POS0850 NAILFOLD CAPILLARY DILATIONS IN RAYNAUD’S PHENOMENON: QUANTIFYING A PREDICTIVE THRESHOLD FOR THE ‘SCLERODERMA PATTERN’

Background:Non-specific abnormalities could be detected by nailfold videocapillaroscopy (NVC) in subject with primary Raynaud’s Phenomenon (RP) several years before the clinical onset of connective tissue diseases (CTD)s [1]. Previous findings from our group proved that ≤30 μm capillary dilations in RP patients have a negative predictive value for developing the ‘scleroderma pattern’ during follow-up [2].Objectives:To investigate the role of NVC >30 μm capillary dilations as positive predictive factors of the ‘scleroderma pattern’ in RP patients later developing systemic sclerosis (SSc)-related RP.Methods:A 10-year retrospective NVC-based investigation evaluated the dataset of sequential NVCs of 18 RP patients later developing SSc (cases) and 19 sex- and age-matched RP patients later developing other CTDs (controls). Both cases and controls had ≥1 NVC performed before the ‘scleroderma pattern’/CTD diagnosis (basal NVC) showing >30 μm dilated capillaries. Each NVC was qualitatively and semi-quantitatively assessed, recording number of total capillaries, number and average/site-specific diameters (arterial, apical, venous) of >30 μm dilated capillaries [3]. Statistical analysis was performed to stratify the risk of developing the ‘scleroderma pattern’.Results:Significant differences of capillary diameters were observed between cases and controls both at basal NVC and during follow-up (p<0.001). The proportion of >30 μm dilated capillaries in basal NVC was the strongest predictor of ‘scleroderma pattern’ in a median 3-year time, with a 27% cut-off (PPV 0.79, 95%CI 0.54,0.94; p<0.001). Additional “Higher risk” NVC hallmarks for ‘scleroderma pattern’ development were apical diameter >40 μm (p<0.001), venous diameter >25 µm (p<0.05) and average diameter ≥35 µm (p<0.005). Conversely, CTDs patients showed a stable NVC ‘non-scleroderma pattern’ over a median 10-year time.Conclusion:This is the first study to show that NVC-detected homogeneous and progressive capillary loop dilations in RP patients significantly contribute to predict the ‘scleroderma pattern’ evolution within a median 3-year time, possibly providing a “very early” window of opportunity in SSc pre-clinical stages.References:[1]Cutolo M et al. Expert Rev Clin Immunol. 2019;15(7):753–64. [2] Trombetta AC et al. J Rheumatol 2016;43:599–606. [3] Smith et al. Autoimmun Rev 2020; 19(3):102458.Disclosure of Interests:None declared

Raynaud’s phenomenon and related vasospastic disorders

Raynaud’s phenomenon, which is characterized by episodic digital pallor, cyanosis and rubor upon exposure to cold environment or to stress, is relatively common, although the prevalence depends on the climate. Still, it is under-diagnosed, under-treated, and often confused with other conditions. Primary Raynaud’s phenomenon (i.e., Raynaud disease) must be distinguished from secondary Raynaud’s phenomenon (i.e., Raynaud syndrome) as long-term morbidity and outcomes differ vastly between the two conditions. Additionally, the practitioner must differentiate between Raynaud’s phenomenon and related vascular disorders, such as acrocyanosis, pernio, and livedo reticularis. In this article, we review differences between the conditions and suggest an approach to diagnosis and treatment strategy for these disorders.

Photoacoustic and High-Frequency Ultrasound Imaging of Systemic Sclerosis Patients

Introduction: Systemic sclerosis starts with an early phase characterized by Raynauds phenomenon, puffy fingers/hands, autoantibodies and a scleroderma nailfold­microscopic pattern. Alterations in the nailfoldmicroscopic pattern are not evident in all early SSc patients. Photoacoustics(PA) and high-frequency ultrasound (HFUS) could fulfill this need. The former can measure oxygen saturation while the latter can measure skin thickening. We hypothesize that photoacoustics and high-frequency ultrasound can distinguish (early) SSc patients from individuals with primary Raynaud's phenomenon (PRP) by measuring oxygenation of the fingertip and skin thickening.Methods: We compared measurements of the third finger in (early)SSc patients to healthy and PRP individuals. The level of oxygenation and skin thickness were compared between groups. Nailfoldcapillaroscopy was performed on all subjects.Results: Thirty-one adult subjects participated in this study: twelve patients with SSc, 5 patients with early SSc, 5 volunteers with PR and 9 healthy controls. We found a significant difference in oxygen saturation between (early) SSc patients (80.8% ± 8.1 and 77,9% ± 10.5 ) and individuals with PRP (93.9% ± 1.1). Measurements of skin thickening showed a significant difference in (early) SSc patients compared to individuals with PRP (0.48 ± 0.06 mm and 0.51 ±0.16 mm vs. 0.27 ± 0.01 mm). There was no significant difference between healthy and PRP individuals in oxygenation or skin thickening.Conclusion: Photoacoustic and high-frequency ultrasound can distinguish between (early)SSc, PRP and healthy individuals in both oxygenation and skin thickening.