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.

Nailfold capillaroscopy-how many fingers should be examined to detect abnormality?

Objectives: Nailfold capillaroscopy is being increasingly used by rheumatologists in the diagnosis of SSc. However, assessment of all nailfolds can be time-consuming in a busy outpatient clinic. Our aim was to answer the question as to how many (and which) fingers a clinician should routinely assess to capture accurately the true state. Methods: A total of 2994 assessments (by an international panel of expert observers) of 1600 images from 173 participants (101 with SSc, 22 with primary RP and 50 healthy controls) were included in this analysis. Seven single-finger or finger combinations (derived from the middle and ring fingers) were then tested for sensitivity for the presence of two markers of capillary abnormality [presence of giant capillaries and an SSc grade (early, active or late)] compared with assessment of all eight fingers. Results: For the eight-finger gold standard, sensitivity against the diagnostic criteria was 74.6% (53.0% for the presence of giants alone and 73.1% for image grade alone). Examining only one finger gave low sensitivity (ranging from right middle 31.7% to left ring 46.6%). Examining both ring fingers gave a sensitivity of 59.8%, whereas examining the four-finger combination of both ring and both middle fingers gave a sensitivity of 66.7%. Conclusion: During routine capillaroscopic examination, ideally all eight nailbeds (excluding thumbs) should be examined, otherwise some abnormalities will be missed. Examining only four fingers reduces capillaroscopy sensitivity.

Automated structure and flow measurement - a promising tool in nailfold capillaroscopy.

OBJECTIVES: Despite increasing interest in nailfold capillaroscopy, objective measures of capillary structure and blood flow have been little studied. We aimed to test the hypothesis that structural measurements, capillary flow, and a combined measure have the predictive power to separate patients with systemic sclerosis (SSc) from those with primary Raynaud's phenomenon (PRP) and healthy controls (HC). METHODS: 50 patients with SSc, 12 with PRP, and 50 HC were imaged using a novel capillaroscopy system that generates high-quality nailfold images and provides fully-automated measurements of capillary structure and blood flow (capillary density, mean width, maximum width, shape score, derangement and mean flow velocity). Population statistics summarise the differences between the three groups. Areas under ROC curves (AZ) were used to measure classification accuracy when assigning individuals to SSc and HC/PRP groups. RESULTS: Statistically significant differences in group means were found between patients with SSc and both HC and patients with PRP, for all measurements, e.g. mean width (µm) ±â€¯SE: 15.0 ±â€¯0.71, 12.7 ±â€¯0.74 and 11.8 ±â€¯0.23 for SSc, PRP and HC respectively. Combining the five structural measurements gave better classification (AZ = 0.919 ±â€¯0.026) than the best single measurement (mean width, AZ = 0.874 ±â€¯0.043), whilst adding flow further improved classification (AZ = 0.930 ±â€¯0.024). CONCLUSIONS: Structural and blood flow measurements are both able to distinguish patients with SSc from those with PRP/HC. Importantly, these hold promise as clinical trial outcome measures for treatments aimed at improving finger blood flow or microvascular remodelling.

Intra-and inter-observer reliability of nailfold videocapillaroscopy - A possible outcome measure for systemic sclerosis-related microangiopathy.

OBJECTIVES: Our aim was to assess the reliability of nailfold capillary assessment in terms of image evaluability, image severity grade ('normal', 'early', 'active', 'late'), capillary density, capillary (apex) width, and presence of giant capillaries, and also to gain further insight into differences in these parameters between patients with systemic sclerosis (SSc), patients with primary Raynaud's phenomenon (PRP) and healthy control subjects. METHODS: Videocapillaroscopy images (magnification 300×) were acquired from all 10 digits from 173 participants: 101 patients with SSc, 22 with PRP and 50 healthy controls. Ten capillaroscopy experts from 7 European centres evaluated the images. Custom image mark-up software allowed extraction of the following outcome measures: overall grade ('normal', 'early', 'active', 'late', 'non-specific', or 'ungradeable'), capillary density (vessels/mm), mean vessel apical width, and presence of giant capillaries. RESULTS: Observers analysed a median of 129 images each. Evaluability (i.e. the availability of measures) varied across outcome measures (e.g. 73.0% for density and 46.2% for overall grade in patients with SSc). Intra-observer reliability for evaluability was consistently higher than inter- (e.g. for density, intra-class correlation coefficient [ICC] was 0.71 within and 0.14 between observers). Conditional on evaluability, both intra- and inter-observer reliability were high for grade (ICC 0.93 and 0.78 respectively), density (0.91 and 0.64) and width (0.91 and 0.85). CONCLUSIONS: Evaluability is one of the major challenges in assessing nailfold capillaries. However, when images are evaluable, the high intra- and inter-reliabilities suggest that overall image grade, capillary density and apex width have potential as outcome measures in longitudinal studies.

Quantitative outcome measures for systemic sclerosis-related Microangiopathy - Reliability of image acquisition in Nailfold Capillaroscopy.

BACKGROUND: Nailfold capillaroscopic parameters hold increasing promise as outcome measures for clinical trials in systemic sclerosis (SSc). Their inclusion as outcomes would often naturally require capillaroscopy images to be captured at several time points during any one study. Our objective was to assess repeatability of image acquisition (which has been little studied), as well as of measurement. METHOD: 41 patients (26 with SSc, 15 with primary Raynaud's phenomenon) and 10 healthy controls returned for repeat high-magnification (300×) videocapillaroscopy mosaic imaging of 10 digits one week after initial imaging (as part of a larger study of reliability). Images were assessed in a random order by an expert blinded observer and 4 outcome measures extracted: (1) overall image grade and then (where possible) distal vessel locations were marked, allowing (2) vessel density (across the whole nailfold) to be calculated (3) apex width measurement and (4) giant vessel count. Intra-rater, intra-visit and intra-rater inter-visit (baseline vs. 1week) reliability were examined in 475 and 392 images respectively. A linear, mixed-effects model was used to estimate variance components, from which intra-class correlation coefficients (ICCs) were determined. RESULTS: Intra-visit and inter-visit reliability estimates (ICCs) were (respectively): overall image grade, 0.97 and 0.90; vessel density, 0.92 and 0.65; mean vessel width, 0.91 and 0.79; presence of giant capillary, 0.68 and 0.56. These estimates were conditional on each parameter being measurable. CONCLUSION: Within-operator image analysis and acquisition are reproducible. Quantitative nailfold capillaroscopy, at least with a single observer, provides reliable outcome measures for clinical studies including randomised controlled trials.

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 study comparing videocapillaroscopy and dermoscopy in the assessment of nailfold capillaries in patients with systemic sclerosis-spectrum disorders.

OBJECTIVES: Nailfold videocapillaroscopy (NVC), the current gold standard for detection of capillary abnormalities suggestive of an SSc-spectrum disorder, is not widely available: a key question is whether lower-magnification, easy-to-use dermoscopy compares favourably. This is especially relevant given the inclusion of capillaroscopic abnormality within the 2013 classification criteria for SSc. Our objectives were to examine the ability to classify capillaries and to evaluate abnormality (severity), by both NVC and dermoscopy, to determine whether these differ between general and specialist rheumatologists, and to compare intra- and interrater reliability of both techniques. METHODS: NVC and dermoscopy images were acquired from all 10 nailbeds of 32 subjects with a range of capillary abnormalities. Images were graded (using a web-based interface) on a 0-3 scale of severity: normal (0), mildly (1), definitely (2) and grossly abnormal (3), and an unclassifiable category. Raters graded images from four subjects (40 nailbeds) using each technique, with five repeated images to estimate intrarater reliability. RESULTS: Forty-eight rheumatologists from 12 countries participated in the study (22 generalists, 26 specialists). While most images could be graded by both techniques, more were graded by NVC (84% vs 70%) and were systematically scored higher by NVC (mean difference 0.43 between the ratings). Agreement between the techniques was moderate. Intra- and interrater reliability were comparable for the two techniques in the classifiability of images and the grading of severity. CONCLUSION: Our results suggest that dermoscopy is comparable to NVC, although NVC images were more likely to be classifiable and were graded more severely.

A longitudinal study of ankle brachial pressure indices in a cohort of patients with systemic sclerosis.

OBJECTIVES: Digital ischaemia, often progressing beyond RP to digital ulceration and sometimes even gangrene, is the most common vascular manifestation of SSc. Both microvascular and macrovascular disease can contribute and coexistence of microvascular and macrovascular (proximal vessel) disease in patients with SSc is potentially limb threatening. The aims of this study were to examine the change over time in the ankle brachial pressure index (ABPI) in a cohort of patients with SSc and to examine whether age, gender, smoking status, disease duration, disease subtype and ACA are associated with ABPI. METHODS: The clinical and laboratory data of 217 patients attending the SSc clinic at a tertiary referral centre and who had their ABPIs checked between 1996 and 2011 were reviewed retrospectively. Data were analysed to see how the ABPI changed with time and linear mixed effects modelling was used to determine which factors were associated with ABPI. RESULTS: In most patients with SSc, the ABPI remained constant over time [median rate of change 0 units/year, interquartile range (IQR) -0.01-0.01]. There was a significant association between lower ABPI and increasing age (P = 0.04), the limited cutaneous subtype of SSc (P = 0.01) and ACA positivity (P = 0.03). Additionally there was an association between ABPI and smoking status of borderline statistical significance (P = 0.08). CONCLUSION: This study provides further evidence for associations between the severity of vascular disease in patients with SSc and increasing age, smoking, limited cutaneous disease and positive ACA. Reassuringly, in most patients ABPI remains stable over time.

A comparison of intense pulsed light and laser treatment of telangiectases in patients with systemic sclerosis: a within-subject randomized trial.

OBJECTIVE: Cutaneous telangiectases are a characteristic and psychologically distressing feature of SSc. Our aim was to assess the efficacy of two light-based treatments: pulsed dye laser (PDL) and intense pulsed light (IPL). METHODS: Nineteen patients with facial or upper limb telangiectases underwent three treatments with PDL and IPL (randomly assigned to left- and right-sided lesions). Outcome measures were clinical photography (assessed by two clinicians), dermoscopy (assessed by two observers), laser Doppler imaging (LDI) and observer and patient opinion, including patient self-assessment psychological questionnaires [Hospital Anxiety and Depression Scale (HADS), Adapted Satisfaction with Appearance Scale (ASWAP)]. RESULTS: Comparison between 16-week follow-up and baseline photography scores (from -2 to +2 on a Likert scale, with >0 being improvement) were a mean score for PDL of 1.7 (95% CI 1.4, 2.0) and for IPL 1.4 (0.9, 1.8), with a mean difference between PDL and IPL of -0.3 (-0.5, -0.1) (P = 0.01). Dermoscopy scores also improved with both therapies: PDL 1.3 (1.1, 1.5) and IPL 0.8 (0.5, 1.1), again greater with PDL (P = 0.01). LDI showed decreases in blood flow at 16 weeks, indicating a response to both therapies. All patients reported benefit from treatment (more preferred PDL at 16 weeks). Psychological questionnaires also indicated improvement after therapy with mean change in ASWAP of -13.9 (95% CI -20.5, -7.4). No side effects were reported for IPL; PDL caused transient bruising in most cases. CONCLUSION: Both PDL and IPL are effective treatments for SSc-related telangiectases. Outcome measures indicate that PDL has better outcomes in terms of appearance, although IPL had fewer side effects.

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.

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.