SP0026 METHODS AND TOOLS FOR QUANTIZATION OF CAPILLAROSCOPIC MORPHOLOGICAL CHANGES
Authors: Alberto Sulli
Journal: Annals of the Rheumatic Diseases (2019)

<h3></h3> Capillaroscopy is routinely used in clinical practice to assess nailfold microvascular structure. Unlike laser techniques that give functional information, capillaroscopy allows a morphological assessment of nailfold capillary bed. It is a recognized tool to early differentiate primary from secondary Raynaud9s phenomenon, as well as to follow scleroderma microangiopathy. As microangiopathy extent correlates with organ involvement degree, nailfold capillaroscopy abnormalities are also considered a possible biomarker in systemic sclerosis.<sup>1,2</sup> Several tools may be used to quantitate morphological capillary changes, from devices with low magnification (20x), to instruments with high magnification (200x or more).<sup>3</sup> The instruments with low magnification allow a global evaluation of the entire nailfold area (wide-field capillaroscopy), and they provide a panoramic vision of the whole nailfold microvascular network. Magnifying glass, ophthalmoscope and dermatoscope are example of optical instruments with low magnification. Obtaining a high-quality documentation may be difficult by these tools, as well as the identification of early capillary changes; furthermore, storing capillary images is not possible. Stereomicroscope, usb-microscope or videocapillaroscope allow a sequential higher magnification up to 600x which enable detailed observation of small nailfold areas or single capillaries. However, by using a microscope, patient's fingers must be placed under the lens, and this may make the exam sometimes difficult, for example in the presence of either finger contractures or arm disabilities. The optical probe videocapillaroscope is currently considered the gold-standard for nailfold videocapillaroscopy, as it has the advantage to be moved to the finger of the patient at direct contact with the nailfold: this facilitates examination of patients with systemic sclerosis and finger flexion contractures, simply by moving the probe. The use of videocapillaroscope has a high sensitivity, a short time of execution after an easy operator training, allows early diagnosis of secondary Raynaud9s phenomenon by very early detection of microvascular changes, and also allows the counting and scoring of capillaroscopic parameters. Connection of the instrument with a software enable image recording, report writing and automated capillary number counting.<sup>4</sup> To quantitate capillaroscopic morphological changes (mainly capillary number, capillary dilations, giant capillaries, microhemorrhages, abnormal shape/ramified capillaries, capillary bed disorganization) a simple rating scale may be adopted to score each capillary abnormalities (score 0-3) (score 0 = no changes; score 1 = less than 33% of capillary alterations/reduction; score 2 = 33-66% of capillary alterations/reduction; score 3 = more than 67% of capillary alterations/reduction, per linear millimetre. Reduction = capillary number per linear millimetre &lt;9).<sup>5</sup> The mean score value for each capillaroscopic parameter is calculated from the analysis of at least two millimetres in the centre of the nailfold, by evaluating the first row of capillaries in each finger from 2<sup>nd</sup> to 5<sup>th</sup>. The Microangiopathy Evolution Score (MES) (sum of scores of progression parameters: capillary number, abnormal shaped/ramified capillaries, capillary bed disorganization - Score 0-9) may be calculated to follow the scleroderma microvascular damage.<sup>5</sup> However, at least the simple capillary number per linear millimetre should be counted, as well as larger capillary diameters measured, to monitor microangiopathy in systemic sclerosis.<sup>4,6,7</sup> <h3>References:</h3> [1] Smith V, et al. J Rheumatol 2013;40:2023-8. [2] Ingegnoli F, et al. Microvasc Res 2013;89:122-8. [3] Cutolo M, et al. Best Pract Res Clin Rheumatol 2013;27:237-48. [4] Cutolo M, et al. Microcirculation 2018;25:e12447. [5] Sulli A, et al. Ann rheum Dis 2008;67:885-7. [6] Cutolo M, et al. Arthritis Rheumatol 2016;68:2527-39. [7] Trombetta AC, et al. J Rheumatol 2016;43:599-606. <h3>Disclosure of Interests:</h3> None declared