Description of the characteristics of the nailfold capillary structure in healthy children: a multi-centric study.

BACKGROUND: Nailfold videocapillaroscopy (NVC) is the primary diagnostic tool for the assessment of microcirculation in the pediatric population. OBJECTIVE: To define and standardize age-specific normal NVC patterns in healthy children and adolescents. METHODS: A cross-sectional observational multicentric study was conducted in 564 participants aged 5-17 years. Dino-Lite CapillaryScope 200 Pro Model MEDL4N Pro was performed at 200× magnification. Quantitative and qualitative NVC parameters were analysed separately for each age group and divided into four groups based on age categories. RESULTS: Of the 564 healthy participants, 54.9% were female. A total of 1184 images and 3384 capillaries were analysed. Positive correlations were observed between age and capillary density (P < 0.001, R = 0.450, CI95% 0.398-0.503). There was also a positive correlation between age and arterial/venous, loop diameter and capillary length, whereas there was a weak negative correlation between intercapillary distance. However, no correlation was found between age and capillary width. In addition, capillary density was significantly lower in the 5-7 age group compared with the other patient groups. Arterial limb diameter was lower in the 5-7 age group, while venous limb diameter was significantly wider in the 15-17 age group compared with the other patient groups. Dilated capillaries (8.7%), capillary tortuosity (14.4%), crossed capillaries (43.1%), micro-haemorrhages (2.7%) and avascular area (4.8%) were present in all age groups. Excellent intra- and interobserver ICC values were obtained for all parameters. CONCLUSION: These findings hold potential significance for future studies, aiding in the analysis and differentiation of children suspected of rheumatological diseases with potential microangiopathy.

Capi-score: a quantitative algorithm for identifying disease patterns in nailfold videocapillaroscopy.

OBJECTIVES: The European Alliance of Associations for Rheumatology (EULAR) supports the use of nailfold videocapillaroscopy (NVC) to identify disease patterns (DPs) associated with systemic sclerosis (SSc) and Raynaud's phenomenon (RP). Recently, EULAR proposed an easy-to-manage procedure, a so-called Fast Track algorithm, to differentiate SSc from non-SSc patterns in NVC specimens. However, subjectivity among capillaroscopists remains a limitation. Our aim was to perform a software-based analysis of NVC peculiarities in a cohort of samples from SSc and RP patients and, subsequently, build a Fast Track-inspired algorithm to identify DPs without the constraint of interobserver variability. METHODS: NVCs were examined by 9 capillaroscopists. Those NVCs whose DPs were consensually agreed (≥2 out of 3 interobservers) were subsequently analysed with an in-house developed software. Each variable's results were grouped according to the consensually agreed DPs in order to identify useful hallmarks to categorise them. RESULTS: Eight-hundred and fifty-one NVCs (21 957 images) whose DPs had been consensually agreed were software-analysed. Appropriate cut-offs set in capillary density and percentage of abnormal and giant capillaries, tortuosities and hemorrhages allowed DP categorization and the development of the CAPI-Score algorithm. This consisted of 4 rules: Rule 1, SSc vs non-SSc, accuracy 0.88; Rules 2 and 3, SSc-early vs SSc-active vs SSc-late, accuracy 0.82; Rule 4, non-SSc normal vs non-SSc non-specific, accuracy 0.73. Accuracy improved when the analysis was limited to NVCs whose DPs had achieved full consensus among interobservers. CONCLUSIONS: The CAPI-Score algorithm may become a useful tool to assign DPs by overcoming the limitations of subjectivity.

Relationship between nailfold videocapillaroscopic findings and cardiovascular risk factors.

BACKGROUND: Nailfold Videocapillaroscopy (NVC) is a valuable tool in the differential diagnosis of Raynaud's phenomenon (RP), present in certain Rheumatic diseases (RD). Knowing that many people have cardiovascular risk factors (CVRF), the main objective was to demonstrate that CVRF and carotid plaques produce NVC alterations. METHODS: Cross-sectional unicentric study carried out from 2020 to 2023. Four groups were formed: subjects with RD and RP, participants with RD without RP, subjects with RP without RD and finally participants without RP or RD (study group). Each subject exhibiting CVRF presented only a single risk factor. The variables collected were: sociodemographic, CVRF (diabetes, tobacco, alcohol (ALC), obesity (OBE), dyslipidemia and arterial hypertension (AH)), diseases, RP, treatments, tortuosities and NVC alterations (ramified capillaries, enlarged capillaries, giant capillaries, haemorrhages and density loss) and carotid ultrasound (CU). RESULTS: 402 subjects were included (76 % women, mean age 51 ± 16 years), 67 % had CVRF, 50 % RP and 38 % RD. Tortuosities were present in 100 % of CVRF participants. A statistically significant association was found between the presence of CVRF and all the NVC alterations: ramified capillaries (OR = 95.6), enlarged capillaries (OR = 59.2), giant capillaries (OR = 8.32), haemorrhages (OR = 17.6) and density loss (OR = 14.4). In particular, an association was found between giant capillaries with AH (p = 0,008) and OBE (p ã€ˆ0,001), and haemorrhages and density loss with ALC and OBE (p < 0,001). On the other hand, 40 subjects presented CU plaques (9.9 %), associated with enlarged capillaries (OR = 8.08), haemorrhages (OR = 4.04) and ramified capillaries (OR = 3.01). The pathological intima-media thickness was also associated with haemorrhages (OR = 3.14). CONCLUSIONS: There is a clear association between CVRF and ultrasound atherosclerotic findings in carotid with NVC alterations. These findings are of special interest for a correct NVC interpretation and to avoid false positives in the diagnosis of primary and secondary RP.

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.

Examination of nailfold videocapillaroscopy findings in ANCA-associated vasculitis.

OBJECTIVE: The objective of this study was to evaluate nailfold videocapillaroscopy (NVC) as a useful tool for assessing the disease activity of ANCA-associated vasculitis (AAV). METHODS: This study enrolled 51 patients with AAV and 21 healthy controls. We scored NVC findings semiquantitatively, and compared them between AAV patients and controls. We examined the association of NVC findings with disease activity indicators, histopathological findings of skin biopsies, and high-resolution CT (HRCT) scores in AAV. Additionally, we repeatedly rated the NVC findings 3 months after immunosuppressive therapy. RESULTS: Of the 51 enrolled patients, 36 (70.6%) showed a microangiopathy pattern and 4 (7.8%) showed a scleroderma pattern in AAV. The scores for microhaemorrhage, capillary loss, neoangiogenesis, and tortuosity were significantly higher in the AAV group than in the control group. NVC abnormalities correlated with the severity of skin, lung and kidney involvement. The scores of giant capillaries significantly correlated with the total BVAS and the chest BVAS; the scores of capillary loss correlated with the chest BVAS and the renal BVAS. The scores of microhaemorrhage significantly correlated with perivascular inflammatory cell infiltrations in the upper dermis of the purpura and tended to correlate with the total ground-glass opacity and consolidation scores on HRCT. In addition, capillary loss scores had a significant positive correlation with serum creatinine levels. Additionally, the microhaemorrhage scores were significantly reduced after 3 months of immunosuppressive therapy. CONCLUSION: In AAV patients, NVC abnormalities are significantly associated with disease severity. This result suggests that NVC is a useful tool for assessing the disease activity and treatment response in AAV.

Utility of nailfold capillary assessment for predicting psoriatic arthritis based on a prospective observational cohort study.

OBJECTIVES: PsA is one of the most serious comorbidities associated with psoriasis. While the early intervention in PsA is demanded, risk factors of PsA development are not well-known. This is the first prospective study to evaluate the clinical significance of nailfold capillary (NFC) changes in patients with psoriasis. METHODS: We conducted a prospective cohort study in a population of 449 psoriasis patients who had not been treated with systemic therapy or topical finger therapy. NFCs were observed by dermoscopy and capillaroscopy, and the correlation of NFC abnormalities, including nailfold bleeding (NFB) and enlarged capillaries, with the prevalence of PsA, incidence of new PsA, and serum levels of TNF-a, IL-17A and IL-23 were analysed. RESULTS: Detailed examination at the time of inclusion revealed that of 449 patients, 236 had Psoriasis vulgaris (PsV) and 213 had PsA. Both NFB and enlarged capillaries were significantly more frequent in patients with PsA (34.7% vs 84.5%, P < 0.0001; 25.4% vs 100%, P < 0.0001). In addition, PsV patients were prospectively observed before they developed PsA (mean 21 months, 95% CI 2, 77 months). Multivariate analysis suggested that the appearance of NFB and enlarged capillaries was a predictor of PsA development (HR 2.75, 95% CI 1.38, 5.47 and HR 4.49, 95% CI 2.25, 8.96, respectively). The degree of NFC abnormalities also correlated with the severity of PsA and serum cytokine levels. CONCLUSIONS: NFC abnormalities were suggested to be a predictor of PsA in psoriasis patients, and at the same time, its degree could be an indicator of disease severity.

Asymmetric dimethylarginine correlates with worsening peripheral microangiopathy in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a connective tissue disease characterized primarily by micro-angiopathy and endothelial dysfunction which stimulate a fibrotic process. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) inhibitor and represents a novel biomarker for vascular dysfunction. Nailfold video capillaroscopy (NVC) represents a non-invasive and reliable technique for the evaluation of microvasculopathy in SSc. OBJECTIVES: The aim of this study was to examine the possible association between ADMA and microvascular involvement in patients with SSc. METHODS: This was a cross-sectional study including consecutive SSc patients attending the Scleroderma Outpatient Clinic. ADMA was measured in serum samples using a commercial enzyme immunoassay. Participants underwent NVC with qualitative and semi-quantitative assessment and all NVC parameters were measured in the distal row of each finger. The findings were classified in one of the three qualitative NVC patterns: early, active, and late. RESULTS: Eighty-one (92,6 % women) SSc individuals with mean age 55.44 ± 13.4 years were included in this analysis. Within-groups comparisons revealed a trend between higher ADMA levels and progressive micro-vasculopathy (1,29 [2,1] vs 1,57 [1,95] vs 2,41 [3,87]; for early, active and late patterns respectively, p = 0.039). Furthermore, ADMA concentration was significantly associated with the number of capillaries/mm (r = -0.235; p = 0.035). CONCLUSIONS: Serum ADMA levels were significantly associated with advancing stages of microcirculatory abnormalities suggesting that ADMA may have a role in promoting microvascular endothelial dysfunction in SSc individuals.

Peripheral nailfold capillary microscopic abnormalities in rheumatoid arthritis are associated with arterial stiffness: Results from a cross-sectional study.

Vascular injury eventually resulting in the establishment of cardiovascular disease is a serious complication in rheumatoid arthritis (RA). Nailfold videocapillaroscopy (NVC) is a non-invasive imaging modality that enables the quantitative and qualitative assessment of the peripheral microvasculature. Nevertheless, capillaroscopic patterns remain inadequately defined in RA, especially regarding their clinical significance as potential markers of systemic vascular impairment. Consecutive RA patients underwent NVC using a standardized protocol, to assess the following parameters: capillary density, avascular areas, capillary dimensions, microhemorrhages, subpapillary venous plexus, and presence of ramified, bushy, crossed and tortuous capillaries. Carotid-femoral pulse wave velocity (PWV) and pulse pressure were measured as well-acknowledged markers of large artery stiffening. The vast majority of our cohort (n = 44) presented a combination of non-specific and abnormal capillaroscopic parameters. Capillary ramification was associated with both PWV and pulse pressure, even after adjustment for cardiovascular risk factors and systemic inflammation. Our study highlights the high prevalence of a wide range of capillaroscopic deviations from the normal patterns in RA. Furthermore, it provides for the first time evidence of an association between structural disorders of the microcirculation and markers of macrovascular dysfunction, suggesting that NVC might have a role as an index of generalised vascular impairment in RA.

Serum kynurenic acid is lower in systemic sclerosis patients with microvascular damage of hands.

BACKGROUND: Endothelial dysfunction occurs early in systemic sclerosis (SSc), leading to tissue hypoxia, vasoconstriction and fibrosis. It has been demonstrated that endothelial cells (ECs) are able to produce kynurenic acid (KYNA) in response to vascular inflammation, due to its anti-inflammatory and anti-oxidants activity. In SSc patients, blood perfusion of hands, assessed by laser speckle contrast analysis (LASCA), correlated negatively with the extent of the nailfold microvascular damage, scored according to nailfold videocapillaroscopy (NVC) classification. Aim of this study was to evaluate the difference of serum KYNA in SSc patients with different stages of microvascular damage. METHODS: Serum KYNA was assessed in 40 SSc patients at the enrolment. NVC was performed to evaluate capillaroscopic patterns (early, active and late). LASCA was performed to evaluate mean peripheral blood perfusion (PBP) of both hands and to evaluate the proximal-distal gradient (PDG). RESULTS: Median PDG was significantly lower in SSc patients with late NVC pattern compared to SSc patients with early and active NVC pattern [3.79 pU (IQR -8.55-18.16) vs 23.55 pU (IQR 14.92-43.80), p < 0.01]. Serum KYNA was significantly lower in SSc patients with late NVC pattern compared to SSc patient with early and active NVC pattern [45.19 ng/mL (IQR 42.70-54.74) vs 52.65 ng/mL (IQR 49.99-60.29), p < 0.05]. Moreover, SSc patients without PDG had significantly lower serum KYNA than in SSc patients with PDG [48.03 ng/mL (IQR 43.87-53.68) vs 59.27 ng/mL (IQR 49.15-71.00), p < 0.05]. CONCLUSION: KYNA is lower in SSc patients with late NCV pattern and without PDG. KYNA may be associated with early endothelial dysfunction.

Utility of nailfold capillary assessment for predicting pustulotic arthro-osteitis in palmoplantar pustulosis based on a prospective cohort study.

BACKGROUND: Pustulotic arthro-osteitis (PAO) is 1 of the most serious comorbidities associated with palmoplantar pustulosis (PPP). Risk factors of PAO development are not well-known. OBJECTIVE: To evaluate the clinical significance of nailfold capillary (NFC) changes in patients with PPP. METHODS: We conducted a prospective cohort study in a population of 102 PPP patients. Correlations of NFC abnormalities, including nailfold bleeding and enlarged capillaries, with the prevalence of PAO, the incidence of new PAO, and serum levels of cytokines were analyzed. RESULTS: Detailed examination revealed that of 102 PPP patients, 52 without PAO and 50 with PAO. Both nailfold bleeding and enlarged capillaries were significantly more frequent in patients with PAO (50.0% vs 92.0%, P < .0001; 50.0% vs 94.0%, P < .0001). In addition, PPP patients without PAO were prospectively observed before they developed PAO (mean 28 months [1-52 months]). Multivariate analysis suggested that these NFC abnormalities were predictors of PAO development (hazard ratio 3.37, 95% confidence interval 1.13-10.07; 3.37, 1.13-10.07) and guselkumab prevent PAO development (0.093, 0.012-0.76). The degree of NFC abnormalities correlated with the severity of PAO and serum cytokine levels. LIMITATIONS: All participants were Japanese. CONCLUSION: NFC abnormalities could be predictors of PAO in PPP patients, and their degree indicators of disease severity.

Nailfold microvascular abnormalities are associated with a higher prevalence of pulmonary arterial hypertension in patients with MCTD.

OBJECTIVE: MCTD manifests with microvasculopathy and overlapping clinical features of SLE, SSc and idiopathic inflammatory myopathies (IIM). The aim of this study was to investigate the clinical significance of microvasculopathy in patients with MCTD using nailfold videocapillaroscopy (NVC). METHODS: Fifty patients with newly diagnosed and untreated MCTD were enrolled in this multicentre, prospective and observational study. Clinical features and NVC findings were assessed at baseline and after 1 year post-intervention, along with disease controls [SLE (n = 40), SSc (n = 70) and IIM (n = 50)]. RESULTS: All MCTD patients presented Raynaud's phenomenon and were positive for anti-U1 RNP antibodies, and 22.0% (11/50) had pulmonary arterial hypertension (PAH). The prevalence of NVC scleroderma patterns in MCTD was 38.0%, which was lower than SSc (88.6%) but higher than SLE (10.0%). In addition, when we divided MCTD patients into two groups by presence or absence of NVC scleroderma patterns, we found a higher prevalence of PAH in patients with NVC scleroderma patterns. Namely, NVC scleroderma patterns were observed in all MCTD patients with PAH, and in 21.0% of those without PAH. After intensive immunosuppressive therapy, NVC scleroderma patterns disappeared in half of the MCTD patients but were not changed in SSc patients. CONCLUSIONS: MCTD differed from SLE, SSc and IIM in terms of the prevalence and responsiveness of NVC scleroderma patterns to immunosuppressive therapy. Detection of nailfold microvascular abnormalities in MCTD could contribute to predicting PAH and help us to understand further aspects of the pathogenesis of MCTD.

Assessing the role for nailfold videocapillaroscopy in interstitial lung disease classfication: a systematic review and meta-analysis.

OBJECTIVES: The nailfold videocapillaroscopy (NVC) has been known to assist with interstitial lung disease (ILD) classification. However, evidence on its diagnostic efficacy is limited, particularly in some connective tissue disease-related interstitial lung diseases (CTD-ILD), and in interstitial pneumonia with autoimmune features (IPAF). This study aimed to address this limitation by conducting a meta-analysis on the efficacy of the NVC in ILD subgroups of CTD-ILD, IPAF and idiopathic pulmonary fibrosis (IPF). METHODS: MEDLINE, EMBASE, CENTRAL were screened from inception to December 2020 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that report prevalence of nailfold abnormalities (NVC+) in CTD-ILD, IPAF and IPF cohorts were included. Data were presented as prevalence ratio (PR) with 95% CI using a random-effects model. Quality of evidence was assessed using GRADE criteria. RESULTS: Twenty-one studies were eligible. Prevalence of NVC+ was highest in CTD-ILD; PR (95 CI%) 80.4% (74.3%, 85.3%), followed by IPAF; 27.4% (10.9%, 53.7%), and IPF; 13.8% (5.7%, 29.9%). Late scleroderma pattern was the most prevalent nailfold pattern; 40.4% (28.1%, 54.1%) in our CTD-ILD cohort. Quality of evidence was low for CTD-ILD, IPAF and IPF cohorts, moderate for the late scleroderma pattern cohort. CONCLUSION: NVC can increase the diagnostic accuracy of ILD when used in a multi-disciplinary setting, and appears to have greatest utility in CTD-ILD, followed by IPAF and IPF. The Late Scleroderma Pattern was the most frequent nailfold capillary pattern in SSc-ILD. Future research will allow for greater understanding of the prognostic value of the NVC in ILD.

Nailfold capillaroscopy in SSc: innocent bystander or promising biomarker for novel severe organ involvement/progression?

OBJECTIVES: Nailfold videocapillaroscopy (NVC) plays a well-established role in differentiating primary from secondary RP due to SSc. However, the association of NVC with novel severe organ involvement/progression in SSc has never been evaluated in a multicentre, multinational study, which we now perform for the first time. METHODS: Follow-up data from 334 SSc patients [265 women; 18 limited SSc (lSSc)/203 lcSSc/113 dcSSc] registered between November 2008 and January 2016 by seven tertiary centres in the EUSTAR-database, were analysed. Novel severe organ involvement/progression was defined as new/progressive involvement of the peripheral vasculature, lungs, heart, skin, gastrointestinal tract, kidneys, musculoskeletal system, or death, at the 12- or 24-month follow-up. NVC images at enrolment were quantitatively and qualitatively evaluated according to the standardized definitions of the EULAR Study Group on Microcirculation in Rheumatic Diseases. Uni- and multivariable logistic regression modelling (ULR, MLR) was performed. RESULTS: Of the 334 included SSc patients, 257 (76.9%) developed novel overall severe organ involvement/progression. Following MLR, normal capillary density was associated with less-frequent novel overall severe organ involvement/progression [odds ratio (OR) = 0.77, P < 0.001] and novel peripheral vascular involvement (OR = 0.79, P = 0.043); microhaemorrhages were associated with less novel pulmonary hypertension (OR = 0.47, P = 0.029); and a 'severe' (active/late) NVC pattern was associated with novel overall severe organ involvement/progression (OR = 2.14, P = 0.002) and skin progression (OR = 1.70, P = 0.049). CONCLUSIONS: Our results suggest that NVC may be a promising biomarker in SSc, certainly warranting further investigation. Despite the participation of tertiary centres, which follow their patients in a standardized way, we were underpowered to detect associations with infrequent severe organ involvement/progression.

Full longitudinal nailfold videocapillaroscopy analysis of microvascular changes during normal pregnancy.

BACKGROUND: Microvascular remodeling is one major responsible for vascular adaptation in pregnancy, still it is not routinely evaluated in the obstetric field. This pilot study aimed to explore the role of nailfold capillaroscopy (NCV) in detecting microvascular changes during normal pregnancy. METHODS: A population of 30 healthy pregnant women was longitudinally followed performing clinical assessment and NVC evaluation at each trimester and post-partum. Thirty non-pregnant age-matched healthy women having received at least two NVCs with a minimum 9 to 12-month interval were selected as controls. All NVC images were evaluated by a qualitative and semi-quantitative assessment using current standardised approach. Statistical analyses were conducted to assess NVC trend throughout gestation and its possible association with pregnancy course. RESULTS: A progressive significant increase of NVC neoangiogenesis and a specular reduction in capillary dilations was observed during pregnancy (p < 0.05). These variations were not found in age-matched controls, who showed stable NVC parameters over a similar time frame (p < 0.05). Additionally, a significant inverse correlation was found between NVC neoangiogenesis rate and maternal systemic BP (rho = -0.72, p < 0.005). CONCLUSION: This first comprehensive longitudinal NVC evaluation during normal pregnancy reports significant but physiological microvascular variations throughout gestation, suggesting NVC as a safe and promising technique for further investigate and define patterns of microvascular changes also in pathological pregnancies.

IL33 and sST2 serum level in systemic sclerosis microvascular involvement.

AIM: Endothelial dysfunction and microvascular damage are hallmarks of systemic sclerosis (SSc). Objective of this study was to evaluate IL33 and ST2 serum levels in SSc patients and healthy controls (HC). Secondary aim was to evaluate the IL33 axis in the SSc microvascular manifestation. METHODS: IL33 and sST2 have been assessed in 46 SSc patients and 24 HC matched for sex and age. Main clinimetric indexes were assessed. Skin perfusion of hands was evaluated by Laser Speckle Contrast Analysis (LASCA) and echocolordoppler ultrasound of renal arteries was performed to evaluate subclinical renal involvement. RESULTS: SSc patients had higher serum level of IL33 and sST2 than HC. IL33 and sST2 were significantly higher in SSc patient with digital ulcers (DUs) compared to SSc patients without DUs. SSc patients with late nailfold videocapillaroscopy (NVC) pattern had higher serum levels of sST2 than SSc patients with active NVC pattern. SSc patients without proximal-distal gradient (PDG) at LASCA had significantly higher sST2 serum level compared to SSc patients with PDG. SSc patients with renal resistive index (RRI) ≥ 0.70 had higher serum levels of sST2 than SSc patients with RRI < 0.70. A positive linear correlation was shown between sST2 and RRI, between sST2 and intrarenal S/D and between sST2 and PI. Kaplan-Meier curves show a significantly reduced free survival from DUs in patients with increased sST2 (p = 0.025). In multivariate analysis, sST2 is associated with the development of new DUs. CONCLUSION: IL33 and sST2 are increased in SSc patients and ST2 might be a marker of microvascular damage.

Nailfold capillaroscopy changes associated with anti-RNP antibodies in systemic lupus erythematosus.

Anti-U1RNP antibody is associated with distinct organ involvement in patients with systemic lupus erythematosus (SLE). Nailfold capillaroscopy (NFC) allows non-invasive assessment of microvascular abnormalities in several connective tissue diseases. The objective of this study is to determine the association of anti-U1RNP antibody with microvascular changes by NFC in RNP-positive SLE patients in comparison with RNP-negative SLE patients (negative disease controls) and mixed connective tissue disease (MCTD) cases (positive disease controls). NFC examination was performed in consecutive patients with SLE with or without anti-U1RNP positivity. MCTD patients were recruited as disease controls. Abnormalities noted in the three groups were compared using non-parametric tests. Ordinal logistic or linear regression was used wherever applicable. 81 patients were studied, of whom 28 were diagnosed as RNP-positive SLE (age 30.0 ± 10.37; 26 females), 26 were RNP-negative SLE (age 29.42 ± 9.20; 25 females) and 27 had MCTD (age36.5 ± 9.70; 25 females). RNP-positive SLE patients had more frequent giant capillaries, enlarged capillaries and ramified capillaries as compared to RNP-negative SLE (p = 0.05, < 0.01 and 0.03, respectively). The capillary density was lower in patients with MCTD as compared with patients with RNP-positive SLE (5.11 ± 1.69/mm vs 7.25 ± 1.38/ mm, p < 0.01) and RNP-negative SLE (8.92 ± 1.13/mm, p < 0.01). The reduction in capillary density was less severe in patients with RNP-negative SLE as compared with RNP-positive SLE (OR = 0.1058 [95% CI = 0.02-0.546], p < 0.01) which was independent of the presence of Raynaud's phenomenon, interstitial lung disease and disease duration. Presence of anti-U1RNP antibody is associated with notable patterns of microvascular abnormalities in SLE. These NFC abnormalities are noted more profoundly in patients with MCTD and are less marked in RNP-negative SLE patients.

The presence of diabetes mellitus further impairs structural and functional capillary density in patients with chronic kidney disease.

OBJECTIVE: Endothelial dysfunction has been associated with increased cardiovascular events and overall mortality. Microvascular damage is prevalent both in diabetes mellitus (DM) and chronic kidney disease (CKD). Our aim was to compare microcirculatory function parameters in diabetic and non-diabetic CKD patients via nailfold video-capillaroscopy. METHODS: We included 48 diabetic and 48 non-diabetic adult CKD patients. All participants underwent nailfold video-capillaroscopy, during which capillary density was measured at normal conditions (baseline), after a 4-minute arterial occlusion (postocclusive reactive hyperemia), and at the end of a 2-minute venous occlusion (congestion phase). RESULTS: Diabetic patients presented significantly lower capillary density during reactive hyperemia (36.3 ± 3.8 vs 38.3 ± 4.3 capillaries/mm2 , P = .022) and at venous congestion (37.8 ± 4.0 vs 39.8 ± 4.2 capillaries/mm2 , P = .015). When stratified according to CKD stages, only in stage 3b capillary density was significantly lower in diabetic compared to non-diabetic subjects at baseline, during postocclusive hyperemia (36.8 ± 2.7 vs 40.0 ± 4.3 capillaries/mm2 , P = .037) and venous congestion (38.3 ± 2.8 vs 41.5 ± 3.5 capillaries/mm2 , P = .022). CONCLUSIONS: Capillary density during postocclusive hyperemia and after venous congestion is lower in diabetic compared to non-diabetic CKD patients, a finding indicative that diabetes is an additional factor contributing to microcirculatory structural and functional impairment in CKD. These differences are more prominent in CKD stage 3b.

Comparison between low cost USB nailfold capillaroscopy and videocapillaroscopy: a pilot study.

OBJECTIVES: Universal serial bus (USB) microscopy (capillaroscopy) could provide all rheumatologists with an easy-to-use, low-cost tool to examine the nailfold capillaries to facilitate early diagnosis of SSc. The objectives of this pilot study were to examine the feasibility of acquiring and analysing images using USB microscopy and to compare results to videocapillaroscopy. METHODS: Videocapillaroscopy and USB microscope images were obtained from the right and left ring fingers of 20 patients with SSc and 20 healthy control subjects. In addition to generating panoramic capillary mosaics from across the whole nailbed, custom software made fully automated measurements of vessel structure including capillary width and density. The area under the receiver operating characteristic curve (AZ) was used to measure separation between the SSc and healthy control groups. RESULTS: High quality images could be generated from the USB microscope, with reconstructed USB images comparing very favourably with those obtained using videocapillaroscopy. Using USB microscope images, the receiver operating characteristic curve AZ for group separation based on mean width was 0.81 (standard error 0.120) compared with 0.81 (standard error 0.095) for the (gold standard) videocapillaroscopy. The receiver operating characteristic curve AZ for group separation using capillary density was 0.48 (standard error 0.16) for USB microscope images, compared with 0.70 (standard error 0.10) for videocapillaroscopy. CONCLUSION: In this pilot study, USB capillaroscopy was able to discriminate between patients with SSc and controls as well as videocapillaroscopy on the basis of capillary width. This finding, together with the high-quality images obtained, highlights the potential of USB capillaroscopy as a low-cost, easily accessible clinical and research tool.

Quantitative nailfold capillaroscopy-update and possible next steps.

We review the exciting potential (and challenges) of quantitative nailfold capillaroscopy, focusing on its role in systemic sclerosis. Quantifying abnormality, including automated analysis of nailfold images, overcomes the subjectivity of qualitative/descriptive image interpretation. First we consider the rationale for quantitative analysis, including the potential for precise discrimination between normal and abnormal capillaries and for reliable measurement of disease progression and treatment response. We discuss nailfold image acquisition and interpretation, and describe how early work on semi-quantitative and quantitative analysis paved the way for semi-automated and automated analysis. Measurement of red blood cell velocity is described briefly. Finally we give a personal view on 'next steps'. From a clinical perspective, increased uptake of nailfold capillaroscopy by general rheumatologists could be achieved via low-cost hand-held devices with cloud-based automated analysis. From a research perspective, automated analysis could facilitate large-scale prospective studies using capillaroscopic parameters as possible biomarkers of systemic sclerosis-spectrum disorders.

Nailfold capillaroscopy findings in patients with coronavirus disease 2019: Broadening the spectrum of COVID-19 microvascular involvement.

OBJECTIVE: Increasing evidence points to endothelial dysfunction as a key pathophysiological factor in coronavirus disease-2019 (COVID-19). No specific methods have been identified to predict, detect and quantify the microvascular alterations during COVID-19. Our aim was to assess microvasculature through nailfold videocapillaroscopy (NVC) in COVID-19 patients. METHODS: We performed NVC in patients with a confirmed diagnosis of COVID-19 pneumonia. Elementary alterations were reported for each finger according to a semi-quantitative score. Capillary density, number of enlarged and giant capillaries, number of micro-hemorrhages and micro-thrombosis (NEMO score) were registered. RESULTS: We enrolled 82 patients (mean age 58.8 ± 13.2 years, male 68.3%) of whom 28 during the hospitalization and 54 after recovery and hospital discharge. At NVC examination we found abnormalities classifiable as non-specific pattern in 53 patients (64.6%). Common abnormalities were pericapillary edema (80.5%), enlarged capillaries (61.0%), sludge flow (53.7%), meandering capillaries and reduced capillary density (50.0%). No pictures suggestive of scleroderma pattern have been observed. Acute COVID-19 patients, compared to recovered patients, showed a higher prevalence of hemosiderin deposits as a result of micro-hemorrhages (P = .027) and micro-thrombosis (P < .016), sludge flow (P = .001), and pericapillary edema (P < .001), while recovered patients showed a higher prevalence of enlarged capillaries (P < .001), loss of capillaries (P = .002), meandering capillaries (P < .001), and empty dermal papillae (P = .006). CONCLUSION: COVID-19 patients present microvascular abnormalities at NVC. Currently ill and recovered subjects are characterized by a different distribution of elementary capillaroscopic alterations, resembling acute and post-acute microvascular damage. Further studies are needed to assess the clinical relevance of NVC in COVID-19.