YKL-40 Is Associated With Ultrasound-Determined Carotid Atherosclerotic Plaque Instability

Frailty is related to serum inflammageing markers: results from the VITAL study

Frailty describes an age-associated state in individuals with an increased vulnerability and less resilience against adverse outcomes. To score frailty, studies have employed the questionnaires, such as the SF-36 and EQ-5D-3L, or the Frailty Index, a composite score based on deficit accumulation. Furthermore, ageing of the immune system is often accompanied by a state of low-grade inflammation (inflammageing). Here, we aimed to associate 29 circulating markers of inflammageing with frailty measures in a prospective cohort study to understand the mechanisms underlying ageing.Frailty measures and inflammageing markers were assessed in 317 participants aged 25-90. We determined four different measures of frailty: the Frailty Index based on 31 deficits, the EQ-5D-3L and two physical domains of the SF-36. Serum/plasma levels of inflammageing markers and CMV/EBV seropositivity were measured using different techniques: Quanterix, Luminex or ELISA.All four measures of frailty strongly correlated with age and BMI. Nineteen biomarkers correlated with age, some in a linear fashion (IL-6, YKL-40), some only in the oldest age brackets (CRP), and some increased at younger ages and then plateaued (CCL2, sIL-6R). After correcting for age, biomarkers, such as IL-6, CRP, IL-1RA, YKL-40 and elastase, were associated with frailty. When corrected for BMI, the number of associations reduced further.In conclusion, inflammageing markers, particularly markers reflecting innate immune activation, are related to frailty. These findings indicate that health decline and the accumulation of deficits with age is accompanied with a low-grade inflammation which can be detected by specific inflammatory markers.

YKL-40 serum levels are predicted by inflammatory state, age and diagnosis of idiopathic inflammatory myopathies

YKL-40 increase according to the aging process, and its functions have been associated with tissue remodeling and systemic inflammation. In Rheumatoid Arthritis (RA) it has been proposed as a possible biomarker of activity and severity, however; in the field of idiopathic inflammatory myopathies (IIM) the role of YKL-40 in IIM is not clear. Thus, we aimed to evaluate if there is an association between the serum levels and muscle tissue expression of YKL-40 with age, IIM phenotype, muscle strength and myositis disease activity. The main finding was that age is the most important variable that affects the YKL-40 serum levels. In muscle biopsy, we observed that YKL-40 is mainly expressed in infiltrating lymphoid cells than in muscle tissue. Using ANCOVA according to the b-coefficients, YKL-40 serum levels are predicted by inflammatory state, age, and IIM diagnosis.

Prognostic performance of serum YKL-40 for one-year clinical outcomes in acute ischemic stroke

BACKGROUND

Effects of YKL-40 on one-year clinical outcomes including poor clinical outcome, all-cause mortality, and stroke recurrence among acute ischemic stroke (AIS) patients remained elusive. The purpose of this study was to explore the association between serum YKL-40 at admission and one-year clinical outcomes in AIS patients.

METHODS

In this prospective cohort study, a total of 1002 participants out of 1361 AIS patients from two centers were included for current analysis. Serum YKL-40 concentrations were measured via enzyme-linked immunosorbent assay. Multivariable logistic or Cox regression were performed to explore the independent association of YKL-40 with one-year clinical outcomes, including poor outcome (modified Rankin Scale of 3-6), all-cause mortality, and recurrent stroke. C-statistic, net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated to evaluate the discriminatory and predictive power of YKL-40 when added to conventional model.

RESULTS

Compared with the first quartile of YKL-40, the adjusted odds ratios or hazard ratios with 95% confidence intervals of the fourth quartile were 3.032 (1.627-5.650) for poor outcome, 2.886 (1.320-6.308) for all-cause mortality and 1.694 (0.906-3.169) for recurrent stroke. The addition of serum YKL-40 to conventional model significantly improved reclassification for poor outcome (NRI 0.053, P = 0.031; IDI 0.018, P = 0.001) and all-cause mortality (NRI 0.162, P = 0.036).

CONCLUSIONS

Elevated serum YKL-40 at admission might be independently associated with one-year poor outcome and all-cause mortality but not stroke recurrence among Chinese AIS patients.

Serum YKL-40 Levels and White Matter Hyperintensities in Patients with Acute Ischemic Stroke

Background

White matter hyperintensity (WMH) is associated with risk of acute ischemic stroke (AIS) and poor outcomes after AIS. The purpose of this prospective study was to evaluate the association between serum YKL-40 levels and WMH burden in patients with AIS.

Methods

From February 2020 to March 2021, a total of 672 consecutive AIS patients with magnetic resonance imaging data were prospectively recruited form two centers. Serum YKL-40 levels were quantified using enzyme-linked immunosorbent assay. The burden of WMH was semiquantitatively measured by the Fazekas visual grading scale. According to severity of overall WMH, patients were dichotomized into none-mild WMH group (Fazekas score 0-2) or moderate-severe WMH group (Fazekas score 3-6). Besides, based on severity of periventricular WMH (PV-WMH) and deep WMH (D-WMH), patients were categorized as none-mild (Fazekas score 0-1) or moderate-severe (Fazekas score 2-3).

Results

Among the 672 patients, 335 (49.9%) participants were identified with moderate-severe overall WMH, 326 (48.5%) with moderate-severe PV-WMH and 262 (39.0%) with moderate-severe D-WMH. Compared with the first quartile of serum YKL-40, the adjusted odds ratio (OR) of the fourth quartile for moderate-severe PV-WMH was 2.473 (95% confidence interval [CI] 1.316-4.646; P=0.005). No significant association was observed between YKL-40 and overall WMH (OR 0.762; 95% CI 0.434-1.336; P=0.343) or D-WMH (OR 0.695; 95% CI 0.413-1.171; P=0.172).

Conclusion

Our results suggested that higher YKL-40 levels appeared to be associated with PV-WMH, but not with overall WMH or D-WMH in patients with AIS.

Myokines: Novel therapeutic targets for diabetic nephropathy

With the increasing incidence of diabetic nephropathy (DN), there is an urgent need to find effective DN preventive and therapeutic modalities. It is widely believed that effective exercise is good for health. However, the beneficial role of exercise in kidney disease, especially in DN, and the underlying molecular mechanisms have rarely been reported. Muscle is not only an important motor organ but also an important endocrine organ, secreting a group of proteins called "myokines" into the blood circulation. Circulating myokines then move to various target organs to play different biological roles. In this review, we summarize the currently known myokines and the progress in research relating them to DN and discuss its potential as a therapeutic target for DN.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.