Mechanisms of Raynaud's disease

Neurofascialvascular training for the treatment of Raynaud's phenomenon: A case report

Primary Raynaud's phenomenon (PRP) is characterised by episodic, reversible, and disabling vasospasms of the peripheral arteries. In the most severe cases, it can lead to ulceration of the fingers and toes. Neuro fascial VascularTraining (NFVT) is a novel therapeutic approach for treating PRP. NFVT aims to enhance peripheral circulation and stimulate the autonomic nervous system (ANS) by engaging multiple physiological mechanisms simultaneously. This integrated approach works to reduce vasospasms and alleviate associated symptoms through neurodynamic and myofascial interventions. A 54-year-old woman, who has experienced pain and hypoesthesia in her hands for 9 years, received a diagnosis of PRP without systemic sclerosis in 2014. The patient reported daily colour changes in her fingers, along with pain and a temporary decrease in tactile sensitivity. The patient engaged in ten 30-minute exercise sessions, and the clinical outcomes were assessed based on several parameters. These included the frequency and duration of vasospastic attacks, evaluated using the Raynaud Condition Score, as well as pain and tingling, measured through the daily Numeric Rating Scale. The Composite Autonomic Symptom Score (COMPASS 31) was utilised to assess dysautonomia, while the frequency of medication use and the Disabilities of the Arm, Shoulder, and Hand questionnaire were also considered. The results indicated a significant improvement in symptoms. NFVT improved symptoms and motor dysfunction in a patient with Raynaud's syndrome, demonstrating how NFVT can increase peripheral blood flow, stimulate the ANS, and improve symptoms in PRP.

Cold hypersensitivity in the hands and feet is associated with erectile dysfunction in young Taiwanese men

Cold hypersensitivity in the hands and feet (CHHF) is a protective or predisposing factor for many diseases; however, the relationship between CHHF and erectile dysfunction (ED) remains unclear. We aimed to investigate associations between CHHF and ED among young men of Southeast Asian origin. In this cross-sectional study, sexually active Taiwanese men aged 20-40 years were enrolled via an online questionnaire comprising general demographic information, comorbidities, subjective thermal sensations of their hands and feet in the past 6 months, and their erectile function using the International Index of Erectile Function-5 (IIEF-5). Participants who reported cold sensation of hands and feet were classified to have CHHF; those with IIEF-5 score ≤ 21 were considered to have ED. Total 54.2% and 27.9% of participants had ED and CHHF, respectively. Men with CHHF were significantly younger, had lower body mass index and IIEF-5 scores (p < 0.001), and a lower prevalence of diabetes mellitus (p = 0.033) along with higher prevalence of ED, psychiatric disorders, and insomnia (p < 0.001). After adjusting for predisposing factors of ED, CHHF (odds ratio 1.410, 95% confidence interval 1.159-1.714; p = 0.001) remained an independent predictor of ED. Thus, CHHF is independently associated with ED, affecting more than a quarter of young Taiwanese men. Autonomic dysregulation and subclinical endothelial dysfunction may be common pathophysiologies of CHHF and ED.

Cure of Fingertip Necrosis after Median Nerve Block Application in Two Cases of Definite and Probable Systemic Sclerosis

One patient with systemic sclerosis with index fingertip necrosis and another with probable systemic sclerosis with index and middle fingertip impending necroses were successfully treated with ultrasound-guided median nerve block application on the affected side. The nailfold temperatures of the affected fingers measured using thermography were below 25°C. Immediately after application, the temperature increased substantially. After repeated applications, the mean basal temperature on the affected side increased by 3.6°C in Case 1 and by 5.9°C in Case 2. Peripheral nerve block can be a basic treatment for fingertip necrosis. The thermographical observation of the extent and region in which the temperature increased is novel.

Inhibiting Intracellular α2C-Adrenoceptor Surface Translocation Using Decoy Peptides: Identification of an Essential Role of the C-Terminus in Receptor Trafficking

The G protein-coupled α2-adrenoceptor subtype C (abbreviated α2C-AR) has been implicated in peripheral vascular conditions and diseases such as cold feet-hands, Raynaud's phenomenon, and scleroderma, contributing to morbidity and mortality. Microvascular α2C-adrenoceptors are expressed in specialized smooth muscle cells and mediate constriction under physiological conditions and the occlusion of blood supply involving vasospastic episodes and tissue damage under pathological conditions. A crucial step for receptor biological activity is the cell surface trafficking of intracellular receptors, triggered by cAMP-Epac-Rap1A GTPase signaling, which involves protein-protein association with the actin-binding protein filamin-2, mediated by critical amino acid residues in the last 14 amino acids of the receptor carboxyl (C)-terminus. This study assessed the role of the C-terminus in Rap1A GTPase coupled receptor trafficking by domain-swapping studies using recombinant tagged receptors in transient co-transfections and compared with wild-type receptors using immunofluorescence microscopy. We further tested the biological relevance of the α2C-AR C-terminus, when introduced as competitor peptides, to selectively inhibit intracellular α2C-AR surface translocation in transfected as well as in microvascular smooth muscle cells expressing endogenous receptors. These studies contribute to establishing proof of principle to target intracellular α2C-adrenoceptors to reduce biological activity, which in clinical conditions can be a target for therapy.

Cold Hands or Feet: Is It Raynaud's or Not?

Raynaud's phenomenon is an exaggerated response to cold stimuli that may be primary or secondary. The diagnosis relies on patient history and physical examination to distinguish RP from other vasomotor dysfunction (e.g. acrocyanosis, pernio, small fiber neuropathy with vasomotor symptoms, and complex regional pain syndrome). Achenbach syndrome, or spontaneous venous hemorrhage, may also be mistaken for RP but is a self-limiting phenomenon. Laboratory evaluation and vascular diagnostic testing may identify SRP causes. Regardless of etiology, treatment includes warming with trigger avoidance, and consideration of vasodilators (eg. calcium channel, alpha-1 blockers). SRP with digital ulceration may require PDE5i, endothelin-1 receptor blockers, and prostanoids. Refractory cases may require pneumatic arterial pumps, botulinum toxin administration, or surgical sympathectomy.

Self-assembled innervated vasculature-on-a-chip to study nociception

Nociceptor sensory neurons play a key role in eliciting pain. An active crosstalk between nociceptor neurons and the vascular system at the molecular and cellular level is required to sense and respond to noxious stimuli. Besides nociception, interaction between nociceptor neurons and vasculature also contributes to neurogenesis and angiogenesis.In vitromodels of innervated vasculature can greatly help delineate these roles while facilitating disease modeling and drug screening. Herein, we report the development of a microfluidic-assisted tissue model of nociception in the presence of microvasculature. The self-assembled innervated microvasculature was engineered using endothelial cells and primary dorsal root ganglion (DRG) neurons. The sensory neurons and the endothelial cells displayed distinct morphologies in presence of each other. The neurons exhibited an elevated response to capsaicin in the presence of vasculature. Concomitantly, increased transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor expression was observed in the DRG neurons in presence of vascularization. Finally, we demonstrated the applicability of this platform for modeling nociception associated with tissue acidosis. While not demonstrated here, this platform could also serve as a tool to study pain resulting from vascular disorders while also paving the way towards the development of innervated microphysiological models.

Skin necrosis following sclerotherapy. Part 2: Risk minimisation and management strategies

Tissue necrosis is a serious but rare complication of sclerotherapy. Early detection and targeted management are essential to prevent progression and minimise serious complications. In the first instalment of this paper, we reviewed the pathogenic mechanisms of post-sclerotherapy necrosis. Here, we describe risk minimisation and management strategies.

Risk factors must be addressed to reduce the chance of necrosis following sclerotherapy. These may be treatment-related including poor choice of sclerosant type, concentration, volume or format, poor injection technique, suboptimal ultrasound visualisation and treatment of vessels in high-risk anatomical areas. Risk factors specific to individual patients should be identified and optimised pre-operatively.

Tissue necrosis is more likely to occur with extravasation of irritant sclerosants such as absolute alcohol, sodium iodide, bleomycin and hypertonic saline, whereas extravasation of foam detergent sclerosants rarely results in tissue loss. Proposed treatments for extravasation of irritant sclerosants include infiltration of an isotonic fluid and hyaluronidase. Management of inadvertent intra-arterial injections may require admission for neurovascular observation and monitoring for ischaemia, intravenous systemic steroids, anticoagulation, thrombolysis and prostanoids infusion when required. Treatment of veno-arteriolar reflex vasospasm (VAR-VAS) necrosis follows the same protocol involving systemic steroids but rarely requires hospital admission and may not require anticoagulation.

In general, treatment of post-sclerotherapy necrosis is challenging and most proposed treatment measures are not evidence-based and only supported by anecdotal personal experience of clinicians. Despite all measures, once the necrosis has set in, it is very difficult to reverse the process and all measures described here may only be useful in prevention of progression and extension of the ulceration.

Mid to long-term measures include addressing exacerbating factors, management of medical and psychosocial comorbidities, treatment of secondary infections and referrals to relevant specialists. All ulcers should be managed with compression and prescribed dressing regimes in line with the healing stage of the ulcer.

The Levels of Serum Serotonin Can Be Related to Skin and Pulmonary Manifestations of Systemic Sclerosis

Background and Objective: The most prominent feature of systemic sclerosis (SSc), besides vasculopathy and autoimmune disorders, is excessive fibrosis. Serotonin affects hemostasis and can induce vasoconstriction, which is presumed to be one of the pathophysiological patterns in SSc that leads to fibrosis. Our aim was to explore the possible association of serotonin with some of the clinical features of SSc in our cohort of patients. Materials and Methods: We measured serotonin levels in sera of 29 female SSc patients. Patients were 41–79 years old, their average disease duration was 9 years. Serotonin values were analyzed in correlation with clinical and laboratory parameters, such as modified Rodnan skin score (mRSS), digital ulcers (DU), and spirometry parameters-forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and lung diffusion capacity of carbon monoxide (DLCO). Statistical analyses were performed using statistical software Statistica. Results: We found correlation of serotonin level with mRSS (r = 0.388, p = 0.038). The highest values of serotonin were documented in patients with refractory DU, but this was not statistically significant. We also found a negative correlation between serotonin and FVC (r = −0.397), although it did not reach the level of significance (p = 0.114). Conclusions: Our study suggests that levels of serum serotonin could affect the course of skin fibrosis and partially restrictive pulmonary dysfunction in patients with SSc. We assume that serotonin might have influence on several features of SSc, but more studies are needed to reveal those relations.

Raynaud's Phenomenon: Reviewing the Pathophysiology and Management Strategies

Raynaud's phenomenon (RP) is a multifactorial vasospastic disorder characterized by a transient, recurrent, and reversible constriction of peripheral blood vessels. RP is documented to affect up to 5% of the general population, but variation in its prevalence is commonly recognized owing to many factors, including varied definitions, gender, genetics, hormones, and region. Furthermore, RP may be idiopathic or be a clinical manifestation of an underlying illness. Patients with RP classically describe a triphasic discoloration of the affected area, beginning with pallor, followed by cyanosis, and finally ending with erythema. This change in color spares the thumb and is often associated with pain. Each attack may persist from several minutes to hours. Moreover, the transient cessation of blood flow in RP is postulated to be mediated by neural and vascular mechanisms. Both structural and functional alterations observed in the blood vessels contribute to the vascular abnormalities documented in RP. However, functional impairment serves as a primary contributor to the pathophysiology of primary Raynaud's. Substances like endothelin-1, angiotensin, and angiopoietin-2 play a significant role in the vessel-mediated pathophysiology of RP. The role of nitric oxide in the development of this phenomenon is still complex. Neural abnormalities resulting in RP are recognized as either being concerned with central mechanisms or peripheral mechanisms. CNS involvement in RP may be suggested by the fact that emotional distress and low temperature serve as major triggers for an attack, but recent observations have highlighted the importance of locally produced factors in this regard as well. Impaired vasodilation, increased vasoconstriction, and several intravascular abnormalities have been documented as potential contributors to the development of this disorder. RP has also been observed to occur as a side effect of various drugs. Recent advances in understanding the mechanism of RP have yielded better pharmacological therapies. However, general lifestyle modifications along with other nonpharmacological interventions remain first-line in the management of these patients. Calcium channel blockers, alpha-1 adrenoreceptor antagonists, angiotensin-converting enzyme inhibitors, nitric oxide, prostaglandin analogs, and phosphodiesterase inhibitors are some of the common classes of drugs that have been found to be therapeutically significant in the management of RP. Additionally, anxiety management, measures to avoid colder temperatures, and smoking cessation, along with other simple modifications, have proven to be effective non-drug strategies in patients experiencing milder symptoms.

Persistent Raynaud's Phenomenon Following Methylphenidate Hydrochloride Use During the COVID-19 Pandemic

Raynaud's phenomenon (RP) is a medical condition characterized by vasospasm of the digital vessels in the fingers and toes. The prevalence of RP in the general population is estimated at 3-5% and can vary based on climate. It is classified into primary and secondary RP based on causality. RP has been reported in some cases diagnosed with coronavirus disease 2019 (COVID-19) infection. We report the case of a 14-year-old Caucasian female who presented during the pandemic with chief complaints of suicidal ideations and attempted suicide and had a history of attention-deficit hyperactivity disorder (ADHD) and persistent RP after a stimulant trial. After an initial failure of treatment with lisdexamfetamine, she was switched to methylphenidate hydrochloride (MPH). Within two months of starting MPH, the patient noticed skin discoloration of the lower legs and feet along with numbness. The discoloration of skin was mainly limited to her feet and gradually moved up her legs. She was advised to discontinue the MPH, but her symptoms persisted for four more months until her admission. Other etiologies were ruled out by multi-specialties and during her hospitalization. She was started on atomoxetine and buspirone with appropriate dose titration. Post-discharge from the hospital, no improvement was observed in the patient's RP at an outpatient follow-up performed within a month. The development of RP following MPH treatment and its persistence after stopping MPH is a fascinating event. Clinicians should be aware of the potential rare side effects of stimulants and stimulant-like medications, including vascular, hematological, and dermatological effects. Adolescents with ADHD may be particularly distressed by the COVID-19 pandemic and display increased behavioral issues. Stress can be a trigger for RP; therefore, minimizing stress in at-risk patients is essential.

Identification of a population of peripheral sensory neurons that regulates blood pressure

The vasculature is innervated by a network of peripheral afferents that sense and regulate blood flow. Here, we describe a system of non-peptidergic sensory neurons with cell bodies in the spinal ganglia that regulate vascular tone in the distal arteries. We identify a population of mechanosensitive neurons, marked by tropomyosin receptor kinase C (TrkC) and tyrosine hydroxylase in the dorsal root ganglia, which projects to blood vessels. Local stimulation of TrkC neurons decreases vessel diameter and blood flow, whereas systemic activation increases systolic blood pressure and heart rate variability via the sympathetic nervous system. Ablation of the neurons provokes variability in local blood flow, leading to a reduction in systolic blood pressure, increased heart rate variability, and ultimately lethality within 48 h. Thus, a population of TrkC⁺ sensory neurons forms part of a sensory-feedback mechanism that maintains cardiovascular homeostasis through the autonomic nervous system.

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TrkC⁺/Th⁺ DRG neurons project to blood vessels

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Local stimulation of TrkC⁺ DRG neurons decreases vessel diameter and blood flow

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Systemic activation of TrkC⁺ DRG neurons increases blood pressure and heart rate

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Ablation of TrkC⁺ neurons dysregulates cardiovascular homeostasis and is lethal

Vasodilators for primary Raynaud's phenomenon

BACKGROUND

Numerous agents have been suggested for the symptomatic treatment of primary Raynaud's phenomenon. Apart from calcium channel blockers, which are considered to be the drugs of choice, evidence of the effects of alternative pharmacological treatments is limited. This is an update of a review first published in 2008.

OBJECTIVES

To assess the effects of drugs with vasodilator effects on primary Raynaud's phenomenon as determined by frequency, severity, and duration of vasospastic attacks; quality of life; adverse events; and Raynauds Condition Score.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov trial register to November 16, 2020.

SELECTION CRITERIA

We included randomized controlled trials evaluating effects of oral, intravenous, and topical formulations of any drug with vasodilator effects on subjective symptoms, severity scores, and radiological outcomes in primary Raynaud's phenomenon. Treatment with calcium channel blockers was not assessed in this review, nor were these agents compared.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed studies using the Cochrane "Risk of bias" tool, and extracted study data. Outcomes of interest included frequency, severity, and duration of attacks; quality of life (QoL); adverse events (AEs); and the Raynaud Condition Score (RCS). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified seven new studies for this update. In total, we included 15 studies involving 635 participants. These studies compared different vasodilators to placebo. Individual studies used different methods and measures to report different outcomes. Angiotensin-converting enzyme (ACE) inhibitors Combining data from three studies revealed a possible small increase in the frequency of attacks per week after treatment (captopril or enalapril) compared to placebo (mean difference [MD] 0.79, 95% confidence interval [CI] 0.43 to 1.17; low-certainty evidence). There was no evidence of a difference between groups in severity of attacks (MD -0.17, 95% CI -4.66 to 4.31; 34 participants, 2 studies; low-certainty evidence); duration of attacks (MD 0.54, 95% CI -2.42 to 1.34; 14 participants, 1 study; low-certainty evidence); or AEs (risk ratio [RR] 1.35, 95% CI 0.67 to 2.73; 46 participants, 3 studies; low-certainty evidence). QoL and RCS were not reported. Alpha blockers Two studies used alpha blockers (buflomedil or moxisylyte). We were unable to combine data due to the way results were presented. Buflomedil probably reduced the frequency of attacks compared to placebo (MD -8.82, 95% CI -11.04 to -6.60; 31 participants, 1 study; moderate-certainty evidence) and may improve severity scores (MD -0.41, 95% CI -0.62 to -0.30; moderate-certainty evidence). With moxisylyte, investigators reported fewer attacks (P < 0.02), less severe symptoms (P < 0.01), and shorter duration of attacks, but the clinical relevance of these results is unclear. No evidence of a difference in AEs between buflomedil and placebo groups was noted (RR 1.41, 95% CI 0.27 to 7.28; 31 participants, 1 study; moderate-certainty evidence). More AEs were observed in participants in the moxisylyte group than in the placebo group. Prostaglandin/prostacyclin analogues One study compared beraprost versus placebo. There was no evidence of benefit for frequency (MD 2.00, 95% CI -0.35 to 4.35; 118 participants, low-certainty evidence) or severity (MD -0.06, 95% CI -0.34 to 0.22; 118 participants, low-certainty evidence) of attacks. Overall, more AEs were noted in the beraprost group (RR 1.59, 95% CI 1.05 to 2.42; 125 participants; low-certainty evidence). This study did not report on duration of attacks, QoL, or RCS. Thromboxane synthase inhibitors One study compared a thromboxane synthase inhibitor (dazoxiben) versus placebo. There was no evidence of benefit for frequency of attacks (MD 0.8, 95% CI -1.81 to 3.41; 6 participants; very low-certainty evidence). Adverse events were not reported in subgroup analyses of participants with primary Raynaud's phenomenon, and the study did not report on duration of attacks, severity of symptoms, QoL, or RCS. Selective serotonin reuptake inhibitors One study compared ketanserin with placebo. There may be a slight reduction in the number of attacks per week with ketanserin compared to placebo (MD -14.0, 95% CI -27.72 to -0.28; 41 participants; very low-certainty evidence) and reduced severity score (MD -133.00, 95% CI -162.40 to -103.60; 41 participants; very low-certainty evidence). There was no evidence that ketanserin reduced the duration of attacks (MD -4.00, 95% CI -14.82 to 6.82; 41 participants; very low-certainty evidence), or that AEs were increased in either group (RR 1.54, 95% CI 0.89 to 2.65; 41 participants; very low-certainty evidence). This study did not report on QoL or RCS. Nitrate/nitrate derivatives Four studies compared topical treatments of nitroglycerin or glyceryl trinitrate versus placebo, each reporting on limited outcomes. Meta-analysis demonstrated no evidence of effect on frequency of attacks per week (MD -1.57, 95% CI -4.31 to 1.17; 86 participants, 2 studies; very low-certainty evidence). We were unable to pool any data for the remaining outcomes. Phosphodiesterase inhibitors Three studies compared phosphodiesterase inhibitors (vardenafil, cilostazol or PF-00489791) to an equivalent placebo. Results showed no evidence of a difference in frequency of attacks (standardized MD [SMD] -0.05, 95% CI -6.71 to 6.61; 111 participants, 2 studies; low-certainty evidence), severity of attacks (MD -0.03, 95% CI -1.04 to 0.97; 111 participants, 2 studies; very low-certainty evidence), duration of attacks (MD -1.60, 95% CI -7.51 to 4.31; 73 participants, 1 study; low-certainty evidence), or RCS (SMD -0.8, 95% CI -1.74 to 0.13; 79 participants, 2 studies; low-certainty evidence). Study authors reported that 35% of participants on cilostazol complained of headaches, which were not reported in the placebo group. PF-00489791 caused 34 of 54 participants to experience AEs versus 43 of 102 participants receiving placebo (RR 1.49). Headache was most common, affecting 14 participants (PF-00489791) versus nine participants (placebo).

AUTHORS' CONCLUSIONS

The included studies investigated several different vasodilators (topical and oral) for treatment of primary Raynaud's phenomenon. Small sample sizes, limited data, and variability in outcome reporting yielded evidence of very low to moderate certainty. Evidence is insufficient to support the use of vasodilators and suggests that vasodilator use may even worsen disease.

Increased cold injuries and the effect of body mass index in patients with peripheral vascular disease

Background

Exposure to extremely or moderate low temperatures is associated with increased morbidity and mortality risk. Peripheral vascular disease (PVD) is a slow and progressive circulation disorder. Given that cold temperature causes constriction of the small arteries and veins in the skin, patients who suffer from peripheral circulation problems, like PVD, may be vulnerable to cold injuries. This study aimed to investigate the association between PVD and cold-induced injuries in the winter among Korean adults. We further analyzed the association stratified by body mass index (BMI) classification.

Methods

We used the 2002–2015 National Health Insurance Service-National Sample Cohort data and included a total of 535,186 adults as the study population. Patients with underlying PVD were identified by ICD-10 code I73. Cold-related illnesses were defined by ICD-10 codes (T690, T691, T698, T699, T330 ~ T339, T340 ~ T349, and T350 ~ T357). Body mass index (BMI) was categorized into underweight, normal weight, overweight, and obese.

Results

A total of 23.21% (n = 124,224) were PVD patients, and 0.59% (n = 3154) had cold-induced injuries. PVD patients were more likely to be diagnosed with cold injuries, but it was valid only in the underweight or normal weight groups. After adjusting for age, sex, income, cigarette smoking, alcohol consumption, regular exercise, high blood pressure, and hyperglycemia, PVD patients had a significantly increased odds ratio (OR) for cold injuries [adjusted OR = 1.11; 95% confidence intervals (95% CI): 1.01–1.21]. Increased OR for cold injuries in PVD patients was also observed in adults (adjusted OR = 1.14; 95% CI: 1.03–1.25 in Model 2), but not in the elderly. When we classified study subjects into the four BMI groups, the adjusted OR of cold injuries in PVD patients was significant in the underweight group (OR = 1.83; 95% CI, 1.26–2.66) and normal weight group (OR = 1.15; 95% CI, 1.03–1.27), not in those with overweight and obese. In adults, a consistent result was found in adults in the underweight group (OR = 1.63; 95% CI, 1.08–2.47 in Model 2) and normal weight group (OR = 1.19; 95% CI, 1.07–1.33 in Model 2). In the elderly, the adjusted OR for cold injuries was only significant in the underweight group (OR = 3.37; 95% CI, 1.08–10.53 in Model 2).

Conclusions

We found a significant association between PVD and cold-induced injuries in the general population. BMI modified the association. Thus, the association observed appears to be clinically applicable to PVD patients being low to normal BMI.

Correlation between the infrared thermogram and microvascular abnormalities of the nailfold in patients with systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is a multisystemic disease with an extensive microvasculopathy. The gold standard for its investigation is nailfold videocapillaroscopy (NVC).

AIM

To assess the value of thermography (IRT) for the assessment of microvasculopathy in patients with SSc.

MATERIAL AND METHODS

Nineteen patients with limited cutaneous SSc were enrolled in the study. They underwent IRT imaging and NVC. An average temperature (Tavg) at the nailfold and a gradient of temperatures (ΔTavg) between the central metacarpus of the hand and the nailfold was determined for all fingers. NVC pictures were classified to capillaroscopic patterns according to Cutolo et al. system and they were analysed quantitatively to measure the density of capillaries and to calculate capillaroscopic skin ulcers risk index (CSURI) for each finger separately.

RESULTS

There was only a moderate correlation (0.4 < r < 0.6) between thermographic parameters and density of capillaries in fingers II-V (r = 0.5; p < 0.001 for Tavg and r = -0.45; p < 0.001 for ΔTavg), but none in thumbs (r = 0.29; p = 0.089 for Tavg and r = -0.19; p = 0.275 for ΔTavg). Early pattern was associated with a significantly greater surface temperature (Tavg) of nailfolds and essentially milder ΔTavg in fingers II-V when compared to all other capillaroscopic patterns in fingers II-V. Surface temperature (Tavg) was significantly lower and ΔTavg was markedly more pronounced in fingers II-V with a greater risk of development of digital ulcers (DU) calculated by CSURI.

CONCLUSIONS

Although IRT measurements correlate only moderately with density of capillaries, this technique seems to be substantial to determine the capillaroscopic pattern and to identify patients at greater risk of DU development.

Public interest in Raynaud's phenomenon: A Google Trends analysis

Raynaud's phenomenon is a common disorder affecting body extremities and other vascular beds. As infodemiological methods have developed, online search tools could be used to explore the public interest of the disease. The study aimed to determine the annual trend, seasonal pattern, and associated topics of Raynaud's phenomenon. Google Trends was used to collect the data. "Raynaud syndrome" was selected as the search term. Data on monthly relative search volume (RSV) were collected from four selected countries (United States, United Kingdom, Australia, and New Zealand) and globally. Related topics were obtained, and annual-related topics were also collected for analysis. The maximum RSV appeared in January 2019, and the minimum value was observed in August 2011. The peak for RSV occurred in winter, and the bottom appeared in summer. In top related topics, "Maurice Raynaud" was the most related. In rising related topics, disease manifestations and autoimmune connective diseases were highly concerned. For annual-related topics, associated diseases were attracting more attention over time. The population is interested in related diseases, pathogenesis, and treatment. There was a peak in winter for searching and supported the importance of season variation on the impact of Raynaud's phenomenon.

Infrared thermography in children: a reliable tool for differential diagnosis of peripheral microvascular dysfunction and Raynaud's phenomenon?

BACKGROUND

Infrared Thermography (IRT) has been used for over 30 years in the assessment of Raynaud Phenomenon (RP) and other peripheral microvascular dysfunctions in adults but, to date, very little experience is available on its use in children for this purpose. The first aim of the study was to assess reproducibility of thermographic examination after cold exposure by comparing inter-observer agreement in thermal imaging interpretation. The secondary aim was to evaluate whether IRT is reliable to diagnose and differentiate peripheral circulation disturbances in children.

METHODS

Children with clinical diagnosis of primary Raynaud's phenomenon (PRP), secondary RP (SRP), acrocyanosis (AC) and age-matched controls underwent sequential measurements of skin temperature at distal interphalangeal (DIP) and metacarpophalangeal (MCP) joints with IRT at baseline and for 10 min after cold challenge test. Intraclass correlation coefficient (ICC) was calculated for inter-rater reliability in IRT interpretation, then temperature variations at MCP and DIP joints and the distal-dorsal difference (DDD) were analysed.

RESULTS

Fourteen PRP, 16 SRP, 14 AC and 15 controls entered the study. ICC showed excellent agreement (> 0.93) for DIPs and MCPs in 192 measures for each subject. Patients with PRP, SRP and acrocyanosis showed significantly slower recovery at MCPs (p < 0.05) and at DIPs (p < 0.001) than controls. At baseline, higher temperature at DIPs and lower at MCPs was observed in PRP compared with SRP with significantly lower DDD (p < 0.001). Differently from AC, both PRP and SRP showed gain of temperature at DIPs and less at MCPs after cold challenge. PRP but not SRP patients returned to DIPs basal temperature by the end of re-warming time. Analysis of DDD confirmed that controls and PRP, SRP and AC patients significantly differed in fingers recovery pattern (p < 0.05).

CONCLUSION

IRT appears reliable and reproducible in identifying children with peripheral microvascular disturbances. Our results show that IRT examination pointed out that PRP, SRP and AC patients present significant differences in basal extremities temperature and in re-warming pattern after cold challenge therefore IRT can be suggested as an objective tool for diagnosis and monitoring of disease.

Mechanism of Membrane Depolarization Involved in α1A-Adrenoceptor-Mediated Contraction in Rat Tail and Iliac Arteries

Our previous studies have shown that phenylephrine-induced contraction of cutaneous arteries is primarily mediated via α_1A-adrenoceptors, but not α_1D-adrenoceptors that generally mediate vascular contraction, and that the larger part of the contraction is induced in a voltage-dependent Ca²⁺ channel (VDCC)-independent manner. Here, we investigated the mechanism underlying the smaller part of the α_1A-adrenoceptor-mediated contraction, i.e., VDCC-dependent one, in cutaneous arteries. Isometric contraction was measured with wire myograph in endothelium-denuded tail and iliac arterial rings isolated from male Wistar rats. LOE908 (10 µM), a cation channel blocker, partially inhibited the contraction induced by phenylephrine in tail and iliac arteries. Nifedipine (10 µM) further suppressed the phenylephrine-induced contraction that remained in the presence of LOE908 (10 µM) in iliac arteries but barely in tail arteries, suggesting that phenylephrine-induced depolarization in tail arteries is due to the activation of LOE908-sensitive cation channels. In iliac arteries, the contraction induced by A-61603, a specific α_1A-adrenoceptor agonist, was also partially inhibited by LOE908 (10 µM); however, nifedipine had little effect on the A-61603-induced contraction that remained in the presence of LOE908 (10 µM), suggesting that depolarization mediated via α_1A-adrenoceptors is due to the activation of LOE908-sensitive cation channels even in iliac arteries. These results suggest that membrane depolarization mediated via α_1Α-adrenoceptors is caused by cation influx through LOE908-sensitive cation channels. Less contribution of VDCC to phenylephrine-induced contraction in tail arteries compared to in iliac arteries is likely due to that α_1Α-adrenoceptor-mediated activation of VDCC is caused only by depolarization via cation influx through LOE908-sensitive cation channels.

Microangiopathy in Naifold Videocapillaroscopy and Its Relations to sE- Selectin, Endothelin-1, and hsCRP as Putative Endothelium Dysfunction Markers among Adolescents with Raynaud's Phenomenon

The aim of this study was to analyze the relationship between the qualitative abnormalities on nailfold videocapillaroscopy (NVC), and the concentrations of selected biomarkers (sE-selectin, endothelin-1, high-sensitivity c-reactive protein (hsCRP)) and lipid metabolism parameters in children and adolescents with Raynaud’s phenomenon (RP). Raynaud’s phenomenon, to assess whether nailfold capillary changes may reflect the degree of systemic blood vessel abnormalities. The study group included 66 patients (34 undifferentiated—uRP and 32 secondary—sRP) aged 6–19 years and the control group. In both groups, NVC was performed and the selected biomarkers were measured (sE-selectin, endothelin-1, hsCRP) and lipid profile. Endothelin-1, sE-selectin and hsCRP concentrations in patients from both RP groups were significantly higher; concentration of HDL fraction was significantly lower compared with the control group. The analysis of multiple linear regression demonstrated that megacapillaries most strongly determine the sE-selectin value (p = 0.04) and hsCRP (p = 0.03). Both the total cholesterol and low-density lipoprotein (LDL) fraction concentrations were determined by the presence of avascular areas (p = 0.02). In conclusion, specific pathologic NVC changes were associated with higher endothelial damage biomarkers concentration and adverse changes in the lipid profile.

Raynaud's phenomenon in Northern Sweden: a population-based nested case-control study

The aim of this study was to determine the association between individual and external exposure factors, and the reporting of Raynaud's phenomenon, with or without concomitant cold sensitivity. In a population-based nested case-control study, cases with Raynaud's phenomenon (N = 578), and matched controls (N = 1156), were asked to respond to a questionnaire focusing on different risk factors. Univariate and multiple conditional logistic regression were performed. Analyses were stratified according to whether the cases reported cold sensitivity or not. In total, 1400 out of 1734 study subjects answered the questionnaire (response rate 80.7%). In the final multiple model, the factor with the strongest association to Raynaud's phenomenon, with and without cold sensitivity, was previous frostbite affecting the hands (OR 12.44; 95% CI 5.84-26.52 and OR 4.01; 95% CI 1.78-9.01, respectively). Upper extremity nerve injury was associated to reporting Raynaud's phenomenon and cold sensitivity (OR 2.23; 95% CI 1.29-3.85), but not Raynaud's phenomenon alone. Reporting any exposure to hand-arm vibration or cumulative cold exposure was significant in univariate analyses for cases with both Raynaud's phenomenon and cold sensitivity, but not in the multiple model. Raynaud's phenomenon is strongly associated to previous cold injury, with a larger effect size among those who also report cold sensitivity. The fact that only upper extremity nerve injury differed significantly between case groups in our multiple model offers additional support to the neural basis for cold sensitivity.

An Autoimmune Basis for Raynaud's Phenomenon: Murine Model and Human Disease

OBJECTIVE

Raynaud's phenomenon (RP) is common in anti-RNP-positive patients with rheumatic diseases but is not itself known to be caused by autoimmunity. The aim of this study was to assess autoantibodies that could mediate this process.

METHODS

Antibodies derived from patient sera and from murine models of anti-RNP autoimmunity were screened for the ability to induce RP-like tissue ischemia and endothelial cell apoptosis in murine models and in vitro systems.

RESULTS

RNP-positive sera from RP patients and murine sera from RNP-positive B cell adoptive transfer recipients induced RP-like tissue ischemia and endothelial cell apoptosis. Proteomic analysis identified cytokeratin 10 (K10) as a candidate autoantigen in RP. Monoclonal anti-K10 antibodies reproduced patterns of ischemic tissue loss and endothelial cell apoptosis; K10 knockout or depletion of anti-K10 activity in serum was protective. Cold exposure enhanced K10 expression and in vivo tissue loss.

CONCLUSION

Anti-K10 antibodies are sufficient to mediate RP-like ischemia in murine models and are implicated in the pathogenesis of RP in patients with anti-RNP autoimmunity.

Differential contribution of calcium channels to α1-adrenoceptor-mediated contraction is responsible for diverse responses to cooling between rat tail and iliac arteries

Our previous studies have shown that α₁-adrenoceptors, in addition to α₂-adrenoceptors, are involved in enhanced contraction of cutaneous blood vessels during cooling. The present study aimed to elucidate the mechanism underlying it. In tail and iliac arteries isolated from rats, isometric contraction was measured using a myograph and the phosphorylation level of myosin phosphatase target subunit 1 (MYPT1) was quantified by western blotting. The phenylephrine-induced contraction was enhanced by cooling to 24 °C in tail arteries, but was suppressed in iliac arteries. Endothelium denudation or treatment with iberiotoxin enhanced the phenylephrine-induced contraction in tail arteries at 37 °C; however, neither affected the contraction at 24 °C. The phenylephrine-induced contraction at 37 °C was largely suppressed by nifedipine in iliac arteries, but only slightly in tail arteries. The Rho kinase inhibitor H-1152 largely suppressed the phenylephrine-induced contraction at 24 °C, but only slightly at 37 °C, in both arteries. The phosphorylation level of MYPT1 at Thr855 in tail arteries was increased by the cooling. Taken together, these results suggest the following mechanism in regard to cooling-induced enhancement of α₁-adrenoceptor-mediated contraction in tail arteries: Cooling enhances the contraction of tail arteries via α₁-adrenoceptor stimulation by reducing endothelium-dependent, large-conductance Ca²⁺-activated K⁺ channel-mediated relaxation and by inducing Rho kinase-mediated Ca²⁺ sensitization, although the latter occurs even in iliac arteries. A smaller contribution of voltage-dependent Ca²⁺ channels, which are largely suppressed by cooling, to α₁-adrenoceptor-mediated contraction in tail arteries seems to be more crucially involved in the appearance of the enhanced contractile response to cooling.

Impairment of microcirculation and vascular responsiveness in adolescents with primary Raynaud phenomenon

BACKGROUND

Raynaud's phenomenon (RP) is a functional vascular disease, presenting with recurrent episodes of ischemia of extremities in response to cold and emotional stress. Investigating cutaneous microcirculation is an important tool in understanding the complex neuro-immuno-vascular interactions in its pathophysiological mechanisms. Since there is no available data on vascular responsiveness in RP in the paediatric population, we investigated skin perfusion and heat-induced hyperaemia in comparison with clinical severity and laboratory parameters of the disease.

METHODS

Fifty two adolescents (27 patients with primary RP and 25 age-matched healthy controls) were investigated in the study. Patients were divided into two groups according to the symptoms existing within the previous 2 months. Following baseline microcirculation measurement with Laser Doppler flowmetry (Periflux 5000 system), all subjects underwent local heating test at 42 °C and 44 °C. Besides routine laboratory parameters, immune-serological tests and the vasoactive sensory neuropeptides somatostatin and pituitary adenylate-cyclase activating polypeptide (PACAP) were measured.

RESULTS

Baseline perfusion measured in perfusion units (PU) at 32 °C was significantly lower in symptomatic RP patients (97.6 ± 22.4 PU) compared with both healthy volunteers (248.3 ± 23.5 PU, p < 0.001) and RP patients without symptoms (187.4 ± 24.9 PU, p < 0.05). After local heating to 42 °C maximum blood flow was significantly reduced in primary RP participants with current symptoms (358.6 ± 43.9 PU, p < 0.001), but not in asymptomatic ones (482.3 ± 28.7 PU, p > 0.05) when compared with healthy subjects (555.9 ± 28.2 PU). Both the area under the response curve and the latency to reach the maximum flow were significantly increased in both RP groups (symptomatic 164.6 ± 7.4 s, p < 0.001, asymptomatic 236.4 ± 17.4 s, p < 0.001) when compared with the control group (101.9 ± 4.7 s). The heat-induced percentage increase from baseline to maximal blood flow was significantly greater in symptomatic RP adolescents in comparison with healthy ones. Laboratory parameters and neuropeptide plasma levels were not altered in any groups.

CONCLUSION

To our knowledge this is the first study in paediatric population to show altered heat-induced cutaneous hyperaemia responses in relation with the clinical severity and symptomatology.

The Role of Botulinum Toxin A in the Treatment of Raynaud Phenomenon

Raynaud phenomenon (RP) is a transient digital ischemia that occurs after exposure to cold temperature or emotional distress. It presents with a triphasic course: the initial white phase is followed by cyanotic discoloration and, subsequently, erythema. The attacks may be associated with pain, paresthesia, and complicate with nonhealing ulceration often leading to amputation. To date, there are no clear-cut therapeutic guidelines and many medications are used off-label. Encouraging results were reported with the use of botulinum neurotoxin-A (BoNT-A). However, there is still ongoing debate regarding indications, contraindications, best injection technique, and mechanism of action. The aim of this study was to address these issues by providing an up-to-date and detailed overview of the use of BoNT-A in RP.A PubMed database search was conducted. The available studies and techniques were evaluated and compared.The search yielded a total of 29 studies. Ten papers, published between 2004 and 2014, were considered relevant. A total of 128 patients underwent BoNT-A injections. Seventy-five percent to 100 % of the patients reported pain reduction after treatment. Healing of ulcers was reported in 75% to 100% of the affected patients. The most common complication was temporary hand weakness, with an average incidence of 14.1%. Injections targeting the neurovascular bundle at or slightly proximal to the A1 pulley were the most commonly performed.Botulinum neurotoxin-A injection proved to be a valid approach in both primary and secondary RP. The available evidence shows the achievement of both symptomatic and functional improvements in this debilitating condition. However, the patient should be adequately informed about the risk of transient hand weakness.

Bilateral Brachial Artery Disease Presenting with Features of Raynaud's Phenomenon: A Case Report and Review of the Literature

Objective

To present a case of bilateral brachial artery disease presenting with features of Raynaud's phenomenon which was successfully treated with angioplasty and stenting, together with a review of the relevant literature.

Case

A 71-year-old female presented with a one-year history of intermittent pallor of both hands precipitated with cold objects. On examination, bilateral radial pulses were reduced. Prior photos showed pallor of the distal aspect of both palms. Angiogram showed high grade stenosis of the right brachial artery and focal occlusion with likely dissection of the left brachial artery. She underwent angioplasty and stenting for both lesions. She was asymptomatic without further episodes of Raynaud's phenomenon after five months on dual antiplatelet therapy. Upper-extremity vascular stenosis is uncommon. Structural changes in the vessel wall can cause vasospastic attacks, a mechanism described in secondary Raynaud's phenomenon. We hypothesize that these attacks may have been precipitated by the bilateral brachial artery disease. Furthermore, resolution of the symptoms after stent further supports our theory.

Conclusion

Bilateral brachial artery disease is uncommon. Physicians should consider this in patients presenting with Raynaud's phenomenon. Brachial artery stenosis and occlusion is a treatable disease with good symptomatic outcomes after angioplasty and stenting.

Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences

The endothelium has increasingly been recognized as a smart barrier and a key regulator of blood flow in micro- and macrovascular beds. Endothelial dysfunction marks a stage of atherosclerosis and is an important prognostic marker for cardiovascular disease. Yet, some people who tend to be slim and physically active and with rather low blood pressure show a propensity to respond to certain stimuli such as emotional stress with endothelial-mediated vascular dysregulation (Flammer syndrome). This leads to characteristic vascular symptoms such as cold hands but also a risk for vascular-mediated diseases such as normal-tension glaucoma. It is the aim of this review to delineate the differences between Flammer syndrome and its "counterpart" endothelial dysfunction in the context of cardiovascular diseases.

Inhibitory effect of Angelica gigas on cold‑induced RhoA activation in vascular cells

The herbal extract Angelica gigas (AG) has been applied as a vasodilating agent for patients suffering from vascular diseases for many years; however, the underlying mechanism has not been fully elucidated. The present study hypothesized that the anti‑vasoconstrictive effect of AG may be effective in the treatment of abnormal cold‑mediated vasospasms that occur in Raynaud's phenomenon (RP). The effect of AG on the activity of ras homolog gene family member A (RhoA) was investigated in cold‑exposed vascular cells. Vascular cells were pretreated to AG, followed by a warm (37˚C) or cold (25˚C) incubation for 30 min and investigated with western blotting, ELISA and confocal microscopy. Cold treatment induced the activation of RhoA in pericytes and vascular endothelial cells, however this was reduced by treatment with AG. Furthermore, AG treatment reduced the endothelin‑1 (ET‑1)‑mediated RhoA activation in pericytes; however, cold‑induced ET‑1 production by vascular endothelial cells was not affected by treatment with AG. In addition, AG treatment suppressed the formation of stress fibers and focal adhesion complexes, and the cold‑induced phosphorylation of focal adhesion kinase, proto‑oncogene tyrosine‑protein kinase Src and extracellular signal‑related kinase. Therefore, AG treatment demonstrated an ability to reduce cold‑induced RhoA activation in pericytes and vascular endothelial cells, and attenuated ET‑1‑mediated RhoA activation in pericytes. In conclusion, the present study indicated that AG may be useful for the treatment of RP.

Postocclusive Hyperemia Measured with Laser Doppler Flowmetry and Transcutaneous Oxygen Tension in the Diagnosis of Primary Raynaud's Phenomenon: A Prospective, Controlled Study

The aim of this study was to measure the sensitivity and specificity of transcutaneous oxygen tension and postocclusive hyperemia testing using laser Doppler flowmetry in patients with primary Raynaud's phenomenon. One hundred patients and one hundred controls were included in the study. Baseline microvascular blood flow and then time to peak flow following occlusion were measured using laser Doppler flowmetry. Afterwards, the transcutaneous oxygen tension was recorded. The sensitivities of baseline microvascular blood flow, postocclusive time to peak flow, and transcutaneous oxygen tension were 79%, 79%, and 77%, respectively. The postocclusive time peak flow had a superior specificity of 90% and area under the curve of 0.92 as compared to 66% and 0.80 for baseline microvascular flow and 64% and 0.76 for transcutaneous oxygen tension. Time to postocclusive peak blood flow measured by laser Doppler flowmetry is a highly accurate test for differentiating patients with primary Raynaud's phenomenon from healthy controls.

Nailfold capillaroscopy assessment of microcirculation abnormalities and endothelial dysfunction in children with primary or secondary Raynaud syndrome

Raynaud syndrome (RS) manifests as episodes of transient spasms of peripheral blood vessels, most often in response to cold. The reason of that symptom (primary RS (pRS)) usually cannot be found but may be accompanied by some autoimmune diseases (secondary RS (sRS)). In this study, we assessed microcapillary status and serum concentrations of chosen cytokines, adhesive molecules, and nitric oxide (NO) in patients with pRS and sRS in comparison with healthy children. Eighty-six patients with RS were enrolled into the study, including 52 with pRS and 34 with sRS. The control group consisted of 29 healthy children. A decrease in myorelaxative and anticoagulant abilities was observed, with simultaneous prevalence of vasopressor substances and procoagulative activity. Therefore, several important factors such as endothelin-1 (ET-1), E-selectin (E-sel), interleukin-18 (IL-18), and nitrogen oxide (NO) were also analyzed. Two types of capillaroscopy status were determined: normal and microangiopathic. There was a significant relationship between presence of microangiopathy and higher serum ET-1 (p = 0.018) and E-sel (p = 0.021) levels. Similarly, we have found a correlation between presence of ANA and higher ET-1 (p = 0.005), but not E-sel (p = 0.241). In patients with pRS, we found significant relationship between ANA and higher ET-1 (p = 0.008). No such relations were observed in sRS patients. Our data indicates that external factor-induced vasoconstrictive effects dominated in pRS, whereas in sRS in the course of connective tissue diseases, it was accompanied by coexistent vasodilation due to endothelial dysfunction. The latter phenomenon is at least partially dependent on insufficient NO release.

Mechanisms of Vascular Smooth Muscle Contraction and the Basis for Pharmacologic Treatment of Smooth Muscle Disorders

The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function.

Hypoxia-induced sensitisation of TRPA1 in painful dysesthesia evoked by transient hindlimb ischemia/reperfusion in mice

Dysesthesia is an unpleasant abnormal sensation, which is often accompanied by peripheral neuropathy or vascular impairment. Here, we examined the roles of transient receptor potential ankyrin 1 (TRPA1) in dysesthesia-like behaviours elicited by transient hindlimb ischemia (15–60 min) by tightly compressing the hindlimb, and reperfusion by releasing the ligature. The paw-withdrawal responses to tactile stimulation were reduced during ischemia and lasted for a while after reperfusion. Hindlimb ischemia/reperfusion elicited spontaneous licking of the ischemic hindpaw that peaked within 10 min. The licking was inhibited by reactive oxygen species (ROS) scavengers, a TRPA1 antagonist, or TRPA1 deficiency, but not by TRPV1 deficiency. In human TRPA1-expressing cells as well as cultured mouse dorsal root ganglion neurons, the H₂O₂-evoked TRPA1 response was significantly increased by pretreatment with hypoxia (80 mmHg) for 30 min. This hypoxia-induced TRPA1 sensitisation to H₂O₂ was inhibited by overexpressing a catalytically-inactive mutant of prolyl hydroxylase (PHD) 2 or in a TRPA1 proline mutant resistant to PHDs. Consistent with these results, a PHD inhibitor increased H₂O₂-evoked nocifensive behaviours through TRPA1 activation. Our results suggest that transient hindlimb ischemia/reperfusion-evoked spontaneous licking, i.e. painful dysesthesia, is caused by ROS-evoked activation of TRPA1 sensitised by hypoxia through inhibiting PHD-mediated hydroxylation of a proline residue in TRPA1.

Thermal Disparity between Fingers after Cold-water Immersion of Hands: A Useful Indicator of Disturbed Peripheral Circulation in Raynaud Phenomenon Patients

OBJECTIVE

To devise an effective method to assess the peripheral circulation using an infrared thermographic analysis.

METHODS

Sequential measurements of the skin temperature before and after cold-water immersion of the hands were analyzed by a thermographic examination in healthy controls and patients diagnosed to have Raynaud phenomenon (RP). The skin temperatures of the dorsum of all fingernail folds and the metacarpophalangeal (MCP) joints were measured at baseline. Then the hands were immersed in 10°C water for 10 s, and the skin temperatures were measured at 0, 3, 5, 10, 15, 20 and 30 min after immersion. The mean temperature, recovery rate and disparity (coefficient of variation) of the nail fold temperatures were calculated. The distal-dorsal difference (DDD) was calculated by subtracting the mean MCP temperature from the mean nail fold temperature. Receiver operating characteristic (ROC) curves were generated to compare these parameters in terms of their capability to differentiate patients with RP.

RESULTS

Thirty-one RP patients and 25 controls were included in the study. The baseline nail fold temperature was significantly lower in RP patients than in the controls. The RP patients had a lower recovery rate, lower DDD and higher disparity than the controls. The disparity and DDD were negatively correlated (r=-0.63, p<0.01), whereas the recovery rate and DDD were positively correlated (r=0.91, p<0.01). The ROC curve analysis revealed that the disparity in nail fold temperature effectively differentiated RP patients from controls (area under the curve: recovery rate 0.72; disparity 0.88; DDD 0.79).

CONCLUSION

The temperature disparity between fingers is a useful thermographic parameter for evaluating disturbed peripheral circulation in patients with Raynaud phenomenon.

Autonomic imbalance assessed by time-domain heart rate variability indices in primary Raynaud's phenomenon

Objectives

The pathogenesis of primary Raynaud’s phenomenon (RP) seems to be multifactorial and autonomic nervous dysfunction is one factor. Heart rate variability (HRV) is one of the most reliable parameters to demonstrate autonomic dysfunction. Our aim was to evaluate the time-domain HRV in patients with primary RP.

Methods

A time analysis of HRV was performed in patients with primary RP and age- and gender-matched healthy controls. The results of the study and control group were compared.

Results

Thirty patients with primary RP [all men, median (IQR) age: 21 (2) years) and 31 age- and gender-matched healthy controls (median (IQR): 21(3) years) were enrolled in the study. We found a statistically significant difference between the primary RP patients and control subjects in terms of time-domain HRV parameters (p < 0.05 for all).

Conclusion

Our study showed the presence of autonomic nervous dysfunction of heart function in patients with primary RP.

Intra-arterial injection of sclerosants: Report of three cases treated with systemic steroids

Intra-arterial injection of sclerosants is a significant but uncommon complication of sclerotherapy that may result in extensive tissue necrosis and in rare cases digit or limb amputation. We have managed three cases in the past 10 years. One patient was referred for immediate treatment following intra-arterial injection of liquid polidocanol. The other two had undergone foam sclerotherapy with polidocanol and sodium tetradecyl sulphate, respectively. All patients were treated with a combination of oral steroids (prednisone 0.5–1 mg/kg) and systemic anticoagulants (enoxaparin 1.5 mg/kg daily subcutaneous injection). One case progressed to skin ulceration where prednisone was started five days after the adverse event and prematurely stopped after four weeks. The other cases did not progress to necrosis or other long-term sequelae. In these patients, prednisone was commenced immediately and slowly reduced over the following 12 weeks. The inflammation that follows ischemia plays a significant role in tissue necrosis and the immediate management of this adverse event may benefit from anti-inflammatory measures and in particular systemic steroid therapy unless contraindicated.

TRPA1 is essential for the vascular response to environmental cold exposure

The cold-induced vascular response, consisting of vasoconstriction followed by vasodilatation, is critical for protecting the cutaneous tissues against cold injury. Whilst this physiological reflex response is historic knowledge, the mechanisms involved are unclear. Here by using a murine model of local environmental cold exposure, we show that TRPA1 acts as a primary vascular cold sensor, as determined through TRPA1 pharmacological antagonism or gene deletion. The initial cold-induced vasoconstriction is mediated via TRPA1-dependent superoxide production that stimulates α_2C-adrenoceptors and Rho-kinase-mediated MLC phosphorylation, downstream of TRPA1 activation. The subsequent restorative blood flow component is also dependent on TRPA1 activation being mediated by sensory nerve-derived dilator neuropeptides CGRP and substance P, and also nNOS-derived NO. The results allow a new understanding of the importance of TRPA1 in cold exposure and provide impetus for further research into developing therapeutic agents aimed at the local protection of the skin in disease and adverse climates.

Blood flow in the skin of mammals changes in response to cold, but the mechanisms driving this response are unclear. Aubdool et al. show that the non-selective cation channel, TRPA1, is a vascular cold sensor and required for the vascular protective response to local cold exposure.

Melanopsin mediates light-dependent relaxation in blood vessels

Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4(-/-) mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ∼430-460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase- and phosphodiesterase 6-dependent but protein kinase G-independent. β-Adrenergic receptor kinase 1 (βARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, light-activated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor.

Oxidative damage and antioxidative therapy in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder of unknown etiology. This disease is characterized by a large variety of clinical patterns, which include the fibrosis of skin and visceral organs causing a variety of clinical manifestations. Genetic and environmental factors participate in the etiology of this disease; however, recently many studies underline the oxidative background influencing the course and complications of this disease. Reactive oxygen species (ROS) synthesized in SSc can mediate extra- and intracellular oxidative processes affecting endothelial cells and fibroblasts. The estimation of prooxidative markers in the pathogenesis of SSc can enable the identification of useful markers for disease activity and, thus, may help in planning appropriate therapy focusing on the fibrotic or vascular pattern. Recently, many attempts have been made to find antioxidative molecules (nutritional and pharmacological) reducing the prooxidant state in a variety of cells—mainly in endothelium and proliferating fibroblasts. This paper presents both the background of oxidative stress processes in systemic sclerosis mediated by different mechanisms and the evidence suggesting which of the dietary and pharmacological antioxidants can be used as therapeutic targets for this disease.

In silico modeling of human α2C-adrenoreceptor interaction with filamin-2

Vascular smooth muscle α2C-adrenoceptors (α2C-ARs) mediate vasoconstriction of small blood vessels, especially arterioles. Studies of endogenous receptors in human arteriolar smooth muscle cells (referred to as microVSM) and transiently transfected receptors in heterologous HEK293 cells show that the α2C-ARs are perinuclear receptors that translocate to the cell surface under cellular stress and elicit a biological response. Recent studies in microVSM unraveled a crucial role of Rap1A-Rho-ROCK-F-actin pathways in receptor translocation, and identified protein-protein interaction of α2C-ARs with the actin binding protein filamin-2 as an essential step in the process. To better understand the molecular nature and specificity of this interaction, in this study, we constructed comparative models of human α2C-AR and human filamin-2 proteins. Finally, we performed in silico protein-protein docking to provide a structural platform for the investigation of human α2C-AR and filamin-2 interactions. We found that electrostatic interactions seem to play a key role in this complex formation which manifests in interactions between the C-terminal arginines of α2C-ARs (particularly R454 and R456) and negatively charged residues from filamin-2 region between residues 1979 and 2206. Phylogenetic and sequence analysis showed that these interactions have evolved in warm-blooded animals.

Abnormal amplitude and kinetics of digital postocclusive reactive hyperemia in systemic sclerosis

OBJECTIVES

Postocclusive reactive hyperemia is mediated by two major mediators: sensory nerves and endothelium-derived hyperpolarizing factors. We hypothesized that the skin microvascular response to 5 min ischemia would differ depending upon the hand location in patients with systemic sclerosis (SSc), primary Raynaud's phenomenon (PRP) and healthy controls.

METHODS

Fifteen patients with SSc, 15 sex- and age-matched patients with PRP and healthy controls were enrolled. Their right hands were subjected to 5 min ischemia followed by a postocclusive hyperemia test, with local microcirculation monitoring by laser speckle contrast imaging on the dorsal face of the hand.

RESULTS

Postocclusive reactive hyperemia was abnormal in terms of peak and area under the curve (AUC) on all fingers except the thumb in patients with SSc and PRP compared with controls. In contrast, the kinetics of the response was longer only in SSc patients, with mean (SD) time to peak on the index, middle and ring finger were respectively 72 (58), 73 (51) and 67 (47) s for SSc; 40 (20), 40 (20) and 36 (19) s for PRP; and 34 (30), 34 (30) and 29 (24) s for controls (P=0.009 for interaction).

CONCLUSIONS

We observed decreased distal digital microvascular perfusion following 5 min of ischemia in patients presenting with PRP or SSc, while the kinetics was prolonged only in SSc. A dynamic assessment of digital skin blood flow using laser speckle contrast imaging following 5 min ischemia could be used as a tool to assess microvascular abnormalities in patients with Raynaud's phenomenon secondary to SSc.

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.

Nail fold capillary diameter changes in acute systemic hypoxia

The present study was undertaken to determine the effect of arterial blood hypoxemia induced by acute systemic hypoxia (pO2=12%) on capillary recruitment and diameter, and red blood cell (RBC) velocity in human nail fold capillaries during rest, arterial post-occlusive reactive hyperemia (PRH), and venous occlusion (VO) using intravital video-capillaroscopy. Capillary recruitment was unchanged in acute systemic hypoxia (H) versus normoxia (N). There was no difference in RBC velocity measurements between normoxia and hypoxia (P<0.63). However, a statistically significant increase in nail fold capillary total width (N, 39.9±9.1 vs. H, 42.7±10.3 μm; P<0.05), apical diameter (N, 15.5±4.3 vs. H, 16.8±4.3 μm; P<0.05), arterial diameter (N, 11.9±3.5 vs. H, 13.9±4.1 μm; P<0.05), and venous diameter (N, 15.5±4.3 vs. H, 17.2±4.8 μm; P<0.05) was observed and continued to be significant most often during post-occlusive reactive hyperemia (PRH) and venous congestion (VO). These data suggest that acute systemic hypoxia does not increase capillary recruitment, but instead increases capillary diameter, resulting in increased capillary blood flow.

International consensus criteria for the diagnosis of Raynaud's phenomenon

Vasoconstriction accompanied by changes in skin color is a normal physiologic response to cold. The distinction between this normal physiology and Raynaud's phenomenon (RP) has yet to be well characterized. In anticipation of the 9th International Congress on Autoimmunity, a panel of 12 RP experts from 9 different institutes and four different countries were assembled for a Delphi exercise to establish new diagnostic criteria for RP. Relevant investigators with highly cited manuscripts in Raynaud's-related research were identified using the Web of Science and invited to participate. Surveys at each stage were administered to participants via the on-line SurveyMonkey software tool. The participants evaluated the level of appropriateness of statements using a scale of 1 (extremely inappropriate) through 9 (extremely appropriate). In the second stage, panel participants were asked to rank rewritten items from the first round that were scored as "uncertain" for the diagnosis of RP, items with significant disagreement (Disagreement Index > 1), and new items suggested by the panel. Results were analyzed using the Interpercentile Range Adjusted for Symmetry (IPRAS) method. A 3-Step Approach to diagnose RP was then developed using items the panelists "agreed" were "appropriate" diagnostic criteria. In the final stage, the panel was presented with the newly developed diagnostic criteria and asked to rate them against previous models. Following the first two iterations of the Delphi exercise, the panel of 12 experts agreed that 36 of the items were "appropriate", 12 items had "uncertain" appropriateness, and 13 items were "inappropriate" to use in the diagnostic criteria of RP. Using an expert committee, we developed a 3-Step Approach for the diagnosis of RP and 5 additional criteria for the diagnosis of primary RP. The committee came to an agreement that the proposed criteria were "appropriate and accurate" for use by physicians to diagnose patients with RP.

Effect of Korean red ginseng on cold hypersensitivity in the hands and feet: study protocol for a randomized controlled trial

Background

Cold hypersensitivity in the hands and feet (CHHF) is one of the most common complaints among Asians, especially in women. Korean red ginseng (KRG), which is a steamed form of Panax ginseng, has vasodilating action in the peripheral vessels and increases blood flow under cold stress. However, few studies have evaluated the effect of KRG on cold hypersensitivity.

Methods/Design

This trial is a randomized, double-blind, placebo-controlled trial in 80 CHHF patients. The trial will be implemented at Kyung Hee University Hospital at Gangdong in Seoul, Korea. The participants will take KRG or a placebo for eight weeks, after which they will be followed-up for four weeks. During the administration period, six capsules of 500 mg KRG or placebo will be provided twice a day. The primary outcome is change of skin temperature in the hands between baseline and after treatment. The secondary outcomes include the visual analogue scale scores of cold hypersensitivity in the hands, change of skin temperature and the VAS scores of cold hypersensitivity in the feet, the recovery rate of the skin temperature by the cold stress test of the hands, the distal-dorsal difference of the hands, power variables of heart rate variability, and the 36-item short form health survey.

Discussion

This study is the first trial to evaluate the efficacy of KRG on CHHF by using infrared thermography. Our study will provide basic evidence regarding CHHF.

Trial registration

CliniacalTrials.gov NCT01664156