POS1488-HPR NAILFOLD VIDEOCAPILLAROSCOPY IN JUVENILE DERMATOMYOSITIS: CORRELATIONS BETWEEN MICROVASCULAR ABNORMALITIES AND CLINICAL FEATURES
Authors: P. F. Bica, E. Hysa, R. Campitiello, E. Gotelli, A. I. Rebollo Giménez, S. Paolino, C. Pizzorni, C. Malattia, S. Rosina, V. Smith, M. Cutolo
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Juvenile dermatomyositis (jDM) is rare and is a type of autoimmune disease that causes skin rash and muscle inflammation. It results in weak muscles [1]. Microvascular involvement is common in adult DM and can be detected by nailfold videocapillaroscopy (NVC) ("scleroderma-like" pattern) [2,3]. Less is known about the possible correlations between NVC abnormalities and jDM organ involvement <h3>Objectives:</h3> Firstly, to explore the prognostic role of NVC in jDM, evaluating the correlation between NVC findings and clinical and serological manifestations. Secondarily, to assess the variations of NVC parameters in jDM patients during one year of follow-up. <h3>Methods:</h3> jDM patients and age- and sex-matched healthy controls (HCs) were recruited at IRCCS Istituto Giannina Gaslini. All patients fulfilled EULAR/ACR 2017 idiopathic inflammatory myopathy classification criteria for jDM [4]. All NVC pictures were evaluated by the same trained Rheumatologist by a qualitative and semi-quantitative standardized assessment [5]. Statistical analysis has been performed using Datatab. <h3>Results:</h3> 28 jDM patients (17 women, mean age 7.1 ± 3 years and mean disease duration 3.1± 3 years) and 27 HCs (18 women, mean age 9.5 ± 3years) were enrolled. In jDM patients, mean DAS disease (8.44±3) and mean number of capillaries significantly correlated (p=0.05), likewise, physical global VAS and presence of giant capillaries (detected in 39% of patients) (p=0.01). In particular, cutaneous involvement (evaluated by skin disease activity- DAS) significantly correlated with mean number of capillaries (p=0.004), as well as with the mean number of giant capillaries (p=0.006) (Figure 2). Furthermore, jDM patients skin VAS strongly correlated with mean number of capillaries and giant capillaries (both p=0.002). Moreover, presence of nailbed skin teleangectasies (expression of neoangiogenesis), occurring in 29% of patients inversely correlated with mean number of capillaries (p=0.003); presence of nailbed erythema was detected in 29% of patients was found correlated with reduced number of capillaries (p=0.03); presence of Gottron's sign, assessed dicotomically was found correlated with reduction of number capillaries (p=0.01). The increased number of giant capillaries significantly correlated with both nailbed skin teleangectasia (p=0.01) and Gottron's sign (p=0.01). On the other hand, heliotropic rash, calcinosis, digital ulcer did not show any correlation with NVC parameters. MSA (myositis specific antibody) positivity correlated significantly with both capillary number reduction (p=0.02) and occurrence of giant capillaries (p=0.04), in particular Tif 1 gamma (Anti-transcription intermediary factor 1) positivity correlated with a more intensive capillary loss than MDA5 (Anti-melanoma differentiation-associated gene 5) and NXP-2(antinuclear matrix protein 2 antibody) (p= 0.03). Statistically significant correlation was observed between ESR values and microhaemorrhages (p=0.03, r =-2.3). Other laboratory parameters (ANA, CPK, AST, ALT, LDH) did not correlate with any NVC findings. <h3>Conclusion:</h3> The reported capillary loss, presence of giant capillaries, as well as neoangiogenesis at NVC reflect the NVC "scleroderma-like pattern" that is observed also in adult DM, however, in jDM, the detected NVC alterations were found significantly associated with the severity of specific clinical and serological parameters. In conclusion, NVC analysis is suggested as important and safe examination for jDM patients. <h3>REFERENCES:</h3> [1] Leung AKC, et al. Curr Pediatr Rev. 2021;17:273-287. <b>2.</b> Cutolo M, et al. Nat Rev Rheumatol. 2021;17:665-677. <b>3.</b> Piette Y, et al. Autoimmun Rev. 2022;21:103087. <b>4.</b> Lundberg IE, et al. Ann Rheum Dis. 2017;76:1955-1964. <b>5.</b> Smith V, et al. Autoimmun Rev. 2020;19:102458. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>