AB0073 ANTIBODY RESPONSE AND COVID-19 DISEASE AFTER SARS-CoV-2 VACCINATION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES RECEIVING BIOLOGICAL TREATMENT

Background: Immune response in patients with immune-mediated inflammatory diseases (IMID) is compromised. The patients have more frequent and severe infections, including COVID-19, and reduced efficacy of vaccinations. As SARS-CoV2 vaccine trials excluded patients with IMID on immunosuppressive therapy, data about vaccination efficacy and safety in this patient group was insufficient. Objectives: Evaluate antibody response to SARS-CoV2 vaccination, incidence and severity of COVID-19 disease in IMID patients on biological therapy compared to healthy individuals. Methods: Consecutive patients from outpatient clinic were included in the study. Demographic data, medical history, data about treatment, COVID-19 vaccinations and COVID-19 infections were collected using questionnaires and from medical records. Disease activity was evaluated. Control group consisted of healthy volunteers, exclusions being IMID and immunosuppressive therapy. Antibodies against SARS-COV-2 S-protein were measured at 3 and 6 months after full vaccination course using Elecsys Anti-SARS-CoV-2 S electrochemiluminescence immunoassay. The follow-up period was 12 months. Results: 170 patients (55.9% females, mean age 51.2 (SD 16.67; 20-84) and 232 controls (81.9% females, mean age 43.9 (SD 12.2; 19-72) were included in the study. 65 (38%) patients had rheumatoid arthritis, 30 (18%) axial spondyloarthritis, 23 (14%) psoriasis, 20 (12%) psoriatic arthritis, 17 (10%) juvenile idiopathic arthritis, 4 (2%) ANCA-vasculitis, 3 (2%) ulcerative colitis, 3 (2%) systemic lupus erythematosus, and 1 (1%) suppurative hidradenitis. Treatment was as follows (n; %): TNF inhibitors (110; 64.7), IL-6 inhibitors (15; 8.8), IL-17 and CD-20 inhibitors (both 12;7), IL-12/23/IL-23 inhibitors (8; 4.7), JAKs (6; 3.5), IL-4/13 inhibitors (4; 2.3), CTLA-4 (2; 1.1) and GM-CSF inhibitors (1; 0.6). 73 (42.9%) patients used one and 9 (5.3%) combination csDMARDs; 21(12.3%) glucocorticoids (GC). The median level of SARS-CoV-2 anti S-protein antibodies in patient and control group was 309.2 (range 0-23540) and 1074 U/ml (108-49620) (p<0.001), respectively, at month 3, and 148.7 (0.4-79700) and 686.4 U/ml (72-86450) (p<0.001) at month 6 after vaccination. (Figure 1). According to linear regression model adjusted to age, sex and BMI, antibody level in patient group was lower by 46%. Antibody levels were not influenced by sex, BMI, smoking, or concomitant disease. Age was a significant factor influencing the antibody level in both groups, with every additional year of age the antibody level being lower by 1%. Antibody levels were significantly influenced by biological treatment (Figure 2). There was no effect of diagnosis, disease activity, GC or csDMARD use. 44 patients (26%) and 56 controls (24%) had COVID-19 infection during the 12 months follow-up period (p=0.689). The level of antibodies in the infected individuals was 1522 and non-infected 1246 U/ml (p=0.5254). Six patients and no controls needed hospitalisation due to severe COVID-19 infection. Hospitalised patients were older (66.8 yrs, SD=9.9; 56-83), had lower antibody levels (median 2.85 (0.4-133.4) vs 287.5 U/ml (0 - 10570), p=0.002) and at least one concomitant disease. 3 patients had been treated with rituximab, 2 with adalimumab and 1 with abatacept. Conclusion: In COVID-19 vaccinated IMID patients on biological therapy, the level of anti-S-protein antibodies was significantly lower and the rate of severe COVID-19 infection requiring hospitalisation was significantly higher than in the control group, correlating with lover levels of anti-S antibodies, higher age, and presence of concomitant disease. Lower antibody levels were associated with rituximab-therapy and older age. Disease activity, csDMARD or GCS use had no effect. The results of the study indicate that despite full course of vaccination, IMID patients on biological therapy remain less protected against severe COVID-19 infection and require extra care in COVID-19 prophylaxis and therapy. REFERENCES: NIL. Acknowledgements: North Estonia Medical Centre, statistician Sigrid Vorobjov, sub-investigators, participants. Disclosure of Interests: Eve-Kai Raussi Berlin Chemie Menarini, Janssen, Abbvie, Stada, Maigi Eisen Abbvie, Novartis, Janssen, Sandoz, Sanofi, Eucerin, Küllike Palk: None declared, Marge Kütt: None declared.