Tendon xanthomas in familial hypercholesterolemia are associated with a differential inflammatory response of macrophages to oxidized LDL

Hyperlipidemia and Rotator Cuff Tears: Exploring Mechanisms and Effective Treatment

The detrimental effects of hyperlipidemia on the healing of rotator cuff tears are well documented. The proposed underlying mechanisms for these effects include alterations in the extracellular matrix, inflammation, and oxidative stress, which hamper the reparative processes in the affected tendon tissues. Recent therapeutic strategies target these pathways, reflecting a growing body of research dedicated to mitigating these effects and promoting healing. This literature review aims to provide a comprehensive understanding of the pathophysiology underlying rotator cuff tears, examine the interplay between hyperlipidemia and rotator cuff tear healing, synthesize current knowledge on contributing biological mechanisms, and outline potential therapeutic interventions to optimize clinical management and treatment outcomes for patients.

Hypercholesterolemia and inflammation-Cooperative cardiovascular risk factors

BACKGROUND

Maintaining low concentrations of plasma low-density lipoprotein cholesterol (LDLc) over time decreases the number of LDL particles trapped within the artery wall, slows the progression of atherosclerosis and delays the age at which mature atherosclerotic plaques develop. This substantially reduces the lifetime risk of atherosclerotic cardiovascular disease (ASCVD) events. In this context, plaque development and vulnerability result not only from lipid accumulation but also from inflammation.

RESULTS

Changes in the composition of immune cells, including macrophages, dendritic cells, T cells, B cells, mast cells and neutrophils, along with altered cytokine and chemokine release, disrupt the equilibrium between inflammation and anti-inflammatory mechanisms at plaque sites. Considering that it is not a competition between LDLc and inflammation, but instead that they are partners in crime, the present narrative review aims to give an overview of the main inflammatory molecular pathways linked to raised LDLc concentrations and to describe the impact of lipid-lowering approaches on the inflammatory and lipid burden. Although remarkable changes in LDLc are driven by the most recent lipid lowering combinations, the relative reduction in plasma C-reactive protein appears to be independent of the magnitude of LDLc lowering.

CONCLUSION

Identifying clinical biomarkers of inflammation (e.g. interleukin-6) and possible targets for therapy holds promise for monitoring and reducing the ASCVD burden in suitable patients.

Factors associated with the presence of tendon xanthomas in familial hypercholesterolemia

INTRODUCTION AND OBJECTIVES

Tendon xanthomas (TX) are lipid deposits highly specific to familial hypercholesterolemia (FH). However, there is significant variability in their presentation among FH patients, primarily due to largely unknown causes. Lipoprotein(a) is a well-established independent risk factor for atherosclerotic cardiovascular disease in the general population as well as in FH. Given the wide variability of lipoprotein(a) among FH individuals and the likelihood that TX may result from a proatherogenic and proinflammatory condition, the objective of this study was to analyze the size of TX in the Achilles tendons of FH participants and the variables associated with their presence, including lipoprotein(a) concentration.

METHODS

A cross-sectional study was conducted on 377 participants with a molecular diagnosis of heterozygous FH. Achilles tendon maximum thickness (ATMT) was measured using ultrasonography with standardized equipment and procedures. Demographic variables and lipid profiles were collected. A multivariate linear regression model using a log-Gaussian approach was used to predict TX size. Classical cardiovascular risk factors and lipoprotein(a) were included as explanatory variables.

RESULTS

The mean low-density lipoprotein cholesterol level was 277mg/dL without lipid-lowering treatment, and the median ATMT was 5.50mm. We demonstrated that age, sex, low-density lipoprotein cholesterol, and lipoprotein(a) were independently associated with ATMT. However, these 4 variables did not account for most the interindividual variability observed (R2=0.205).

CONCLUSIONS

TX, a characteristic hallmark of FH, exhibit heterogeneity in their presentation. Interindividual variability can partially be explained by age, male sex, low-density lipoprotein cholesterol, and lipoprotein(a) but these factors account for only 20% of this heterogeneity.

Advances in familial hypercholesterolemia

Familial hypercholesterolemia (FH), a semi-dominant genetic disease affecting more than 25 million people worldwide, is associated with severe hypercholesterolemia and premature atherosclerotic cardiovascular disease. Over the last decade, advances in data analysis, screening, diagnosis and cardiovascular risk stratification has significantly improved our ability to deliver precision medicine for these patients. Furthermore, recent updates on guideline recommendations and new therapeutic approaches have also proven to be highly beneficial. It is anticipated that both ongoing and upcoming clinical trials will offer further insights for the care and treatment of FH patients.

Dyslipidemia is associated with risk for rotator cuff repair failure: a systematic review and meta-analysis

Background

Lipid deposition secondary to dyslipidemia (DLD) is shown to have a significant impact on tendon pathology, including tendon elasticity, fatty infiltration, and healing properties. Rotator cuff repair is a common procedure, susceptible to influence from many tear-related and patient-related characteristics. The purpose of this study was to determine the relationship between DLD and rotator cuff repair outcomes with analysis of retear risk and function.

Methods

PubMed, Embase, and SPORTDiscus were searched for all English-language, peer-reviewed studies between 2000 and the present, which analyzed relationships between patient-related factors and outcomes of rotator cuff repair. Studies that explicitly examined the effect of DLD on rotator cuff repair outcomes were chosen for inclusion. Included studies were assessed for methodological quality, and data were extracted for meta-analysis.

Results

Of the 3087 titles, 424 were screened by abstract, and 67 were reviewed in full. Inclusion criteria were met by 11 studies. Of these studies, 5 studies assessed retear, 2 studies measured function, 3 studies reported both retear and function, and 1 study evaluated the risk of retear necessitating a revision surgery. The studies report no significant difference in functional outcomes. Meta-analysis revealed that DLD patients had a significantly higher risk of retear after primary rotator cuff repair (odds ratio 1.32, 95% confidence interval 1.06-1.64).

Conclusion

DLD leads to an increased risk of retear after rotator cuff repair, although function appears to be unimpaired. DLD should be considered among other risk factors when counseling patients regarding expected rotator cuff repair outcomes.

HDL Cholesterol Efflux and Serum Cholesterol Loading Capacity Alterations Associate to Macrophage Cholesterol Accumulation in FH Patients with Achilles Tendon Xanthoma

Achilles tendon xanthoma (ATX) formation involves macrophage cholesterol accumulation within the tendon, similar to that occurring in atheroma. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, namely the high-density lipoprotein (HDL) capacity to promote cell cholesterol efflux (cholesterol efflux capacity, CEC) and the serum cholesterol loading capacity (CLC). We explored the HDL-CEC and serum CLC, comparing 16 FH patients with ATX to 29 FH patients without ATX. HDL-CEC through the main efflux mechanisms mediated by the transporters ATP binding cassette G1 (ABCG1) and A1 (ABCA1) and the aqueous diffusion (AD) process was determined by a cell-based radioisotopic technique and serum CLC fluorimetrically. Between the two groups, no significant differences were found in terms of plasma lipid profile. A trend toward reduction of cholesterol efflux via AD and a significant increase in ABCA1-mediated HDL-CEC (+18.6%) was observed in ATX compared to no ATX patients. In ATX-presenting patients, ABCG1-mediated HDL-CEC was lower (−11%) and serum CLC was higher (+14%) compared to patients without ATX. Considering all the patients together, ABCG1 HDL-CEC and serum CLC correlated with ATX thickness inversely (p = 0.013) and directly (p < 0.0001), respectively. In conclusion, lipoprotein dysfunctions seem to be involved in ATX physiopathology and progression in FH patients.

Is there a relation between plantar fasciitis and total cholesterol levels?

BACKGROUND

The main objective of this study is to investigate the relationship between hypercholesterolemia and Plantar Fasciitis (PF).

METHODS

The study includes patients who presented to the orthopedics outpatient clinic with heel pain and were diagnosed with PF. The control group was composed of patients who came to the orthopedics outpatient clinic, with complaints other than heel pain. The two groups were compared in terms of epidemiological data, total cholesterol (TC) levels, and hypercholesterolemia prevalence. We also performed an in-group analysis of PF patients in terms of age, sex, body mass index, and duration of symptoms.

RESULTS

There were 238 patients (mean age, 46.7) in the PF group and 240 patients (mean age, 47.9) in the control group. There was a significant difference between the PF group and the control group in TC levels (207.6 ± 47.5 versus 195.1 ± 30.1, p = 0.001). Hypercholesterolemia (TC level > 240 mg/dL) was found in 22.7% (n = 54) of the patients in the PF group whereas in the control group this rate was 10.8% (n = 26) (p < 0.001). It was seen that the TC levels were significantly higher in patients over the age of 45 in the PF group (p = 0.038). We also found that TC levels were higher in PF patients with symptoms for longer than a year (p = 0.026).

CONCLUSION

Significantly higher TC levels were found in PF patients in comparison with other orthopedic outpatients. Besides, being over the age of 45 and having a duration of symptoms longer than a year is associated with higher cholesterol levels for PF patients.

LEVEL OF CLINICAL EVIDENCE

4.

Relations of physical signs to genotype, lipid and inflammatory markers, coronary stenosis or calcification, and outcomes in patients with heterozygous familial hypercholesterolemia

BACKGROUND

Although the presence of physical signs [tendon xanthomas and/or corneal arcus (TX/CA)], are associated with the risk of coronary artery disease in patients with heterozygous familial hypercholesterolemia (HeFH), their relationship with genotypes and clinical characteristics has not been fully determined. This study aimed to examine the association of TX/CA with genetic mutation, lipid- and inflammation-related markers, the severity of coronary stenosis or calcification, and cardiovascular events (CVEs) in patients with HeFH.

METHODS

LDLR, APOB, and PCSK9 genes were screened in 523 HeFH patients, and patients with TX/CA (n = 50) were 1:4 propensity score-matched to patients without TX/CA (n = 200) to adjust for age and sex. Laboratory markers (proprotein convertase subtilisin/kexin type 9 [PCSK9], lipoprotein(a) and high-sensitivity C-reactive protein [hsCRP]), computed tomography angiography, coronary angiography, and follow-up for CVEs were performed.

RESULTS

Patients with physical signs had significantly higher low-density lipoprotein cholesterol levels; higher PCSK9 or hsCRP concentrations; more LDLR positive mutations; and higher prevalence of high tertiles of Gensini, SYNTAX and Jeopardy scores as well as coronary artery calcium scores than did those without. Over an average follow-up of 3.7 years, the incidence of CVEs was significantly higher in patients with TX/CA (log-rank p < 0.001). Patients with physical signs and mutation positivity had threefold higher risks of CVEs (adjusted hazard ratio 3.34, 95% confidence interval 1.04-10.72, p = 0.024).

CONCLUSIONS

Physical signs were associated with genotypes and phenotypes, and worse outcomes in patients with HeFH, suggesting that these signs may help in risk stratification in these patients.

Shortcomings on genetic testing of Familial hypercholesterolemia (FH) in India: Can we collaborate to establish Indian FH registry?

Familial hypercholesterolemia (FH) is a common autosomal dominant disorder that affects ∼1 in 250–500 individuals globally. The only prevalence study in India shows FH in 15% of patients with premature CAD in North Indians. There are only 6 genetic studies in India of the total mutations, 32% are LDLR mutations, 4% are ApoB, 2% are PCSK9 mutations and the mutational spectrum for 37% is unknown. This calls for widespread genetic screening which could help identify definite FH patients.

European Atherosclerosis Society-Familial Hypercholesterolemia Studies Collaboration (EAS- FHSC) has taken an initiative to develop a worldwide registry of FH. India is also a part of the collaboration and 3 groups from Mumbai, Delhi and Chennai are actively contributing to this registry. We believe this review might help to understand the Indian scenario of FH and investigators across India can contribute in managing FH in India and further help in the detection, diagnosis and treatment.

Achilles tendon thickness is associated with coronary lesion severity in acute coronary syndrome patients without familial hypercholesterolemia

BACKGROUND

Thickening of Achilles tendon (≥9 mm on radiography) is one of the diagnostic criteria for familial hypercholesterolemia (FH). Since FH is associated with premature coronary artery disease (CAD) including acute coronary syndrome (ACS), measurement of Achilles tendon thickness (ATT) is important for early diagnosis of FH. However, clinical significance of mild thickening of Achilles tendon in non-FH patients with CAD is unclear. The present study investigated the association of ATT with coronary lesion severity in early-onset ACS without clinically diagnosed FH.

METHODS

From outpatients who had a history of ACS under 60 years old, 76 clinically non-FH subjects (71 men and 5 women; mean age at the onset of ACS, 50.5 years) with maximum ATT of <9 mm were enrolled in this study. The severity of coronary lesions was assessed by SYNTAX score derived from coronary angiography at the onset of ACS.

RESULTS

ATT levels were not significantly different among patients with ST-elevation myocardial infarction (STEMI, n=47), non-STEMI (n=12), and unstable angina (n=17). Whereas, both average and maximum ATT were significantly larger in patients with multivessel lesions (n=25) than in those with single-vessel disease (n=51). Furthermore, SYNTAX score was positively correlated with average ATT (r=0.368, p=0.0011) and maximum ATT (r=0.388, p=0.0005). As for the relation to clinical parameters, maximum ATT had positive correlations with body mass index and C-reactive protein. A multiple regression analysis revealed that average and maximum ATT were significantly associated with SYNTAX score, independently of various confounding factors.

CONCLUSIONS

Our findings demonstrated that ATT, even though its level was <9 mm, was associated with coronary lesion severity in clinically non-FH patients with early-onset ACS. Apart from diagnosing FH, ATT may be a predictor of the progression of CAD.

Can Achilles tendon xanthoma be distinguished from Achilles tendinopathy using Dixon method MRI? A cross-sectional exploratory study

Background

Familial hypercholesterolemia is a genetic condition characterized by life-long elevations of plasma low-density lipoprotein cholesterol. In addition to life-threatening cardiovascular complications, intratendinous cholesterol deposits (xanthomas) can lead to pain and tendon thickening, particularly in the Achilles. Clinical detection of xanthomas currently relies upon visual assessment and palpation, or ultrasound-based measures of tendon thickening or echotexture. Misdiagnosis of xanthoma can delay the commencement of potentially life-saving lipid-lowering therapy. Our primary purpose was to determine whether analysis of separated fat and water magnetic resonance images may be able to differentiate between xanthomatic and nonxanthomatic Achilles tendons through quantification of intratendinous fat content. The main hypothesis was that Achilles tendon xanthomas will demonstrate greater lipid content than Achilles tendinopathy or healthy control tendons.

Methods

Bilateral MRI scans of Achilles tendons from 30 participants (n = 10 Achilles tendon xanthoma, n = 10 Achilles overuse tendinopathy, n = 10 healthy controls) were analyzed for total lipid content using the Dixon method of fat and water signal separation. Secondary outcome measures included tendon water content, as well as ultrasound characterization of tendon tissue organization and thickness.

Results

Fat content was greater in Achilles tendon xanthomas compared to the tendinopathy (p < 0.0001) and control groups (p < 0.0001). Water content was also greater in Achilles tendon xanthomas compared to the tendinopathy (p < 0.0001) and control groups (p = 0.0002). Ultrasound tissue characterization revealed worse tissue organization in Achilles tendon xanthoma tendons compared to Achilles tendinopathy (p < 0.05) but demonstrated largely overlapping distributions. Achilles tendon xanthoma tendons were, on average, significantly thicker than the tendons of the other two groups (p < 0.01 and p < 0.001, respectively).

Conclusion

MRI-derived measures of Achilles tendon fat content may be able to distinguish xanthomas from control and tendinopathic tissue. Dixon method MRI warrants further evaluation in an adequately powered study to develop and test clinically relevant diagnostic thresholds.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04494-0.

Factors Associated with Carotid Atherosclerosis and Achilles Tendon Thickness in Japanese Patients with Familial Hypercholesterolemia: A Subanalysis of the Familial Hypercholesterolemia Expert Forum (FAME) Study

AIMS

Familial hypercholesterolemia (FH) is characterized by high low-density lipoprotein (LDL) cholesterol levels, xanthomas including Achilles tendon thickening, and premature coronary artery disease (CAD). Carotid intima-media thickness (IMT) is a well-established surrogate marker for CAD in FH and Achilles tendon thickening is a specific physical finding in patients with FH. The objective of the present study was to identify factors associated with carotid IMT and Achilles tendon thickness in FH heterozygotes on lipid-lowering therapy. This study also aimed to examine the follow-up changes in carotid IMT and Achilles tendon thickness among them in the current real-world FH practice.

METHODS

The current study is a subanalysis of the Familial Hypercholesterolemia Expert Forum (FAME) Study. The severity of carotid atherosclerosis was assessed with the maximal and mean IMT using ultrasonography, and Achilles tendon thickness was measured using X-rays. The present study used 571 patients under medical treatment for heterozygous FH who had baseline measurements for maximal IMT (n=511), mean IMT (n=459), or Achilles tendon thickness (n=486). The IMT was measured annually, and Achilles tendon thickness was evaluated every two years.

RESULTS

Higher LDL cholesterol (LDL-C) level and lower HDL cholesterol (HDL-C) level were associated with greater maximal and mean IMT as well as greater Achilles tendon thickness. Achilles tendon thickness tended to be greater in patients who had a smoking history than in never-smokers. Maximal IMT and Achilles tendon thickness were significantly greater in patients with CAD than in those without. Additionally, lower HDL-C level and hypertension were associated with higher values of maximal and mean IMT, suggesting the importance of comprehensive risk management including reduced HDL-C and blood pressure control in FH care. In longitudinal observations, percentage changes in maximal IMT and mean IMT gradually increased during the observation period. In contrast, percentage changes in Achilles tendon thickness became progressively thinner throughout the observation period.

CONCLUSIONS

We found a positive association between LDL-C levels and severity of carotid atherosclerosis in heterozygous FH patients on treatment. This observation suggests the insufficiency of lipid-lowering therapy and the presence of therapeutic inertia among clinicians in the real-world FH practice.

The value of physical signs in identifying patients with familial hypercholesterolemia in the era of genetic testing

Familial hypercholesterolemia (FH) is a common, inherited disorder of cholesterol metabolism characterized by very high plasma concentrations of low-density lipoprotein cholesterol. It is crucial to diagnose and treat this disorder early since if left untreated it increases the risk for coronary artery disease (CAD) at least by 10-fold. Although genetic testing for FH, when available and affordable, should ideally be offered to most individuals with clinical phenotype suggestive of FH, it is underutilized in most countries. Therefore, FH diagnosis in the majority of cases is made by combining cholesterol levels and clinical characteristics of the patient leaving the need for genetic testing usually in equivocal cases. The presence of some cutaneous and ocular signs can raise the suspicion or even lead to the diagnosis of FH among usually "healthy" individuals. These physical signs comprise cutaneous lesions such as tendon xanthomas or the less specific xanthelasmata and ocular signs, such as corneal arcus in individuals under the age of 45 years. The presence of these signs should prompt the physician to request lipid tests and use clinical scores to diagnose FH. If the diagnosis of FH is likely, aggressive lipid-lowering therapy should be initiated to reduce the risk of CAD and a cascade screening of family members should also be requested.

The atherogenic role of immune cells in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism that mainly occurs due to mutations in the low-density lipoprotein receptor gene and is characterized by increased levels of low-density lipoprotein cholesterol, leading to accelerated atherogenesis and premature coronary heart disease. Both innate and adaptive immune responses, which mainly include monocytes, macrophages, neutrophils, T lymphocytes, and B lymphocytes, have been shown to play a key role for the initiation and progression of atherogenesis in the general population. In FH patients, these immune cells have been suggested to play specific pro-atherosclerotic activities, from the initial leukocyte recruitment to plaque rupture. In fact, the accumulation of cholesterol crystals and oxLDL in the vessels in FH patients is particularly high, with consequent abnormal mobilization of immune cells and secretion of various pro-inflammatory and chemokines. In addition, cholesterol accumulation in immune cells is exaggerated with chronic exposure to relevant pro-atherosclerotic triggers. The topics considered in this review may provide a more specific focus on the immune system alterations in FH and open new insights toward immune cells as potential therapeutic targets in FH.

Inflammatory Biomarkers for Cardiovascular Risk Stratification in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a frequent autosomal genetic disease characterized by elevated concentrations of low-density lipoprotein cholesterol (LDL) from birth with increased risk of premature atherosclerotic complications. Accumulating evidence has shown enhanced inflammation in patients with FH. In vessels, the deposition of modified cholesterol lipoproteins triggers local inflammation. Then, inflammation facilitates fatty streak formation by activating the endothelium to produce chemokines and adhesion molecules. This process eventually results in the uptake of vascular oxidized LDL (OxLDL) by scavenger receptors in monocyte-derived macrophages and formation of foam cells. Further leukocyte recruitment into the sub-endothelial space leads to plaque progression and activation of smooth muscle cells proliferation. Several inflammatory biomarkers have been reported in this setting which can be directly synthetized by activated inflammatory/vascular cells or can be indirectly produced by organs other than vessels, e.g., liver. Of note, inflammation is boosted in FH patients. Inflammatory biomarkers might improve the risk stratification for coronary heart disease and predict atherosclerotic events in FH patients. This review aims at summarizing the current knowledge about the role of inflammation in FH and the potential application of inflammatory biomarkers for cardiovascular risk estimation in these patients.

Familial Hypercholesterolemia with Tendinous Xanthomas and Achilles Tendinitis – A Forgotten Dermato-Rheumatologic Association

Familial hypercholesterolemia (FH) is a disorder of lipoprotein metabolism with dermatological and rhematological manifestations. Tendinous xanthomata (TX) are a hallmark of this disease. They are associated with recurrent tendinitis and tendon damage, an aspect of the clinical presentation, which is not well-known among dermatologists. We report two cases of heterozygous familial hypercholesterolemia, where the patients started developing tendinous xanthomata early in their life, with progressive increase in the number and size of lesions. However, they presented late, only when the recurrent attacks of tendinitis became severe. We present these cases to highlight the rheumatologic features, which may be the first symptom of heterozygous familial hypercholesterolemia.

A modified algorithm with lipoprotein(a) added for diagnosis of familial hypercholesterolemia

BACKGROUND

Previous studies have observed that high level of lipoprotein (a) [Lp(a)] was common in the phenotypic familial hypercholesterolemia (FH) and may explain part of the clinical diagnosis of FH.

HYPOTHESIS

We aim to develop a modified model including Lp(a) and compare its diagnostic performance with Dutch Lipid Clinic Network (DLCN) criteria.

METHODS

Data of 10 449 individuals were utilized for the model establishment (7806 for derivation and 2643 for validation) from January 2011 to March 2018. The novel score model was modified on the basis of DLCN. Furthermore, 718 patients were screened for LDLR, APOB, and PCSK9 gene mutations.

RESULTS

The novel modified model consisted of untreated low-density lipoprotein cholesterol (LDL-C) level, Lp(a), personal premature coronary heart disease (CHD), tendon xanthomas and family history of CHD and/or hypercholesterolemia. It has shown high discrimination (area under curve [AUC] 0.991, 95% confidence interval [CI[ 0.988-0.994, P < .001) for distinguishing clinical FH from non-FH diagnosed using DLCN. Furthermore, a concordance analysis was performed to compare the modified model with DLCN and it showed a good agreement with DLCN (κ = 0.765). External validation of the novel model also showed good accordance (κ = 0.700). Further genetic analysis showed that the agreements between the new model and mutation improved a little compared to that between DLCN and mutation.

CONCLUSIONS

The novel modified model, including Lp(a), could provide new insights into FH diagnosis in Chinese population with more concerns on the patients with high level of Lp(a).

Achilles tendon ultrasonography - A useful screening tool for cardiovascular risk estimation in patients with severe hypercholesterolemia

BACKGROUND AND AIMS

Achilles tendon lesions have long been associated with genetic defects in lipid metabolism and increased risk of cardiovascular diseases (CVD). With this study we aimed to evaluate the usefulness of Achilles tendon ultrasonography in identifying people at greater risk among subjects with severe hypercholesterolemia (SH) in a high-risk population.

METHODS

During the period of 2016-2017 a total of 213 participants were enrolled in this case-control study. Data of 110 patients with SH and 103 age and sex matched controls without dyslipidaeplemia and established CVD was collected.

RESULTS

Achilles tendinopathy (AT) was present in 42.7% of subjects with SH and in 29.1% of controls (p = 0.039). Stronger association between SH and AT was seen in women - 24.1% vs 2.0% (p = 0.001). SH increased odds of AT by 1.815 (95% CI, 1.028-3.206). Prevalence of AT was higher in males despite presence (SH⁺) or absence (SH^-) of severe hypercholesterolemia (SH⁺ 60.7% vs 24.1%, SH^- 55.8% vs 2.0%, p < 0.001). AT was associated with higher proportion of subjects exceeding normal mean values of TC (80.5% vs 52.9%, p = 0.001), LDL-C (76.6% vs 52.2%), TG (54.5% vs. 22.1%), ApoB (57.1% vs 22.2%), ApoE (44.0% vs 22.4%) levels and ApoB/ApoA ratio (46.1% vs 21.5%) (p = 0.001) and family history of premature coronary heart disease (CHD).

CONCLUSIONS

AT is more prevalent among subjects with SH and is associated with higher levels of TC, TG, LDL-C, ApoB, ApoE, ApoB/ApoA ratio, family history of premature CHD. SH increases the odds of developing AT.

Tendon pathology in hypercholesterolaemia patients: Epidemiology, pathogenesis and management

Tendon pathology is a general term used to describe a group of musculoskeletal conditions related to tendons and surrounding structures. There is only limited evidence available regarding the exact aetiology and natural history of tendon pathology. In hypercholesterolaemia environments, lipids could accumulate within the extracellular matrix of the tendon and thus affect the mechanical properties of the tendon. Current evidence suggested that hypercholesterolaemia was an important risk factor in the development and progression of tendon pathology. The severity of hypercholesterolaemia was correlated with the severity of tendon pathology.

The translational potential of this article: Hypercholesterolaemia lead to the structural, inflammatory and mechanical changes in tendons, which predispose hypercholesterolaemia patients to a greater risk of tendon pathology. Measurements of serum cholesterol are suggested to be performed in patients presenting with tendon pathology. The strict control of hypercholesterolaemia would mitigate the development and progression of tendon pathology.

Association between non-cholesterol sterol concentrations and Achilles tendon thickness in patients with genetic familial hypercholesterolemia

Background

Familial hypercholesterolemia (FH) is a genetic disorder that result in abnormally high low-density lipoprotein cholesterol levels, markedly increased risk of coronary heart disease (CHD) and tendon xanthomas (TX). However, the clinical expression is highly variable. TX are present in other metabolic diseases that associate increased sterol concentration. If non-cholesterol sterols are involved in the development of TX in FH has not been analyzed.

Methods

Clinical and biochemical characteristics, non-cholesterol sterols concentrations and Aquilles tendon thickness were determined in subjects with genetic FH with (n = 63) and without (n = 40) TX. Student-t test o Mann–Whitney test were used accordingly. Categorical variables were compared using a Chi square test. ANOVA and Kruskal–Wallis tests were performed to multiple independent variables comparison. Post hoc adjusted comparisons were performed with Bonferroni correction when applicable. Correlations of parameters in selected groups were calculated applying the non-parametric Spearman correlation procedure. To identify variables associated with Achilles tendon thickness changes, multiple linear regression were applied.

Results

Patients with TX presented higher concentrations of non-cholesterol sterols in plasma than patients without xanthomas (P = 0.006 and 0.034, respectively). Furthermore, there was a significant association between 5α-cholestanol, β-sitosterol, desmosterol, 24S-hydroxycholesterol and 27-hydroxycholesterol concentrations and Achilles tendon thickness (p = 0.002, 0.012, 0.020, 0.045 and 0.040, respectively).

Conclusions

Our results indicate that non-cholesterol sterol concentrations are associated with the presence of TX. Since cholesterol and non-cholesterol sterols are present in the same lipoproteins, further studies would be needed to elucidate their potential role in the development of TX.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1380-3) contains supplementary material, which is available to authorized users.

Achilles Tendon Ultrasonography for Diagnosis of Familial Hypercholesterolemia Among Japanese Subjects

BACKGROUND

Difficulty in detecting and measuring Achilles tendon (AT) xanthomas may be responsible for underdiagnosis of familial hypercholesterolemia (FH). We aimed to determine a cutoff value for AT thickness (AT-T) using ultrasonography to diagnose FH, and to investigate the relationship between AT-T and atherosclerosis.

METHODS AND RESULTS

Ultrasonographic AT-T and carotid intima-media thickness (IMT) were evaluated in 130 genetically diagnosed FH patients and 155 non-FH patients. The outline and internal properties of the AT could be clearly determined using ultrasonography, and a good correlation in AT-T was observed between ultrasonography and the conventional method of X-ray radiography (r=0.924, P<0.001). Cutoff values for the diagnosis of FH derived from receiver-operating curves were 5.8 mm (sensitivity 71%, specificity 78%) in men, and 5.5 mm (sensitivity 80%, specificity 81%) in women. Importantly, increased AT-T was positively associated with carotid IMT only in the FH group. Additionally, increased AT-T was associated with the presence of coronary artery disease in a logistic regression analysis adjusted for traditional cardiovascular risk factors.

CONCLUSIONS

This is the first study to determine a cutoff value for AT-T based on ultrasonography for the diagnosis of FH in Japanese subjects. Clearer detection and easier measurement of AT-T using ultrasonography would encourage clinicians to diagnose FH more actively, and could solve the problem of underdiagnosis of FH.

Perioperative Serum Lipid Status and Statin Use Affect the Revision Surgery Rate After Arthroscopic Rotator Cuff Repair

BACKGROUND

Recent animal studies have demonstrated that hyperlipidemia is associated with poor tendon-bone healing after rotator cuff repair; however, these findings have not been substantiated in human studies.

PURPOSE

To examine any association between hyperlipidemia and the failure of arthroscopic rotator cuff repair requiring revision surgery and to investigate whether the use of statin lipid-lowering agents had any influence on observed associations.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From a national insurance database, patients who underwent arthroscopic rotator cuff repair with perioperative lipid levels (total cholesterol, low-density lipoprotein [LDL], and triglycerides) recorded were reviewed. For each lipid test, patients were stratified into normal, moderate, and high groups based on published standards. For the total cholesterol and LDL cohorts, a subgroup analysis of patients stratified by statin use was performed. The primary outcome measure was ipsilateral revision rotator cuff surgery, including revision repair or debridement. A logistic regression analysis controlling for patient demographics and comorbidities was utilized for comparison.

RESULTS

There were 30,638 patients included in the study. The rate of revision rotator cuff surgery was significantly increased in patients with moderate (odds ratio [OR], 1.20; 95% CI, 1.03-1.40; P = .022) and high total cholesterol levels (OR, 1.36; 95% CI, 1.10-1.55; P = .006) compared with patients with normal total cholesterol levels perioperatively. Within each of these groups, patients without statin use had significantly higher rates of revision surgery, while those with statin prescriptions did not. The absolute risk reduction for statin use ranged from 0.24% to 1.87% when stratified by the total cholesterol level, yielding a number needed to treat from 54 to 408 patients. The rate of revision surgery was significantly increased in patients with moderate (OR, 1.24; 95% CI, 1.10-1.41; P = .001) and high LDL levels (OR, 1.46; 95% CI, 1.08-1.99; P = .014) compared with patients with normal LDL levels perioperatively. Again, patients without statin prescriptions had significantly increased rates of revision surgery, whereas patients with statin use did not. The absolute risk reduction for statin use ranged from 0.26% to 1.89% when stratified by the LDL level, yielding a number needed to treat from 53 to 387 patients. There were no significant differences in the rates of revision rotator cuff surgery between patients with moderate and high triglyceride levels compared with patients with normal triglyceride levels.

CONCLUSION

The present study found a significant association between moderate and high perioperative total cholesterol and LDL levels and the rate of revision surgery after primary arthroscopic rotator cuff repair. Furthermore, the use of statin agents appeared to mitigate the need for revision rotator cuff repair. Further prospective studies are necessary to validate these preliminary findings and determine if better perioperative lipid control can improve clinical outcomes after arthroscopic rotator cuff repair.

Achilles tendon xanthomas are associated with the presence and burden of subclinical coronary atherosclerosis in heterozygous familial hypercholesterolemia: A pilot study

BACKGROUND AND AIMS

Achilles tendon xanthomas (ATX) are a sign of long-term exposure to high blood cholesterol in familial hypercholesterolemia (FH) patients, which have been associated with cardiovascular disease. We evaluated the ATX association with the presence and extent of subclinical coronary atherosclerosis in heterozygous FH patients.

METHODS

102 FH patients diagnosed by US-MEDPED criteria (67% with genetically proven FH), with median LDL-C 279 mg/dL (interquartile range: 240; 313), asymptomatic for cardiovascular disease, underwent computed tomography angiography and coronary artery calcium (CAC) quantification. Subclinical coronary atherosclerosis was quantified by CAC, segment-stenosis (SSS) and segment-involvement (SIS) scores. Adjusted Poisson regression was used to assess the association of ATX with subclinical atherosclerosis burden as continuous variables.

RESULTS

Patients with ATX (n = 21, 21%) had higher LDL-C and lipoprotein(a) [Lp(a)] concentrations as well as greater CAC scores, SIS and SSS (p < 0.05). After adjusting for age, sex, smoking, hypertension, previous statin use, HDL-C, LDL-C and Lp(a) concentrations, there was an independent positive association of ATX presence with CAC scores (β = 1.017, p < 0.001), SSS (β = 0.809, p < 0.001) and SIS (β = 0.640, p < 0.001).

CONCLUSIONS

ATX are independently associated with the extension of subclinical coronary atherosclerosis quantified by tomographic scores in FH patients.

Multiple large xanthomas: A case report

A 23-year-old male patient presented with multiple large masses in his elbows, buttocks, knees, Achilles tendons, feet, shoulders and hands. The large masses in the elbows and buttocks measured ~6×5×5 cm and ~7×5×4 cm, respectively. The patient presented with an elevated level of low-density lipoprotein cholesterol, and had been previously diagnosed with homozygous familial hypercholesterolemia (FH) and multiple xanthomas. Local surgical excisions were performed to remove the massive xanthomas from the elbows and buttocks, and histological analysis of the surgical specimens confirmed the previous diagnosis of homozygous FH (HoFH). The aim of the present study was to report a rare case of HoFH coinciding with multiple, large and widely-distributed xanthomas and to discuss the clinical characteristics, in order to provide a better understanding of xanthomas and FH.

Tendons Involvement in Congenital Metabolic Disorders

Congenital metabolic disorders are consequence of defects involving single genes that code for enzymes. Blocking metabolic pathways, the defect leads to the shortage of essential compounds, and/or to the accumulation of huge quantities of precursors, which interfere with normal functions. Only few of these diseases are characterized by a clinically significant tendon involvement.Heterozygous Familial Hypercholesterolaemia results from the inheritance of a mutant low-density lipoprotein receptor gene; patients show high cholesterol levels, precocious coronary artery disease, and may develop tendon xanthomata (mainly in Achilles tendon). The detection of xanthomata is important, because it allows an early diagnosis and treatment of the disorder. Cerebrotendinous Xanthomatosis is a rare genetic metabolic disorder of cholesterol and bile acid metabolism, characterized by accumulation of cholestanol in brain and tendons. Tendon abnormalities are similar to those reported in Heterozygous Familial Hypercholesterolaemia. Alkaptonuria is caused by a deficiency of the enzyme homogentisic acid oxidase. Due to the accumulation of the homogentisic acid, tendons and ligaments are characterized by a typical ochre/yellow pigmentation (ochronosis), with ensuing inflammation, calcification and rupture. In Congenital Hypergalactosemia an increased tendon collagen cross-linking by non-enzymatic galactosylation can be observed. Finally, Congenital Hypophosphatasia may be associated to deposition of hydroxyapatite crystals in rotator cuff, elbow, and Achilles tendons.

Association Between Cholesterol Efflux Capacity and Atherosclerotic Cardiovascular Disease in Patients With Familial Hypercholesterolemia

OBJECTIVE

Patients with familial hypercholesterolemia (FH) are at high risk for premature atherosclerotic cardiovascular disease (ASCVD), especially because of long-term exposure to high low-density lipoprotein cholesterol levels. It has been reported that low-density lipoprotein-lowering therapy delays the onset of ASCVD. However, it still remains difficult to prevent it. Therefore, novel biomarkers and therapeutic targets are necessary to evaluate and prevent atherosclerosis in FH. The aim of this study was to investigate associations of cholesterol efflux capacity with the presence of ASCVD and clinical features in patients with heterozygous FH.

APPROACH AND RESULTS

We measured cholesterol efflux capacity in 227 patients with heterozygous FH under pharmaceutical treatment. Seventy-six (33.5%) of them were known to have ASCVD. In a logistic-regression analysis adjusted for risk factors, increased efflux capacity was associated with decreased risk of ASCVD even after the addition of high-density lipoprotein cholesterol level as a covariate (odds ratio per 1-SD increase, 0.95; 95% confidence interval, 0.90-0.99; P<0.05). Decreased cholesterol efflux capacity was associated with the presence of corneal arcus after adjusting for age and sex. In addition, inverse relationships between cholesterol efflux capacity and Achilles tendon thickness, as well as carotid intima-media thickness, were observed after adjustment for age, sex, and traditional cardiovascular risk factors.

CONCLUSIONS

Cholesterol efflux capacity was independently and inversely associated with the presence of ASCVD in heterozygous FH. In view of residual risks after treatment with statins, cholesterol efflux capacity might be a novel biomarker and a therapeutic target for preventing atherosclerosis in patients with FH.

Cascade Screening in Familial Hypercholesterolemia: Advancing Forward

Familial hypercholesterolemia is a genetic disorder associated with elevated LDL-cholesterol and high lifetime cardiovascular risk. Both clinical and molecular cascade screening programs have been implemented to increase early definition and treatment. In this systematic review, we discuss the main issues found in 65 different articles related to cascade screening and familial hypercholesterolemia, covering a range of topics including different types/strategies, considerations both positive and negative regarding cascade screening in general and associated with the different strategies, cost and coverage consideration, direct and indirect contact with patients, public policy around life insurance and doctor-patient confidentiality, the "right to know," and public health concerns regarding familial hypercholesterolemia.

Elevated atherosclerosis-related gene expression, monocyte activation and microparticle-release are related to increased lipoprotein-associated oxidative stress in familial hypercholesterolemia

Objective

Animal and in vitro studies have suggested that hypercholesterolemia and increased oxidative stress predisposes to monocyte activation and enhanced accumulation of oxidized LDL cholesterol (oxLDL-C) through a CD36-dependent mechanism. The aim of this study was to investigate the hypothesis that elevated oxLDL-C induce proinflammatory monocytes and increased release of monocyte-derived microparticles (MMPs), as well as up-regulation of CD36, chemokine receptors and proinflammatory factors through CD36-dependent pathways and that this is associated with accelerated atherosclerosis in subjects with heterozygous familial hypercholesterolemia (FH), in particular in the presence of Achilles tendon xanthomas (ATX).

Approach and Results

We studied thirty FH subjects with and without ATX and twenty-three healthy control subjects. Intima-media thickness (IMT) and Achilles tendon (AT) thickness were measured by ultrasonography. Monocyte classification and MMP analysis were performed by flow cytometry. Monocyte expression of genes involved in atherosclerosis was determined by quantitative PCR. IMT and oxLDL-C were increased in FH subjects, especially in the presence of ATX. In addition, FH subjects had elevated proportions of intermediate CD14++CD16+ monocytes and higher circulating MMP levels. Stepwise linear regression identified oxLDL-C, gender and intermediate monocytes as predictors of MMPs. Monocyte expression of pro-atherogenic and pro-inflammatory genes regulated by oxLDL-C-CD36 interaction was increased in FH, especially in ATX+ subjects. Monocyte chemokine receptor CX₃CR1 was identified as an independent contributor to IMT.

Conclusions

Our data support that lipoprotein-associated oxidative stress is involved in accelerated atherosclerosis in FH, particularly in the presence of ATX, by inducing pro-inflammatory monocytes and increased release of MMPs along with elevated monocyte expression of oxLDL-C-induced atherosclerosis-related genes.

Familial hypercholesterolaemia with tuberous and tendinous xanthomas: case report and mutation analysis

Xanthomas are important clinical manifestations of disordered lipid metabolism, which are mostly found in patients with familial hypercholesterolaemia (FH), an inherited disorder that is predominantly caused by mutations in the low-density lipoprotein receptor gene (LDLR). Tuberous and tendinous xanthomas with wide distribution and large size are rare; however, they may indicate the severity of FH, and tend to be found in homozygous FH. In this study, we investigated the clinical and genetic aspects of a young patient with FH presenting with multiple large masses in various locations. The lesions on the elbows and buttocks were locally excised and subsequently confirmed by biopsy to be xanthomas. Genetic analysis further confirmed that the patient was compound heterozygous for two mutations in both alleles of the LDLR gene. This rare case of compound heterozygous FH presenting with multiple large and widely distributed xanthomas provides a better understanding of FH and xanthomas.

Xanthomas: clinical and pathophysiological relations

BACKGROUND

Xanthomas are well circumscribed lesions in the connective tissue of the skin, tendons or fasciae that predominantly consist of foam cells; these specific cells are formed from macrophages as a result of an excessive uptake of low density lipoprotein (LDL) particles and their oxidative modification.

RESULTS

Until recently, xanthelasma was considered to be only a cosmetic lesion; however, according to the results of recent prospective studies it is connected with an increased cardiovascular risk and reduced average lifespan. Pathogenetic mechanisms involved in the development of xanthomas resemble early stages of atherogenesis. In clinical practice, xanthomas can signalise various congenital or acquired dyslipidemias. The most prevalent form of xanthomas is xanthelasma palpebrarum. Tendinous and tuberous xanthomas are typical for autosomal dominant hypercholesterolemia, as well as for some rare conditions, such as cerebrotendinous xanthomatosis and familial β-sitosterolemia. In patients with familial hypercholesterolemia, the presence of tendinous xanthomas has been shown to be associated with a two to four times higher risk for cardiovascular disease. Eruptive xanthomas are skin manifestations of a severe hypertriglyceridemia and implicate an elevated risk for acute pancreatitis or type 2 diabetes mellitus. Xanthoma striatum palmare is pathognomic for primary dysbetalipoproteinemia, whereas diffuse plane xanthomas are frequently associated with paraproteinemia and lymphoproliferative disorders.

CONCLUSION

Thorough familiarity with the clinical presentation of xanthomas helps in the diagnosis and follow-up of different forms of dyslipidemia. Moreover, xanthelasma palpebrarum, the most prevalent form of xanthomas, is connected with increased risk of atherothrombotic disease independently of conventional cardiovascular risk factors. To fully understand the pathogenesis, further experimental and clinical research is required.

Marked Multiple Tendinitis at the Onset of Rheumatoid Arthritis in a Patient with Heterozygous Familial Hypercholesterolemia: Ultrasonographic Observation

A 59-year-old woman who had been diagnosed with heterozygous familial hypercholesterolemia developed rheumatoid arthritis (RA). She presented with marked tendinitis of the Achilles tendons, patellar tendons, and finger extensor tendons at the onset of RA. Ultrasonographic examination revealed that tendon lesions were predominantly tendinitis rather than paratenonitis, and that the tendinitis was of the noninsertional variety, rather than the insertional variety. Preexisting tendon xanthomas might have contributed to the unusually dominant noninsertional tendinitis of multiple tendons.

Occurrence of tendon pathologies in metabolic disorders

This article reviews the pathogenetic role of metabolic disorders, which are of paramount relevance to the progression of tendon damage. In diabetes, the prevalence of rheumatological diseases is high, mainly because of the deleterious effects of advanced glycation end products that deteriorate the biological and mechanical functions of tendons and ligaments. In heterozygous familial hypercholesterolaemia, most patients develop Achilles xanthomatosis, a marker of high risk for cardiovascular disease caused by cholesterol deposition in the tendons. Tendon degeneration has also been observed in non-familial hypercholesterolaemia. Monosodium urate crystal deposition in soft tissues is a hallmark of chronic gouty arthritis. In this group of diseases, the mobilization of cholesterol and uric acid crystals is presumably followed by low-grade inflammation, which is responsible for tendon degeneration. Adiposity may contribute to tendon disorders via two different mechanisms: increased weight on the load-bearing tendons and systemic dysmetabolic factors that trigger subclinical persistent inflammation. Finally, tendon abnormalities have been observed in some rare congenital metabolism disorders such as alkaptonuria.

Tendon xanthomas

Tendon xanthomas usually present over the tendo Achilles and are associated with hyperlipidaemias. A brief review of xanthomas is presented.

Overexpression of the CXCL3 gene in response to oxidized low-density lipoprotein is associated with the presence of tendon xanthomas in familial hypercholesterolemia

To examine if overexpression of certain chemokines and proinflammatory cytokines in response to oxidized low-density lipoprotein could be involved in the onset and development of tendon xanthomas (TX), we quantified IL-1beta, TNF-alpha, and IL-8 and compared gene expression of PPAR-gamma, NF-kappaBIA, IL-8, IL-1beta, CXCL3, tryptase, and TNF-alpha in macrophages of familial hypercholesterolemia subjects with and without TX stimulated with oxidized low-density lipoprotein at 1, 3, 6, and 18 h of incubation. We propose that chemokines belonging to the CXC family could play an important role in the etiology of TX, with CXCL3 being a possible biological marker of onset and development of TX.

Atorvastatin decreases stearoyl-CoA desaturase gene expression in THP-1 macrophages incubated with oxidized LDL

Statins, inhibitors of HMG-CoA reductase, reduce plasma low-density lipoprotein (LDL) cholesterol levels decreasing the incidence of coronary events. However, the observed benefit of statins appears to extend beyond their lipid-lowering effects. Previous studies by our group have demonstrated that atorvastatin in oxidized LDL incubated macrophages modifies the gene expression profile of certain enzymes involved in fatty acid metabolism, mainly stearoyl-CoA desaturase (SCD). SCD is a rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids and its expression is mediated by sterol regulatory element-binding protein-1 (SREBP-1). The aim of this study was to determine whether atorvastatin might affect the fatty acid composition in macrophages and if their SCD gene expression profile could explain this effect. Therefore, THP-1 macrophages were treated with atorvastatin and native or oxidized LDL, their fatty acid composition was determined by gas-chromatography, and the SCD and SREBP-1 gene expression profile was analysed using quantitative RT-PCR. We found that atorvastatin reduces the percentage of palmitoleic and oleic acids in THP-1 cells incubated with oxLDL, which could be explained by the inhibition of SCD and SREBP-1 gene expression. The observed results were reversed when mevalonate was added to THP-1 macrophages. This would suggest that inhibition of SCD in THP-1 macrophages incubated with oxLDL and the change in fatty acid composition is an important effect of atorvastatin.

Femoral atherosclerosis in heterozygous familial hypercholesterolemia: influence of the genetic defect

OBJECTIVE

The purpose of this study was to assess femoral atherosclerosis by ultrasound in patients with molecularly defined heterozygous familial hypercholesterolemia (FH) in comparison with matched control subjects and in relation to mutational class in the LDL receptor and apolipoprotein B (APOB) genes.

METHODS AND RESULTS

Femoral intima-media thickness (IMT) and plaque were evaluated in 146 FH patients carrying null alleles (n=48), defective-receptor alleles (n=62), undetermined-function alleles (n=25), or APOB defects (n=11) and in 193 healthy subjects. Twenty-three patients had coronary heart disease (CHD). The frequency of both tendon xanthomas and CHD was approximately 2-fold higher and average LDL cholesterol was 30 mg/dL higher in null-allele genotype compared with receptor-defective mutations. All femoral measurements were increased in FH patients versus controls (P<0.001), and null-allele mutations showed higher age-, sex-, and LDL cholesterol-adjusted maximum IMT than receptor-defective or APOB defects (P for trend, 0.001). By multivariate analysis, independent associations of mean IMT, a measure of early atherosclerosis, were age, LDL cholesterol, sex, and systolic blood pressure. Age, null-allele genotype, sex, and smoking explained 42% of the variability of maximum IMT, a measure of advanced atherosclerosis.

CONCLUSIONS

FH patients have increased femoral IMT in relation to mutational class. The findings support the usefulness of genetic testing in FH beyond securing the diagnosis.

Individual variation of scavenger receptor expression in human macrophages with oxidized low-density lipoprotein is associated with a differential inflammatory response

Atherosclerosis is an inflammatory disease in which oxidized low-density lipoprotein (oxLDL) plays important roles. Scavenger receptors (SR) CD36, SR-A, and LOX-1 uptake over 90% of the oxLDL leading to foam cell formation and secretion of inflammatory cytokines. To investigate whether the interindividual differences in macrophage SR gene expression could determine the inflammatory variability in response to oxLDL, we quantified the gene and protein expression of SR and inflammatory molecules from macrophages isolated from 18 volunteer subjects and incubated with oxLDL for 1, 3, 6, and 18 h. The individual gene expression profile of the studied SR at 1 h of incubation was highly variable, showing a wide fold-change range: CD36: -3.57-4.22, SR-A: -5.0-4.43, and LOX-1: -1.56-75.32. We identified subjects as high and low responders depending on whether their SR gene expression was above or below the median, showing a different inflammation response pattern. CD36 and LOX-1 gene expression correlated positively with IL-1beta; SR-A correlated negatively with IL-8 and positively with PPARgamma and NF-kappaBIotaA. These results were confirmed in the same subjects 3 mo after the first sampling. Furthermore, a negative correlation existed between CD36 and SR-A at protein level after 18 h of oxLDL incubation (R = -0.926, p = 0.024). These data would suggest that the type of SR could determine the macrophage activation: more proinflammatory when associated to CD36 and LOX-1 than when associated with SR-A.

Varied Presentations of Enthesopathy

BACKGROUND

The concept of "enthesis organ" allows a new look at the nature of enthesis involvement in some rheumatic and nonrheumatic systemic disorders.

OBJECTIVES

To describe the various presentations of enthesopathy in the course of systemic medical disorders using the available literature data.

METHODS

Review of relevant articles from 1996 to 2006 retrieved by a Medline search utilizing the index terms "enthesis," "enthesitis," and "tendonitis." The list of articles reviewed herein is not exhaustive, with preference given, where possible, to studies and surveys over case reports as well as the most recent literature reflecting new developments on the subject.

RESULTS

Enthesis is defined as the site of insertion of a tendon, ligament, fascia, or articular capsule into bone. Pain originating in the free nerve endings enriched entheses (enthesalgia) may represent a potential cause of chronic musculoskeletal pain in some individuals. Enthesis involvement in the disease process is well appreciated in spondyloarthropathies and in rheumatoid arthritis, though overshadowed by synovitis in the latter. Calcium deposition diseases may constitute the most significant articular cause of enthesopathies in the general population. New data may shed light on the possible pathophysiologic role of enthesopathy in the development of osteoarthritis. Various metabolic and endocrine conditions may manifest with enthesopathy features. The pathogenic mechanisms of enthesis involvement are not uniform and differ in the diverse disorders.

CONCLUSIONS

The concept of enthesopathy as a variety of syndromes in the course of many rheumatic, metabolic, and endocrine disorders should be appreciated. Exercise of a high level of suspicion toward enthesopathic involvement, and greater knowledge of enthesopathy's characteristic patterns and diagnostic possibilities, may allow better management of many patients in rheumatology practice.