No abstract

Background: Reports describing post-vaccine autoimmune phenomena, in previously healthy individuals, increased the concerns regarding the risk of disease flare-ups in patients with immune diseases. We aimed to assess the potential risk of disease flare-up, after receiving the COVID-19 (Coronavirus disease 2019) vaccine, during a follow-up period of 6 months. Methods: We performed a prospective cohort study, enrolling the patients with autoimmune- and immune-mediated diseases who voluntarily completed our questionnaire, both online and during hospital evaluations. Based on their decision to receive the vaccine, the patients were divided into two groups (vaccinated and non-vaccinated). Participants who chose not to receive the vaccine served as a control group in terms of flare-ups. Results: A total of 623 patients, 416 vaccinated and 207 non-vaccinated, were included in the study during hospital evaluations (222/623) and after online (401/623) enrolment. There was no difference concerning the risk of flare-up between vaccinated and non-vaccinated patients (1.16, versus 1.72 flare-ups/100 patients-months, p = 0.245). The flare-ups were associated with having more than one immune disease, and with a previous flare-up during the past year. Conclusions: We did not find an increased risk of flare-up following COVID-19 vaccination in patients with autoimmune-/immune-mediated diseases, after a median follow-up of 5.9 months. According to our results, there should not be an obvious reason for vaccine hesitancy among this category of patients.

Introduction: COVID-19 disease was associated with both thrombo-embolic events and in-situ thrombi formation in small vessels. Antiphospholipidic antibodies were found in some studies.Aim: Assessment of protein S activity in patients with COVID-19 as a cause this prothrombotic state, and of the association of protein S activity with worse outcome.Methods: All patients admitted for COVID-19 disease in a university hospital between 15th of May and 15th of July 2020 were prospectively enrolled into this cohort study. Patients treated with antivitamin K anticoagulants and with liver disease were excluded. All patients had protein S activity determined at admission. The main outcome was survival, secondary outcomes were clinical severity and lung damage.Results: 91 patients were included, of which 21 (23.3%) died. Protein S activity was decreased in 65% of the patients. Death was associated with lower activity of protein S (median 42% vs. 58%, p<0.001), and the association remained after adjustment for age, inflammation markers and ALAT. There was a dose-response relationship between protein S activity and clinical severity (Kendall_tau coefficient = -0.320, p < 0.001; Jonckheere-Terpstra for trend: p<0.001) or pulmonary damage on CT scan (Kendall_tau coefficient = -0.290, p<0.001; Jonckheere-Terpstra for trend: p<0.001). High neutrophil count was also independently associated with death (p=0.002).Conclusion: Protein S activity was lower in COVID-19 patients, and its level was associated with survival and disease severity, suggesting that it may have a role in the thrombotic manifestations of the disease.