Nailfold Videocapillaroscopy Results In Covid-19 Patients Recovered From Different Disease Severity

Background:COVID-19 is a multifaceted condition with a wide range of clinical manifestations, including microvascular/endothelial dysfunction, that starts in the early phase of the disease and may become dramatically harmful in the late stage, causing a massive pro-thrombotic state. Nailfold videocapillaroscopy (NVC) is the most used tool to identify microvascular status in a large spectrum of diseases [1]. Recently, non-specific NVC abnormalities have been described in a cohort of COVID-19 patients (no controls used) [2].Objectives:To assess microvascular damage in recovered COVID-19 patients (range of 40-270 days from recovery) by considering the previous severity of the disease, and, as mandatory, the comparison with matched individuals suffering from primary Raynaud’s phenomenon (PRP) and healthy volunteers (HV).Methods:NVC investigations were performed during standard clinical assessments in forty-four recovered COVID-19 patients (mean age 58±14 years, mean days from disease onset 129±54, mean days from disease recovery 106±52), twenty-two patients with PRP (mean age 60±15 years, mean years from disease onset 11±10) and twenty-two HV (mean age 60±14 years). COVID-19 patients were divided into two subgroups, according to the need of oxygen supplementation: twenty-two patients with severe lung involvement (need of Continuous Positive Airways Pressure and/or mechanical ventilation, mean age 57±12 years) vs twenty-two patients with mild-moderate lung involvement (need of Venturi mask or no need of oxygen supplementation, mean age 59±15 years). Clinical and demographic data of all the enrolled subjects were collected, during NVC examination. The following capillaroscopic parameters were evaluated: capillary number, dilated capillaries, giant capillaries, microhemorrhages, angiogenesis, disorganization of the microvascular array. A validated semiquantitative scoring (0-3) was adopted for NVC abnormalities [3-5]. Statistical analysis was carried out by non-parametric tests.Results:After COVID-19 recovery, no statistically significant difference was observed between COVID-19 patients and control groups of subjects concerning the score for the following NVC parameters: dilated capillaries, giant capillaries, disorganization of the microvascular array, angiogenesis. However, the capillary number per linear millimeter was significantly lower in COVID-19 patients (8.3±0.9) than in PRP (8.8±0.7, p=0.05) and HV (9.3±0.6, p<0.0001). Surprisingly, recovered COVID-19 patients showed significantly less microhemorrhages (score 0.4±0.3) than subjects of the other groups (PRP 0.6±0.5, p=0.01; HV 0.6±0.6, p=0.05). In particular, recovered patients who had more severe COVID-19 showed less microhemorrhages than patients with mild/moderate disease (score 0.18±0.4 vs 0.36±0.5), but this didn’t reach the statistical significance (p=0.18). On the other hand, patients recovered from severe SARS-CoV-2 infection also showed higher rate of angiogenesis (0.18±0.4) than patients with mild/moderate disease (no case, p=0.04).Conclusion:COVID-19 doesn’t seem to significantly induce, in short-term, specific alterations in peripheral microvascular array as evaluated by NVC, despite the severity of the disease, except for a significant reduction of the absolute number of nailfold capillaries. The topic needs longer time of evaluation and larger number of COVID-19 recovered cases to also assess the role of concomitant therapies.References:[1]Ingegnoli F et al. Curr Rheumatol Rev. 2018;14:5-11.[2]Natalello G et al. Microvasc Res. 2021;133:104071.[3]Smith V et al. Autoimmun Rev 2020;19:102458.[4]Cutolo M et al. Clin Rheumatol. 2019;38:2293-2297.[5]Sulli A et al. Ann Rheum Dis. 2008;67:885-7.Disclosure of Interests:None declared