AB0330 ANTIPHOSPHOLIPID ANTIBODIES AND ANTICOAGULANT TREATMENT: CAPILLAROSCOPIC FINDINGS
Authors: G. Ferrari, E. Gotelli, G. Pesce, L. Nanni, B. Colombo, S. Paolino, C. Pizzorni, A. Sulli, V. Smith, M. Cutolo
Journal: Annals of the Rheumatic Diseases (2021)

Background: Antiphospholipid syndrome (APS) is an autoimmune condition characterized by arterial and/or venous thrombosis and/or obstetric morbidity, associated with the presence in the serum of antiphospholipid antibodies (aPL) [1]. Subjects with confirmed positivity of aPL in absence of thrombotic/obstetric manifestations are identified as aPL carriers [2] The microangiopathy detected by nailfold videocapillaroscopy (NVC) in APS and in aPL-carrier patients is poorly investigated, as well as the possible interference of anticoagulant drugs [3]. Objectives: To compare microvascular damage in APS, aPL carriers and a group of patients (CTR) without aPL positivity and on regular warfarin therapy for cardiovascular indications Methods: NVC investigations were performed as part of standard procedures in APS patients (18, mean age 50.0±12.8 years), aPL carriers (24, mean age 46.4±16.4 years) and CTR without aPL (18, mean age 74±12.5 years) in therapy with oral anticoagulant (warfarin) for non-immunological vascular complications (atrial fibrillation, mechanical heart valve, deep venous thrombosis). Only patients affected by primary APS form were selected from data files (2006 Sapporo classification criteria). The following NVC parameters were availble: dilated capillaries, giant capillaries, microhemorrhages (with particular attention to linear and thin hemosiderin deposits, arranged perpendicularly and parallel to the nailfold bed, “comb-like”), abnormal shape (i.e. brunched “bushy” capillaries) and capillary number reduction. Those parameters were scored according to a semi-quantitative scale [4,5]. Statistical analysis was performed by non-parametric tests. Any p values equal or lower than 0.05 was considered statistically significant. Results: APS patients showed a higher score for dilated capillaries (p=0.001), more frequent microhemorrhages (p=0.03), in particular “comb-like” microhemorrhages (p=0.007) than simply aPL carriers. Of note, there wasn’t a statistically significant difference in the number of microhemorrhages between APS and CTR group (p=0.23), but again the number of “comb-like” hemorrhages, was almost absent in the CTR group (p=0.03). No significant correlation was found between the different aPL subtypes and the NVC parameters. Conclusion: APS patients showed significantly higher number of non-specific NVC abnormalities than aPL carriers. Anticoagulant treatment could represent a further risk factor for the appearance of microhemorrhages in all the patients, being the NVC “comb-like“ pattern mainly associated with the APS. Further investigations with larger cohorts of patients are needed for the definition of a possible APS specific NVC-pattern. References: [1]Ruiz-Irastorza G et al. Lancet. 2010;376(9751):1498-509. 2. Pengo V et al. Semin Thromb Hemost. 2012;38:322-7. 3. Sulli A et al. J Rheumatol. 2000;27:1574-6. 4. Smith V et al. 2020. Autoimmun Rev. 19:102458. 5. Sulli A et al. Ann Rheum Dis. 2008;67:885-7. Disclosure of Interests: None declared