State-of-the-art technologies provide new insights linking skin and blood vessel abnormalities in SSc-related disorders.

OBJECTIVE: A key unanswered question in systemic sclerosis (SSc) is how microvascular abnormality and fibrosis inter-relate. Our aim was to use state-of-the-art non-invasive imaging methods to gain new insights into pathophysiology, comparing patients with different subtypes of SSc, including early dcSSc, not only to healthy controls but also to patients with causes of Raynaud's phenomenon not progressing to fibrosis. METHODS: Laser Doppler imaging, nailfold capillaroscopy, spectroscopy, and ultrasound measured (respectively) perfusion, microvascular structure, oxygenation/oxidative stress, and skin thickening in the hands of 265 subjects: 31 patients with primary Raynaud's phenomenon (PRP), 35 with undifferentiated connective tissue disease (UCTD), 93 with limited cutaneous SSc (lcSSc), 46 with diffuse cutaneous SSc (dcSSc, including 27 'early') and 60 healthy controls. RESULTS: Mean perfusion was reduced in SSc groups compared to controls (lcSSc 172 perfusion units [standard deviation 157], late-dcSSc 90 [145], early-dcSSc 68 [137] vs. controls 211 [146]; p = 0.0002) as was finger-oxygenation (lcSSc 12.1 [13.6] arbitrary units [AU], late-dcSSc 12.2 [8.4], early-dcSSc 11.1 [11.3] vs controls 14.9 [10.5]; p = 0.0049). Oxidative stress was increased at the hand-dorsum in SSc groups (p = 0.0007). Perfusion positively correlated with oxygenation (r = 0.23, p < 0.001), and capillary density negatively with skin thickness (r = -0.26, p < 0.001). CONCLUSION: Our findings lend support to the hypothesis that in SSc, particularly early dcSSc, (but not in PRP or UCTD), reduced perfusion (together with structural microvascular abnormality) associates with reduced oxygenation, with oxidative stress and with skin thickening/fibrosis, most likely driving a vicious cycle which ultimately results in irreversible tissue injury. Findings in skin may mirror alterations in internal organs.

A Multicenter Study of the Validity and Reliability of Responses to Hand Cold Challenge as Measured by Laser Speckle Contrast Imaging and Thermography: Outcome Measures for Systemic Sclerosis-Related Raynaud's Phenomenon.

OBJECTIVE: Reliable and objective outcome measures to facilitate clinical trials of novel treatments for systemic sclerosis (SSc)-related Raynaud's phenomenon (RP) are badly needed. Laser speckle contrast imaging (LSCI) and thermography are noninvasive measures of perfusion that have shown excellent potential. This multicenter study was undertaken to determine the reliability and validity of a hand cold challenge protocol using LSCI, standard thermography, and low-cost cell phone/mobile phone thermography (henceforth referred to as mobile thermography) in patients with SSc-related RP. METHODS: Patients with RP secondary to SSc were recruited from 6 UK tertiary care centers. The patients underwent cold challenge on 2 consecutive days. Changes in cutaneous blood flow/skin temperature at each visit were imaged simultaneously using LSCI, standard thermography, and mobile thermography. Measurements included area under the curve (AUC) for reperfusion/rewarming and maximum blood flow rate/skin temperature after rewarming (MAX). Test-retest reliability was assessed using intraclass correlation coefficients (ICCs). Estimated latent correlations (estimated from multilevel models, taking values between -1 and 1; denoted as rho values) were used to assess the convergent validity of LSCI and thermography. RESULTS: In total, 159 patients (77% with limited cutaneous SSc) were recruited (84% female, median age 63.3 years). LSCI and standard thermography both had substantial reliability, with ICCs for the reperfusion/rewarming AUC of 0.67 (95% confidence interval [95% CI] 0.54, 0.76) and 0.68 (95% CI 0.58, 0.80), respectively, and ICCs for the MAX of 0.64 (95% CI 0.52, 0.75) and 0.72 (95% CI 0.64, 0.81), respectively. Very high latent correlations were present for the AUCs of LSCI and thermography (ρ = 0.94; 95% CI 0.87, 1.00) and for the AUCs of standard and mobile thermography (ρ = 0.98; 95% CI 0.94, 1.00). CONCLUSION: This is the first multicenter study to examine the reliability and validity of cold challenge using LSCI and thermography in patients with SSc-related RP. LSCI and thermography both demonstrated good potential as outcome measures. LSCI, standard thermography, and mobile thermography had very high convergent validity.

Pilot study assessing pathophysiology and healing of digital ulcers in patients with systemic sclerosis using laser Doppler imaging and thermography.

OBJECTIVES: Systemic sclerosis (SSc)-related digital ulcers (DU) cause significant pain and disability and are often a primary endpoint in clinical trials. However, their pathophysiology has been little studied. The objectives of this prospective study were to determine whether laser Doppler imaging (LDI) and thermography can identify ischaemic components in both fingertip and extensor surface DU and assess ulcer healing. METHODS: Patients prospectively reported new DU over a year. Patients' DU underwent imaging until the ulcer had healed. Ischaemia was defined as lower blood flow or skin temperature (and inflammation as higher) within the ulcer, compared to a non-affected site. RESULTS: 53 ulcers (19 fingertip, 18 extensor, 16 'other' sites) in 17 patients were imaged (53 with LDI, 52 with thermography). For LDI data 32 (60%) ulcers were ischaemic; median perfusion ulcer/unaffected area; 0.79 (range 0.11-2.9). For thermography data 35 (66%) were ischaemic; 0.98 (0.89 to 1.1). Inflammation in the surrounding area was identified for all ulcers by LDI but not thermography. In the 36 ulcers with repeat imaging, LDI showed trends (with healing) towards increased ulcer perfusion (p=0.23) and decreased hyperaemia in adjacent areas (p=0.59). Skin temperature at the ulcer site showed no significant change (p=0.13) but adjacent area showed decreased temperature (p=0.04 signifying decreased blood flow). CONCLUSIONS: LDI and thermography are sufficiently sensitive to measure ischaemia in both fingertip and extensor ulcers. LDI was better suited to monitoring change in perfusion with healing (due to higher imaging resolution, or vascular changes occurring in more superficial skin layers).

Non-invasive Imaging of Localised Scleroderma for Assessment of Skin Blood Flow and Structure.

Extensive morphoea causes major morbidity, disability and disfigurement; pathophysiology is poorly understood. The aim of this study was to investigate, with non-invasive imaging, the relationship between localised abnormalities of skin structure and perfusion, which characterise morphoea. Thirty-two patients with morphoea underwent imaging at affected and unaffected sites. Skin thickness was imaged with optical coherence tomography (OCT) and high-frequency ultrasound (HFUS). Perfusion was imaged with dual-wavelength laser Doppler imaging (LDI) and thermography. Epidermal thickness showed a small increase from affected to unaffected site (OCT, active and inactive plaques [p = 0.005 and p = 0.004], HFUS active plaques only [p = 0.03]). Deeper perfusion was higher within affected than unaffected sites (LDI p < 0.001, thermography p < 0.0001, active and inactive plaques). Epidermal thickness was inversely related to superficial (but not deeper) perfusion. This novel study of OCT, HFUS, LDI and thermography confirms loss of epidermal thickness and increased deeper perfusion in morphea plaques.

A double-blind, randomized, placebo-controlled crossover trial of the α2C-adrenoceptor antagonist ORM-12741 for prevention of cold-induced vasospasm in patients with systemic sclerosis.

OBJECTIVES: Our primary purpose was to evaluate the efficacy of the high-potency α2C-adrenoceptor antagonist ORM-12741 in the attenuation of a cold-induced reduction in finger blood flow and temperature in patients with RP secondary to SSc. Secondary objectives were to assess safety and tolerability. METHODS: This was a phase IIa, randomized, double-blind, crossover, single-dose, placebo-controlled, single-centre study. Patients attended five times: initial screening, treatment visits 1-3 (each at least 1 week apart) and 1-2 weeks after the last treatment. At each treatment visit, each subject received a single oral dose of 30 mg or 100 mg of ORM-12741 or placebo. Thirty minutes later the subject underwent a cold challenge. Blood flow to the fingers was assessed by three methods [temperature by probe, laser Doppler imaging (LDI) and infrared thermography] performed before, during and after the cold challenge. RESULTS: Twelve patients (10 female, mean age 58 years) were included. The area under the rewarming curve (LDI) of the right index finger (arbitrary flux units × time) was lower for both 30 mg (P = 0.043) and 100 mg (P = 0.025) of ORM-12741 compared with placebo, indicating delayed reperfusion. The time to 70% temperature recovery (middle finger probe) was longer with active than placebo treatment: mean (s.d.) values for placebo, 30 mg of ORM-12741 and 100 mg of ORM-12741 were 21.4 min (12.4), 25.7 min (12.2) and 26.9 min (13.9), respectively. Overall ORM-12741 was well tolerated. CONCLUSION: ORM-12741 did not expedite recovery from a cold challenge in the fingers of patients with SSc. TRIAL REGISTRATION: https://www.clinicaltrialsregister.eu/; no. 2010-024005-13.

Noninvasive measurement of skin autofluorescence is increased in patients with systemic sclerosis: an indicator of increased advanced glycation endproducts?

OBJECTIVE: Skin autofluorescence noninvasively assesses expression of advanced glycation endproducts and therefore potentially the presence of oxidative stress that is implicated in the pathogenesis of systemic sclerosis (SSc). We investigated whether autofluorescence was increased in patients with SSc, primary Raynaud's phenomenon (RP), and morphea as compared to healthy controls. METHODS: Measurements of autofluorescence were made at 5 upper limb sites in 16 healthy controls, 16 patients with diffuse cutaneous SSc (dcSSc), 15 with limited cutaneous SSc (lcSSc), 15 with primary RP, and 13 with morphea. For patients with morphea, additional measurements were made at the affected and an adjacent unaffected site. RESULTS: Autofluorescence was significantly increased in patients with dcSSc but not lcSSc as compared to controls at the proximal phalanx [dcSSc median 0.15, interquartile range (IQR) 0.10-0.24, vs control 0.10, IQR 0.07-0.13; p = 0.014], dorsum of the hand (dcSSc 0.17, IQR 0.11-0.36, vs control 0.12, IQR 0.09-0.17; p = 0.031), the wrist (dcSSc 0.22, IQR 0.13-0.33, vs control 0.13, IQR 0.09-0.18; p = 0.005), and forearm (dcSSc 0.19, IQR 0.12-0.47, vs control 0.14, IQR 0.10-0.16; p = 0.022). There was a trend for autofluorescence to be increased in patients with lcSSc and at morphea sites, compared to noninvolved skin. CONCLUSION: Autofluorescence is increased in patients with dcSSc compared to primary RP and to healthy controls. This suggests increased oxidative stress and the potential for autofluorescence as a biomarker.

The influence of measurement location on reliability of quantitative nailfold videocapillaroscopy in patients with SSc.

OBJECTIVES: Nailfold videocapillaroscopy is being increasingly used as a marker of SSc-related microvascular disease, including in response to treatment. However, it requires further validation. Our aim was to assess the inter-observer, intra-observer and test-retest variability of semi-automated measurement of capillary features as well as of a manual density measurement. METHODS: All capillary apexes in images from 58 patients with SSc were marked up independently by two trained observers (inter-observer variability). The first observer then re-marked the images (intra-observer variability), and finally, the first observer marked up a second image of the same nailfold (test-retest). Mark-up of capillaries was carried out on cropped mosaic images (cropped independently by the observers to a fixed width, to allow the same length of nail bed to be studied for each patient) and on whole mosaic images (examining the whole nail bed). RESULTS: Reproducibility of independently cropped mosaic images was poor and was due to the variation in the positioning of the cropped area. However, quantification of whole mosaic images was highly reproducible, e.g. for inter-capillary distance, the intra-class correlation coefficient for inter-observer, intra-observer and test-retest reliability was 0.95, 0.98 and 0.90 (compared with 0.88, 0.79 and 0.89 for cropped mosaic images), respectively. Intra-observer limits of agreement for whole mosaic images were better than inter-observer reproducibility. CONCLUSION: Quantitative assessment of SSc-related change in nailfold capillaries is unreliable if examination of the same set of capillaries cannot be guaranteed. Conversely a wide-field, high-magnification system that allows visualization of the whole nail bed offers a highly reproducible approach for quantitative assessment and therefore has potential as an outcome measure.

A multicentre study on the reliability of qualitative and quantitative nail-fold videocapillaroscopy assessment.

OBJECTIVE: To investigate the inter- and intra-observer reliability of both qualitative and quantitative parameters used in the assessment of nail-fold capillaroscopy images. METHODS: Fifty mosaic nail-fold images of healthy controls (n = 10), patients with primary RP (n = 10) and SSc (n = 30) were assessed in random order by two blinded observers on two occasions at centres in Sweden, UK and The Netherlands. Each image was therefore scored by six observers twice. RESULTS: Inter- and intra-observer reliability of quantitative parameters showed substantial to almost perfect agreement [inter- and intra-observer weighted κ's for the number of widened capillaries was 0.75 and 0.87 and giant capillaries was 0.84 and 0.92, intra-class correlation coefficients (ICCs) for capillary density was 0.87 and 0.92 and total loop width was 0.94 and 0.98, respectively]. Qualitative parameters including architecture, avascularity, haemorrhage, crossed, ramified and bushy capillaries showed moderate to substantial inter-observer reproducibility (weighted κ ranging from 0.47 to 0.73), and substantial intra-observer repeatability (weighted κ ranging from 0.71 to 0.80), whereas the scoring of tortuous and bizarre capillaries showed poor inter-observer and substantial intra-observer agreement (inter-observer weighted κ's was 0.39 and 0.21 and intra-observer weighted κ's was 0.68 and 0.76, respectively). CONCLUSION: All quantitative and certain qualitative parameters are highly reliable in terms of inter- and intra-observer agreement. A combination of parameters with the highest reliability should be incorporated into future capillaroscopic scoring systems in studies of prediction and monitoring of SSc spectrum disorders.

Preliminary clinical evaluation of semi-automated nailfold capillaroscopy in the assessment of patients with Raynaud's phenomenon.

OBJECTIVES: Nailfold capillaroscopy is well established in screening patients with Raynaud's phenomenon for underlying SSc-spectrum disorders, by identifying abnormal capillaries. Our aim was to compare semi-automatic feature measurement from newly developed software with manual measurements, and determine the degree to which semi-automated data allows disease group classification. METHODS: Images from 46 healthy controls, 21 patients with PRP and 49 with SSc were preprocessed, and semi-automated measurements of intercapillary distance and capillary width, tortuosity, and derangement were performed. These were compared with manual measurements. Features were used to classify images into the three subject groups. RESULTS: Comparison of automatic and manual measures for distance, width, tortuosity, and derangement had correlations of r=0.583, 0.624, 0.495 (p<0.001), and 0.195 (p=0.040). For automatic measures, correlations were found between width and intercapillary distance, r=0.374, and width and tortuosity, r=0.573 (p<0.001). Significant differences between subject groups were found for all features (p<0.002). Overall, 75% of images correctly matched clinical classification using semi-automated features, compared with 71% for manual measurements. CONCLUSIONS: Semi-automatic and manual measurements of distance, width, and tortuosity showed moderate (but statistically significant) correlations. Correlation for derangement was weaker. Semi-automatic measurements are faster than manual measurements. Semi-automatic parameters identify differences between groups, and are as good as manual measurements for between-group classification.

Nail-fold capillary abnormalities are associated with anti-centromere antibody and severity of digital ischaemia.

OBJECTIVES: Advances in nail-fold capillaroscopy allow capillary abnormalities to be quantified. Our aim was to investigate, in patients with SSc, the relationships between the degree of nail-fold capillary abnormality and disease subtypes (lcSSc and dcSSc), duration of RP and the presence of (i) severe digital ischaemia (as defined by previous i.v. vasodilators, debridements or amputations), (ii) a positive ACA, (iii) clinically evident calcinosis, (iv) pulmonary arterial hypertension and (v) telangiectases. METHODS: This was a retrospective study of 176 patients. Six capillary measurements (four semi-automated and two manual) were calculated (automated width, distance between capillaries, tortuosity and derangement, and manual distance and density). Relationships between these measurements and the different clinical features of SSc were examined using multiple linear regressions (adjusted for age, sex and smoking status). RESULTS: One hundred and forty-two patients had lcSSc and 34 had dcSSc. Sixty-eight (39%) had a history of severe digital ischaemia, 66 (38%) were anti-centromere positive, 53 (30%) had clinically evident calcinosis and 26 (15%) had an estimated pulmonary artery pressure of >30 mmHg. Positive associations were found between both automated and manually measured distance between capillaries and (i) presence of severe digital ischaemia and (ii) positive ACA, and reduced density was also associated with positive anti-centromere. Patients with moderate/severe telangiectases had wider capillaries compared with those with 'mild' lesions. CONCLUSIONS: Both severe digital ischaemia and positive ACA are associated with measurable nail-fold capillaroscopic change, which has the potential of being an outcome measure for the structural microvascular disease associated with SSc-spectrum disorders.

Quantitative nailfold video capillaroscopy in patients with idiopathic inflammatory myopathy.

OBJECTIVES: To quantify nailfold capillary density and dimensions in patients with idiopathic inflammatory myopathy (IIM) and compare them with those in healthy controls; to look for associations with microvascular disease in IIM; and to determine whether nailfold capillary density and dimensions change over time. METHODS: Nailfold video microscopy (x300 magnification) was performed on 24 patients with IIM and 35 healthy controls. Capillary density and dimensions (total width and apical width) were quantified. Patients were clinically assessed and disease activity recorded using the Myositis Disease Activity Assessment Tool. Disease severity and physical function were assessed using the myositis damage index and Stanford HAQ, respectively. Findings were analysed using linear and logistic regression, adjusted for age and sex. In a subgroup of 16 patients with IIM and 27 controls, the process was repeated 6-12 months later and the results were analysed using Student's t-test. RESULTS: Capillary density was lower and dimensions were higher in patients with IIM compared with healthy controls (P < 0.001 for all). Anti-Jo-1 antibody was associated with reduced capillary density. In the longitudinal cohort, the mean change in capillary density was -1.4 in patients vs -0.4 in controls (P = 0.07). Mean change in capillary dimensions did not differ between patients and controls, but some patients demonstrated pronounced changes in capillary morphology over time. CONCLUSIONS: Reduced capillary density and increased dimensions in patients with IIM can be quantified using nailfold capillaroscopy, suggesting that nailfold capillaroscopy may be useful as an outcome measure of microvascular disease in studies of IIM.

Lack of effect of 8 weeks atorvastatin on microvascular endothelial function in patients with systemic sclerosis.

OBJECTIVE: The aim of this study was to test the hypothesis that statin therapy confers benefit on the microvasculature, including improving endothelial function, in patients with SSc. METHODS: This was a randomized, parallel group, double-blind study, with assessments at baseline, 4 and 8 weeks. Thirty-six patients were randomly assigned to receive 8 weeks treatment with atorvastatin 20 mg/day or placebo. The primary end-point was endothelial-dependent vasodilation, as assessed by response to iontophoresis with acetylcholine chloride (ACh) as measured by laser Doppler imaging. Secondary end-points included endothelial-independent vasodilation, microvascular structure as assessed by videocapillaroscopy, von Willebrand factor, high-sensitivity CRP and plasma cholesterol. RESULTS: Eighteen patients were randomly assigned to atorvastatin and 18 to placebo. Eight weeks treatment resulted in no statistically significant differences in any of the outcome measures (other than cholesterol) between atorvastatin and placebo groups. The median area under the curve for ACh iontophoresis at baseline was 1569 perfusion units (PU).time in the atorvastatin group and 1450 PU.time in the placebo group, and at 8 weeks 2146 and 1822 PU.time, respectively. Mean difference (95% CI) at 8 weeks was 355 (-835, 1544) PU.time. CONCLUSION: Atorvastatin 20 mg/day, given for 8 weeks, was not associated with changes in microvascular function or structure. The large variation in outcome scores means that it is not possible to rule out an effect on the basis of this trial. Future studies should be of longer duration and include patients with early disease who are unlikely to have irreversible structural vascular disease. TRIAL REGISTRATION: EudraCT, https://eudract.emea.europa.eu/, 2005-003775-21.

Reliability of dermoscopy in the assessment of patients with Raynaud's phenomenon.

OBJECTIVE: Few rheumatologists have access to wide field or video capillaroscopy (abnormal capillaries being highly predictive of CTD), and a key question is whether they should, therefore, purchase a dermatoscope. The aim of this study was to estimate the inter- and intra-observer variability of dermoscopy (magnification 10x) among rheumatologists with little or no experience of the technique. Good reliability is a necessary prerequisite for a test to be a valid clinical or research tool. METHODS: Dermoscopy was performed in all 10 nail folds from 16 subjects with a range of capillary normality/abnormality. The 160 nail fold images thus acquired were made into two PowerPoint presentations, each of 80 images with 16 duplicate slides. Each participating rheumatologist graded one of the sets of 96 images, grading scale (0-3): normal, mildly abnormal/'suspicious', definitely abnormal, grossly abnormal capillaries or 'unclassifiable' when capillaries could not be adequately identified. Data from both presentations were pooled for analysis. RESULTS: Twenty-eight rheumatologists participated in the study. For the decision as to whether an image could be classified or not, the inter- and intra-observer kappa-coefficients were 0.59 (95% CI 0.51, 0.67) and 0.63 (95% CI 0.45, 0.74), respectively. Conditional on being able to classify, the intra-class correlation coefficient for inter- and intra-observer reliability was 0.72 (95% CI 0.66, 0.77) and 0.85 (95% CI 0.82, 0.92), respectively. CONCLUSIONS: Inter- and intra-observer reliability were good, suggesting that with little training, dermoscopy is likely to be a useful technique to identify capillary distortions/underlying CTD.

Noninvasive imaging techniques in the assessment of scleroderma spectrum disorders.

OBJECTIVE: Systemic sclerosis (SSc) affects both microvascular structure and function. Laser Doppler imaging (LDI) and thermal imaging can be used to measure cutaneous blood vessel function. Nailfold capillaroscopy (NC) measures capillary morphology. The aim of this study was to investigate the relationship between capillary morphology and blood flow, and to determine which combination of techniques allows the best discrimination between patients with SSc, primary Raynaud's phenomenon (RP), and healthy controls. METHODS: NC was performed in 16 patients with SSc, 14 patients with primary RP, and 16 healthy controls. In addition, participants underwent cold stimulus with cold water. Hands were imaged to monitor rewarming and reperfusion. Nailfold morphologic features were measured and baseline images and rewarming curves were analyzed. RESULTS: Significant differences were found between groups (analysis of variance) for capillary morphologic features and rewarming curve characteristics. A correlation (P < 0.001) was found between LDI and thermal imaging at baseline (0.667) and maximum (0.729) blood flow and skin temperature, and for the areas under the rewarming curves (0.684). Receiver operating characteristic curves indicated that NC, thermal imaging, and LDI allowed 89%, 74%, and 72%, respectively, of SSc patient data to be correctly classified versus primary RP patients and controls. CONCLUSION: NC, LDI, and thermal imaging each independently provide good discrimination between patients with SSc and those with primary RP and healthy controls (NC being the most suitable technique for classifying patient groups). However, a combination of all 3 techniques improves classification. LDI and thermal imaging give equivalent information on dynamic changes in the cutaneous microcirculation; however, these only weakly correspond to capillary morphology.

Possible therapeutic use of vasodilator iontophoresis.

BACKGROUND: Investigation into the effects of a novel vasodilator delivery method (for the eventual treatment of scleroderma related digital ulceration) on healthy controls is reported. When Raynaud's phenomenon (episodic cold-induced colour changes of the fingers) occurs in the context of scleroderma, it can be extremely severe, leading to ulceration and sometimes gangrene. The current treatment of choice for scleroderma-related critical digital ischaemia and/or ulceration is intravenous prostanoid therapy, necessitating hospitalisation. However, iloprost is often poorly tolerated and may be ineffective. METHODS: This study utilises a newly designed iontophoresis chamber which has the potential to allow a therapeutic, rather than diagnostic application for vasodilatory iontophoresis. Ten healthy controls underwent whole finger iontophoresis with 1% acetylcholine chloride for 2 min at 100 microA. Iontophoresis with varying treatment times and currents was carried out on a subset of subjects to determine the effect on perfusion increase. RESULTS: A significant increase in perfusion following iontophoresis was found, compared to the adjacent, untreated finger (P < 0.001). Maximum increase as a percentage from baseline, mean [SD] = 100 [66]%. Both treatment time and current have an approximately linear relationship with perfusion increase. CONCLUSIONS: Iontophoresis of the whole finger administers drugs locally with no systemic effects and warrants further investigation as a therapy.