RESUMO
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.
RESUMO
La capilaroscopia es un método no invasivo y seguro que permite la visualización de los capilares a nivel del lecho periungueal de los dedos de las manos. Es útil en la evaluación del Fenómeno de Raynaud y de las colagenopatías, principalmente de la esclerodermia; sin embargo, se conoce poco acerca de la prevalencia y distribución de los cambios capilaroscópicos en sujetos sanos, siendo el objetivo de este estudio evaluar y describir las alteraciones capilaroscópicas en este grupo. A 100 participantes seleccionados por criterios de inclusión y exclusión se les realizó una videocapilaroscopia del lecho ungueal del cuarto y quinto dedo de la mano no dominante; el 86% de la población estudiada presentó hallazgos capilaroscópicos como: capilares tortuosos, entrecruzados y arborificados. Además, las alteraciones capilaroscópicas fueron más frecuentes en sujetos que consumían tabaco, se encontró una relación significativa entre el tabaco y la presencia de arborificaciones. Este es el primer estudio descriptivo de alteraciones capilaroscópicas en sujetos sanos en el Ecuador.
Capillaroscopy is a noninvasive and safe method that allows visualizationof capillaries in the nailbed. It is useful in the assesment ofRaynauds phenomenon and collagen diseases, especially scleroderma;however, little is known about the prevalence and distributionof capillaroscopic changes in healthy subjects, hence the aim ofthis study was to assess and describe the microvascular alterationsin this group. 100 participants selected by inclusion and exclusioncriteria underwent videocapillaroscopy of the nailfold of the fourthand fifth fingers of the nondominant hand; 86% of the study populationpresented capillaroscopic findings such as tortuous capillaries,crisscrossing and arborifications. Also, the microvascular alterationswere more frequent in subjects who had history of tobaccosmoking: a significant relationship between smoking and the presenceof arborifications was found. This is the first descriptive studyof microvascular alterations in healthy subjects in Ecuador.
