Histopathological aid at the diagnosis of the Ehlers-Danlos syndrome, gravis and mitis types

Ex vivo nonlinear microscopy imaging of Ehlers-Danlos syndrome-affected skin

Ehlers-Danlos syndrome (EDS) is the name for a heterogenous group of rare genetic connective tissue disorders with an overall incidence of 1 in 5000. The histological characteristics of EDS have been previously described in detail in the late 1970s and early 1980s. Since that time, the classification of EDS has undergone significant changes, yet the description of the histological features of collagen morphology in different EDS subtypes has endured the test of time. Nonlinear microscopy techniques can be utilized for non-invasive in vivo label-free imaging of the skin. Among these techniques, two-photon absorption fluorescence (TPF) microscopy can visualize endogenous fluorophores, such as elastin, while the morphology of collagen fibers can be assessed by second-harmonic generation (SHG) microscopy. In our present work, we performed TPF and SHG microscopy imaging on ex vivo skin samples of one patient with classical EDS and two patients with vascular EDS and two healthy controls. We detected irregular, loosely dispersed collagen fibers in a non-parallel arrangement in the dermis of the EDS patients, while as expected, there was no noticeable impairment in the elastin content. Based on further studies on a larger number of patients, in vivo nonlinear microscopic imaging could be utilized for the assessment of the skin status of EDS patients in the future.

Neurovascular manifestations of connective-tissue diseases: A review

Patients with connective tissue diseases are thought to be at a higher risk for a number of cerebrovascular diseases such as intracranial aneurysms, dissections, and acute ischemic strokes. In this report, we aim to understand the prevalence and occurrences of such neurovascular manifestations in four heritable connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome, Neurofibromatosis Type 1, and Loeys-Dietz syndrome. We discuss the fact that although there are various case studies reporting neurovascular findings in these connective tissue diseases, there is a general lack of case-control and prospective studies investigating the true prevalence of these findings in these patient populations. Furthermore, the differences observed in the manifestations and histology of such disease pathologies encourages future multi-center registries and studies in better characterizing the pathophysiology, prevalence, and ideal treatment options of neurovascular lesions in patents with connective tissue diseases.

Ultrastructural Alterations of Elastic Fibers and Other Dermal Components in Ehlers-Danlos Syndrome of the Hypermobile Type

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective tissue disorders with varied molecular abnormalities. Some morphologic alterations are described in collagen and elastic fibers. We report on previously undescribed ultrastructural changes in the elastic fibers found in the skin of 22 of 29 patients suffering from the hypermobile type of EDS. They existed in variable combinations of a fragmented appearance with frayed contours, internal microcavities, some elastotic-like changes, and discrete calcified foci. The collagen fibrils and their bundles were also altered with morphologic aspects reminiscent of those found in the classical type of EDS. Large globules of hyaluronic acid were also dispersed in the amorphous matrix.

A four-generation Ehlers-Danlos syndrome with vascular dissections. Skin ultrastructure and biomechanical properties

Ehlers-Danlos syndrome (EDS) is heterogenous with regard to genetic traits, clinical manifestation, the biomechanical and microscopic properties of connective tissues, and basic molecular defects. We report on nine relatives of four generations who suffered from large vessel dissections and cutaneous microscopic changes consistent with EDS. Measurements of the mechanical properties of skin were performed using a computerized suction device (Cutometer). Morphological and biomechanical alterations suggestive of EDS were present in all examined subjects. A loose network of collagen bundles was admixed with clumsy elastic fibres. Factor XIIIa-positive dermal dendrocytes looked almost normal but were slim and rarefied in four subjects. The severity in ultrastructural alterations of the collagen network differed among the subjects. The group with the most prominent changes showed the most striking biomechanical alterations characterized by increased biologic elasticity without any excess in skin extensibility. A positive correlation was found between skin extensibility and elasticity. In conclusion, distinct alterations in the collagen scaffolding were found to be correlated to variable severity in biomechanical alterations of the skin. The predictive value of these changes for large vessel dissections in some families at risk remains to be settled.

Collagen fibril arabesques in connective tissue disorders

BACKGROUND

In various connective tissue disorders, collagen fibrils and elastic fibers may exhibit some ultrastructural abnormalities.

OBJECTIVE

This electron microscopy study focused on collagen fibril orientation and unusual shapes in the dermis of Ehlers-Danlos syndrome (EDS) and related entities, including spontaneous cervical artery dissection syndrome and recurrent preterm premature rupture of fetal membranes syndrome.

RESULTS

In addition to some abnormal fibril shapes typically found in these syndromes, other conformations (hook shaped, S shaped, ring shaped) that have not been illustrated previously in the literature were observed.

CONCLUSION

The abnormal collagen fibril conformations observed in EDS and other related conditions characterized by tissue fragility likely affect both the internal cohesiveness of the bundles and the mechanobiologic properties of the tissue.

Ehlers-Danlos-like dermal abnormalities in women with recurrent preterm premature rupture of fetal membranes

Preterm premature rupture of membranes (PPROM) likely results from weakening of the constituent connective tissue. It is uncertain if the alterations are limited to the fetal membranes or are also present in other sites such as the skin. The aim of the study was to compare the dermal structure of women suffering from recurrent PPROM with the dermis of both non-pregnant women and women with uneventful gestation. Skin biopsies were taken from 42 women who recently underwent PPROM, 33 women with uneventful gestation and 33 non-pregnant women. Histochemistry, immunohistochemistry, and electron microscopy were performed on these specimens and analyzed blindly. Morphologic changes were found in the dermis of most (33 of 42 at optical microscopy and 40 of 42 at ultrastructure) of the women suffering from PPROM. They were reminiscent of those found in some types of Ehlers-Danlos Syndrome (EDS). However, there was no clinical evidence suggesting a recognized form of EDS. We conclude that some cases of PPROM are a systemic connective tissue disorder representing a yet unidentified type of EDS.

Factor XIIIa-positive Dendrocyte Rarefaction in Ehlers-Danlos Syndrome, Classic Type

The Ehlers-Danlos syndrome (EDS) represents a heterogeneous group of connective tissue disorders recognized by distinct clinical, microscopic, and biochemical aspects. In particular, some histologic and ultrastructural clues have been reported in the literature. We present a novel immunohistochemical aid to the diagnosis of the most frequent type of EDS. Factor XIIIa-positive dendrocytes are almost absent in the reticular dermis and markedly reduced in number and size in the adventitial dermis. By contrast, the densities of vimentin-positive cells and CD34-positive cells were unremarkable. The biologic significance of this finding is unknown. However, at least a subset of dermal dendrocytes interacts with fibroblasts. This mechanism could be affected in the classic form of EDS.

Wrinkly skin syndrome: ultrastructural alterations of the elastic fibers

We report the clinical and pathologic features of a patient with wrinkly skin syndrome. The essential clinical features were wrinkly skin with poor elasticity over the abdomen and on the dorsum of the hands and feet, increased palmar and plantar creases, and a prominent venous pattern over the chest. On light microscopy, histopathologic findings included appreciable heterogeneity in the structure, amount, and distribution pattern of elastic fibers. Agglutination and fragmentation of the microfibrillar component and a remarkable decrease in elastin were the major ultrastructural features. The differential diagnosis with other connective tissue disorders is discussed.

Mechanical properties of skin in Ehlers-Danlos syndrome, types I, II, and III

Mechanical properties of skin were evaluated in vivo in 17 children suffering from Ehlers-Danlos syndrome (EDS) types I, II, and III. These were compared with normal values from 63 healthy children. Noninvasive measurements were performed under suction of 500 mbar using a Cutometer equipped with a 4-mm probe. Prominent increases in skin extensibility and elasticity were the most distinctive and diagnostic features of all three EDS types. Differences in the average values of biomechanical variables were present among the three types. Patients with EDS-I were the most affected, whereas those with EDS-III had virtually normal skin. However, interindividual differences in the severity of rheological alterations were found within each type, illustrating a continuum in the variation of mechanical properties of EDS skin rather than yielding step differences among the types.

The Ehlers-Danlos syndrome: recognition, characterization, and importance of a milder variant of the classic form. A preliminary study

The diagnosis of Ehlers-Danlos syndrome is based on the clinical criteria of joint hypermobility, increased skin extensibility, abnormal scarring, and easy bruisibility. The literature reports this syndrome as rare, yet our experience dictated to the contrary. The present study of the prevalence of Ehlers-Danlos syndrome in a general dermatology population revealed (1) a milder variant of the classic mitis form of Ehlers-Danlos syndrome was common and present in 9% of the population studied, (2) these patients could be easily identified by the use of a defined clinical scoring system, and (3) a statistically significant association existed between clinical findings in Ehlers-Danlos syndrome and electron microscopic collagen abnormalities. The identification of this syndrome may be important prognostically in patients with diseases or conditions in which collagen plays a major role, such as joint disease (dislocations), bruising disease (pigmented purpura), and potentially scarring diseases (acne, patients undergoing cutaneous surgery).

Morphometric study of cauliflower collagen fibrils in Ehlers-Danlos syndrome type I

The abnormal cauliflower collagen fibrils present in skin of patients with Ehlers-Danlos type I were studied by electron microscopy and computerized image analysis. The size control of the few fibrils displaying a cauliflower shape is apparently lost, eventuating in an increased amount of collagen polymers constitutive of these fibrils. This situation is fundamentally different from that occurring in dermatosparaxis, an animal disease considered as a model for Ehlers-Danlos syndrome.

Reduced collagen content and fibre bundle disorganization in skin biopsies of patients with Ehlers-Danlos syndrome

Skin biopsies from 25 patients with the Ehlers-Danlos Syndrome and 15 site, sex and age matched controls were studied by the picrosirius polarization procedure, a specific method for collagen detection in tissue sections. When used in conjunction with histophotometry, this technique permits a quantitative assay of collagen content in the dermis. The light emission measurements obtained showed a statistically significant reduction in the dermal collagen density of Ehlers-Danlos syndrome patients as compared to their controls. Qualitatively, the dermal collagen fibres of these patients appeared frayed and of reduced diameter. These findings indicate that collagen is quantitatively decreased in skin biopsies of patients with the Ehlers-Danlos syndrome.