Nailfold capillaroscopy is a useful tool to diagnose endocrine, cardiovascular, neuropsychiatric, rheumatic and other diseases. Diagnoses are made on the presence or absence of certain types of capillary loops which are classified according to their shape. We have surveyed six clinicians, asking them to classify 217 capillary loops, in order to establish quantitative nailfold capillary loop classification criteria. The participating clinicians were not unanimous about the classification of any capillary, and there was no consensus about the class of 17% of the capillary loops. Some of the clinicians classified two occurrences of the same shape differently. This clearly demonstrates the need for well established classification criteria. Nailfold capillary loop classes can be divided into two major groups: Descriptive Classes (DC); "cuticulis", "open", "tortuous", "crossed", "bizarre" and "bushy", and Label Classes; "enlarged", "elongated" and "giant". Furthermore label classes can be divided into two groups, Width Anomaly Classes (WAC); "enlarged" and "giant", and Length Anomaly Class (LAC), "elongated". While descriptive classes give information about the shape of a loop, label classes emphasise dimensional anomalities of a loop. Assignment of a loop with one the descriptive or label classes causes information loss about the dimensions or shape, respectively. In order to preserve as much information as possible within a class, we propose a new class system that contains 17 classes which are the combination of WAC, LAC and DC. We propose quantitative classification criteria for commonly used classes: "cuticulis", "open", "tortuous", "elongated" and "giant". Although the class "enlarged" can be expressed quantitatively, inappropriate assignments of "enlarged" by the paricipating clinicians have not allowed us to set quantitative classification criteria. While definition of the class "crossed" is purely qualitative, a classification mechanism that is neither qualitative nor quantitative is proposed for "bizarre" and "bushy" loops. We propose the use of pattern recognition algorithms that are based on the evaluation of the capillary shape parameters such as loop length, loop width, limb width, the curvature, orientation, etc., to classify capillaries. By the use of mathematical morphology, skeletonization, topological relations, feature vectors, in an hierarchical structure, the software TANCCAS (The Automated Nailfold Capillary Classification and Analysis System) has been developed to calculate the shape parameters and to classify the capillary loops. These algorithms have been implemented on a Pentium PC and have resulted in an 88% accuracy level which is compared to participating clinicians' overall classifications of the test images.

Capillaroscopy is a non-invasive and safe tool which allows the evaluation of the morphology of the microcirculation. Since its recent incorporation in the 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for systemic sclerosis together with its assessed role to monitor disease progression, capillaroscopy became a ‘mainstream’ investigation for rheumatologists. Given its increasing use by a variety of physicians internationally both in daily practice to differentiate primary from secondary Raynaud's phenomenon, as well as in research context to predict disease progression and monitor treatment effects, standardisation in capillaroscopic image acquisition and analysis seems paramount. To step forward to this need, experts in the field of capillaroscopy/microcirculation provide in this very consensus paper their view on image acquisition and analysis, different capillaroscopic techniques, normal and abnormal capillaroscopic characteristics and their meaning, scoring systems and reliability of image acquisition and interpretation. / Revisión por pares

Objetivos. Analisar prospectivamente os dados de capilaroscopiaperiungueal (CPU) em pacientes com dermatomiosite recém-diagnosticada (DM) e correlacioná-los com citocinas angiogênicas séricas e características clínicas e laboratoriais. Métodos. Vinte e três pacientes com DM com < 12 meses de sintomas foram incluídos no estudo. Para avaliar os níveis de citocinas séricas, os pacientes foram pareados 23 voluntários saudáveis por idade, sexo e etnia. As características da CPU e os parâmetros da atividade da DM foram analisados. Resultados. Foram observados níveis aumentados de angiogenina (ANG) e de fator de crescimento de endotélio vascular-1 (VEGF1) séricos de forma significativa em pacientes com DM em comparação com os controles saudáveis. Os níveis de ANG sérica correlacionaram-se positiva e negativamente, respectivamente, com a densidade capilar e as áreas avasculares. Além disso, a densidade capilar correlacionou-se inversamente com o número de capilares ectasiados, capilares gigantes e áreas avasculares. O número de capilares ectasiados correlacionou-se positivamente com a Escala Visual Analógica (EVA) do paciente e do médico, a presença de eritema facial, capilares gigantes e micro-hemorragias. Os capilares gigantes apresentaram correlação positiva com EVA do médico e da atividade cutânea, capilares ectasiados, áreas avasculares, micro-hemorragias e capilares em forma de arbustos e correlação negativa com a densidade capilar. Micro-hemorragias correlacionaram-se positivamente com o sinal de \"V do decote\" e EVA do médico. O VEGF1 sérico não mostrou relação com os parâmetros da CPU ou com características clínicas e laboratoriais relacionadas a DM. Além disso, 15 dos 23 pacientes foram avaliados prospectivamente após 3,21 anos. Todos os pacientes tiveram resposta clínica com melhora significativa em todos os parâmetros da CPU, exceto em relação a capilares ectasiados e número de capilares em forma de arbustos. Conclusões. A CPU pode ser uma ferramenta útil para avaliar a atividade da doença em DM de início recente e a sua correlação com a ANG sérica sugere a participação desta citocina na neoangiogênese da doença / Objectives. To prospectively analyze nailfold capillaroscopy (NC) findings in new-onset dermatomyositis (DM) and to correlate NC findings with serum angiogenic cytokines and DM clinical and laboratory features. Methods. Twenty-three patients with DM who experienced < 12 months of symptoms were included in the study. To assess serum cytokine levels, 23 age-, sexand ethnicity-matched healthy volunteers were used. NC characteristics and DM activity parameters were analyzed. Results. Significantly higher serum angiogenin (ANG) and vascular endothelial growth factor-1 (VEGF1) levels were observed in DM patients than in controls. Capillary density and avascular areas correlated positively and negatively, respectively, with serum levels of ANG. Moreover, the capillary density correlated inversely with the number of enlarged and giant capillaries and avascular areas. The number of enlarged capillaries correlated positively with patient and physician VAS, the presence of a facial rash, giant capillaries and microhemorrhages. Giant capillaries had a positive correlation with physician and cutaneous VAS, enlarged capillaries, avascular areas, microhemorrhages and bushy capillaries and a negative correlation with capillary density. Microhemorrhages correlated positively with the \"V-neck\" sign and physician VAS. VEGF1 showed no relationship with the NC parameters with DMrelated clinical and laboratory features. Additionally, 15 out of 23 patients were assessed prospectively after 3.21 years. All patients had a major clinical response with significant improvement in all NC parameters, except for enlarged and bushy capillaries. Conclusions. The NC may be a useful tool to assess disease activity in recent-onset DM, and it can also reinforce the role of ANG in the angiogenesis of this myopathy