Background: Antiphospholipid syndrome (APS) is an autoimmune disease often associated with severe, life-threatening vascular complications. The majority of patients (and in case of secondary APS, in 100% of cases) receive immunosuppressive therapy. Immunization with pneumococcal vaccines in patients with both primary APS (PAPS) and APS+SLE or secondary (sAPS) is necessary to prevent severe respiratory infections in these patients.

Objectives: Purpose of the study - to study the tolerance and safety of 23-valent polysaccharide pneumococcal vaccine (PPV-23) in patients with PAPS and sAPS.

Methods: At this stage, the study included 28 patients with APS, of which 10 with PAPS, 18 with sAPS proceeding against the background of systemic lupus erythematosus (SLE), of which 23 women (82%), 5 men (18%). The average age (Me) of patients was 43 (35.5; 53.0) g. 20 patients received glucocorticoids (GC) 5-30 mg/day equivalent to prednisone, 17- hydroxychloroquine, 6- cytostatics (3-cyclophosphamide, 2-azathioprine, 1- mycophenolate mofetil), 8- biologics: 5-rituximab (RTM), 3-belimumab (BLM); 20-received anticoagulants (direct-10, indirect-10).

1 dose (0.5 ml) of PPV-23 was administered subcutaneously. The follow-up time was 1 year in 23 patients and 5-5.5 months in 5-5.5 months. During the visits, standard clinical and laboratory tests were performed, immunological blood test and the level of antibodies to S.pneumoniae

Results: Vaccination was well tolerated in all patients. In 29% of cases, vaccine reactions of mild severity were observed: in 7 (25%) - a local reaction (pain in the arm for 1-3 days-at 7, redness up to 2 cm at the injection site-at 1), in 1 (3,6%), the patient experienced general weakness (moderately pronounced) for 1 month. Vaccinal reactions were completely reversible and did not require additional prescriptions. Post-vaccination complications develop, as a rule, in the first 1-2 months after vaccination. During the observation period, none of the patients had an exacerbation of the disease, reliably associated with the vaccination. There was no recurrence of thrombosis, both in patients receiving anticoagulant therapy and without it. No new autoimmune phenomena, both clinical and laboratory, were identified. The dynamics of the production of anti-streptococcal antibodies during the year was followed in 16 patients. One year after vaccination, 31% of patients showed a significant (more than 2-fold compared to the initial) increase in the concentration of antibodies to polysaccharides of the cell wall of S. pneumoniae (“responders”), 69% of patients were “non-responders” to the vaccine. At the same time, all 5 patients with PAPS were “non-responders”, and 45.5% “respondents” with sAPS.

Conclusion: Preliminary results show that patients with APS tolerate PPV-23 vaccination well. In the next post-vaccination period, exacerbations of the disease, thrombosis were not recorded. Attention is drawn to the large number of “non-responders” in PAPS, however, to obtain statistically reliable results, it is necessary to continue the study and recruit more patients.

Disclosure of Interests: None declared