using a TaqMan allelic discrimination assay for genotyping in a cohort of 701 PCa patients and 701 healthy controls. Results indicated that there were no significant associations of PCa susceptibility with these four CHI3L1 SNPs. However, among elderly PCa patients (aged >65 years), it was observed that polymorphic variants (GA + AA) of CHI3L1 rs6691378 and 10399805 were significantly linked to reduced risks of several clinicopathological characteristics, including a high Gleason grade, advanced pathologic T stage and tumour cell invasion. Moreover, analyses of The Cancer Genome Atlas database revealed that CHI3L1 expression levels were elevated in PCa tissues compared with normal tissues. Interestingly, higher CHI3L1 expression levels were found to be associated with longer progression-free survival rates in PCa patients. Our findings indicated that levels of CHI3L1 may influence the progression of PCa, and the rs6691378 and 10399805 SNP genetic variants of CHI3L1 are linked to the clinicopathological development of PCa within a Taiwanese population.

Association between YKL-40 and asthma: a systematic meta-analysis

PURPOSE

Many studies have shown that chitinase-3-like protein 1 (CHI3L1), also known as YKL-40, is associated with asthma. The purpose of this meta-analysis was to evaluate the role of serum YKL-40 in the diagnosis and differential diagnosis of asthma, severity grading, and determination of disease state.

METHODS

The PubMed, Ovid, and Cochrane databases were searched. A total of 17 articles involving 5696 subjects were included in this meta-analysis.

RESULTS

The results showed that the level of YKL-40 was significantly higher in asthmatic patients than in the normal group regardless of age and residential location, and increased with severity and acute exacerbation (p < 0.05). YKL-40 levels were significantly different between chronic obstructive pulmonary disease (COPD) and asthma, and also between asthma-COPD overlap syndrome (ACO) and asthma (p < 0.05).

CONCLUSION

YKL-40 may act as a potential serological marker for the diagnosis of asthma, assessment of severity, indicator of the disease state, and differential diagnosis of COPD, ACO, and asthma.

Significant Association of Chitinase 3-like 1 Genotypes to Asthma Risk in Taiwan

BACKGROUND/AIM

Chitinase 3-like 1 (CHI3L1) is overexpressed in asthma, and negatively associated with forced expiratory volume in the first second. This study aimed at evaluating whether CHI3L1 genotypes affect asthma risk.

MATERIALS AND METHODS

The blood samples of 198 asthma patients and 453 control subjects were collected, and the genotypic patterns of CHI3L1 -131C/G (rs4950928) and -247G/A (rs1262491437) were examined.

RESULTS

The percentages of CG and GG at CHI3L1 -131C/G were 32.8% and 7.6% among the asthma cases, respectively, significantly higher than the 23.8% and 3.1% among the non-asthmatic healthy subjects (p for trend=0.0009). The allelic frequency distribution analysis showed that the G allele at CHI3L1 - 131C/G conferred a significantly higher asthma risk than the wild-type C allele (p<0.0001). The genotypic and allelic frequency analyses for CHI3L1 -247G/A did not show any significant difference.

CONCLUSION

The G allele at CHI3L1-131C/G serves as a biomarker in determining personal susceptibility to asthma in Taiwan.

Analysis of China's carbon emission driving factors based on the perspective of eight major economic regions

Low-carbon transition has gradually become the focus of research on environmental issues. This paper takes China's eight major economic regions as the entry point. First, carbon emissions are measured according to United Nations' baseline methodologies. Second, the stochastic nonparametric data envelope analysis (StoNED) model is used to measure energy efficiency to improve the accuracy of the measurement. Finally, considering the temporal and spatial nonstationarity of carbon emission data, this paper constructs geographically and temporally weighted regression-stochastic impacts by regression on population, affluence, and technology (GTWR-STIRPAT) model, which can accurately analyze the impact of each driving factor of carbon emissions. This paper also explores efficient emission reduction paths in conjunction with the forcing mechanism. According to the study, China's carbon emissions show a decreasing trend from coastal areas to inland areas. In addition, there are significant problems with carbon emissions in China: some regions focus on improving energy efficiency but neglect increasing energy consumption; some regions focus on industrial development but neglect long-term emission reductions. Among the driving factors, energy efficiency, foreign trade, environmental regulations, and industrial structure have the effects of spatiotemporal heterogeneity, spatial heterogeneity, and time lag on carbon emissions, respectively. Graphical abstract.

Association of CHI3L1 gene variants with YKL-40 levels and hypertension incidence: A population-based nested case-control study in China

YKL‐40 was reported to be associated with the risk of hypertension. Whether the variants of CHI3L1 gene were associated with both YKL‐40 levels and hypertension needs to be further elucidated. In a 1:1 matched case‐control study of 507 pairs with available YKL‐40 levels and DNA samples nested in a prospective cohort of Chinese subjects, the 15 tag single nucleotide polymorphisms (SNPs) of CHI3L1 gene were genotyped. The levels of YKL‐40 among different genotypes of each SNP were compared after false discovery rate adjustment. Multivariable conditional logistic regression analyses were used to explore the association between the genotypes and the risk of hypertension. Subjects with the genetic variants for rs10399931, rs1538372, rs2071580, rs2297839 and rs4950928 had lower YKL‐40 levels. The genetic variant for rs10399805 was associated with higher YKL‐40 level. Subjects with the genotype of GA/AA of rs10399805 had a 1.34‐fold risk of hypertension compared with those with GG genotype in the total population (P = .05). Subjects with heterozygote/rare homozygote genotype of rs4950928 and rs2297839 both had a significantly lower risk of hypertension compared with those with major homozygote genotype among men. The ORs (95% CIs) were 0.46 (0.23‐0.89) and 0.49 (0.26‐0.91), respectively. The above three SNPs could significantly improve the accuracy of risk prediction for hypertension based on the conventional factors. The genotypes of rs10399805, rs4950928 and rs2297839 may hopefully become stable biomarkers for predicting the risk of hypertension.

Airway mechanical compression: its role in asthma pathogenesis and progression

The lung is a mechanically active organ, but uncontrolled or excessive mechanical forces disrupt normal lung function and can contribute to the development of disease. In asthma, bronchoconstriction leads to airway narrowing and airway wall buckling. A growing body of evidence suggests that pathological mechanical forces induced by airway buckling alone can perpetuate disease processes in asthma. Here, we review the data obtained from a variety of experimental models, including in vitro, ex vivo and in vivo approaches, which have been used to study the impact of mechanical forces in asthma pathogenesis. We review the evidence showing that mechanical compression alters the biological and biophysical properties of the airway epithelium, including activation of the epidermal growth factor receptor pathway, overproduction of asthma-associated mediators, goblet cell hyperplasia, and a phase transition of epithelium from a static jammed phase to a mobile unjammed phase. We also define questions regarding the impact of mechanical forces on the pathology of asthma, with a focus on known triggers of asthma exacerbations such as viral infection.

Chitinase 3-like 1 polymorphisms and risk of chronic obstructive pulmonary disease and asthma in a Chinese population

BACKGROUND

Chitinase 3-like 1 (CHI3L1) plays an important role in airway inflammation and tissue remodeling; however, its pathogenic role in lung diseases remains unclear. In the present study, we investigated whether CHI3L1 polymorphisms are associated with the risk of chronic obstructive pulmonary disease (COPD) and asthma in a Chinese population.

METHODS

We detected seven single nucleotide polymorphisms in CHI3L1 among 361 patients and 527 age- and sex-matched control subjects. We analysed genotype and allele distributions using Stata software (StataCorp,CollegeStation,TX,USA). We used haplotype disease analysis and haplotype phenotype analysis to assess the relationship between seven polymorphisms and the risk of COPD and asthma.

RESULTS

The results showed significant differences between controls and patients with COPD/asthma in the genotype distributions of the polymorphism rs4950928. Additionally, significant differences were observed in the genotype and allele distributions of rs10399805 and rs10399931 between COPD patients and controls. Moreover, the frequencies of haplotype G-G-T-G-T-C-G, G-G-T-G-T-C-C and G-A-T-G-T-C-G (alleles of rs12141494, rs7542294, rs880633, rs10399805, rs10399931, rs946261 and rs4950928, respectively) were significantly higher in patients with COPD. Consideration of the haplotypes of these seven single nucleotide polymorphisms in CHI3L1 in asthma patients revealed a significant association with homocysteine levels (p < 0.001).

CONCLUSIONS

Our findings suggest that the CHI3L1 polymorphisms rs4950928, rs10399805 and rs10399931 can be used as genetic markers for predicting COPD and asthma risk in the Chinese population.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Functional study of the association of CHI3L1 polymorphisms with asthma susceptibility in the Southwest Chinese Han population

Background: Chitinase 3-like 1 (CHI3L1) is involved in the Th2 cell mediated pathway, tissue remodeling and fibrosis. Correlations of CHI3L1 gene polymorphisms with asthma in previous studies have been inconsistent. The present study was designed to investigate the association between CHI3L1 polymorphisms and asthma in the southwest Chinese Han population. Methods: Two single nucleotide polymorphisms (SNPs), rs4950928 and rs10399931, were genotyped in 410 asthma patients and 418 healthy controls from Southwest China. Dual-luciferase reporter gene analysis was performed to detect allele-dependent promoter activity of CHI3L1 variants in HEK293 cells. Real-time quantitative PCR was applied to detect the relative mRNA expression associated with different genotypes of CHI3L1 rs10399931. A meta-analysis was performed using data collected from previously published reports and the present study. Results: No significant association was found between rs4950928 and asthma. The rs10399931 CT/TT genotype increased the risk of asthma under the dominant model (P = 0.031, OR = 1.428, 95% CI, 1.033-1.974), while the CT genotype showed the same tendency under the heterozygous model (P = 0.003, OR = 1.680, 95% CI, 1.186-2.380). No statistically significant difference was found between alleles T and C of rs10399931in the dual-luciferase reporter gene analysis (P = 0.201). The rs10399931 CT/TT genotypes reduced the relative mRNA expression detected by real-time quantitative PCR (P = 0.002). There was no significant association between the CHI3L1 rs4950928 polymorphism and the risk of asthma in the meta-analysis. Conclusion: In the southwest Chinese Han population, the CHI3L1 rs10399931 CT/TT genotypes may increase the risk of asthma. rs10399931 may be a functional variant of CHI3L1 due to its effect on mRNA expression.

Single Nucleotide Polymorphism in SMAD7 and CHI3L1 and Colorectal Cancer Risk

Colorectal cancer (CRC) is one of the leading cancers throughout the world. It represents the third most common cancer and the fourth in mortality. Most of CRC are sporadic, arise with no known high-penetrant genetic variation and with no previous family history. The etiology of sporadic CRC is considered to be multifactorial and arises from the interaction of genetic variants of low-penetrant genes and environmental risk factors. The most common well-studied genetic variation is single nucleotide polymorphisms (SNPs). SNP arises as a point mutation. If the frequency of the sequence variation reaches 1% or more in the population, it is referred to as polymorphism, but if it is lower than 1%, the allele is typically considered as a mutation. Lots of SNPs have been associated with CRC development and progression, for example, genes of TGF-β1 and CHI3L1 pathways. TGF-β1 is a pleiotropic cytokine with a dual role in cancer development and progression. TGF-β1 mediates its actions through canonical and noncanonical pathways. The most important negative regulatory protein for TGF-β1 activity is termed SMAD7. The production of TGF-β can be controlled by another protein called YKL-40. YKL-40 is a glycoprotein with an important role in cancer initiation and metastasis. YKL-40 is encoded by the CHI3L1 gene. The aim of the present review is to give a brief introduction of CRC, SNP, and examples of some SNPs that have been documented to be associated with CRC. We also discuss two important signaling pathways TGF-β1 and CHI3L1 that influence the incidence and progression of CRC.

Linkage and Genetic Association in Severe Asthma

A significant body of work in the genetics of asthma currently exists. However, current knowledge has not been clarifying in understanding the pathophysiology of asthma and therapeutic treatment of the disease. Severe asthma in adults and children is a significant burden in relation to disproportionate disease morbidity, mortality, and health utilization. This disease phenotype is not well understood; current effective treatment regimens are limited. Genetic studies may lead to improved understanding of the pathophysiology of severe asthma and identification of relevant subsets, which allow more targeted and effective therapies and the realization of Precision Medicine in asthma.

CHI3L1 is correlated with childhood asthma

OBJECTIVE

The aim of this study was to assess the association between CHI3L1 gene two single nucleotide polymorphisms (SNPs) (rs12141494 and rs4950928) and susceptibility to pediatric asthma in a Chinese Han population.

METHODS

The case-control study was carried out on 115 children with asthma and 108 healthy controls. Genotypes of rs12141494 and rs4950928 within CHI3L1 gene were determined with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. Chi-square test was employed to analyze the differences of genotype and allele frequencies of the two polymorphisms between case and control groups. Odds ratios (ORs) and 95% confidence intervals (CIs) were applied to explain relative susceptibility of pediatric asthma.

RESULTS

The frequencies of genotypes and alleles of rs4950928 in CHI3L1 gene showed a significant difference between asthmatic children and healthy controls (P<0.05). However, no significant differences were found in CHI3L1 SNP rs12141494 between two groups (P>0.05).

CONCLUSION

Our results suggested that rs4950928 in CHI3L1 gene was associated with pediatric asthma risk in a Chinese Han population, while rs12141494 was not.

Genetic and epigenetic regulation of YKL-40 in childhood

BACKGROUND

Circulating levels of the chitinase-like protein YKL-40 are influenced by genetic variation in its encoding gene (chitinase 3-like 1 [CHI3L1]) and are increased in patients with several diseases, including asthma. Epigenetic regulation of circulating YKL-40 early in life is unknown.

OBJECTIVE

We sought to determine (1) whether methylation levels at CHI3L1 CpG sites mediate the association of CHI3L1 single nucleotide polymorphisms (SNPs) with YKL-40 levels in the blood and (2) whether these biomarkers (CHI3L1 SNPs, methylation profiles, and YKL-40 levels) are associated with asthma in early childhood.

METHODS

We used data from up to 2405 participants from the Spanish Infancia y Medio Ambiente; the Swedish Barn/Children, Allergy, Milieu, Stockholm, Epidemiological survey; and the Dutch Prevention and Incidence of Asthma and Mite Allergy birth cohorts. Associations between 68 CHI3L1 SNPs, methylation levels at 14 CHI3L1 CpG sites in whole-blood DNA, and circulating YKL-40 levels at 4 years of age were tested by using correlation analysis, multivariable regression, and mediation analysis. Each of these biomarkers was also tested for association with asthma at 4 years of age by using multivariable logistic regression.

RESULTS

YKL-40 levels were significantly associated with 7 SNPs and with methylation at 5 CpG sites. Consistent associations between these 7 SNPs (particularly rs10399931 and rs4950928) and 5 CpG sites were observed. Alleles linked to lower YKL-40 levels were associated with higher methylation levels. Participants with high YKL-40 levels (defined as the highest YKL-40 tertile) had increased odds for asthma compared with subjects with low YKL-40 levels (meta-analyzed adjusted odds ratio, 1.90 [95% CI, 1.08-3.36]). In contrast, neither SNPs nor methylation levels at CpG sites in CHI3L1 were associated with asthma.

CONCLUSIONS

The effects of CHI3L1 genetic variation on circulating YKL-40 levels are partly mediated by methylation profiles. In our study YKL-40 levels, but not CHI3L1 SNPs or methylation levels, were associated with childhood asthma.

New Insights Into the Relationship Between Chitinase-3-Like-1 and Asthma

PURPOSE OF REVIEW

CHI3L1 (also known as YKL-40), a member of "mammalian chitinase-like proteins," is a serum protein lacking enzymatic activity. Although the protein is highly conserved in mammals, a consensus regarding its role in human pathologies is currently lacking. In an attempt to shed light on the many physiological functions of the protein, specifically with regard to asthma, a comprehensive overview of recent studies is provided.

RECENT FINDINGS

In asthma, CHI3L1 is secreted from macrophages and airway epithelial cells through an IL-13 related mechanism. Th2-associated inflammatory responses due to allergen exposure, resulting in airway hyper-responsiveness and smooth muscle contraction, play a role in tissue remodeling. The importance of CHI3L1 in initiation and development of asthma is not limited to its involvement in highly orchestrated events of inflammatory cytokines but further research is needed for further elucidation. Levels of the protein are associated with severity for numerous pathologies, including asthma, suggesting limited specificity as a biomarker.

Personalized management of asthma exacerbations: lessons from genetic studies

INTRODUCTION

The genetics of severe asthma and asthma exacerbations are distinct from milder forms of asthma. Gene-environmental interactions contribute to the complexity and heterogeneity of severe asthma and asthma exacerbations, and pharmacogenomic studies have also identified genes that affect susceptibility to asthma exacerbations.

AREAS COVERED

Studies on the genetics, gene-environment interactions, and pharmacogenomics of asthma exacerbations are reviewed. Multiple individual genetic variants have been identified to be associated with asthma exacerbations but each genetic polymorphism explains only a fraction of the disease and by itself is not able to translate into clinical practice. Research is shifting from candidate gene studies and genome wide association studies towards more integrative approaches to translate genetic findings into clinical diagnostic and therapeutic tools.

EXPERT COMMENTARY

Integrative approaches combining polygenic or genomic data with multi-omics technologies have the potential to discover new biologic mechanisms and biomarkers for severe asthma and asthma exacerbations. Greater understanding of genomics and underlying biologic pathways will also lead to improved prevention and treatment, lowering costs, morbidity, and mortality. The utilization of genomic testing and personalized medicine may revolutionize asthma management, in particular for patients with severe, refractory asthma.

CHI3L1 polymorphisms, cord blood YKL-40 levels and later asthma development

BACKGROUND

Single nucleotide polymorphisms (SNPs) in chitinase 3-like 1 (CHI3L1), the gene encoding YKL-40, and increased serum YKL-40 levels are associated with severe forms of asthma. It has never been addressed whether SNPs in CHI3L1 and cord blood YKL-40 levels could already serve as potential biomarkers for milder forms of asthma. We assessed in an unselected population whether SNPs in CHI3L1 and cord blood YKL-40 levels at birth are associated with respiratory symptoms, lung function changes, asthma, and atopy.

METHODS

In a prospective birth cohort of healthy term-born neonates (n = 260), we studied CHI3L1 polymorphisms, and measured cord blood YKL-40 levels by ELISA in (n = 170) infants. Lung function was performed at 5 weeks and 6 years. Respiratory health during the first year of life was assessed weekly by telephone interviews. Diagnosis of asthma and allergic sensitisation was assessed at 6 years (n = 142).

RESULTS

The SNP rs10399805 was significantly associated with asthma at 6 years. The odds ratio for asthma was 4.5 (95 % CI 1.59-12.94) per T-allele. This finding was unchanged when adjusting for cord blood YKL-40 levels. There was no significant association for cord blood YKL-40 levels and asthma. SNPs in CHI3L1 and cord blood YKL-40 were not associated with lung function measurements at 5 weeks and 6 years, respiratory symptoms in the first year, and allergic sensitisation at 6 years.

CONCLUSION

Genetic variation in CHI3L1 might be related to the development of milder forms of asthma. Larger studies are warranted to establish the role of YKL-40 in that pathway.

Putting the Squeeze on Airway Epithelia

Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells.

The role of chitin, chitinases, and chitinase-like proteins in pediatric lung diseases

Chitin, after cellulose, the second most abundant biopolymer on earth, is a key component of insects, fungi, and house-dust mites. Lower life forms are endowed with chitinases to defend themselves against chitin-bearing pathogens. Unexpectedly, humans were also found to express chitinases as well as chitinase-like proteins that modulate immune responses. Particularly, increased levels of the chitinase-like protein YKL-40 have been associated with severe asthma, cystic fibrosis, and other inflammatory disease conditions. Here, we summarize and discuss the potential role of chitin, chitinases, and chitinase-like proteins in pediatric lung diseases.

YKL-40 is correlated with FEV1 and the asthma control test (ACT) in asthmatic patients: influence of treatment

Background

YKL-40 is also called chitinase-3-like-1 (CHI3L1) protein and may be a marker for asthma. The aims of the present study were to investigate whether serum YKL-40 levels are stable or decreased in patients with asthma after appropriate treatment and to evaluate the correlation of YKL-40 levels with lung function and asthma control test (ACT) results.

Methods

A total of 103 asthmatic patients (mean age 33.1 ± 0.9 years) with diagnosed asthma were enrolled in our study. All patients underwent a detailed clinical examination and completed the ACT questionnaire, serum YKL-40 measurement, and spirometry before (visit 1) and 8 weeks after initiation of treatment (visit 2).

Results

At the follow-up, the median serum YKL-40 level was significantly decreased compared to the levels at visit 1 (75.2 [55.8-86.8] ng/ml versus 54.5 [46.4-58.4] ng/ml, p < 0.001). The serum YKL-40 level was negatively correlated with %FEV₁ (r = -0.37, p < 0.001) and ACT score (r = -0.26, p = 0.007) at visit 1. The change in serum YKL-40 levels between the visits was significantly correlated with changes in FEV₁ (r = -0.28, p = 0.006) and ACT score (r = -0.22, p = 0.037). Patients with elevated YKL-40 levels had significantly greater corticosteroid use than patients with lower levels.

Conclusions

YKL-40 was reduced in the serum of asthmatic patients after appropriate treatment, and the levels correlated with improvements in %FEV₁ and ACT. High levels of serum YKL-40 may be refractory to current asthma treatments.

Trial registration

ChiCTR-OCC-13003316

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2466-15-1) contains supplementary material, which is available to authorized users.