Thymic stromal lymphopoietin and digital microvascular damage in systemic sclerosis patients: A pilot study.

BACKGROUND: Systemic sclerosis (SSc) is a complex autoimmune connective-tissue disease, characterised by vasculopathy and fibrosis of the skin and internal organs. Activation of microvascular endothelial cells (ECs) causes the intimal hyperplasia that characterises the vascular remodelling in SSc. The most frequent complication of SSc is the development of digital ulcers (DUs). Thymic stromal lymphopoietin (TSLP) may trigger fibrosis and sustain vascular damage. Aim of this study was to evaluate the correlation between serum level of TSLP and DUs. METHODS: 75 consecutive SSc patients were enrolled and serum TSLP levels were measured. The presence of history of DUs (HDU) was evaluated. Recurrent new DUs were defined as the presence of at least 3 episodes of DUs in a 12-months follow up period. The risk of developing new DUs was calculated by applying the capillaroscopic skin ulcer risk index (CSURI). RESULTS: The median value of TSLP was higher in patients with HDU than patients without HDU [181.67 pg/ml (IQR 144.67; 265.66) vs 154.67 pg/ml (IQR 110.67; 171.33), p < 0.01]. The median value of TSLP was higher in patients with an increased CSURI index than patients without an increased CSURI [188 pg/ml (IQR 171.33; 246.33) vs 159.33 pg/ml (IQR 128.67; 218), p < 0.01]. Kaplan-Meier curves demonstrated that free survival from new DUs was significantly (p < 0.01) lower in SSc patients with increased TSLP serum levels. CONCLUSION: TSLP might have a key role in digital microvascular damage of SSc patients.

Critical peripheral ischemia: Higher prevalence in Indian systemic lupus erythematosus inception cohort for research (INSPIRE).

INTRODUCTION: There is limited literature on digital ischemia in systemic Lupus erythematosus (SLE). We report the prevalence, associations and outcome of digital infarcts and gangrene from the Indian SLE inception cohort (INSPIRE). METHODS: From the web-based database of INSPIRE, we extracted information for patients with 'Digital Infarct' and 'Digital gangrene' at enrolment into cohort, together considered as critical peripheral ischemia (CPI); all others were controls. We describe the associations of CPI with SLE clinical phenotype, autoantibodies, and disease activity at enrolment. We also report short term outcomes viz. Digital tissue loss and early mortality up to 6 months and recurrence of digital ischemic events in cases till date. RESULTS: Of 2503 SLE patients enrolled into the INSPIRE cohort, we identified 75 (2.9%) patients with CPI, 72 (96%) women and 6 (8%) children. Of them, 55 (73.3%) had digital gangrene and 21 (28%) patients had digital infarcts. Majority of digital gangrene resulted in amputation distal to terminal phalanx (63.6%). Multivariable analysis showed that pulmonary hypertension AOR [6.34 (1.99, 20.2)], coexistent thrombosis AOR [27.8 (15.7, 48.7)], triple antiphospholipid antibody positivity AOR [5.36 (1.67, 16.9)] and the presence of anti-Scl-70-antibody AOR [5.59 (1.86, 16.7)] were more likely while patients with class 3 or 4 lupus nephritis AOR [0.37 (0.15, 0.95)] and anti-nucleosome antibodies AOR [0.47 (0.23, 0.99)] were less likely to be associated with CPI. SLEDAI and short-term mortality were similar between cases and controls. CONCLUSIONS: CPI occurred in a higher proportion (2.9%) of SLE patients in the INSPIRE cohort as compared to earlier reports. Both prothrombotic state and vasculopathy contribute to its occurrence.

Amputated Digit Replantations: Critical Digit Ischemia Timing, Temperature, and Other Predictors of Survival.

INTRODUCTION: A common consideration for replantation success is the ischemia time following injury and the preservation temperature. A classic principle within the hand surgery community describes 12 hours of warm ischemia and 24 hours of cold ischemia as the upper limits for digit replantation; however, these limits are largely anecdotal and based on older studies. We aimed to compare survival data from the large body of literature to aid surgeons and all those involved in the replantation process in hopes of optimizing success rates. METHODS: The PubMed database was queried on April 4th, 2023, for articles that included data on digit replantation survival in terms of temperature of preservation and ischemia time. All primary outcomes were analyzed with the Mantel-Haenszel method within a random effects model. Secondary outcomes were pooled and analyzed using the chi-square statistic. Statistical analysis and forest plot generation were completed with RevMan 5.4 software with odds ratios calculated within a 95% confidence interval. RESULTS: Our meta-analysis identified that digits preserved in cold ischemia for over 12 hours had significantly higher odds of replantation success than the amputated digits replanted with 0-12 hours of warm ischemia time ( P ≤ 0.05). The odds of survival in the early (0-6 hours) replantation group were around 40% greater than the later (6-12 hours) replantation group ( P ≤ 0.05). Secondary outcomes that were associated with higher survival rates included a clean-cut amputation, increased venous and arterial anastomosis, a repair that did not require a vein graft, and replants performed in nonsmokers ( P ≤ 0.05). DISCUSSION: Overall, these findings suggest that when predicting digit replantation success, time is of the essence when the digit has yet to be preserved in a cold environment. This benefit, however, is almost completely diminished when the amputated digit is appropriately maintained in a cold environment soon after injury. In conclusion, our results suggest that there is potential for broadening the ischemia time limits for digit replant survival outlined in the literature, particularly for digits that have been stored correctly in cold ischemia.

Evaluation of Automated Finger Compression for Capillary Refill Time Measurement in Pediatrics.

OBJECTIVES: Early shock reversal is crucial to improve patient outcomes. Capillary refill time (CRT) is clinically important to identify and monitor shock in children but has issues with inconsistency. To minimize inconsistency, we evaluated a CRT monitoring system using an automated compression device. Our objective was to determine proper compression pressure in children. METHODS: Clinician force for CRT was collected during manual CRT measurement as a reference for automated compression in a previous study (12.9 N, 95% confidence interval, 12.5-13.4; n = 454). An automated compression device with a soft inflation bladder was fitted with a force sensor. We evaluated the effectiveness of the automated pressure to eliminate pulsatile blood flow from the distal phalange. Median and variance of CRT analysis at each pressure was compared. RESULTS: A comparison of pressures at 300 to 500 mm Hg on a simulated finger yielded a force of 5 to 10 N, and these pressures were subsequently used for automated compression for CRT. Automated compression was tested in 44 subjects (median age, 33 months; interquartile range [IQR], 14-56 months). At interim analysis of 17 subjects, there was significant difference in the waveform with residual pulsatile blood flow (9/50: 18% at 300 mm Hg, 5/50:10% at 400 mm Hg, 0/51: 0% at 500 mm Hg, P = 0.008). With subsequent enrollment of 27 subjects at 400 and 500 mm Hg, none had residual pulsatile blood flow. There was no difference in the CRT: median 1.8 (IQR, 1.06-2.875) in 400 mm Hg vs median 1.87 (IQR, 1.25-2.8325) in 500 mm Hg, P = 0.81. The variance of CRT was significantly larger in 400 mm Hg: 2.99 in 400 mm Hg vs. 1.35 in 500 mm Hg, P = 0.02, Levene's test. Intraclass correlation coefficient for automated CRT was 0.56 at 400 mm Hg and 0.78 at 500 mm Hg. CONCLUSIONS: Using clinician CRT measurement data, we determined either 400 or 500 mm Hg is an appropriate pressure for automated CRT, although 500 mm Hg demonstrates superior consistency.

DDP-FedFV: A Dual-Decoupling Personalized Federated Learning Framework for Finger Vein Recognition.

Finger vein recognition methods, as emerging biometric technologies, have attracted increasing attention in identity verification due to their high accuracy and live detection capabilities. However, as privacy protection awareness increases, traditional centralized finger vein recognition algorithms face privacy and security issues. Federated learning, a distributed training method that protects data privacy without sharing data across endpoints, is gradually being promoted and applied. Nevertheless, its performance is severely limited by heterogeneity among datasets. To address these issues, this paper proposes a dual-decoupling personalized federated learning framework for finger vein recognition (DDP-FedFV). The DDP-FedFV method combines generalization and personalization. In the first stage, the DDP-FedFV method implements a dual-decoupling mechanism involving model and feature decoupling to optimize feature representations and enhance the generalizability of the global model. In the second stage, the DDP-FedFV method implements a personalized weight aggregation method, federated personalization weight ratio reduction (FedPWRR), to optimize the parameter aggregation process based on data distribution information, thereby enhancing the personalization of the client models. To evaluate the performance of the DDP-FedFV method, theoretical analyses and experiments were conducted based on six public finger vein datasets. The experimental results indicate that the proposed algorithm outperforms centralized training models without increasing communication costs or privacy leakage risks.

A Degraded Finger Vein Image Recovery and Enhancement Algorithm Based on Atmospheric Scattering Theory.

With the development of biometric identification technology, finger vein identification has received more and more widespread attention for its security, efficiency, and stability. However, because of the performance of the current standard finger vein image acquisition device and the complex internal organization of the finger, the acquired images are often heavily degraded and have lost their texture characteristics. This makes the topology of the finger veins inconspicuous or even difficult to distinguish, greatly affecting the identification accuracy. Therefore, this paper proposes a finger vein image recovery and enhancement algorithm using atmospheric scattering theory. Firstly, to normalize the local over-bright and over-dark regions of finger vein images within a certain threshold, the Gamma transform method is improved in this paper to correct and measure the gray value of a given image. Then, we reconstruct the image based on atmospheric scattering theory and design a pixel mutation filter to segment the venous and non-venous contact zones. Finally, the degraded finger vein images are recovered and enhanced by global image gray value normalization. Experiments on SDUMLA-HMT and ZJ-UVM datasets show that our proposed method effectively achieves the recovery and enhancement of degraded finger vein images. The image restoration and enhancement algorithm proposed in this paper performs well in finger vein recognition using traditional methods, machine learning, and deep learning. The recognition accuracy of the processed image is improved by more than 10% compared to the original image.

Effect of Skin Pigmentation and Finger Choice on Accuracy of Oxygen Saturation Measurement in an IoT-Based Pulse Oximeter.

Pulse oximeters are widely used in hospitals and homes for measurement of blood oxygen saturation level (SpO2) and heart rate (HR). Concern has been raised regarding a possible bias in obtaining pulse oximeter measurements from different fingertips and the potential effect of skin pigmentation (white, brown, and dark). In this study, we obtained 600 SpO2 measurements from 20 volunteers using three UK NHS-approved commercial pulse oximeters alongside our custom-developed sensor, and used the Munsell colour system (5YR and 7.5YR cards) to classify the participants' skin pigmentation into three distinct categories (white, brown, and dark). The statistical analysis using ANOVA post hoc tests (Bonferroni correction), a Bland-Altman plot, and a correlation test were then carried out to determine if there was clinical significance in measuring the SpO2 from different fingertips and to highlight if skin pigmentation affects the accuracy of SpO2 measurement. The results indicate that although the three commercial pulse oximeters had different means and standard deviations, these differences had no clinical significance.

Evaluation of pulse oximeter at the nasal septum during general anesthesia: comparison with finger oximeter.

PURPOSE: Though the finger is generally recommended for pulse oxygen saturation (SpO2) monitoring site, its reliability may be compromised in conditions of poor peripheral perfusion. Therefore, we compared the performance of nasal septum SpO2 monitoring with finger SpO2 monitoring relative to simultaneous arterial oxygen saturation (SaO2) monitoring in generally anesthetized patients. METHODS: In 23 adult patients, comparisons of SpO2 measured at the nasal septum and finger with simultaneous SaO2 were made at four time points during the 90 min study period. A pulse oximetry monitoring failure was defined as a > 10 s continuous failure of in an adequate SpO2 data acquisition. Core temperature as well as finger-tip and nasal septum temperatures were simultaneously measured at 10 min intervals. RESULTS: A total of 92 sets of SpO2 and SaO2 measurements were obtained in 23 patients. The bias and precision for SpO2 measured at the nasal septum were - 0.8 ± 1.3 (95% confidence interval: - 1.1 to - 0.6), which was similar to those for SpO2 measured at the finger (- 0.6 ± 1.4; 95% confidence interval: - 0.9 to - 0.4) (p = 0.154). Finger-tip temperatures were consistently lower than other two temperatures at all time points (p < 0.05), reaching 33.5 ± 2.3 °C at 90 min after induction of anesthesia. While pulse oximetry monitoring failure did not occur for nasal septum probe, two cases of failure occurred for finger probe. CONCLUSIONS: Considering the higher stability to hypothermia with a similar accuracy, nasal septum pulse oximetry may be an attractive alternative to finger pulse oximetry. Trail registration This study was registered with Clinical Research Information Service (CRIS: https://cris.nih.go.kr/cris/en/ ; ref: KCT0008352).

Microcirculatory response to cold stress test in the healthy hand.

OBJECTIVE: Cold sensitivity of the fingers is common in several conditions. It has been linked to digital vasospasm, microvascular dysfunction, and neural mechanisms. This study aimed to investigate the normal digital microvascular response to a cold stress test in healthy individuals using Laser Speckle Contrast Imaging (LSCI). METHODS: Twenty-six healthy individuals, mean age 31 (SD 9) years were included. Skin perfusion of digits II-V was measured using Laser Speckle Contrast Imaging before and after a standardized cold stress test. Changes in skin perfusion from baseline were analyzed between hands, digits, and sexes. RESULTS: Skin perfusion was significantly (p < 0.0001) affected by cold provocation in both the cold exposed and the contralateral hands in all participants of the study. This effect was significantly different between the radial (digit II and III) and the ulnar (digit V) side of the hands (p < 0.001). There was a trend towards a larger decrease in perfusion in men (ns), and a faster recovery to baseline values in women (ns). A larger inter subject variability was seen in perfusion values in women. CONCLUSIONS: The normal microvascular response to cold provocation may involve both centrally and regionally mediated processes. When exposing one hand to a cold stress test, the contralateral hand responds with simultaneous but smaller decreases in perfusion.

Effects on blood parameters from hand-arm vibrations exposure.

Vibration exposure from handheld tools can affect the hands with neurological symptoms and vibration-induced Raynaud's phenomenon (VRP). The underlying pathophysiological mechanisms are not fully known, however, changes in the composition of blood parameters may contribute to VRP with an increase in blood viscosity and inflammatory response. The aim of this study was to examine the effect on blood parameters in capillary blood from fingers that had been exposed to a vibrating hand-held tool. This study involved nine healthy participants who had been exposed to vibration and an unexposed control group of six participants. Capillary blood samples were collected before and after vibration exposure for the exposed group, and repeated samples also from the control group. The exposed groups were exposed to vibration for a 15-min period or until they reached a 5.0 m/s2 vibration dose. Analysis of blood status and differential counting of leucocytes was performed on the capillary blood samples. The results of the blood samples showed an increase in mean value for erythrocyte volume fraction (EVF), hemoglobin, red blood cell count, white blood cell count and neutrophils, as well as a decrease of mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration. The increase of EVF and neutrophils was statistically significant for samples taken from the index finger but not the little finger. Even though the study was small it showed that an acute vibration exposure to the hands might increase EVF and neutrophilic granulocytes levels in the capillary blood taken from index fingers.

Simultaneous bilateral distal venous arterialization between redial artery and cephalic vein in dorsal hand for Raynaud's phenomenon in both hands: A case report.

Raynaud's phenomenon (RP) is characterized by episodic vasospasm in peripheral vessels and ischemia of the fingers. Venous arterialization is thought to induce neovascularization and increased oxygen tension. In this report, we describe a patient with RP in the fingers of both hands in whom venous arterialization achieved an acceptable result in both hands. The patient was a 62-year-old woman with a 10-year history of worsening pain and cold sensation in the tips of the index, middle, ring, and little fingers on both sides. The venous arterialization procedure was performed on both hands simultaneously at the level of the anatomical snuff box between radial artery and cephalic vein in dorsal hand. There was no need for valvectomy in the level of hands. To prevent development of the steal phenomenon in the arterialized veins, the superficial basilic and median veins of the forearm were ligated via 1 cm skin incisions. The pain and cold sensation in the fingertips of both hands remained decreased, and the nonhealing ulcers on the fingertips healed without the need for amputation. The observation period was 14 months, and the surface temperature of the fingers was increased after venous arterialization, as was the temperature of the palm and forearm. There was no problem when administering intravenous infusion into the forearm on either side postoperatively. The case showed venous arterialization was effective for RP without increasing intravenous pressure in the affected limb, and further investigation is necessary.

A Finger Vein Liveness Detection System Based on Multi-Scale Spatial-Temporal Map and Light-ViT Model.

Prosthetic attack is a problem that must be prevented in current finger vein recognition applications. To solve this problem, a finger vein liveness detection system was established in this study. The system begins by capturing short-term static finger vein videos using uniform near-infrared lighting. Subsequently, it employs Gabor filters without a direct-current (DC) component for vein area segmentation. The vein area is then divided into blocks to compute a multi-scale spatial-temporal map (MSTmap), which facilitates the extraction of coarse liveness features. Finally, these features are trained for refinement and used to predict liveness detection results with the proposed Light Vision Transformer (Light-ViT) model, which is equipped with an enhanced Light-ViT backbone, meticulously designed by interleaving multiple MN blocks and Light-ViT blocks, ensuring improved performance in the task. This architecture effectively balances the learning of local image features, controls network parameter complexity, and substantially improves the accuracy of liveness detection. The accuracy of the Light-ViT model was verified to be 99.63% on a self-made living/prosthetic finger vein video dataset. This proposed system can also be directly applied to the finger vein recognition terminal after the model is made lightweight.

Deep Learning-Based Wrist Vascular Biometric Recognition.

The need for contactless vascular biometric systems has significantly increased. In recent years, deep learning has proven to be efficient for vein segmentation and matching. Palm and finger vein biometrics are well researched; however, research on wrist vein biometrics is limited. Wrist vein biometrics is promising due to it not having finger or palm patterns on the skin surface making the image acquisition process easier. This paper presents a deep learning-based novel low-cost end-to-end contactless wrist vein biometric recognition system. FYO wrist vein dataset was used to train a novel U-Net CNN structure to extract and segment wrist vein patterns effectively. The extracted images were evaluated to have a Dice Coefficient of 0.723. A CNN and Siamese Neural Network were implemented to match wrist vein images obtaining the highest F1-score of 84.7%. The average matching time is less than 3 s on a Raspberry Pi. All the subsystems were integrated with the help of a designed GUI to form a functional end-to-end deep learning-based wrist biometric recognition system.

An Improved Multimodal Biometric Identification System Employing Score-Level Fuzzification of Finger Texture and Finger Vein Biometrics.

This research work focuses on a Near-Infra-Red (NIR) finger-images-based multimodal biometric system based on Finger Texture and Finger Vein biometrics. The individual results of the biometric characteristics are fused using a fuzzy system, and the final identification result is achieved. Experiments are performed for three different databases, i.e., the Near-Infra-Red Hand Images (NIRHI), Hong Kong Polytechnic University (HKPU) and University of Twente Finger Vein Pattern (UTFVP) databases. First, the Finger Texture biometric employs an efficient texture feature extracting algorithm, i.e., Linear Binary Pattern. Then, the classification is performed using Support Vector Machine, a proven machine learning classification algorithm. Second, the transfer learning of pre-trained convolutional neural networks (CNNs) is performed for the Finger Vein biometric, employing two approaches. The three selected CNNs are AlexNet, VGG16 and VGG19. In Approach 1, before feeding the images for the training of the CNN, the necessary preprocessing of NIR images is performed. In Approach 2, before the pre-processing step, image intensity optimization is also employed to regularize the image intensity. NIRHI outperforms HKPU and UTFVP for both of the modalities of focus, in a unimodal setup as well as in a multimodal one. The proposed multimodal biometric system demonstrates a better overall identification accuracy of 99.62% in comparison with 99.51% and 99.50% reported in the recent state-of-the-art systems.

[Methodology and clinical use of superb microvascular imaging in assessing micro-circulation changes of fingertips in systemic sclerosis].

OBJECTIVE: To explore the feasibility of superb microvascular imaging (SMI) in evaluating microcirculation damage of the finger of systemic sclerosis (SSc), and determining the optimal scanning method by assessing the effect of scanning position (finger pulp or nail bed), plane (transverse or sagittal) and Doppler gain on the results. METHODS: In the study, 32 SSc patients and 32 non-SSc volunteers admitted to Peking University Third Hospital from February to October 2022 were included. The SMI image under different gain set (40 dB or 35 dB) of the third fingertip (sagittal scans or transverse scan of nail bed or pulp) of both hands were collected while vascular index (VI) was measured. RESULTS: Non-SSc volunteer presented abundant SMI signal distributed in the third fingertip. Arteriole of nail bed was observed on the dorsal side of the distal phalanx under SMI and gave off multiple vertical branches towards the nail. The arteriole of finger pulp ran parallel to the skin and gave off vertical branches towards the skin distributing subcutaneously as a network. In SSc group, the SMI signal in nail bed and finger pulp was reduced. The arteriole of nail bed and finger pulp was discontinuous and presented as sporadic dots and short rod-like color signal under SMI. The vascular index of the SSc patients was significantly lower than that of the non-SSc controls (P < 0.001). Among different positions and sections, the area under the receiver operating characteristic curve (AUC) of the sagittal plane of nail bed was the highest. Under low gain, the AUC of sagittal plane of nail bed was 0.871, the cut-off value was 5.4%, the sensitivity was 90.6%, and the specificity was 74.2%. Under high gain, the AUC was 0.893, the cut-off value was 14.0%, the sensitivity was 75.0%, and the specificity was 93.6%. Multivariate analysis showed that there was statistical significance on the diagnostic impact of the sagittal plane of nail bed (P < 0.005 for high gain condition; P < 0.05 for low gain condition). CONCLUSION: SMI can be used to evaluate the abnormal changes of vascular in patients with SSc. Using the sagittal scan of nail bed with high gain can evaluate the vascular loss of the fingertip in SSc patient accurately and specifically.

Performance of finger systolic blood pressure measurement to detect digital occlusive arterial disease in systemic sclerosis.

OBJECTIVE: Digital ulcers related to digital occlusive arterial disease (DOAD) are frequent in patients with SSc. Finger systolic blood pressure (FSBP) and digital-brachial pressure index (DBI) using laser Doppler flowmetry constitute a non-invasive means of detecting DOAD in SSc, although thresholds have yet to be established for defining DOAD. The purpose of this study was to ascertain FSBP and DBI thresholds to detect DOAD in SSc patients. The intra/interday reproducibility of curve reading by four vascular physicians in relation to finger pressure measurement was also investigated. METHODS: SSc patients were followed in this single-centre study (Rennes University Hospital, France) between November 2017 and October 2019.These patients underwent tests before and after heating at two visits spaced 10 days apart. DOAD was diagnosed on the basis of post-warming skin blood flow of ≤206 arbitrary units measured by laser Doppler flowmetry, contingent on previous results validated by arteriography as a gold standard. An interday kappa coefficient with a 95% confidence interval was used to assess reproducibility. RESULTS: Sixteen [10 females; mean age: 63 (9) years] SSc patients were included. Mean time interval between visits was 9 (5) days. The best FSBP threshold for DOAD diagnosis was 76 mmHg and DBI was 0.74 after warming. FSBP and DBI sensitivity/specificity were 59.1% (95% CI: 49.6, 68.5%)/92.5% (95% CI: 85.3, 99.6%) and 73.3% (95% CI: 64.9, 81.8%)/83.0% (95% CI: 72.9, 93.1%), respectively. Intra/interday reproducibility ranged from fair to good. CONCLUSION: The conclusions drawn from this study suggest that FSBP ≤ 76 mmHg and DBI ≤ 0.74 thresholds are potentially reliable indicators of DOAD and demonstrate fair to good intra- and interday reproducibility. TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT03264820.

Definition and application of proximal-distal gradient finger perfusion in systemic sclerosis by laser speckle contrast analysis.

OBJECTIVE: In patients with systemic sclerosis (SSc) the perfusion of the fingers shows an alteration of the physiological proximal-distal gradient (PDG). The aim of this study is to provide a generalizable definition of PDG, applying it in a cohort of SSc patients and healthy controls (HC) using laser speckle contrast analysis (LASCA). METHODS: Adult consecutive SSc patients and HC were enrolled. Peripheral blood perfusion of the hands was evaluated by LASCA, subsequently obtaining 3 different regions of interest: from the distal interphalangeal joint to the fingertip (DIST), from the metacarpophalangeal joint to the distal interphalangeal joint (PROX), and of the whole finger (TOT). A PDG formula independent of both intra- and inter-personal factors was then built. The PDG formula so obtained was: [(DIST × 2.63) - PROX]/TOT. RESULTS: Ninety-four SSc patients (79.8% female, mean age 58.7 years) were enrolled. Applying the PDG formula, SSc patients revealed mean PDG values significantly lower than HC (1.82 ± 0.44 PU vs 2.70 ± 0.38 PU; p < 0.0001). Patients with a previous history of digital ulcers presented significant lower PDG values (p = 0.002). The ROC curve analysis identified in 2.28 PU the best PDG cut-off value between SSc and HC, with 86% sensibility and 90% specificity. CONCLUSION: This study provided a PDG formula generalizable to all kind of subjects, applying it in SSc with great sensibility and specificity using LASCA, the best non-invasive imaging technique for the dynamical evaluation of peripheral perfusion. LASCA-PDG appears also as a tool able to identify a subclinical microangiopathic impairment.

Correlation of nailfold capillaroscopy findings with history of digital ulcer on same finger: Results of SCLEROCAP study.

Systemic sclerosis may be complicated by digital ulcers. Nailfold capillaroscopy on one finger might reflect an increased risk of digital ulcer (DU). In the present study we studied the correlations between a history of ulcer and capillary findings on the finger. METHOD: This study is part of Sclerocap, a multicenter study aiming at validating prospectively the prognostic value of Maricq's and Cutolo's capillaroscopic classifications during a three-year longitudinal follow-up. A history of past or present digital ulcer was recorded at inclusion and nailfold capillaroscopy was performed. Elementary findings as well as Cutolo and Maricq's classifications were assessed. RESULTS: 387 patients were included in Sclerocap (327 females, 60 males) and 3096 fingers were examined by capillaroscopy at inclusion: 316 fingers (10%) belonging to 113 patients had a history of DU. Late Cutolo's stage was statistically correlated with a history of DU, both by univariate: OR 2.08 [1.09-3.96] and multivariate analysis: OR 1.97 [1.06-3.63]. Among the elemental abnormalities, only edema and decreased capillary density were correlated with a history of DU by multivariate analysis: respectively OR 1.92 [1.17-3.16] and 0.65 [0.49-0.85]. CONCLUSION: This cross-sectional study in a large cohort of patients with systemic sclerosis shows a correlation between a history of digital ulcer and edema, a decrease in capillary density and the late stage in Cutolo's classification. The extent of capillary abnormalities on one finger is associated with a history of local digital ulcer. Capillaroscopy might be used to predict the risk of DU but these results need first to be confirmed by prospective studies.

Digital pressure with laser Doppler flowmetry is better than photoplethysmography to characterize peripheral arterial disease of the upper limbs in end-stage renal disease patients.

OBJECTIVE: There is no consensual definition of significant peripheral arterial disease of the upper limbs. Patients with end-stage renal disease are usually explored with Doppler ultrasound, which seems insufficient to characterize and quantify the arterial disease in this anatomic site. Candidates for haemodialysis access tend to be increasingly older and have polyvascular disease, and a better assessment of the vascular status of their upper limbs with finger systolic blood pressure is necessary. Photoplethysmography is simple and currently used in practice, but laser Doppler flowmetry may be more sensitive for low values. Our objective is to investigate additional information in the digit assessment over the ultrasound assessment of the upper limbs of patients awaiting haemodialysis and compare digital pressure values taken by photoplethysmography and laser Doppler. METHODS: All included patients with end-stage renal disease scheduled for haemodialysis access received a prospective evaluation of their upper limbs with a clinical examination of the hands, an arterial upper limb Doppler ultrasound, and finger systolic blood pressure using photoplethysmography and laser Doppler flowmetry. Significant upper limb arterial disease was defined by a finger systolic blood pressure below 60 mm Hg or a finger brachial pressure index below 0.7. RESULTS: Twenty-four patients were included in the study. In all, 41.7% of patients (n = 10) had parietal calcifications to the antebrachial arteries on Doppler ultrasound, 8.3% of patients (n = 2) had bilateral finger systolic blood pressure values below 60 mm Hg with laser Doppler flowmetry (but not confirmed with photoplethysmography), and 16.6% of patients (n = 4) had a finger brachial pressure index below 0.7 on both laser Doppler flowmetry and photoplethysmography. While there was an agreement between these two methods, higher values were recorded with photoplethysmography. The Pearson coefficient was 0.493 for the median of basal digital pressures in absolute values and 0.489 for finger brachial pressure index (p < 0.001). CONCLUSION: Our study confirms the need to evaluate significant upper limb arterial disease in patients with end-stage renal disease not only with Doppler ultrasound but also with an evaluation of the finger systolic blood pressure. The correlation of the finger systolic blood pressure values using laser Doppler flowmetry and photoplethysmography was poor, which was probably due to an overestimation of the pressures with photoplethysmography. Despite the absence of a gold standard, we suggest that Laser Doppler flowmetry should be used rather than photoplethysmography to better characterize significant peripheral arterial disease of the upper limbs in patients with end-stage renal disease, particularly before creation of a new haemodialysis access. Protocol Record on clinical trial 38RC19.285.

Predictive value of laser speckle contrast analysis in systemic sclerosis. A systematic review and pilot study.

OBJECTIVES: To assess whether tools to functionally examine the microcirculation, such as laser speckle contrast analysis (LASCA), are predictive of ischaemic digital trophic lesions ([i]DTL) in patients with systemic sclerosis (SSc). METHODS: First, a systematic review (according to PRISMA) was conducted to identify studies describing a link between LASCA and SSc-related (i)DTL. In the additional pilot study, consecutive SSc patients underwent clinical and LASCA examinations (to assess the peripheral blood perfusion [PBP] of both hands) at enrolment. For one year, a monthly telephone survey was conducted to investigate (i)DTL occurrence. Logistic regression and ROC analysis were performed. RESULTS: None of the three manuscripts retained through the systematic review examined the predictive value of LASCA for future (i)DTL. In our pilot study, 7/106 (6.6%) SSc patients developed at least one iDTL during follow-up, with PBP not found to be predictive (OR = 0.995, p = .418; ROC-AUC = 0.597). Post hoc, when only patients not taking vasodilators were analysed (n = 57), all three who developed iDTL had an average PBP ≤ 70 PU, while only 9/54 (16.7%) patients without iDTL occurrence had such values. CONCLUSION: A predictive role of LASCA for (i)DTL has not yet been described in the literature and could also not be attested by our additional pilot study, due to a lower-than-expected iDTL incidence in our day-to-day SSc population in which patients were allowed to continue their vasodilator medication. However, the promising observations in the subgroup of vasodilator-naïve patients encourage further investigation of this potential added value of LASCA.