POS0144 NOVEL APPLICATION OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AND NAILFOLD CAPILLAROSCOPY IN PSORIATIC ARTHRITIS - DIAGNOSTIC AND PROGNOSTIC ACCURACY IN RELATION TO PSORIASIS AND HAND OSTEOARTHRITIS
Authors: J. Guldberg-Møller, T. Schjødt Jørgensen, M. Henriksen, K. Ellegaard, M. Mogensen, L. E. Kristensen
Journal: Annals of the Rheumatic Diseases (2021)

Background: Nailfold video capillaroscopy (NVC) and angiographic optical coherence tomography (OCTA) have potential in diagnosing psoriatic arthritis (PsA) and differentiating it from psoriasis vulgaris (PsO) and hand osteoarthritis (OA). Objectives: To assess the diagnostic properties of NVC and OCTA in patients with PsA compared to patients with PsO and hand OA based on nailfold capillary patterns. Methods: Patients with distal interphalangeal-joint PsA and nail involvement (n=50), PsO with nail involvement (n=12); and OA (n=13) were included in this cross-sectional study. Capillaries were evaluated semi-quantitatively and qualitatively. Differences in capillary findings between groups were assessed using mixed linear models. Binary logistic regression analyses were performed to determine the probability for PsA diagnosis based on capillaroscopy findings. Results: Reduced capillary density and reduced nailfold blood flow in OCTA images distinguished PsA from both PsO (p=0.004 and p=0.052) and OA (p=0.024 and p&lt;0.001). Qualitative analysis revealed that glomerular capillaries were found in only 3% of PsA patients but in 13% of PsO patients (P=0.003). Furthermore, coiled vessels were only seen in 55% of PsA patients and 71% in PsO patients (P=0.043). NVC microhaemorrhage was dominant in PsA patients (13 % and 17 %) and significantly different to OA patients (p=0.05). No capillary pattern was associated with an increased probability of the PsA diagnosis. Conclusion: A pathognomic pattern for PsA diagnosis was not identified, however we demonstrated characteristics significant capillaroscopy findings for PsA such as decreased capillary density, reduced blood flow, and less coiled vessels in OCTA and presence of NVC microhemorrhages. Table 1. NVC-rating PsA (n=188) PsO (n=42) OA (n=48) PsA vs PsO PsA vs OA NVC ad modum Cutolo Reduced capillary density 51 % 31 % 51 % P=0.107 0.770 Irregularly enlarged capillaries 22 % 33 % 25 % P=0.082 P=0.988 Giant capillary 2 % 0 0 P=0.400 P=0.375 Microhaemorrhages 13 % 7 % 2 % P=0.327 P=0.05 Capillary ramifications 14 % 24 % 29 % P=0.054 P=0.307 Capillary disorganisation 45 % 57 % 48 % P=0.170 P=0.685 OCTA-rating PsA n=193 PsO n=48 OA n=52 PsA vs PsO PsA vs OA OCTA ad modum Cutolo Reduced capillary density 53 % 21 % 33 % P=0.004 P=0.024 Irregularly enlarged capillaries 34 % 56 % 19 % p=0.015 P=0.178 Giant capillary 0 0 0 - - Microhaemorrhages 0 0 0 - - Capillary ramifications 0 0 0 - - Capillary disorganisation 55 % 46 % 49 % P=0.209 0.723 OCT Nail thickness*, mm., mean (SD) 0.62 (0.13) 0.73 (0.39) 0.59 (0.08) p=0.876 P=0.020 OCTA blood flow percentage, mean (SD) 6.00 (2.94) 6.94 (3.08) 7.88 (3.30) P=0.052 P&lt;0.001 Capillary morphology PsA n=192 PsO n=48 OA n=52 PsA vs PsO PsA vs OA Qualitative evaluation of NVC morphology Tortuous/Coiled capillaries 55 % 71 % 56 % P=0.043 P=0.890 Enlarged capillary diameter 17 % 21 % 17 % P=0.557 P=0.984 Ramified capillaries 13 % 15 % 19 % P=0.701 P=0.215 Microhaemorrhages 17 % 6 % 8 % P=0.068 P=0.106 Elongated capillaries 6 % 4 % 4 % P=0.669 P=0.592 Different capillary shapes, glomerular 3 % 13 % 2 % P=0.003 P=0.779 The distribution of NVC and OCTA capillary morphology between PsA, PsO and OA, and qualitative evaluation of NVC morphology. Data are presented as percentage of capillary findings within the group. Differences between PsA and the other groups are presented as p-values. PsA: psoriatic arthritis, PsO: psoriasis vulgaris, OA: hand osteoarthritis, NVC nailfold video capillaroscopy, OCTA: angiographic optical coherence tomography. *: 1 patient (PsO group) was excluded from the analysis because of nail thickness&gt;2.0 mm exceeding the maximum penetration depth of the OCT laser, representing an outlier. Figure 1. Optical coherence tomography angiography of the nail and nailbed blood vessels in patients with psoriatic arthritis, psoriasis, and hand osteoarthritis. *: nail plate. ¤: cuticle. #: proximal nailfold. §: one-millimetre field. Acknowledgements: The data-analysis of blood flow in angiographic OCT images was kindly performed as a batch analysis by CEO Jon Holmes, Michelson Diagnostics Ltd., Kent. Disclosure of Interests: Jørgen Guldberg-Møller Speakers bureau: AbbVie, NOVARTIS, Eli-Lilly and BK Ultrasound outside the present work., Tanja Schjødt Jørgensen Speakers bureau: AbbVie, Pfizer, Roche, Novartis, UCB, Biogen and Eli Lilly., Consultant of: AbbVie, Pfizer, Roche, Novartis, UCB, Biogen and Eli Lilly., Marius Henriksen Consultant of: Advisory Board member of Thuasne Group, France, Karen Ellegaard: None declared, Mette Mogensen: None declared, Lars Erik Kristensen Speakers bureau: Pfizer, AbbVie, Amgen, UCB, Gilead, Biogen, BMS, MSD, Novartis, Eli Lilly, and Janssen pharmaceuticals., Consultant of: Pfizer, AbbVie, Amgen, UCB, Gilead, Biogen, BMS, MSD, Novartis, Eli Lilly, and Janssen pharmaceuticals.