Digital vascular responses and serum endothelin-1 concentrations in primary and secondary Raynaud's phenomenon

Rapid free thiol rebound is a physiological response following cold-induced vasoconstriction in healthy humans, primary Raynaud and systemic sclerosis

Raynaud's phenomenon (RP) is often the first sign of systemic sclerosis (SSc). Molecular mechanisms involved are incompletely understood, but reactive oxygen, nitrogen, and sulfur species are thought to play an important role in the pathogenesis of SSc. Free thiol groups play a protective role against oxidative stress and may represent an attractive therapeutic target. We aimed to investigate the effects of hypothermia-induced vasoconstriction on the responsiveness of redox-related markers. Thirty participants (n = 10/group [SSc, primary Raynaud's phenomenon (PRP), healthy controls (HC)]) were included in this study. Fingertip photoelectric plethysmography was performed during a standardized cooling and recovery experiment. Venous blood was collected at four predetermined time points. Free thiols, NO-derived species (nitros(yl)ated species, nitrite, nitrate), sulfate and endothelin-1 were measured. Lower baseline concentrations of free thiols were observed in PRP and SSc patients (HC: 5.87 [5.41-5.99] μmol/g; PRP: 5.17 [4.74-5.61]; SSc 5.28 [4.75-5.80], P = 0.04). Redox-related markers remained unchanged during cooling. However, an unexpected increase in systemic free thiol concentrations was observed in all groups during the recovery phase. The response of this marker differed between groups, with a higher increase found in SSc patients (HC Δ = 1.30 [1.48-1.17]; PRP Δ = 1.04 [1.06-1.03]; SSc Δ = 1.72 [1.13-1.49], P = 0.04). NO-derived species, sulfate and endothelin-1 levels remained unchanged throughout the recovery phase. This exploratory study sheds light on the rapid responsiveness of systemic free thiol concentrations following reperfusion, which may reflect overall redox balance. The robust response to reperfusion in SSc patients suggests that reductive systems involved in this response are functionally intact in these patients.

A vascular mechanistic approach to understanding Raynaud phenomenon

During exposure to cold, our bodies attempt to maintain normal core temperature by restricting heat loss through cutaneous vasoconstriction, and by increasing heat production through shivering and nonshivering thermogenesis. In selected areas of human skin (including on the fingers and toes), the vascular system has specialized structural and functional features that enable it to contribute to thermoregulation. These features include arteriovenous anastomoses, which directly connect the arterial and venous systems and bypass the nutritional capillaries supplying blood to the skin tissue. Of note, Raynaud phenomenon predominantly affects the arterial territories supplying these specialized areas of skin. Indeed, Raynaud phenomenon can be considered a disorder of vascular thermoregulatory control. This Review presents an understanding of Raynaud phenomenon in the context of vascular and thermoregulatory control mechanisms, including the role of unique thermosensitive vascular structural and functional specialization, and describes the potential role of thermogenesis in this disorder. This new approach provides remarkable insight into the disease process and builds a framework to critically appraise the existing knowledge base. This paradigm also explains the deficiencies in some current therapeutic approaches, and highlights new areas of potential relevance to the pathogenesis and treatment of Raynaud phenomenon that should be expanded and explored.

The association between vibration and vascular injury in rheumatic diseases: a review of the literature

Vascular manifestations can be seen early in the pathogenesis of inflammatory rheumatic diseases. Animal experiments, laboratory and clinical findings indicated that acute or long-term vibration exposure can induce vascular abnormalities. Recent years, in addition to Raynaud's phenomenon (RP), vibration as a risk factor for other rheumatic diseases has also received corresponding considered. This review is concentrated upon the role of vibration in the disease of systemic sclerosis (SSc). In this review, we are going to discuss the main mechanisms which are thought to be important in pathophysiology of vascular injury under the three broad headings of "vascular", "neural" and "intravascular". Aspects on the vibration and vascular inflammation are briefly discussed. And the epidemiological studies related to vibration studies in SSc and other rheumatic diseases are taken into account.

Herbal Prescription, DSGOST, Prevents Cold-Induced RhoA Activation and Endothelin-1 Production in Endothelial Cells

Herbal prescription, Danggui-Sayuk-Ga-Osuyu-Saenggang-tang (DSGOST), has long been used to treat Raynaud's phenomenon (RP) in traditional Chinese medicine (TCM). However, a biological mechanism by which DSGOST ameliorates RP is yet deciphered. In this study, we demonstrate that DSGOST inhibits cold-induced activation of RhoA, in both vascular smooth muscle cells (VSMC) and endothelial cells (EC), and blocks endothelin-1-mediated paracrine path for cold response on vessels. While cold induced RhoA activity in both cell types, DSGOST pretreatment prevented cold-induced RhoA activation. DSGOST inhibition of cold-induced RhoA activation further blocked α2c-adrenoreceptor translocation to the plasma membrane in VSMC. In addition, DSGOST inhibited endothelin-1-mediated RhoA activation and α2c-adrenoreceptor translocation in VSMC. Meanwhile, DSGOST inhibited cold-induced or RhoA-dependent phosphorylation of FAK, SRC, and ERK. Consistently, DSGOST inhibited cold-induced endothelin-1 expression in EC. Therefore, DSGOST prevents cold-induced RhoA in EC and blocks endothelin-1-mediated paracrine path between EC and VSMC. In conclusion, our data suggest that DSGOST is beneficial for treating RP-like syndrome.

Avaliação da capilaroscopia usando Endotelina-1 como um marcador de ativação endotelial na lesão microvascular e úlceras cutâneas

OBJETIVO: Avaliar a presença da ET-1 em pacientes portadores de esclerodermia e a sua correlação com o nível de atividade da doença; verificar se os níveis de endotelina estão associados com o perfil clínico e de autoanticorpos da esclerodermia e, ainda, se há associação com lesão microvascular detectada pela capilaroscopia periungueal. MÉTODOS: Um total de 74 pacientes, sendo 37 portadores de esclerodermia e o restante controle, foram submetidos à dosagem de ET-1 por meio de teste de ELISA. Pacientes com esclerodermia foram analisados através de um questionário sobre características da doença e pesquisa de autoanticorpos. A gravidade da doença foi definida pelos critérios de Medsger e a doença microvascular foi acessada através de capilaroscopia periungueal. RESULTADOS: Dos 37 pacientes com esclerodermia três (8,1%) eram homens e 34 (91,89%) mulheres, com idade média de 48,97 ? 13,36 anos e tempo médio de doença de 42,54 ? 13,35 anos. Os valores da ET-1 nos controles foram de 0,41 a 5,65 pg/ml (mediana de 2,26 pg/ml) e nos com esclerodermia de 0,41 a 8.82 pg/ml (mediana de 0,41 pg/ml) com p de 0,0007. Não houve correlação com o tempo de doença, idade do paciente e com o nível de acometimento cutâneo. Não encontrou-se correlação entre nível de ET-1 sérica e gravidade da doença (p=0,13). Níveis maiores de ET-1 foram observados na forma de superposição (1,49 a 6,82 pg/ml). CONCLUSÃO: Os níveis de ET-1 em esclerodérmicos mostraram-se inferiores aos controles. Não houve associação dos níveis de ET-1 com as variáveis estudadas.

Care of patients with scleroderma in the intensive care setting

Scleroderma or systemic sclerosis (SSc) is a connective tissue disease (CTD) associated with fibrosing and vascular complications involving multiple organs. The care of these patients in the critical care setting is frequently challenging due to multiple complications and refractory organ involvement. However, awareness of specific organ involvement associated with scleroderma can allow many complications to be anticipated and effectively treated. Cardiac involvement can lead to arrhythmias and heart failure, whereas pulmonary involvement can be associated with pulmonary arterial hypertension, fibrosis, or both. Renal vascular disease and scleroderma renal crisis (SRC), once a uniformly fatal complication, is particularly important to recognize early, as it can be treated successfully. Gastrointestinal involvement can lead to bleeding, aspiration, obstruction, and malabsorption. Severe Raynaud may lead to digital ischemia and gangrene. Therapies must target involved organ system or organ systems. Corticosteroids, a mainstay for related CTDs, do not typically provide any benefit and may cause harm. Vasodilators can effectively treat vascular complications but must target the appropriate vascular bed. Proactive utilization of proton pump inhibitors, recognition of bleeding from gastrointestinal vascular ectasia, and nutritional support can considerably ameliorate gastrointestinal morbidities. Effective treatment of fibrotic complications remains elusive and is the current frontier for scleroderma therapeutics.

[Primary and secondary Raynaud's phenomenon]

The term Raynaud's phenomenon describes an abnormal vasospastic response to cold or emotional stress. It is a common condition with a prevalence of 3-5% of the population. Clinically, Raynaud's phenomenon manifests as sharply demarcated colour changes of the skin of the digits that is often accompanied by paraesthesia. Raynaud's phenomenon can be subdivided into primary, or idiopathic, and secondary forms, in the latter of which associated diseases or causes can be identified. The pathogenesis of the disease is incompletely understood. Pathologic changes have been observed primarily in vascular smooth muscle cells, endothelial cells and perineuronal microvasculature. Current therapeutic strategies include supportive treatments, topical therapeutic approaches and systemic medication. Drug therapies with proven efficacy include calcium channel blockers, prostacyclin analogues, fluoxetine, losartan and sildenafil.

Acute dermatomyositis associated with generalized subcutaneous edema

Generalized subcutaneous edema is an uncommon manifestation of inflammatory myopathy. We report a 48-year-old female patient who presented with severe generalized edema, an erythematous skin rash, dysphagia and proximal muscle weakness. She was diagnosed with dermatomyositis from the clinical signs, increased muscle enzymes, electromyographic findings and a muscle biopsy. Magnetic resonance imaging revealed increased signal intensity in the muscular and subcutaneous layers. The conditions causing generalized edema were excluded. It was concluded that the generalized edema was secondary to dermatomyositis. Aggressive treatments with high-dose glucocorticoids and immunosuppressive agents were used to control the severe subcutaneous edema.

Severe subcutaneous generalized edema in a patient with dermatomyositis

Subcutaneous generalized edema associated with dermatomyositis (DM)/polymyositis (PM) is extremely rare. Herein we report a case of severe subcutaneous generalized edema complicating DM. A 78-year-old woman was hospitalized in our department because of massive edema in the four limbs. Elevated muscle enzymes, heliotrope rash, results of electromyography, and muscle biopsy confirmed the diagnosis of DM. The absence of other diseases that could cause the symptoms indicated that massive edema was correlated with the pathophysiology of DM. Although myopathy and edema responded well to oral prednisolone, dysphagia persisted. We conclude that subcutaneous generalized edema can occur during the course of DM/PM, and subcutaneous vasculopathy may be involved in the pathogenesis of DM/PM.

A cold-response index for the assessment of Raynaud's phenomenon

BACKGROUND

Quantification of Raynaud's phenomenon (RP) is a prerequisite in the evaluation of novel therapeutic strategies. Fingertip rewarming in response to local cold provocation has been used in many studies but not been systematically validated. We have previously described the time elapsed before 63% of pre-cooling temperature is reached as a RP activity index.

OBJECTIVE

A comprehensive evaluation of fingertip rewarming in primary and scleroderma-associated RP.

METHODS

We defined a cold-response index (CRI) as the log transformation of the 63% rewarming time upon cold challenge.

RESULTS

The CRI shows high intra-individual reproducibility. The mean CRI values were (mean+/-S.D.): 2.4+/-0.3 in controls (n=53) versus 2.7+/-0.3 in RP (n=50, p<0.0001 versus controls), and 2.7+/-0.3 in scleroderma patients (n=46, p<0.0001). In addition, baseline fingertip temperature was also found to be significantly reduced both in primary as well as scleroderma-associated RP. Kinetic analysis of rewarming temperature curves demonstrates that the CRI is independent of individual rewarming patterns. Finally, the CRI decreases significantly upon a single low-level systemic hyperthermia treatment in scleroderma patients (2.68+/-0.28 before versus 2.45+/-0.33 after, p=0.0003), while the extent of cooling remained unchanged, thus demonstrating sensitivity to change.

CONCLUSION

Our results provide a solid basis for using the cold-response assay as an endpoint in addition to clinical activity scores in RP treatment trials.

Raynaud-Phänomen in der Dermatologie

Raynaud phenomenon (RP) is characterized by recurrent spasms of small digital arterioles/arteries at fingers and toes, usually triggered by cold and emotional stress. Clinically a sudden pallor of individual digits is followed by reactive hyperemia, in severe cases also by cyanosis. One distinguishes between primary RP, i.e. RP without an underlying disease or drug intake, and secondary RP, which is causally related to an underlying disease or to intake of certain drugs (e.g. interferon, cisplatin). Primary RP is frequent (prevalence of about 13-20% in northern or central Europe), while secondary RP is rare, but the major presenting symptom for systemic sclerosis (SSc). Differential diagnosis includes cold-induced pallor, acute embolic events, paroxysmal hematoma of the finger or erythromelalgia. Vasoconstrictive mechanisms outweigh vasodilatory ones in endothelial cells and vascular smooth muscle. Although soluble mediators such as endothelin or certain prostaglandins have been exploited successfully for therapy, the extent of their involvement in the initial pathophysiology of RP is unclear. Secondary RP (associated with SSc) additionally features morphological alterations with compromise of the vessel lumen. As RP can result in severe discomfort and complications, timely diagnosis and treatment is essential.

Mechanisms of Raynaud's disease

Raynaud's phenomenon is due to transient cessation of blood flow to the digits of the hands or feet. An attack of Raynaud's phenomenon is classically manifested as triphasic color changes. The white phase is due to excessive vasoconstriction and cessation of regional blood flow. This phase is followed by a cyanotic phase, as the residual blood in the finger desaturates. The red phase is due to hyperemia as the attack subsides and blood flow is restored. An attack is frequently associated with pain and/or paresthesia due to sensory nerve ischemia. Variants of Raynaud's phenomenon include acrocyanosis and primary livedo reticularis, each of which is associated with reduced skin blood flow, exacerbated by cold or emotional upset. Raynaud's phenomenon in the absence of other disorders is primary Raynaud's phenomenon, or Raynaud's disease. The mechanisms of Raynaud's disease include increased activation of the sympathetic nerves, in response to cold or emotion; an impaired habituation of the cardiovascular response to stress may contribute. In addition, there appears to be a local fault, which is likely multifactorial. This local fault is due to an alteration in vascular function rather than vascular structure. The alteration in vascular function may be related to increased sensitivity to cold of the adrenergic receptors on the digital artery vascular smooth muscle. In some cases, locally released or systemically circulating vasoconstrictors may participate, including endothelin, 5-hydroxytryptamine and thromboxane. A deficiency or increased degradation of nitric oxide, possibly due to increased oxidative stress, may be involved in some cases. These recent pathophysiological insights may lead to new therapeutic options.

Infrared-monitored cold response in the assessment of Raynaud's phenomenon

BACKGROUND

Evaluation of treatments for Raynaud's phenomenon (RP) requires objective response parameters in addition to clinical activity scores. Thermographic monitoring of fingertip re-warming after cold challenge has been widely used but usually requires sophisticated equipment. We have previously shown that fingertip re-warming after cold challenge follows a first-order transient response curve that can be described by a single variable, designated tau.

OBJECTIVES

Here, we describe a novel device termed a duosensor, which records the tau value upon cold challenge in an automated manner.

METHODS

We determined tau values in healthy probands, patients with primary or secondary RP associated with autoimmune disease and patients with scleroderma-associated RP following cold challenge, to determine assay variability, sensitivity and specificity.

RESULTS

Duosensor-based thermography exhibited low intraindividual variability in healthy probands. As expected, tau values in RP patients were significantly increased compared with controls (8.08 +/- 3.65 min vs. 3.23 +/- 1.65 min). The duosensor-determined tau value yielded a specificity of 94.6% and predictive value of 95.3% for the presence of RP in a retrospective analysis of 139 patients. Furthermore, in a cohort of scleroderma patients with RP, patient self-assessment of RP severity correlated with tau values.

CONCLUSIONS

Taken together, the present data suggest that tau value determination provides a suitable outcome measure for clinical studies of novel RP treatments. As the duosensor is a simple stand-alone device requiring no supporting equipment and minimal personnel attention, it should allow RP activity monitoring even in clinical settings with minimal technical infrastructure.

Pathogenesis of Raynaud's phenomenon

The pathogenesis of Raynaud's phenomenon is not fully understood. However, the last 20 yr have witnessed enormous increases in our understanding of different mechanisms which, singly or in combination, may contribute. A key point is that Raynaud's phenomenon can be either primary (idiopathic) or secondary to a number of underlying conditions, and that the pathogenesis and pathophysiology vary between these conditions. This review concentrates upon those subtypes of Raynaud's phenomenon of most interest to rheumatologists: systemic sclerosis-related Raynaud's phenomenon, primary Raynaud's phenomenon and Raynaud's phenomenon secondary to hand-arm vibration syndrome. In this review, I shall discuss the main mechanisms thought to be important in pathophysiology under the three broad headings of 'vascular', 'neural' and 'intravascular'. While these are false distinctions because all interrelate, they facilitate discussion of the key elements: the blood vessel wall (particularly the endothelium), the neural control of vascular tone, and the many circulating factors which can impair blood flow and/or cause endothelial injury. Vascular abnormalities include those of both structure and function. Neural abnormalities include deficiency of the vasodilator calcitonin gene-related peptide (released from sensory afferents), alpha(2)-adrenoreceptor activation (possibly with up-regulation of the normally 'silent' alpha(2C)-adrenoreceptor) and a central nervous system component. Intravascular abnormalities include platelet activation, impaired fibrinolysis, increased viscosity and probably oxidant stress. As our understanding of the pathophysiology of Raynaud's phenomenon increases, so do our possibilities for identifying effective treatments.

Raynaud’s Phenomenon and Endothelial Dysfunction in End-Stage Renal Disease Patients Treated with Hemodialysis

BACKGROUND/AIMS

Steal syndrome is a well-known complication of arteriovenous shunt placement. Increased frequency of Raynaud's phenomenon (RP) especially concerning shunt limb is reported among hemodialysis (HD) patients. The aim of the study was to assess the relation of impairment of peripheral circulation diagnosed with cold stress test (CST) and thermography to the AV shunt location and markers of endothelial dysfunction in HD patients.

METHODS

The study group comprised 21 patients (6 male, 15 female, mean age 32.6 +/- 15.0 years) treated with HD for a mean of 69 +/- 54 months. 10 healthy individuals (4 male, 6 female, mean age 38.6 +/- 14.7 years) served as controls. The diagnosis of RP was made upon the results of thermographic measurements during CST. Von Willebrand factor activity and antigen, endothelin-1 and plasma total homocysteine (tHcy) were measured in all subjects.

RESULTS

RP was found significantly more often in HD patients than in controls: 11/21 vs. 1/10 (p = 0.04). RP occurred in both hands in 7/11 (64%) patients. tHcy was higher in HD patients than in the controls (31.7 +/- 13.9 vs. 10.9 +/- 3.2 microg/l, p < 0.0001). tHcy and von Willebrand factor antigen were significantly higher in the RP-positive than RP-negative patients or controls.

CONCLUSION

Small vessel dysfunction diagnosed as positive RP is a frequent finding in HD patients. It seems that endothelial injury rather than AV shunt steal syndrome is responsible for development of RP in HD patients.

Laser Doppler-recorded venoarteriolar reflex in Raynaud's phenomenon

The aim of the study was to assess whether Laser Doppler-recorded venoarteriolar reflex (VAR) response to hand lowering can contribute to differentiate primary from secondary Raynaud's phenomena.

MATERIALS AND METHODS

Skin fingerpulp perfusion (PU) of each hand of 60 persons was investigated: 15 healthy controls; 15 primary Raynaud's phenomenon (RP) patients; 15 patients with Raynaud's phenomenon secondary to systemic sclerosis (SSc); 15 patients with Raynaud's phenomenon secondary to vibration exposure. Blood perfusion was monitored by Laser Doppler flowmetry (LDF) as initial values and at a temperature of 32 degrees C with hands on the sternum (PUh) and in dependency (PUd). VAR indices were analyzed: delta VAR (DeltaVAR) calculated as (PUd-PUh); percent change of perfusion--[(DeltaVAR/PUh) x 100]; and vasoconstriction response--(PUd/PUh).

RESULTS

Initial mean superficial skin temperatures and perfusions in Raynaud's phenomenon groups were significantly lower compared to healthy controls but with wide overlap of the values in individual cases. Venoarteriolar indices were significantly different between secondary Raynaud's phenomenon groups and healthy controls and between secondary and primary Raynaud's phenomenon groups. Percent changes were significantly higher in control and primary RP groups compared to secondary RP groups. Vasoconstriction indices between primary and secondary RP patients (p<0.0001) and between controls and secondary RP patients (p<0.0001) also differed. A loss of venoarteriolar reflex (DeltaPU>or=0) was established in 10.0% of primary, 53.3% of sclerodermic, and 36.7% of vibration-induced Raynaud's phenomenon patients. The significantly higher prevalence rate of impaired venoarteriolar reflex in secondary Raynaud's phenomenon patients proves local vasomotor dysfunction and reflects either postganglionar sympathetic insufficiency with vascular tone failure or altered smooth muscle cells' responses.

CONCLUSIONS

Laser Doppler flowmetry is a valuable noninvasive method for investigation of the very early skin venoarteriolar dysfunctions, for evaluation of focal autonomic dysregulation and skin vasomotor abnormalities in RP patients. Laser Doppler-recorded venoarteriolar reflex testing is a simple procedure and an adequate additional diagnostic tool, which contributes to diagnose RP and differentiate primary from secondary RP.

The vasculopathy of Raynaud's phenomenon and scleroderma

The scleroderma (SSc) disease process involves dramatic dysfunction in acute and chronic vascular regulatory mechanisms; it presents initially with heightened vasoconstrictor or vasospastic activity and progresses to structural derangement or vasculopathy of the microcirculation. This article discusses the regulatory mechanisms that contribute to this dysfunction and the vascular changes in the context of the other aspects of the SSc disease process in a novel attempt to integrate the individual pathologies of the disease process.

Current Treatment Options in Raynaud's Phenomenon

The treatment of Raynaud's phenomenon (RP) strictly depends on the severity of symptoms and on the presence of an underlying systemic disease. For this reason, any patient with RP should be carefully assessed for signs and symptoms that may herald an underlying disease. Primary RP can usually be managed with conservative nonpharmacologic lifestyle modifications (eg, avoidance of cold temperatures, tobacco, caffeine, and any drug interfering with vascular tone) and pharmacologic treatment added only if attacks are poorly controlled. Vasodilating drugs (eg, calcium channel blockers, angiotensin II receptor antagonists, topical nitrates, and prostanoids) are still the mainstay of medical therapy for RP. Anecdotal reports with different kinds of therapies appear regularly but always need evidence-based confirmation. In particular, antioxidant agents may be useful in limiting the progressive endothelial damage. Novel therapeutic tools interfering either with primary or secondary pathogenetic processes (ie, endothelial and peripheral nervous system dysfunction and smooth muscle cell hypertrophy) are awaited.

Raynaud's phenomenon: epidemiology and risk factors

Although originally described more than 100 years ago, the pathophysiology of Raynaud's phenomenon (RP) remains incompletely understood. Epidemiologic studies have the potential to improve our understanding of the pathogenesis of RP and to identify potential targets for therapeutic interventions. Such studies require standardized instruments to accurately identify subjects with RP. Dr. Maricq was the first to develop and validate a standardized instrument to classify patients with this disorder. Her work has facilitated many of the epidemiologic studies of RP that are discussed in this review.

Raynaud's phenomenon

Raynaud's phenomenon is characterised by episodic vasospasm of the fingers and toes typically precipitated by exposure to cold. Mild Raynaud's is common and is not usually a harbinger of clinically important disability; its onset, however, can be startling and uncomfortable for patients, and the well recognised association in some cases with systemic rheumatic conditions often precipitates aggressive assessments for underlying diseases. Advances in vascular physiology have shed light on the role of the endothelium as well as endothelium-independent mechanisms in the altered vasoregulation of Raynaud's. We review clinical aspects of the disorder and new insights with respect to pathophysiology, and we discuss potential new therapeutics based on the disease mechanism, such as prostacyclin analogues, serotonin antagonists, and calcitonin gene-related peptides.