Skeletal fragility: an emerging complication of Ehlers-Danlos syndrome

Type 1 collagen: Synthesis, structure and key functions in bone mineralization

Collagen is a highly abundant protein in the extracellular matrix of humans and mammals, and it plays a critical role in maintaining the body's structural integrity. Type I collagen is the most prevalent collagen type and is essential for the structural integrity of various tissues. It is present in nearly all connective tissues and is the main constituent of the interstitial matrix. Mutations that affect collagen fiber formation, structure, and function can result in various bone pathologies, underscoring the significance of collagen in sustaining healthy bone tissue. Studies on type 1 collagen have revealed that mutations in its encoding gene can lead to diverse bone diseases, such as osteogenesis imperfecta, a disorder characterized by fragile bones that are susceptible to fractures. Knowledge of collagen's molecular structure, synthesis, assembly, and breakdown is vital for comprehending embryonic and foetal development and several aspects of human physiology. In this review, we summarize the structure, molecular biology of type 1 collagen, its biomineralization and pathologies affecting bone.

Cutis Laxa and the Value of Rhytidectomy: 4 Patients and Years of Follow-Up

The modalities of the esthetic treatment of cutis laxa (CL) patients have rarely been discussed. Here, the authors present 4 CL rhytidectomy cases. The surgery method was designed based on the traditional full-incision face-lift technique combined with lamellar superficial musculoaponeurotic system flap elevation and plication. Temporal, buccal, mandibular, and cervical regions were targeted. The shortest follow-up was 30 months, and the longest was 72. The results were assessed by subjective satisfaction and third-party photo evaluation. The subjective satisfaction was graded into worse than preoperation, no improvement, slight improvement, moderate improvement, and obvious improvement. The satisfaction rate was the sum of moderate and obvious improvement. Eighteen uncorrelated professionals participated in the third-party photo evaluation, in which the preoperative and follow-up photos were presented, and frontal, temporal, mid-face (including jowl), and cervical (including mandibular line) regions were evaluated as improved or nonimproved. The outcome of the subjective satisfaction was graded as no improvement (2/12, 16.7%), slight improvement (3/12, 25%), moderate improvement (4/12, 33.3%), and obvious improvement (3/12, 25%). The satisfaction rate was 58.3%, most investigators denied the frontal and temporal region improvement, 60% observed mid-face improvement, and 80% noticed cervical improvement. Most patients and their parents had positive attitudes towards the treatment results; however, the full expectation was not achieved. The cervical region maintained the best improvement after our treatment and the mid-face ranked second. This surgery method conduces to the esthetic requirement of CL patients; however, skin laxity remains a challenge.

Child Abuse, Misdiagnosed by an Expertise Center-Part II-Misuse of Bayes' Theorem

A newborn girl had, from two weeks on, small bruises on varying body locations, but not on her chest. Her Armenian grandmother easily bruised, too. Her mother was diagnosed with hypermobility-type Ehlers-Danlos-Syndrome (hEDS), an autosomal dominant connective tissue disorder, with a 50% inheritance probability. Referral to a University Medical Center located "Dutch Expertise Center for Child Abuse" resulted (prior to consultation) in physical abuse suspicion. Protocol-based skeletal X-rays showed three healed, asymptomatic rib fractures. A protocol-based Bayesian likelihood ratio guesstimation gave 10-100, erroneously used to suggest a 10-100 times likelier non-accidental-than-accidental cause. Foster care placement followed, even in a secret home, where she also bruised, suggesting hEDS inheritance. Correct non-accidental/accidental Bayes' probability of symptoms is (likelihood ratio) × (physical abuse incidence). From the literature, we derived an infant abuse incidence between about ≈0.0009 and ≈0.0026 and a likelihood ratio of <5 for bruises. For rib fractures, we used a zero likelihood ratio, arguing their cause was birth trauma from the extra delivery pressure on the chest, combined with fragile bones as the daughter of an hEDS-mother. We thus derived a negligible abuse/accidental probability between <5 × 0.0009 <0.005 and <5 × 0.0026 <0.013. The small abuse incidence implies that correctly using Bayes' theorem will also miss true infant physical abuse cases. Curiously, because likelihood ratios assess how more often symptoms develop if abuse did occur versus non-abuse, Bayes' theorem then implies a 100% infant abuse incidence (unwittingly) used by LECK. In conclusion, probabilities should never replace differential diagnostic procedures, the accepted medical method of care. Well-known from literature, supported by the present case, is that (child abuse pediatrics) physicians, child protection workers, and judges were unlikely to understand Bayesian statistics. Its use without statistics consultation should therefore not have occurred. Thus, Bayesian statistics, and certainly (misused) likelihood ratios, should never be applied in cases of physical child abuse suspicion. Finally, parental innocence follows from clarifying what could have caused the girl's bruises (inherited hEDS), and rib fractures (birth trauma from fragile bones).

New tools for bone health assessment in secreting pituitary adenomas

Pituitary hormones regulate skeletal physiology, and excess levels affect bone remodeling and alter bone microstructure. Vertebral fractures (VFs) are an early phenomenon of impaired bone health in secreting pituitary adenomas. However, they are not accurately predicted by areal bone mineral density (BMD). Emerging data demonstrate that a morphometric approach is essential for evaluating bone health in this clinical setting and is considered to be the gold standard method in acromegaly. Several novel tools have been proposed as alternative or additional methods for the prediction of fractures, particularly in pituitary-driven osteopathies. This review highlights the novel potential biomarkers and diagnostic methods for bone fragility, including their pathophysiological, clinical, radiological, and therapeutic implications in acromegaly, prolactinomas, and Cushing's disease.

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Are patients with hypermobile Ehlers-Danlos syndrome or hypermobility spectrum disorder so different?

Diagnosing hypermobile Ehlers–Danlos syndrome (hEDS) remains challenging, despite new 2017 criteria. Patients not fulfilling these criteria are considered to have hypermobile spectrum disorder (HSD). Our first aim was to evaluate whether patients hEDS were more severely affected and had higher prevalence of extra-articular manifestations than HSD. Second aim was to compare their outcome after coordinated physical therapy. Patients fulfilling hEDS/HSD criteria were included in this real-life prospective cohort (November 2017/April 2019). They completed a 16-item Clinical Severity Score (CSS-16). We recorded bone involvement, neuropathic pain (DN4) and symptoms of mast cell disorders (MCAS) as extra-articular manifestations. After a standardized initial evaluation (T0), all patients were offered the same coordinated physical therapy, were followed-up at 6 months (T1) and at least 1 year later (T2), and were asked whether or not their condition had subjectively improved at T2. We included 97 patients (61 hEDS, 36 HSD). Median age was 40 (range 18–73); 92.7% were females. Three items from CSS-16 (pain, motricity problems, and bleeding) were significantly more severe with hEDS than HSD. Bone fragility, neuropathic pain and MCAS were equally prevalent. At T2 (20 months [range 18–26]) 54% of patients reported improvement (no difference between groups). On multivariable analysis, only family history of hypermobility predicted (favorable) outcome (p = 0.01). hEDS and HDS patients showed similar disease severity score except for pain, motricity problems and bleeding, and similar spectrum of extra-articular manifestations. Long-term improvement was observed in > 50% of patients in both groups. These results add weight to a clinical pragmatic proposition to consider hEDS/HSD as a single entity that requires the same treatments.

Effects of Medical Treatment of Prostate Cancer on Bone Health

Medical treatment of prostate cancer (PC) is multidisciplinary, resulting in prolonged survival. Androgen-deprivation therapy (ADT) can have negative effects on skeletal metabolism, particularly if combined with glucocorticoids. We discuss the pathophysiology and effects of ADT and glucocorticoids on skeletal endpoints, as well as the awareness and management of bone fragility. Coadministration of glucocorticoids is necessary with abiraterone because this causes a novel acquired form of 17-hydroxylase deficiency and synergistically increases the risk of fracture by affecting bone quality. Bone antiresorptive agents [selective estrogen receptor modulators (SERMS), bisphosphonates, and denosumab] increase bone mineral density (BMD) and in some instances reduce fracture risk in PC patients on ADT. Awareness and management of bone health in PC can be improved by integrating endocrinologists into the multidisciplinary PC team.

Multisystemic manifestations in a cohort of 75 classical Ehlers-Danlos syndrome patients: natural history and nosological perspectives

Background

The Ehlers-Danlos syndromes (EDS) are rare connective tissue disorders consisting of 13 subtypes with overlapping features including joint hypermobility, skin and generalized connective tissue fragility. Classical EDS (cEDS) is principally caused by heterozygous COL5A1 or COL5A2 variants and rarely by the COL1A1 p.(Arg312Cys) substitution. Current major criteria are (1) skin hyperextensibility plus atrophic scars and (2) generalized joint hypermobility (gJHM). Minor criteria include additional mucocutaneous signs, epicanthal folds, gJHM complications, and an affected first-degree relative. Minimal criteria prompting molecular testing are major criterion 1 plus either major criterion 2 or 3 minor criteria. In addition to these features, the clinical picture also involves multiple organ systems, but large-scale cohort studies are still missing. This study aimed to investigate the multisystemic involvement and natural history of cEDS through a cross-sectional study on a cohort of 75 molecularly confirmed patients evaluated from 2010 to 2019 in a tertiary referral center. The diagnostic criteria, additional mucocutaneous, osteoarticular, musculoskeletal, cardiovascular, gastrointestinal, uro-gynecological, neuropsychiatric, and atopic issues, and facial/ocular features were ascertained, and feature rates compared by sex and age.

Results

Our study confirms that cEDS is mainly characterized by cutaneous and articular involvement, though none of their hallmarks was represented in all cases and suggests a milder multisystemic involvement and a more favorable natural history compared to other EDS subtypes. Abnormal scarring was the most frequent and characteristic sign, skin hyperextensibility and gJHM were less common, all without any sex and age bias; joint instability complications were more recurrent in adults. Some orthopedic features showed a high prevalence, whereas the other issues related to the investigated organ systems were less recurrent with few exceptions and age-related differences.

Conclusions

Our findings define the diagnostic relevance of cutaneous and articular features and additional clinical signs associated to cEDS. Furthermore, our data suggest an update of the current EDS nosology concerning scarring that should be considered separately from skin hyperextensibility and that the clinical diagnosis of cEDS may be enhanced by the accurate evaluation of orthopedic manifestations at all ages, faciocutaneous indicators in children, and some acquired traits related to joint instability complications, premature skin aging, and patterning of abnormal scarring in older individuals.

The first experience of denosumab therapy on patients with Ehlers-Danlos syndrome and osteoporosis: detailed observation of two patients

Previous studies have shown decreased bone mineral density (BMD) due to an unknown mechanism in Ehlers-Danlos Syndrome (EDS) patients and described approaches to treatment for osteoporosis in EDS. To date, however, there is no established method of treatment. In this study, we investigated two patients with EDS to clarify the efficacy and safety of denosumab treatment in EDS patients with osteoporosis. We retrospectively enrolled two EDS patients with osteoporosis who underwent denosumab therapy. Patient 1 was a 59-year-old male with classical EDS and osteoporosis who received a 48-month course of denosumab therapy. His lumbar BMD and total hip BMD were 1.335 g/cm² and 0.762 g/cm² before treatment, respectively. Forty-eight months later, the lumbar and total hip BMD showed gains of 1.6% and 11.4%, respectively. Patient 2 was a 42-year-old male with vascular EDS and osteoporosis who received an 18-month course of denosumab therapy. His lumbar BMD and total hip BMD were 0.763 g/cm² and 0.583 g/cm² before treatment, respectively. Eighteen months later, the lumbar and total hip BMD showed gains of 5.0% and 1.8%, respectively. No fractures or other complications were recorded during the observational period in both cases. This is the first experience of denosmab therapy on patients with EDS and osteoporosis. Denosumab, administered safely with no serious adverse effects such as fractures, exerted a fluctuating but probably positive effect regarding BMD and could be a treatment option on these patients.

Hyperprolactinemia and bone

Prolactin (PRL) has direct and indirect effects on bone metabolism. Experimental studies showed that in the presence of high PRL levels bone resorption was increased as well as bone formation was suppressed. Increased PRL levels in humans caused a reduction in sex hormone levels which turn may have detrimental effects on bone. Patients with hyperprolactinemia did have often decreased bone mineral density as well as an increased risk of fractures. Since PRL control may be relevant to bone health it is a clinical open issue the inclusion of skeletal health in future guidelines as indication to proactive screening, prevention and treatment particularly in high risk patients such as hyperprolactinemic women after menopause and patients with drug induced hyperprolactinemia.

Bone Disease in Patients with Ehlers-Danlos Syndromes

PURPOSE OF REVIEW

To summarize the bone findings, mainly bone mass and fracture risk, in Ehlers-Danlos syndromes (EDS).

RECENT FINDINGS

Low bone mineral density and fractures seem to be frequent in some of the rare EDS types (kyphoscoliotic, arthrochalasia, spondylodysplastic, and classic-like EDS). For the more prevalent hypermobile and classic EDS types, some case-control studies found mildly decreased bone mineral density, but it was not clear that fracture rates were increased. Nevertheless, abnormalities in vertebral shape seem to be common in classical and hypermobile EDS types. In a cohort of individuals with EDS followed since birth, no fractures were observed during infancy. Bone mineral density varies widely among the different types of EDS, and vertebral abnormalities seem to be common in classical and hypermobile EDS. It might be justified to perform spine radiographs and bone mineral density assessments in newly diagnosed EDS.

Clinical and Molecular Characterization of Classical-Like Ehlers-Danlos Syndrome Due to a Novel TNXB Variant

The Ehlers-Danlos syndromes (EDS) constitute a clinically and genetically heterogeneous group of connective tissue disorders. Tenascin X (TNX) deficiency is a rare type of EDS, defined as classical-like EDS (clEDS), since it phenotypically resembles the classical form of EDS, though lacking atrophic scarring. Although most patients display a well-defined phenotype, the diagnosis of TNX-deficiency is often delayed or overlooked. Here, we described an additional patient with clEDS due to a homozygous null-mutation in the TNXB gene. A review of the literature was performed, summarizing the most important and distinctive clinical signs of this disorder. Characterization of the cellular phenotype demonstrated a distinct organization of the extracellular matrix (ECM), whereby clEDS distinguishes itself from most other EDS subtypes by normal deposition of fibronectin in the ECM and a normal organization of the α5β1 integrin.

Risk of vertebral fractures in hypoparathyroidism

Parathyroid hormone (PTH) exerts both anabolic and catabolic actions on bone,depending on the duration and periodicity of exposure. Hypoparathyroidism is defined by inadequate production of PTH in the presence oflow serum calcium. In hypoparathyroidism it has been reported an increase in corticaland trabecular bone mass, but it is still unknown if these quantitative variations maybe accompanied by qualitative ones and increased bone strength. Despite the extensive data available on the effects of hypoparathyroidism on bone, itseffect on the hard end point in this area which is the risk of fractures still remainsunresolved and highly debated. As a matter of fact no previous review has focused onthis relevant clinical topic. This review will deal with the various aspects of bone metabolism (turn-over,density, quality) in hypoparathyroidism, focusing on the few data available on therisk of fracture and in particular of morphometric vertebral fractures, the emerging way to assess actual skeletal fragility particularly in secondary forms of osteoporosis.